Title of Invention	VARIABLE- WIDTH TELESCOPIC CHASSIS FOR AN AGRICULTURAL IMPLEMENT
Abstract	The present invention relates to a variable-width telescopic chassis (1) for an agricultural implement (3), comprising a central beam (4) and, on either side, at least one sliding extension (5, 6), the said telescopic chassis (1) supporting work tools (2) distributed with a defined and adjustable spacing, the said telescopic chassis (1) also having a reduced size when the spacing between the said work tools (2) is at a minimum, the said central beam (4) for its part having a length substantially similar to that of the said telescopic chassis (1) in its reduced-size position. The telescopic chassis in notable in that the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4). The present invention also relates to an agricultural implement equipped with at least one telescopic chassis (1) such as this.

Title of Invention

VARIABLE- WIDTH TELESCOPIC CHASSIS FOR AN AGRICULTURAL IMPLEMENT

Abstract

The present invention relates to a variable-width telescopic chassis (1) for an agricultural implement (3), comprising a central beam (4) and, on either side, at least one sliding extension (5, 6), the said telescopic chassis (1) supporting work tools (2) distributed with a defined and adjustable spacing, the said telescopic chassis (1) also having a reduced size when the spacing between the said work tools (2) is at a minimum, the said central beam (4) for its part having a length substantially similar to that of the said telescopic chassis (1) in its reduced-size position. The telescopic chassis in notable in that the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4). The present invention also relates to an agricultural implement equipped with at least one telescopic chassis (1) such as this.

Full Text	FORM 2 THE PATENT ACT 1970 (39 of 1970) The Patents Rules, 2003 COMPLETE SPECIFICATION [See Section 10, and rule 13 TITLE OF INVENTION IMPROVED TELESCOPIC CHASSIS AND AGRICULTURAL IMPLEMENT WITH SUCH A CHASSIS APPLICANT (S) a) Name b) Nationality c) Address KUHN S . A. FRENCH Company 4, IMPASSE DES FABRIQUES, F-67700 SAVERNE, FRANCE 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - IN THE MATTER OF an Application for a French Patent in the name of Kuhn SA filed under No. 07/57,267, and IN THE MATTER OF an Application for an Indian Patent. RWS Group Ltd, of Europa House, Marsham Way, Gerrards Cross, Buckinghamshire, England, hereby solemnly and sincerely declares that to the best of its knowledge and belief, the following document, prepared by one of its translators competent in the art and conversant with the English and French languages is a true and correct translation of the Patent Application filed under No. 07/57,267 by Kuhn SA in France on 30 August 2007 for "Improved telescopic chassis and agricultural machinery with such a chassis". Date: 9 July 2008 C. E. SITCH Managing Director - UK Translation Division For and on behalf of RWS Group Ltd The present invention relates to the overall technical field of agricultural machinery. It relates more specifically to a variable-width telescopic chassis for an agricultural implement comprising a central beam and, on either side, at least one sliding extension, the said telescopic chassis supporting work tools distributed with a defined and adjustable spacing, the said telescopic chassis also having a reduced size when the spacing between the said work tools is at a minimum, the said central beam for its part having a length substantially similar to that of the said telescopic chassis in its reduced-size position. The invention finds it application in the field of seed-drills, of precision seeders. In general, the invention relates to an agricultural machine intended to work on parallel lines or rows spaced a certain distance apart. A telescopic chassis such as this is known to those skilled in the art from document FR 2 862181. That telescopic chassis carries six work tools. It comprises a central beam and, on either side, two sliding extensions. A first extension slides in the central beam and a second extension slides in the first extension. The central beam carries two work tools whilst each extension carries a single work tool. It is known that the spacing between the work tools varies according to the crop being planted. It is thus possible for the telescopic chassis to be converted from a small size to a larger size and vice versa. The telescopic chassis is of small size when the spacing between the said work tools is at a minimum. From this position, the first and second extensions slide outwards until the desired spacing between the work tools is reached. The central beam is of a length substantially similar to that of the telescopic chassis in its small size. When this telescopic chassis is used for planting corn, the spacing between two adjacent work tools is approximately 75 cm. The telescopic chassis is opened out and the first and second extensions are deployed. In this opened-out position, the guiding length of the extensions is small because the length of the first and second extensions is relatively short. The guiding length corresponds to the length remaining inside the central beam or inside the first extension when the chassis opens out. With a short guiding length, there is a greater risk that the telescopic 2 chassis will become deformed and broken and consequently opening out and closing up the chassis will become difficult. These disadvantages become all the greater the more the telescopic chassis opens out. Because the guiding length is small, the stability of the work tools is also reduced. It is an object of the present invention to propose a telescopic chassis that is able to overcome the disadvantages of the prior art, particularly by offering a compact telescopic chassis with improved rigidity. To this end, one important feature of the invention is that the length of each extension is substantially equal to the length of the said central beam. The rigidity of the telescopic chassis is therefore improved irrespective of what spacing has been set between the work tools. By virtue of the long length of the sliding extensions, the guiding length is great and there is a lower risk that the telescopic chassis will become deformed. According to another feature of the invention, the extensions remain nested one inside the other irrespective of their position within the central beam. According to a highly advantageous additional feature of the invention, each sliding extension has a different cross section. This then yields a telescopic chassis that piles up perfectly and which is compact. Other features of the invention, to be considered separately or in any feasible combination, will become apparent from the following description of a non-limiting exemplary embodiment of the invention which is depicted in the attached drawings in which: - Figure 1 depicts a view from above of a telescopic chassis according to the invention, 3 - Figure 2 depicts a view from above of the telescopic chassis with a minimum spacing between the work tools, - Figure 3 depicts a view from above of the telescopic chassis with a maximum spacing between the work tools, - Figure 4 is a depiction of the telescopic chassis in horizontal section with minimum spacing, - Figure 5 is a depiction of the telescopic chassis in horizontal section with maximum spacing. The variable-width telescopic chassis (1) depicted in Figure 1 bears work tools (2). This telescopic chassis (1) for an agricultural implement (3) such as a planter comprises a central beam (4) and, on either side, at least one sliding extension (5, 6). The central beam (4) is advantageously hollow. This telescopic chassis (1) can be converted from a minimum size to a maximum size and vice versa through the sliding of the extensions (5, 6) in the central beam (4). To reduce the size of the chassis (1), the sliding extensions (5, 6) are retracted telescopically into the central beam (4), whereas to increase the size, the sliding extensions (5, 6) are deployed in the central beam (4). The telescopic chassis (1) is hollow and preferably has a polygonal cross section, which cross section prevents rotation of the sliding extensions (5, 6) with respect to the central beam (4). The shape of the cross section is square, rectangular, or H-shaped as is known. The telescopic chassis (1) supports work tools (2) distributed with a defined and adjustable spacing. The design of the chassis (1) of the invention allows the spacing between the work tools (2) to be altered quickly; it is an indexable chassis. The range of adjustment for the spacing is from 43 to 80 cm. In the exemplary embodiment of Figure 1, the agricultural machine (3) is a precision seed drill or a planter. A planter such as this can plant various types of seeds in the ground and the spacing between 4 the drills is tailored to suit the species of seed being sown. In a way known per se, it is standard practice to set a spacing of 45 or 50 cm for sowing beetroot whereas the preferred spacing for sowing corn is 75 or 80 cm. In the case of a planter such as this, the work tools (2) are planting elements. Figure 2 depicts the telescopic chassis (1) with a reduced size corresponding to a spacing of 45 cm between the work tools (2). The central beam (4) has a length substantially similar to the width of the telescopic chassis (1) in the small size configuration. As a preference, the length oi the central beam (4) is less than the width of the telescopic chassis (1). Figure 3 for its part depicts the telescopic chassis (1) at its maximum size corresponding to a spacing of 80 cm. The sliding extensions (5, 6) are deployed, the telescopic chassis (1) is opened out to its maximum extent. This telescopic chassis (1) allows the user easily to adapt to the species of seed being sown (beetroot, corn, etc.) while allowing the minimum spacing between the work tools (2) to be adjusted. The width of the telescopic chassis (1) is therefore adaptable. To make it easier to alter the spacing between the work tools (2), the telescopic chassis (1) is controlled from the cab of the tractor, for example hydraulically, pneumatically or electrically. The telescopic chassis (1) is moved around, during work and during transport, by a tractor (not depicted) in a direction and sense of forward travel indicated by the arrow (A). The central beam (4) has a coupling frame (7) allowing it to be attached to the tractor. In the exemplary embodiment of the figures, the agricultural implement (3) is a planter comprising six work tools (2) advantageously distributed at regular intervals along the telescopic chassis (1). It allows seeds to be planted individually in six clearly defined rows. The telescopic chassis (1) is positioned substantially horizontally and substantially at right angles to the direction of forward travel (A). The telescopic chassis (1) also supports wheels (8) intended to rest on the ground and mechanisms for driving the distribution. The telescopic chassis (1) is symmetric with respect to a vertical mid-plane (12) substantially parallel to the direction of forward travel (A). It comprises a first extension (5) which is intended to slide in the 5 left-hand part of the central beam (4) with respect to the direction of forward travel (A). It also comprises a second extension (6) which is intended to slide in the right-hand part of the central beam (4) with respect to the direction of forward travel (A). The work tools (2) are mounted on the chassis (1), in a known way, via respective deformable parallelograms (9). As a result, the work tool (2) is free in the heightwise direction and can faithfully follow the unevenness of the ground, thereby remaining parallel to the ground. In the case of a planter, each planting element has a hopper (10) that constitutes a supply of seeds, a distribution system and a planting device. The distribution system allows the seeds to be taken one by one from the hopper (10) and delivered into the drill at uniform intervals. The planting device creates a furrow at a determined depth in which the seed is placed and then earthed over. Each planting element further comprises a gauge wheel for controlling the planting depth and a weighting device for pressing the seeds down into the furrow. The planting element may be equipped at the front with a device for clearing away debris. According to an important feature of the present invention, the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4). By virtue of this great length of the sliding extensions (5, 6), the rigidity of the telescopic chassis (1) is improved. The length of the central beam (4) is substantially shorter than that of the telescopic chassis in its smallest-size position. Figure 4 depicts the telescopic chassis (1) in horizontal section with a small size corresponding to a spacing of 45 cm. Each sliding extension (5, 6) has an outer end (13) and an inner end (14). The length of a sliding extension (5, 6) therefore corresponds to the distance between the outer end (3) and the inner end (14). It may be noted that the outer end (13) extends beyond the central beam (4) while the inner end (14) extends inside the central beam (4). The outer end (13) oi a respective sliding extension (5, 6) lies on one side of the vertical mid-plane (12) while the inner end (14) lies on the other side of the vertical mid-plane (12) of the telescopic chassis (1). Advantageously, the outer 6 end (13) and the inner end (14) of a corresponding sliding extension (5, 6) always extend on a different side of the vertical mid-plane (12). Figure 5 depicts the telescopic chassis (1) in horizontal section with its maximum size corresponding to a spacing of 80 cm. Each extension (5, 6) has a guiding length, which corresponds to the length that remains inside the central beam (4), substantially equal to at least half the length of this central beam (4). The guiding length is great. The rigidity of the telescopic chassis (1) is therefore significantly improved even when this chassis is opened out to the maximum extent. According to an additional advantage, the first sliding extension (5) and the second sliding extension (6) remain nested one inside the other inside the central beam (4) irrespective of what spacing has been set. The rigidity is thus increased by virtue of the inner ends (14) of the sliding extensions (5, 6) which remain nested one inside the other. Deformation of the telescopic chassis (1) is thus reduced. The sliding extensions (5, 6), on the one hand, slide in the central beam (4) and, on the other hand, slide one inside the other. They are therefore hollow. The sliding extensions (5, 6) have sections of corresponding shapes but different sizes allowing them a telescopic piling. Each end of the central beam (4) has skids (22) making it possible to guide the corresponding sliding extension (5, 6). These skids (22) encourage the sliding extensions (5/ 6) to slide in the central beam (4). In the exemplary embodiment depicted, the cross section of the central beam (4) and of the sliding extensions (5, 6) is square. To achieve a chassis (1) of small size, the dimensions of the square sections of the two extensions (5, 6) differ. According to Figures 4 and 5, the dimensions of the cross section of the first extension (5) are greater than the cross section of the second extension (6). The second extension (6) slides in the first extension (5). The extensions (5, 6) slide in the central beam (4), so the square cross section of the central beam (4) is larger than that of the extensions (5, 6). The internal cross section of the central beam (4) is substantially equal to the external cross section of the first extension (5). The internal cross section of the first extension (5) is substantially equal to the external cross section of the second 7 extension (6). A minimal clearance is needed to ensure the extensions (5, 6) slide properly. By virtue.of the difference in cross section, the sliding extensions (5, 6) pile up optimally inside the central beam (4) and the telescopic chassis (1) can have a minimal size. As can be seen from Figure 1, the telescopic chassis (1) carries four work tools (2) that can move along the central beam (4). Each sliding extension (5, 6) carries one work tool (2). It is therefore possible to see two central work tools (2A), two intermediate work tools (2B) and two outer work tools (2C). In the remainder of the description and to allow for a better understanding thereof, the qualifier (A, B or C) is added after the reference numeral of the term designated as the central, intermediate or outer one. An outer work tool (2C) is connected to a respective sliding extension (5, 6) and the intermediate and central work tools (2B, 2A) are connected to the central beam (4) via a respective sleeve (20). Each sleeve (20) slides on the central beam (4) according to the spacing set. The work tools (2) are connected to one another by tie rods (21). These tie rods (21) are longitudinal rods the cross section of which allows them to have tension applied to them. Each tie rod (21) is provided with holes for adjusting the spacing between the work tools (2). The desired spacing between the work tools (2) is obtained by virtue of an opening stop (23) and/or a closing stop (24). According to another feature of the invention, the extensions (5, 6) slide in the central beam (4) via a single cylinder (15). The cylinder (15) comprises a body (16) and a rod (17). The cylinder (15) is preferably built into the hollow telescopic chassis (1). Advantageously, the body (16) is connected to the first sliding extension (5) which has a larger cross section, and the rod (17) is connected to the second sliding extension (6) of smaller cross section. The body (16) is connected to the first extension (5) by means of a first articulation (18) the axis of which is substantially vertical, and the rod (17) is connected to the second extension (6) by means of a second articulation (19). The articulations (18,19) are in the vicinity of the outer ends (13) of the extensions (5, 6). Thus, the cylinder (15) is deployed or retracted until each 8 tie rod (21) comes up against the opening stop (23) or against the closing stop (24). The position of the opening or closing stops (23, 24) is altered to suit the desired spacing. In the exemplary embodiment depicted, the range of adjustment of the spacing between two adjacent rows is great. The spacing can vary between 45 and 80 cm, with a minimum setting of 43 cm. To convert from a small spacing (Figure 2) to an intermediate spacing or to the maximum spacing (Figure 3), the telescopic chassis (5) is deployed by means of the cylinder (15). The latter is deployed and gradually drives the outer work tools (2C), the intermediate work tools (2B) and the central work tools (2A). To do that, the telescopic chassis (1) is preferably held clear of the ground by means of the three-point hitch of the tractor. The sliding extensions (5, 6) connected to the cylinder (15) slide out of the central beam (4) until the outer tie rods (21C) are resting against the opening stops (23C). The tie rod (21C) is connected to the corresponding sliding extension (5, 6). Thanks to the opening stop (23C), the desired spacing between the outer work tool (2C) and the intermediate work tool (2B) is obtained. When the outer tie rods (21C) come into abutment, it is the intermediate work tools (2B) with their respective sleeve (20B) which slide along the central beam (4) as the cylinder (15) deploys. The intermediate work tools (2B) therefore move away from the vertical mid-plane (12) until the intermediate tie rods (21B) come up against the corresponding opening stops (23B). Next, it is the two central work tools (2A) with their respective sleeve (20A) that move away from the vertical mid-plane (12) until the central tie rods (21A) come up against their stop. When closing up, the rod (17) is retracted into the body (16) o£ the cylinder (15) and the widthwise size of the telescopic chassis (1) is reduced. In this case, it is the closing stops (24) that are used. When converting to a shorter spacing, the work tools (2) move closer together and, each one also moves closer to the vertical mid-plane (12). In the figures, the spacing between the various work tools (2) is uniform. There is no need for all the work tools (2) to be equidistant from one another. It is also possible to conceive of a non-uniform distribution of the work tools (2) on the 9 telescopic chassis (1) to suit the requirements specific to a particular crop or particular terrain. It is also possible to add a work tool in the vertical mid-plane (12). In a particularly advantageous manner, the coupling frame (7) is attached only to the central beam (4) at the vertical mid-plane (12). The respective sleeves (20) of the central and intermediate work tools (2A, 2B) can therefore get even closer to the vertical mid-plane (12) by sliding under the coupling frame (7). A design such as this for the frame/beam connection makes it possible to reduce the widthwise size of the telescopic chassis (1) to 2.50 metres with a spacing of 43 cm. Set up in this way, the telescopic chassis (1) can be transported by road, being connected to the three-point hitch of the tractor. This connection also allows additional equipment of the fertilizing device type to be added to the central work tools (2A). Fitting a fertilizing device such as this onto the telescopic chassis (1) allows fertilizer to be spread and seeds planted in a single pass. To do that, a burying coulter (26) is mounted at the front of the work tool (2). The burying coulter (26) of the central work tool (2A) advantageously slips under the coupling frame (7) when the telescopic chassis (1) is retracted. The burying coulters (26) are depicted only on the left-hand part of the planter with respect to the direction of forward travel (A). For the fertilizer to be brought up close to the seeds, the burying coulter (26) is offset sideways with respect to the work tool (2). The planter is therefore equipped with a hopper in which granules are stored and with conveying devices to the burying coulters. Advantageously, a wheel (8) is mounted on each intermediate sleeve (20B). The wheels (8) therefore move along with the intermediate work tool (2B). They are mounted offset sideways relative to the intermediate work tool (2B). As a result, the seeds are not sown in the tracks left by the wheels (8). The frame/beam connection allows the intermediate sleeves (20B) carrying the wheels (8) to move as close as possible to the vertical mid-plane (12). In order to sow the seeds with a constant spacing, the distribution speed is adapted to the speed of forward travel of the planter. Thus, the planter wheels (8) drive a 10 gearbox (11) which transmits morion to the planting elements via a drive bar (27). The gearbox (11) is arranged substantially in the vertical mid-plane (12) of the telescopic chassis (1). Siting the gearbox (11) centrally allows a better distribution of the torque transmission to the six planting elements. The design of the drive bar (27) is also telescopic and retractable. It has to drive the various work tools (2) irrespective of the spacing set between them. This spacing varies from 43 to 80 cm. The drive bar (27) is advantageously parallel to the telescopic chassis (1). It is made up of male elements (28) which slide in female elements (29). The internal cross section of the female element (29) corresponds to the external cross section of the male element (28). Advantageously, the cross section is polygonal (square or hexagonal)/ with no possibility of rotation. The drive bar (27) additionally comprises a sleeve (30) positioned between the central implement (2A) and the intermediate implement (2B). This sleeve (30) ensures continuity of the drive between the female element (29) and the male element (28) when the chosen spacing is substantially at its maximum (80 cm). The internal cross section of the sleeve (30) corresponds to the external cross section of the female element (29) and is advantageously polygonal. For better guidance of the lateral sliding of the intermediate sleeves (20B) on the central beam (4), the sliding extensions (5, 6) each have two tie rods (21C), one tie rod (21C) being positioned at the front and the other at the rear of the corresponding sliding extension (5r 6) with reference to the direction of forward travel (A). With two tie rods (21C), the tensile force applied by the sliding extension (5/ 6) to the intermediate sleeve (20B) is better distributed. The central beam (4) and the two sliding extensions (5, 6) are positioned in the same plane perpendicular to the direction of forward travel (A). The lengthwise size, in the direction of forward travel (A), of the telescopic chassis (1) is reduced. The telescopic chassis (1) is compact and its overhang is small. The telescopic chassis (1) that has just been described is merely one exemplary embodiment and example of use which does not in any way restrict the scope of 11 protection defined by the claims which follow. Various modifications remain possible, particularly as regards the construction of the various elements, or by substituting technical equivalents. It is entirely possible to have a different number than six work tools distributed along the telescopic chassis. A telescopic chassis with seven, eight or more work tools also forms part of the scope of protection of the invention. The minimum and maximum sizes would then change. 12 WE CLAIM: 1. Variable-width telescopic chassis (1) for an agricultural implement (3), comprising a central beam (4) and, on either side, at least one sliding extension (5, 6), the said telescopic chassis (1) supporting work tools (2) distributed with a defined and adjustable spacing, the said telescopic chassis (1) also having a reduced size when the spacing between the said work tools (2) is at a minimum, the said central beam (4) for its part having a length substantially similar to that of the said telescopic chassis (1) in its reduced-size position, characterized in that the length oi each sliding extension (5, 6) is substantially equal to the length of the said central beam (4). 2. Telescopic chassis according to Claim 1, characterized in that it has a vertical mid-plane (12), and in that each sliding extension (5, 6) has an outer end (13) and an inner end (14), the said outer end (13) and the said inner end (14) always lying on a different side of the said vertical mid-plane (12). 3. Telescopic chassis according to Claim 1 or 2, characterized in that the said sliding extensions (5, 6) remain nested one inside the other irrespective of the spacing defined between the said work tools (2). 4. Telescopic chassis according to any one of Claims 1 to 3, characterized in that it comprises a first sliding extension (5) and a second sliding extension (6), and in that the said sliding extensions (5,6) have cross sections of corresponding shapes but different sizes. 5. Telescopic chassis according to any one of Claims 1 to 4, characterized, in that the said sliding extensions (5, 6) are moved relative to the central beam (4) using a single cylinder (15). 13 6. Telescopic chassis according to Claim 5, characterized in that the said cylinder (15) is built into the said telescopic chassis (1) between a first articulation (18) and a second articulation (19) and has just one rod (17). 7. Telescopic chassis according to any one of Claims 1 to 6, characterized in that it has a drive bar (27) made up of male elements (28) sliding in female elements (29), the said drive bar (27) additionally comprising a sleeve (30). 8. Telescopic chassis according to Claim 7, characterized in that the said sleeve (30) allows the work tools (2) to be driven when the spacing is substantially at its maximum. 9. Telescopic chassis according to any one of Claims 1 to 8, characterized in that it comprises a coupling frame (7) attached to the said central beam (4) in the region of the said vertical mid-plane (12). 10. Agricultural implement (3), characterized in that it comprises a telescopic chassis (1) according to any one o£ claims 1 to 9, 11. Agricultural implement according to Claim 10, characterized in that it is a seed drill. 12. Agricultural implement according to Claim 11, characterized in that it is a planter. Dated this 21st day of August 2008 14 ABSTRACT The present invention relates to a variable-width telescopic chassis (1) for an agricultural implement (3), comprising a central beam (4) and, on either side, at least one sliding extension (5, 6), the said telescopic chassis (1) supporting work tools (2) distributed with a defined and adjustable spacing, the said telescopic chassis (1) also having a reduced size when the spacing between the said work tools (2) is at a minimum, the said central beam (4) for its part having a length substantially similar to that of the said telescopic chassis (1) in its reduced-size position. The telescopic chassis in notable in that the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4). The present invention also relates to an agricultural implement equipped with at least one telescopic chassis (1) such as this. To, The Controller of Patents, The Patents Office, Mumbai Fig-1) 15 22 AUG 2008 NAME OF APPLICANT : KUHN S. A. APPLICATION NO. / / NO. OF SHEETS :03 SHEET NO. :01 HIRAL CHANDRAKANT JOSHI AGENT FOR KUHN S.A. 22 AUG 2008 (NAME OF APPLICANT : KUHN S. A. APPLICATION NO. / / NO. OF SHEETS :03 SHEET NO. :02 Fig. 2 22 AUG 2008 NAME OF APPLICANT : KUHN S. A. APPLICATION NO. : / / NO. OF SHEETS :03 SHEET NO. :03 Fig. 4 17 13 Fig. 5 HIRAL CHANDRAKANT JOSHI AGENT FOR KUHN S.A. 22 AUG 2008 Description The present invention relates to the overall technical field of agricultural machinery. It relates more 5 specifically to a variable-width telescopic chassis for an agricultural implement, comprising a central beam and, on either side, at least, one sliding extension, the said telescopic chassis supporting work tools distributed with a defined and adjustable spacing, the 10 said telescopic chassis also having a reduced size when the spacing between the said work tools is at a minimum, the said central beam for its part having a length substantially similar to that of the said telescopic chassis in its reduced-size position. The 15 invention finds it application in the field of seed-drills, of precision seeders. In general, the invention relates to an agricultural machine intended to work on parallel lines or rows spaced a certain distance apart. 2 0 A telescopic chassis such as this is known to those skilled in the art from document FR 2 862 181 . That telescopic chassis carries six work tools. It comprises a central beam and, on either side, two sliding extensions. A first extension slides in the central 2 5 beam and a second extension slides in the first extension. The central beam carries two work tools whilst each extension carries a single work tool. It is known that the spacing between the work tools varies according to the crop being planted. It is thus 3 0 possible for the telescopic chassis to be converted from a small size to a larger size and vice versa. The telescopic chassis is of small size when the spacing between the said work tools is at a minimum. From this position, the first and second extensions slide 35 outwards until the desired spacing between the work tools is reached. The central beam is of a length substantially similar to that of the telescopic chassis in its small size. - 2 - When this telescopic chassis is used for planting corn, the spacing between two adjacent work tools is approximately 75 cm. The telescopic chassis is opened out and the first and second extensions are deployed. 5 In this opened-out position, the guiding length of the extensions is small because the length of the first and second extensions is relatively short. The guiding length corresponds to the length remaining inside the central beam or inside the first extension when the 10 chassis opens out. With a short guiding length, there is a greater risk that the telescopic chassis will become deformed and broken and consequently opening out and closing up the chassis will become difficult. These disadvantages become all the greater the more the 15 telescopic chassis opens out. Because the guiding length is small, the stability of the work tools is also reduced. It is an object of the present invention to propose a 20 telescopic chassis that is able to overcome the disadvantages of the prior art, particularly by offering a compact telescopic chassis with improved rigidity. 25 To this end, one important feature of the invention is that the length of each extension is substantially equal to the length of the said central beam. The rigidity of the telescopic chassis is therefore improved irrespective of what spacing has been set 30 between the work tools. By virtue of the long length of the sliding extensions, the guiding length is great and there is a lower risk that the telescopic chassis will become deformed. 35 According to another feature of the invention, the extensions remain nested one inside the other irrespective of their position within the central beam. - 3 -According to a highly advantageous additional feature of the invention, each sliding extension has a different cross section. This then yields a telescopic chassis that piles up perfectly and which is compact. 5 Other features of the invention, to be considered separately or in any feasible combination, will become apparent from the following description of a non-limiting exemplary embodiment of the invention which is 10 depicted in the attached drawings in which: Figure 1 depicts a view from above of a telescopic chassis according to the invention, 15 - Figure 2 depicts a view from above of the telescopic chassis with a minimum spacing between the work tools, Figure 3 depicts a view from above of the 2 0 telescopic chassis with a maximum spacing between the work tools. Figure 4 is a depiction of the telescopic chassis in horizontal section with minimum spacing, 25 Figure 5 is a depiction of the telescopic chassis in horizontal section with maximum spacing. The variable-width telescopic chassis {1) depicted in 3 0 Figure 1 bears work tools (2) . This telescopic chassis (1) for an agricultural implement (3} such as a planter comprises a central beam (4) and, on either side, at least one sliding extension (5, 6} . The central beam (4) is advantageously hollow. This telescopic chassis 35 (1) can be converted from a minimum size to a maximum size and vice versa through the sliding of the extensions (5, 6} in the central beam (4) . To reduce the size of the chassis (1), the sliding extensions (5, 6) are retracted telescopically into the central beam - 4 - (4} , whereas to increase the size, the sliding extensions (5, 6) are deployed in the central beam (4). The telescopic chassis (1} is hollow and preferably has a polygonal cross section, which cross section prevents 5 rotation of the sliding extensions (5, 6) with respect to the central beam (4). The shape of the cross section is square, rectangular, or H-shaped as is known. The telescopic chassis (1} supports work tools (2) 10 distributed with a defined and adjustable spacing. The design of the chassis (1) of the invention allows the spacing between the work tools (2) to be altered quickly; it is an indexable chassis. The range of adjustment for the spacing is from 43 to 80 cm. In the 15 exemplary embodiment of Figure 1, the agricultural machine (3) is a precision seed drill or a planter. A planter such as this can plant various types of seeds in the ground and the spacing between the drills is tailored to suit the species of seed being sown. In a 20 way known per se, it is standard practice to set a spacing of 4 5 or 5 0 cm for sowing beetroot whereas the preferred spacing for sowing corn is 75 or 80 cm. In the case of a planter such as this, the work tools (2) are planting elements. 25 Figure 2 depicts the telescopic chassis (1) with a reduced size corresponding to a spacing of 45 cm between the work tools (2). The central beam (4) has a length substantially similar to the width of the 30 telescopic chassis (1) in the small size configuration. As a preference, the length of the central beam (4) is less than the width of the telescopic chassis (1) . Figure 3 for its part depicts the telescopic chassis (1) at its maximum size corresponding to a spacing of 35 80 cm. The sliding extensions '{5, 6) are deployed, the telescopic chassis (1) is opened out to ' its maximum extent. This telescopic chassis (I) allows the user easily to adapt to the species of seed being sown (beetroot, corn, etc.) while allowing the minimum - 5 -spacing between the work tools (2) to be adjusted. The width of the telescopic chassis (1) is therefore adaptable. To make it easier to alter the spacing between the work tools (2), the telescopic chassis (1) 5 is controlled from the cab of the tractor, for example hydraulically, pneumatically or electrically. The telescopic chassis {1) is moved around, during work and during transport, by a tractor (not depicted) in a 10 direction and sense of forward travel indicated by the arrow (A) . The central beam (4) has a coupling frame (7) allowing it to be attached to the tractor. In the exemplary embodiment of the figures, the agricultural implement (3) is a planter comprising six work tools 15 (2) advantageously distributed at regular intervals along the telescopic chassis (1}. It allows seeds to be planted individually in six clearly defined rows. The telescopic chassis (1) is positioned substantially horizontally and substantially at right angles to the 20 direction of forward travel' (A). The telescopic chassis (1) also supports wheels (8) intended to rest on the ground and mechanisms for driving the distribution. The telescopic chassis (1) is symmetric with respect to a vertical mid-plane (12) substantially parallel to the 2 5 direction of forward travel (A) . It comprises a first extension (5) which is intended to slide in the left-hand part of the central beam (4) with respect to the direction of forward travel (A) . It also comprises a second extension (6) which is intended to slide in the 30 right-hand part of the central beam (4) with respect to the direction of forward travel. (A). The work tools (2) are mounted on the chassis (1), in a known way, via respective deformable parallelograms 35 (9) . As a result, the work tool (2) is free in the heightwise direction and can faithfully follow the unevenness of the ground, thereby remaining parallel to the ground. In the case of a planter, each planting element has a hopper (10) that constitutes a supply of - 6 - seeds, a distribution system and a planting device. The distribution system allows the seeds to be taken one by one from the hopper (10) and delivered into the drill at uniform intervals. The planting device creates a 5 furrow at a determined depth in which the seed is placed and then earthed over. Each planting element further comprises a gauge wheel for controlling the planting depth and a weighting device for pressing the seeds down into the furrow. The-planting element may be 10 equipped at the front with a device for clearing away debris. According to an important feature of the present invention, the length of each sliding extension (5, 6) 15 is substantially equal to the length of the said central beam {4}. By virtue of this great length of the sliding extensions (5, 6), the rigidity of the telescopic chassis (1) is improved. The length of the central beam (4} is substantially shorter than that of 20 the telescopic chassis in its smallest-size position. Figure 4 depicts the telescopic chassis (!) in horizontal section with a small size corresponding to a spacing of 45 cm. Each sliding extension (5, 6) has an outer end (13) and an inner end (14) . The length of a 25 sliding extension (5, 6) therefore corresponds to the distance between the outer end (3) and the inner end (14) . It may be noted that the outer end {13) extends beyond the central beam (4) while the inner end (14) extends inside the central beam (4). The outer end (13) 3 0 of a respective sliding extension (5, 6) lies on one side of the vertical mid-plane (12) while the inner end (14) lies on the other side of the vertical mid-plane (12) of the telescopic chassis (1). Advantageously, the outer end (13) and the inner end (14} of a 3 5 corresponding sliding extension (5, 6) always extend- on a different side of the vertical mid-plane (12). Figure 5 depicts the telescopic chassis (1) in horizontal section with its maximum size corresponding - 7 - to a spacing of 80 cm. Each extension (5, 6) has a guiding length, which corresponds to the length that remains inside the central beam (4), substantially equal to at least half the length of this central beam 5 (4). The guiding length is great. The rigidity of the telescopic chassis (l) is therefore significantly improved even when this chassis is opened out to the maximum extent. According to an additional advantage, the first sliding extension (5) and the second sliding 10 extension (6) remain nested one inside the other inside the central beam (4) irrespective of what spacing has been set. The rigidity is thus increased by virtue of the inner ends (14) of the slicing extensions (5, 6) which remain nested one inside the other. Deformation 15 of the telescopic chassis (1) is thus reduced. The sliding extensions (5, 6) , on the one hand, slide in the central beam (4) and, on the other hand, slide one inside the other. They are therefore hollow. The 20 sliding extensions (5, 6) have sections of corresponding shapes but different sizes allowing them a telescopic piling. Each end of the central beam (4) has skids (22) making it possible to guide the corresponding sliding extension (5, 6) . These skids 2 5 (22) encourage the sliding extensions (5, 6) to slide in the central beam (4) . In the exemplary embodiment depicted, the cross section of the central beam (4) and of the sliding extensions (5, 6) is square. To achieve a chassis (1) of small size, the dimensions of the 30 square sections of the two extensions (5, 6) differ. According to Figures 4 and 5, the dimensions of the cross section of the first extension (5) are greater than the cross section of the second extension (6). The second extension (6) slides in the first extension (5). 3 5 The extensions (5, 6) slide in the central beam (4), so the square cross section of the central beam (4) is larger than that of the extensions (5, 6). The internal cross section of the central beam (4) is substantially equal to the external cross Section of the first - 8 - extension (5) . The internal cross section of the first extension (5) is substantially equal to the external cross section of the second extension (6) . A minimal clearance is needed to ensure the extensions (5, 6) 5 slide properly. By virtue of the difference in cross section, the sliding extensions (5, 6) pile up optimally inside the central beam (4) and the telescopic chassis (1) can have a minimal size. 10 As can be seen from Figure 1, the telescopic chassis (1) carries four work tools (2) that can move along the central beam (4). Each sliding extension (5, 6) carries one work tool (2) . It is therefore possible to see two central work tools (2A) , two intermediate work tools 15 (2B) and two outer work tools (2C). in the remainder of the description and to allow for a better understanding thereof, the qualifier {A, B or c) is added after the reference numeral of the term designated as the central, intermediate or outer one. An outer work tool 20 (2C) is connected to a respective sliding extension (5, 6) and the intermediate and central work tools (2B, 2A) are connected to the central beam {4} via a respective sleeve (20) . Each sleeve (20) slides on the central beam (4) according to the spacing set. The work tools 25 (2) are connected to one another by tie rods (21) . These tie rods {21} are longitudinal rods the cross section of which allows them to have tension applied to them. Each tie rod (21) is provided with holes for adjusting the spacing between the work tools (2} . The 3 0 desired spacing between the work tools (2) is obtained by virtue of an opening stop (23} and/or a closing stop ' (24) . According to another feature of the invention, the 3 5 extensions (5, 6) slide in the central beam (4) via a single cylinder (15) . The cylinder (15) comprises a body (16) and a rod (17). The cylinder (15) is preferably built into the hollow telescopic chassis (1). Advantageously, the body (16) is connected to the - 9 -first sliding extension (5) which has a larger cross section, and the rod (17) is connected "to the second sliding extension (6) of smaller cross section. The body (16} is connected to the first extension (5) by 5 means of a first articulation (18) the axis of which is substantially vertical, and the rod (17) is connected to the second extension (6) by means of a second articulation (19). The articulations (18, 19) are in the vicinity of the outer ends (13) of the extensions 10 (5, 6) . Thus, the cylinder (15) is deployed or retracted until each tie rod (21) comes up against the opening stop (23) or against the closing stop (24). The position of the opening or closing stops (23, 24) is altered to suit the desired spacing. In the exemplary 15 embodiment depicted, the range of adjustment of the spacing between two adjacent rows is great. The spacing can vary between 4 5 and 80 cm, with a minimum setting of 43 cm. 20 To convert from a small spacing (Figure 2) to an intermediate spacing or to the maximum spacing (Figure 3), the telescopic chassis (5) is deployed by means of the cylinder (15). The latter is deployed and gradually drives the outer work tools (2C), the intermediate work 25 tools (2B) and the central work tools (2/A) . To do that, the telescopic chassis (1) is preferably held clear of the ground by means of the three-point hitch of the tractor. The sliding extensions (5, 6) connected to the cylinder (15) slide out of the central beam (4) until 30 the outer tie rods (21C) are resting against the opening stops (23C). The tie rod (21C) is connected to the corresponding sliding extension (5, 6) . Thanks to the opening stop (23C), the desired spacing between the outer work tool (2C) and the intermediate work tool 3 5 (2B) is obtained. When the outer tie rods (21C) come into abutment, it is the intermediate work tools (2B) with their respective sleeve (20B) which slide along the central beam (4) as the cylinder (15) deploys. The intermediate work tools (2B) therefore move, away from - 10 -the vertical mid-plane (12) until the intermediate tie rods (21B) come up against the corresponding opening stops (2 3B) . Next, it is the two central work tools (2A) with their respective sleeve (20A) that move away 5 from the vertical mid-plane (12) until the central tie rods (21A) come up against their stop. When closing up, the rod (17) is retracted into the body (16) of the cylinder (15) and the widthwise size 10 of the telescopic chassis (1) is reduced. In this case, it is the closing stops (24) that are used. When converting to a shorter spacing, the work tools (2} move closer'together and each one also moves closer to the vertical mid-plane (12) . In the figures, the 15 spacing between the various work tools (2) is uniform. There is no need for all the work tools (2} to be equidistant from one another. It is also possible to conceive of a non-uniform distribution of the work tools (2) on the telescopic chassis (1) to suit the 20 requirements specific to a particular crop or particular terrain. It is also possible to add a work tool in the vertical mid-plane (12). In a particularly advantageous manner, the coupling 25 frame (7) is attached only to the central beam (4) at the vertical mid-plane (12) . The respective sleeves (2 0) of the central and intermediate work tools (2A, 2B) can therefore get even closer to the vertical mid- plane (12) by sliding under the coupling frame (7). A 3 0 design such as this for the frame/beam connection makes it possible to reduce the widthwise size of the telescopic chassis (1) to 2.50 metres with a spacing of 4 3 cm. Set up in. this way, the telescopic chassis (1) can be transported by road, being connected to the 3 5 three-point hitch of the tractor. This connection also allows additional equipment of the fertilizing device type to be added to the central work tools (2A) . Fitting a fertilizing device such as this onto the telescopic chassis (1) allows fertilizer to be spread - 11 - and seeds planted in a single pass. To do that, a burying coulter (26) is mounted at the front of the work tool (2). The burying coulter (26) of the central work tool (2A) advantageously slips under the coupling 5 frame (7) when the telescopic chassis (1) is retracted. The burying coulters (26) are depicted only on the left-hand part of. the planter with respect to the direction of forward travel (A) . For the fertilizer to be brought up close to the seeds, the burying coulter 10 (26) is offset sideways with respect to the work tool (2). The planter is therefore equipped with a hopper in which granules are stored and with conveying devices to the burying coulters. 15 Advantageously, a wheel (8) is mounted on each intermediate sleeve (2 OB) . The wheels (8) therefore move along with the intermediate work tool (2B) . They are mounted offset sideways relative to the intermediate work tool (2B). As a result, the seeds are 20 not sown in the tracks left by the wheels (8) . The frame/beam connection allows the intermediate sleeves (2 OB) carrying the wheels (8) to move as close as possible to the vertical mid-plan^ (12). 25 In order to sow the seeds with a constant spacing, the distribution speed is adapted to the speed of forward travel of the planter. Thus, the planter wheels (8) drive a gearbox (11) which transmits motion to the planting elements via a drive far (27) . The gearbox 3 0 (11) is arranged substantially in the vertical mid-plane (12) of the telescopic chassis (1) . Siting the gearbox (11) centrally allows a petter distribution of the torque transmission to the six planting elements. The design of the drive bar (27) is also telescopic and 35 retractable. It has to drive the various work tools (2) irrespective of the spacing set; between them. This spacing varies from 43 to 80 cm. The drive bar (27) is advantageously parallel to the telescopic chassis (1) . It is made up of male elements (28) which slide in - 12 -female elements (29). The internal cross section of the female element (29) corresponds to the external cross section of the male element (28) . Advantageously, the cross section is polygonal (square or hexagonal), with 5 no possibility of rotation. The drive bar (2 7) additionally comprises a sleeve (30) positioned between the central implement (2A) and the intermediate implement (2B) . This sleeve (30) ensures continuity of the drive between the female element (29) and the male 10 element (28) when the chosen spacing is substantially , at its maximum (80 cm). The internal cross section of the sleeve (30) corresponds to the external cross section of the female element (29) and is advantageously polygonal. 15 For better guidance of the lateral sliding of the intermediate sleeves (20B) on the central beam (4), the sliding extensions (5, 6) each have two tie rods (2-1C) , one tie rod (21C) being positioned at the front and the 20 other at the rear of the Corresponding sliding extension (5, 6) with reference to the direction of forward travel (A). With two tie rods (21C), the tensile force applied by the sliding extension (5, 6) to the intermediate sleeve (20B) is better distributed. 25 The central beam (4) and the two sliding extensions (5, 6) are positioned in the same plane perpendicular 'to the direction of forward travel (A) . The lengthwise size, in the direction of forward travel (A) , of the 3 0 telescopic chassis (1) is reduced. The telescopic chassis (1) is compact and its overhang is small. The telescopic chassis (1) that has just been described is merely one exemplary embodiment and example of use 3 5 which does not in any way restrict the scope cf protection defined by the claims which follow. Various modifications remain possible, particularly as regards the construction of the various elements, or by substituting technical equivalents. - 13 - It is entirely possible to have a different number than six work tools distributed a long the telescopic chassis. A telescopic chassis with seven, eight or more 5 work tools also forms part of the scope of protection of the invention. The minimum and maximum sizes would then change. - 14 -Claims Variable-width telescopic chassis (1) for an agricultural implement (3), comprising a central beam (4) and, on either side, at least one sliding extension (5, 6) , the said telescopic chassis (1) supporting work tools (2) distributed with a defined and adjustable spacing, the said telescopic chassis (1) also having a reduced size when the spacing between the said work tools (2) is at a minimum, the said central beam (4) for its part having a length substantially similar to that of the said telescopic chassis (1) in its reduced-size position, characterized in that the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4). Telescopic chassis according to Claim 1, characterized in that it has a vertical mid-plane (12), and in that each sliding extension (5, 6) has an outer end (13) and an inner end (14), the said outer end (13) and the said inner end (14) always lying on a different side of the said vertical mid-plane (12). Telescopic chassis according to Claim 1 . or 2, characterized in that the said sliding extensions (5, 6) remain nested one inside the other irrespective of the spacing defined between the said work tools (2). Telescopic chassis according to any one of Claims 1 to 3, characterized in that it comprises a first sliding extension (5) and a second sliding extension (6), and in that the said sliding extensions (5, 6) have cross sections of correspondina shapes but different sizes. - 15 - 5. Telescopic chassis according to any one of Claims 1 to 4, characterized in that the said sliding extensions (5, 6) are moved relative to the central beam (4) using a single cylinder (15). 6. Telescopic chassis according to Claim 5, characterized in that the said cylinder (15) is built into the said telescopic chassis (1) between a first articulation (18) and a second articulation (19) and has just one rod (17). 7. Telescopic chassis according to any one of Claims 1 to 6, characterized in that it has a drive bar (2 7) made up of male elements (28) sliding in female elements (29) , the said drive bar (27) additionally comprising a sleeve (30). 8. Telescopic chassis according to Claim 7, characterized in that the said sleeve (30) allows the work tools (2) to be driven when the spacing is substantially at its maximum. 9. Telescopic chassis according to any one of Claims 1 to 8, characterized in that it comprises a coupling frame (7) attached to the said central beam (4) in the region of the said vertical mid-plane (12) . 10. Agricultural implement (3), characterized in that it comprises a telescopic chassis (1) according to any one of claims 1 to 9, 11. Agricultural implement according to Claim 10, characterized in that it is a seed drill. 12. Agricultural implement according to Claim 11, characterized in that it is a planter.

Full Text

FORM 2
THE PATENT ACT 1970 (39 of 1970)
The Patents Rules, 2003 COMPLETE SPECIFICATION [See Section 10, and rule 13
TITLE OF INVENTION
IMPROVED TELESCOPIC CHASSIS AND AGRICULTURAL IMPLEMENT WITH SUCH
A CHASSIS

APPLICANT (S)
a) Name
b) Nationality
c) Address

KUHN S . A.
FRENCH Company
4, IMPASSE DES FABRIQUES,
F-67700 SAVERNE,
FRANCE

3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed : -

IN THE MATTER OF an Application
for a French Patent
in the name of
Kuhn SA
filed under No. 07/57,267, and
IN THE MATTER OF an Application
for an Indian Patent.
RWS Group Ltd, of Europa House, Marsham Way, Gerrards Cross, Buckinghamshire, England, hereby solemnly and sincerely declares that to the best of its knowledge and belief, the following document, prepared by one of its translators competent in the art and conversant with the English and French languages is a true and correct translation of the Patent Application filed under No. 07/57,267
by Kuhn SA
in France on 30 August 2007
for "Improved telescopic chassis and agricultural machinery with such a chassis".
Date: 9 July 2008

C. E. SITCH
Managing Director - UK Translation Division For and on behalf of RWS Group Ltd

The present invention relates to the overall technical field of agricultural machinery. It relates more specifically to a variable-width telescopic chassis for an agricultural implement comprising a central beam and, on either side, at least one sliding extension, the said telescopic chassis supporting work tools distributed with a defined and adjustable spacing, the said telescopic chassis also having a reduced size when the spacing between the said work tools is at a minimum, the said central beam for its part having a length substantially similar to that of the said telescopic chassis in its reduced-size position. The invention finds it application in the field of seed-drills, of precision seeders. In general, the invention relates to an agricultural machine intended to work on parallel lines or rows spaced a certain distance apart.
A telescopic chassis such as this is known to those skilled in the art from document FR 2 862181. That telescopic chassis carries six work tools. It comprises a central beam and, on either side, two sliding extensions. A first extension slides in the central beam and a second extension slides in the first extension. The central beam carries two work tools whilst each extension carries a single work tool. It is known that the spacing between the work tools varies according to the crop being planted. It is thus possible for the telescopic chassis to be converted from a small size to a larger size and vice versa. The telescopic chassis is of small size when the spacing between the said work tools is at a minimum. From this position, the first and second extensions slide outwards until the desired spacing between the work tools is reached. The central beam is of a length substantially similar to that of the telescopic chassis in its small size.
When this telescopic chassis is used for planting corn, the spacing between two adjacent work tools is approximately 75 cm. The telescopic chassis is opened out and the first and second extensions are deployed. In this opened-out position, the guiding length of the extensions is small because the length of the first and second extensions is relatively short. The guiding length corresponds to the length remaining inside the central beam or inside the first extension when the chassis opens out. With a short guiding length, there is a greater risk that the telescopic
2

chassis will become deformed and broken and consequently opening out and closing up the chassis will become difficult. These disadvantages become all the greater the more the telescopic chassis opens out. Because the guiding length is small, the stability of the work tools is also reduced.
It is an object of the present invention to propose a telescopic chassis that is able to overcome the disadvantages of the prior art, particularly by offering a compact telescopic chassis with improved rigidity.
To this end, one important feature of the invention is that the length of each extension is substantially equal to the length of the said central beam. The rigidity of the telescopic chassis is therefore improved irrespective of what spacing has been set between the work tools. By virtue of the long length of the sliding extensions, the guiding length is great and there is a lower risk that the telescopic chassis will become deformed.
According to another feature of the invention, the extensions remain nested one inside the other irrespective of their position within the central beam.
According to a highly advantageous additional feature of the invention, each sliding extension has a different cross section. This then yields a telescopic chassis that piles up perfectly and which is compact.
Other features of the invention, to be considered separately or in any feasible combination, will become apparent from the following description of a non-limiting exemplary embodiment of the invention which is depicted in the attached drawings in which:
- Figure 1 depicts a view from above of a telescopic chassis according to the invention,
3

- Figure 2 depicts a view from above of the telescopic chassis with a minimum
spacing between the work tools,
- Figure 3 depicts a view from above of the telescopic chassis with a maximum
spacing between the work tools,
- Figure 4 is a depiction of the telescopic chassis in horizontal section with
minimum spacing,
- Figure 5 is a depiction of the telescopic chassis in horizontal section with
maximum spacing.
The variable-width telescopic chassis (1) depicted in Figure 1 bears work tools (2). This telescopic chassis (1) for an agricultural implement (3) such as a planter comprises a central beam (4) and, on either side, at least one sliding extension (5, 6). The central beam (4) is advantageously hollow. This telescopic chassis (1) can be converted from a minimum size to a maximum size and vice versa through the sliding of the extensions (5, 6) in the central beam (4). To reduce the size of the chassis (1), the sliding extensions (5, 6) are retracted telescopically into the central beam (4), whereas to increase the size, the sliding extensions (5, 6) are deployed in the central beam (4). The telescopic chassis (1) is hollow and preferably has a polygonal cross section, which cross section prevents rotation of the sliding extensions (5, 6) with respect to the central beam (4). The shape of the cross section is square, rectangular, or H-shaped as is known.
The telescopic chassis (1) supports work tools (2) distributed with a defined and adjustable spacing. The design of the chassis (1) of the invention allows the spacing between the work tools (2) to be altered quickly; it is an indexable chassis. The range of adjustment for the spacing is from 43 to 80 cm. In the exemplary embodiment of Figure 1, the agricultural machine (3) is a precision seed drill or a planter. A planter such as this can plant various types of seeds in the ground and the spacing between
4

the drills is tailored to suit the species of seed being sown. In a way known per se, it is standard practice to set a spacing of 45 or 50 cm for sowing beetroot whereas the preferred spacing for sowing corn is 75 or 80 cm. In the case of a planter such as this, the work tools (2) are planting elements.
Figure 2 depicts the telescopic chassis (1) with a reduced size corresponding to a spacing of 45 cm between the work tools (2). The central beam (4) has a length substantially similar to the width of the telescopic chassis (1) in the small size configuration. As a preference, the length oi the central beam (4) is less than the width of the telescopic chassis (1). Figure 3 for its part depicts the telescopic chassis (1) at its maximum size corresponding to a spacing of 80 cm. The sliding extensions (5, 6) are deployed, the telescopic chassis (1) is opened out to its maximum extent. This telescopic chassis (1) allows the user easily to adapt to the species of seed being sown (beetroot, corn, etc.) while allowing the minimum spacing between the work tools (2) to be adjusted. The width of the telescopic chassis (1) is therefore adaptable. To make it easier to alter the spacing between the work tools (2), the telescopic chassis (1) is controlled from the cab of the tractor, for example hydraulically, pneumatically or electrically.
The telescopic chassis (1) is moved around, during work and during transport, by a tractor (not depicted) in a direction and sense of forward travel indicated by the arrow (A). The central beam (4) has a coupling frame (7) allowing it to be attached to the tractor. In the exemplary embodiment of the figures, the agricultural implement (3) is a planter comprising six work tools (2) advantageously distributed at regular intervals along the telescopic chassis (1). It allows seeds to be planted individually in six clearly defined rows. The telescopic chassis (1) is positioned substantially horizontally and substantially at right angles to the direction of forward travel (A). The telescopic chassis (1) also supports wheels (8) intended to rest on the ground and mechanisms for driving the distribution. The telescopic chassis (1) is symmetric with respect to a vertical mid-plane (12) substantially parallel to the direction of forward travel (A). It comprises a first extension (5) which is intended to slide in the
5

left-hand part of the central beam (4) with respect to the direction of forward travel (A). It also comprises a second extension (6) which is intended to slide in the right-hand part of the central beam (4) with respect to the direction of forward travel (A).
The work tools (2) are mounted on the chassis (1), in a known way, via respective deformable parallelograms (9). As a result, the work tool (2) is free in the heightwise direction and can faithfully follow the unevenness of the ground, thereby remaining parallel to the ground. In the case of a planter, each planting element has a hopper (10) that constitutes a supply of seeds, a distribution system and a planting device. The distribution system allows the seeds to be taken one by one from the hopper (10) and delivered into the drill at uniform intervals. The planting device creates a furrow at a determined depth in which the seed is placed and then earthed over. Each planting element further comprises a gauge wheel for controlling the planting depth and a weighting device for pressing the seeds down into the furrow. The planting element may be equipped at the front with a device for clearing away debris.
According to an important feature of the present invention, the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4). By virtue of this great length of the sliding extensions (5, 6), the rigidity of the telescopic chassis (1) is improved. The length of the central beam (4) is substantially shorter than that of the telescopic chassis in its smallest-size position. Figure 4 depicts the telescopic chassis (1) in horizontal section with a small size corresponding to a spacing of 45 cm. Each sliding extension (5, 6) has an outer end (13) and an inner end (14). The length of a sliding extension (5, 6) therefore corresponds to the distance between the outer end (3) and the inner end (14). It may be noted that the outer end (13) extends beyond the central beam (4) while the inner end (14) extends inside the central beam (4). The outer end (13) oi a respective sliding extension (5, 6) lies on one side of the vertical mid-plane (12) while the inner end (14) lies on the other side of the vertical mid-plane (12) of the telescopic chassis (1). Advantageously, the outer
6

end (13) and the inner end (14) of a corresponding sliding extension (5, 6) always extend on a different side of the vertical mid-plane (12).
Figure 5 depicts the telescopic chassis (1) in horizontal section with its maximum size corresponding to a spacing of 80 cm. Each extension (5, 6) has a guiding length, which corresponds to the length that remains inside the central beam (4), substantially equal to at least half the length of this central beam (4). The guiding length is great. The rigidity of the telescopic chassis (1) is therefore significantly improved even when this chassis is opened out to the maximum extent. According to an additional advantage, the first sliding extension (5) and the second sliding extension (6) remain nested one inside the other inside the central beam (4) irrespective of what spacing has been set. The rigidity is thus increased by virtue of the inner ends (14) of the sliding extensions (5, 6) which remain nested one inside the other. Deformation of the telescopic chassis (1) is thus reduced.
The sliding extensions (5, 6), on the one hand, slide in the central beam (4) and, on the other hand, slide one inside the other. They are therefore hollow. The sliding extensions (5, 6) have sections of corresponding shapes but different sizes allowing them a telescopic piling. Each end of the central beam (4) has skids (22) making it possible to guide the corresponding sliding extension (5, 6). These skids (22) encourage the sliding extensions (5/ 6) to slide in the central beam (4). In the exemplary embodiment depicted, the cross section of the central beam (4) and of the sliding extensions (5, 6) is square. To achieve a chassis (1) of small size, the dimensions of the square sections of the two extensions (5, 6) differ. According to Figures 4 and 5, the dimensions of the cross section of the first extension (5) are greater than the cross section of the second extension (6). The second extension (6) slides in the first extension (5). The extensions (5, 6) slide in the central beam (4), so the square cross section of the central beam (4) is larger than that of the extensions (5, 6). The internal cross section of the central beam (4) is substantially equal to the external cross section of the first extension (5). The internal cross section of the first extension (5) is substantially equal to the external cross section of the second
7

extension (6). A minimal clearance is needed to ensure the extensions (5, 6) slide properly. By virtue.of the difference in cross section, the sliding extensions (5, 6) pile up optimally inside the central beam (4) and the telescopic chassis (1) can have a minimal size.
As can be seen from Figure 1, the telescopic chassis (1) carries four work tools (2) that can move along the central beam (4). Each sliding extension (5, 6) carries one work tool (2). It is therefore possible to see two central work tools (2A), two intermediate work tools (2B) and two outer work tools (2C). In the remainder of the description and to allow for a better understanding thereof, the qualifier (A, B or C) is added after the reference numeral of the term designated as the central, intermediate or outer one. An outer work tool (2C) is connected to a respective sliding extension (5, 6) and the intermediate and central work tools (2B, 2A) are connected to the central beam (4) via a respective sleeve (20). Each sleeve (20) slides on the central beam (4) according to the spacing set. The work tools (2) are connected to one another by tie rods (21). These tie rods (21) are longitudinal rods the cross section of which allows them to have tension applied to them. Each tie rod (21) is provided with holes for adjusting the spacing between the work tools (2). The desired spacing between the work tools (2) is obtained by virtue of an opening stop (23) and/or a closing stop (24).
According to another feature of the invention, the extensions (5, 6) slide in the central beam (4) via a single cylinder (15). The cylinder (15) comprises a body (16) and a rod (17). The cylinder (15) is preferably built into the hollow telescopic chassis (1). Advantageously, the body (16) is connected to the first sliding extension (5) which has a larger cross section, and the rod (17) is connected to the second sliding extension (6) of smaller cross section. The body (16) is connected to the first extension (5) by means of a first articulation (18) the axis of which is substantially vertical, and the rod (17) is connected to the second extension (6) by means of a second articulation (19). The articulations (18,19) are in the vicinity of the outer ends (13) of the extensions (5, 6). Thus, the cylinder (15) is deployed or retracted until each
8

tie rod (21) comes up against the opening stop (23) or against the closing stop (24). The position of the opening or closing stops (23, 24) is altered to suit the desired spacing. In the exemplary embodiment depicted, the range of adjustment of the spacing between two adjacent rows is great. The spacing can vary between 45 and 80 cm, with a minimum setting of 43 cm.
To convert from a small spacing (Figure 2) to an intermediate spacing or to the maximum spacing (Figure 3), the telescopic chassis (5) is deployed by means of the cylinder (15). The latter is deployed and gradually drives the outer work tools (2C), the intermediate work tools (2B) and the central work tools (2A). To do that, the telescopic chassis (1) is preferably held clear of the ground by means of the three-point hitch of the tractor. The sliding extensions (5, 6) connected to the cylinder (15) slide out of the central beam (4) until the outer tie rods (21C) are resting against the opening stops (23C). The tie rod (21C) is connected to the corresponding sliding extension (5, 6). Thanks to the opening stop (23C), the desired spacing between the outer work tool (2C) and the intermediate work tool (2B) is obtained. When the outer tie rods (21C) come into abutment, it is the intermediate work tools (2B) with their respective sleeve (20B) which slide along the central beam (4) as the cylinder (15) deploys. The intermediate work tools (2B) therefore move away from the vertical mid-plane (12) until the intermediate tie rods (21B) come up against the corresponding opening stops (23B). Next, it is the two central work tools (2A) with their respective sleeve (20A) that move away from the vertical mid-plane (12) until the central tie rods (21A) come up against their stop.
When closing up, the rod (17) is retracted into the body (16) o£ the cylinder (15) and the widthwise size of the telescopic chassis (1) is reduced. In this case, it is the closing stops (24) that are used. When converting to a shorter spacing, the work tools (2) move closer together and, each one also moves closer to the vertical mid-plane (12). In the figures, the spacing between the various work tools (2) is uniform. There is no need for all the work tools (2) to be equidistant from one another. It is also possible to conceive of a non-uniform distribution of the work tools (2) on the
9

telescopic chassis (1) to suit the requirements specific to a particular crop or particular terrain. It is also possible to add a work tool in the vertical mid-plane (12).
In a particularly advantageous manner, the coupling frame (7) is attached only to the central beam (4) at the vertical mid-plane (12). The respective sleeves (20) of the central and intermediate work tools (2A, 2B) can therefore get even closer to the vertical mid-plane (12) by sliding under the coupling frame (7). A design such as this for the frame/beam connection makes it possible to reduce the widthwise size of the telescopic chassis (1) to 2.50 metres with a spacing of 43 cm. Set up in this way, the telescopic chassis (1) can be transported by road, being connected to the three-point hitch of the tractor. This connection also allows additional equipment of the fertilizing device type to be added to the central work tools (2A). Fitting a fertilizing device such as this onto the telescopic chassis (1) allows fertilizer to be spread and seeds planted in a single pass. To do that, a burying coulter (26) is mounted at the front of the work tool (2). The burying coulter (26) of the central work tool (2A) advantageously slips under the coupling frame (7) when the telescopic chassis (1) is retracted. The burying coulters (26) are depicted only on the left-hand part of the planter with respect to the direction of forward travel (A). For the fertilizer to be brought up close to the seeds, the burying coulter (26) is offset sideways with respect to the work tool (2). The planter is therefore equipped with a hopper in which granules are stored and with conveying devices to the burying coulters.
Advantageously, a wheel (8) is mounted on each intermediate sleeve (20B). The wheels (8) therefore move along with the intermediate work tool (2B). They are mounted offset sideways relative to the intermediate work tool (2B). As a result, the seeds are not sown in the tracks left by the wheels (8). The frame/beam connection allows the intermediate sleeves (20B) carrying the wheels (8) to move as close as possible to the vertical mid-plane (12).
In order to sow the seeds with a constant spacing, the distribution speed is adapted to the speed of forward travel of the planter. Thus, the planter wheels (8) drive a
10

gearbox (11) which transmits morion to the planting elements via a drive bar (27). The gearbox (11) is arranged substantially in the vertical mid-plane (12) of the telescopic chassis (1). Siting the gearbox (11) centrally allows a better distribution of the torque transmission to the six planting elements. The design of the drive bar (27) is also telescopic and retractable. It has to drive the various work tools (2) irrespective of the spacing set between them. This spacing varies from 43 to 80 cm. The drive bar (27) is advantageously parallel to the telescopic chassis (1). It is made up of male elements (28) which slide in female elements (29). The internal cross section of the female element (29) corresponds to the external cross section of the male element (28). Advantageously, the cross section is polygonal (square or hexagonal)/ with no possibility of rotation. The drive bar (27) additionally comprises a sleeve (30) positioned between the central implement (2A) and the intermediate implement (2B). This sleeve (30) ensures continuity of the drive between the female element (29) and the male element (28) when the chosen spacing is substantially at its maximum (80 cm). The internal cross section of the sleeve (30) corresponds to the external cross section of the female element (29) and is advantageously polygonal.
For better guidance of the lateral sliding of the intermediate sleeves (20B) on the central beam (4), the sliding extensions (5, 6) each have two tie rods (21C), one tie rod (21C) being positioned at the front and the other at the rear of the corresponding sliding extension (5r 6) with reference to the direction of forward travel (A). With two tie rods (21C), the tensile force applied by the sliding extension (5/ 6) to the intermediate sleeve (20B) is better distributed.
The central beam (4) and the two sliding extensions (5, 6) are positioned in the same plane perpendicular to the direction of forward travel (A). The lengthwise size, in the direction of forward travel (A), of the telescopic chassis (1) is reduced. The telescopic chassis (1) is compact and its overhang is small.
The telescopic chassis (1) that has just been described is merely one exemplary embodiment and example of use which does not in any way restrict the scope of
11

protection defined by the claims which follow. Various modifications remain possible, particularly as regards the construction of the various elements, or by substituting technical equivalents.
It is entirely possible to have a different number than six work tools distributed along the telescopic chassis. A telescopic chassis with seven, eight or more work tools also forms part of the scope of protection of the invention. The minimum and maximum sizes would then change.
12

WE CLAIM:
1. Variable-width telescopic chassis (1) for an agricultural implement (3),
comprising a central beam (4) and, on either side, at least one sliding
extension (5, 6), the said telescopic chassis (1) supporting work tools (2)
distributed with a defined and adjustable spacing, the said telescopic chassis
(1) also having a reduced size when the spacing between the said work tools
(2) is at a minimum, the said central beam (4) for its part having a length
substantially similar to that of the said telescopic chassis (1) in its reduced-size
position, characterized in that the length oi each sliding extension (5, 6) is
substantially equal to the length of the said central beam (4).
2. Telescopic chassis according to Claim 1, characterized in that it has a vertical mid-plane (12), and in that each sliding extension (5, 6) has an outer end (13) and an inner end (14), the said outer end (13) and the said inner end (14) always lying on a different side of the said vertical mid-plane (12).
3. Telescopic chassis according to Claim 1 or 2, characterized in that the said sliding extensions (5, 6) remain nested one inside the other irrespective of the spacing defined between the said work tools (2).
4. Telescopic chassis according to any one of Claims 1 to 3, characterized in that it comprises a first sliding extension (5) and a second sliding extension (6), and in that the said sliding extensions (5,6) have cross sections of corresponding shapes but different sizes.
5. Telescopic chassis according to any one of Claims 1 to 4, characterized, in that the said sliding extensions (5, 6) are moved relative to the central beam (4) using a single cylinder (15).
13

6. Telescopic chassis according to Claim 5, characterized in that the said cylinder (15) is built into the said telescopic chassis (1) between a first articulation (18) and a second articulation (19) and has just one rod (17).
7. Telescopic chassis according to any one of Claims 1 to 6, characterized in that it has a drive bar (27) made up of male elements (28) sliding in female elements (29), the said drive bar (27) additionally comprising a sleeve (30).
8. Telescopic chassis according to Claim 7, characterized in that the said sleeve (30) allows the work tools (2) to be driven when the spacing is substantially at its maximum.
9. Telescopic chassis according to any one of Claims 1 to 8, characterized in that it comprises a coupling frame (7) attached to the said central beam (4) in the region of the said vertical mid-plane (12).
10. Agricultural implement (3), characterized in that it comprises a telescopic chassis (1) according to any one o£ claims 1 to 9,
11. Agricultural implement according to Claim 10, characterized in that it is a seed drill.
12. Agricultural implement according to Claim 11, characterized in that it is a planter.
Dated this 21st day of August 2008

14

ABSTRACT
The present invention relates to a variable-width telescopic chassis (1) for an agricultural implement (3), comprising a central beam (4) and, on either side, at least one sliding extension (5, 6), the said telescopic chassis (1) supporting work tools (2) distributed with a defined and adjustable spacing, the said telescopic chassis (1) also having a reduced size when the spacing between the said work tools (2) is at a minimum, the said central beam (4) for its part having a length substantially similar to that of the said telescopic chassis (1) in its reduced-size position.
The telescopic chassis in notable in that the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4).
The present invention also relates to an agricultural implement equipped with at least one telescopic chassis (1) such as this.
To,
The Controller of Patents,
The Patents Office,
Mumbai
Fig-1)

15

22 AUG 2008

NAME OF APPLICANT : KUHN S. A.
APPLICATION NO. / /

NO. OF SHEETS :03
SHEET NO. :01

HIRAL CHANDRAKANT JOSHI
AGENT FOR KUHN S.A.
22 AUG 2008

(NAME OF APPLICANT : KUHN S. A.
APPLICATION NO. / /

NO. OF SHEETS :03
SHEET NO. :02

Fig. 2

22 AUG 2008

NAME OF APPLICANT : KUHN S. A.
APPLICATION NO. : / /

NO. OF SHEETS :03
SHEET NO. :03

Fig. 4
17 13

Fig. 5

HIRAL CHANDRAKANT JOSHI
AGENT FOR KUHN S.A.
22 AUG 2008

Description
The present invention relates to the overall technical field of agricultural machinery. It relates more 5 specifically to a variable-width telescopic chassis for an agricultural implement, comprising a central beam and, on either side, at least, one sliding extension, the said telescopic chassis supporting work tools distributed with a defined and adjustable spacing, the
10 said telescopic chassis also having a reduced size when the spacing between the said work tools is at a minimum, the said central beam for its part having a length substantially similar to that of the said telescopic chassis in its reduced-size position. The
15 invention finds it application in the field of seed-drills, of precision seeders. In general, the invention relates to an agricultural machine intended to work on parallel lines or rows spaced a certain distance apart.
2 0 A telescopic chassis such as this is known to those skilled in the art from document FR 2 862 181 . That telescopic chassis carries six work tools. It comprises a central beam and, on either side, two sliding extensions. A first extension slides in the central
2 5 beam and a second extension slides in the first
extension. The central beam carries two work tools whilst each extension carries a single work tool. It is known that the spacing between the work tools varies according to the crop being planted. It is thus
3 0 possible for the telescopic chassis to be converted
from a small size to a larger size and vice versa. The telescopic chassis is of small size when the spacing between the said work tools is at a minimum. From this position, the first and second extensions slide 35 outwards until the desired spacing between the work tools is reached. The central beam is of a length substantially similar to that of the telescopic chassis in its small size.

- 2 -
When this telescopic chassis is used for planting corn, the spacing between two adjacent work tools is approximately 75 cm. The telescopic chassis is opened out and the first and second extensions are deployed. 5 In this opened-out position, the guiding length of the extensions is small because the length of the first and second extensions is relatively short. The guiding length corresponds to the length remaining inside the central beam or inside the first extension when the
10 chassis opens out. With a short guiding length, there is a greater risk that the telescopic chassis will become deformed and broken and consequently opening out and closing up the chassis will become difficult. These disadvantages become all the greater the more the
15 telescopic chassis opens out. Because the guiding length is small, the stability of the work tools is also reduced.
It is an object of the present invention to propose a 20 telescopic chassis that is able to overcome the disadvantages of the prior art, particularly by offering a compact telescopic chassis with improved rigidity.
25 To this end, one important feature of the invention is that the length of each extension is substantially equal to the length of the said central beam. The rigidity of the telescopic chassis is therefore improved irrespective of what spacing has been set
30 between the work tools. By virtue of the long length of the sliding extensions, the guiding length is great and there is a lower risk that the telescopic chassis will become deformed.
35 According to another feature of the invention, the extensions remain nested one inside the other irrespective of their position within the central beam.

- 3 -According to a highly advantageous additional feature of the invention, each sliding extension has a different cross section. This then yields a telescopic chassis that piles up perfectly and which is compact. 5
Other features of the invention, to be considered separately or in any feasible combination, will become apparent from the following description of a non-limiting exemplary embodiment of the invention which is 10 depicted in the attached drawings in which:
Figure 1 depicts a view from above of a telescopic chassis according to the invention,
15 - Figure 2 depicts a view from above of the telescopic chassis with a minimum spacing between the work tools,
Figure 3 depicts a view from above of the
2 0 telescopic chassis with a maximum spacing between the
work tools.
Figure 4 is a depiction of the telescopic chassis
in horizontal section with minimum spacing,
25
Figure 5 is a depiction of the telescopic chassis
in horizontal section with maximum spacing.
The variable-width telescopic chassis {1) depicted in
3 0 Figure 1 bears work tools (2) . This telescopic chassis
(1) for an agricultural implement (3} such as a planter comprises a central beam (4) and, on either side, at least one sliding extension (5, 6} . The central beam (4) is advantageously hollow. This telescopic chassis 35 (1) can be converted from a minimum size to a maximum size and vice versa through the sliding of the extensions (5, 6} in the central beam (4) . To reduce the size of the chassis (1), the sliding extensions (5, 6) are retracted telescopically into the central beam

- 4 -
(4} , whereas to increase the size, the sliding extensions (5, 6) are deployed in the central beam (4). The telescopic chassis (1} is hollow and preferably has a polygonal cross section, which cross section prevents 5 rotation of the sliding extensions (5, 6) with respect to the central beam (4). The shape of the cross section is square, rectangular, or H-shaped as is known.
The telescopic chassis (1} supports work tools (2) 10 distributed with a defined and adjustable spacing. The design of the chassis (1) of the invention allows the spacing between the work tools (2) to be altered quickly; it is an indexable chassis. The range of adjustment for the spacing is from 43 to 80 cm. In the
15 exemplary embodiment of Figure 1, the agricultural machine (3) is a precision seed drill or a planter. A planter such as this can plant various types of seeds in the ground and the spacing between the drills is tailored to suit the species of seed being sown. In a
20 way known per se, it is standard practice to set a spacing of 4 5 or 5 0 cm for sowing beetroot whereas the preferred spacing for sowing corn is 75 or 80 cm. In the case of a planter such as this, the work tools (2) are planting elements.
25
Figure 2 depicts the telescopic chassis (1) with a reduced size corresponding to a spacing of 45 cm between the work tools (2). The central beam (4) has a length substantially similar to the width of the
30 telescopic chassis (1) in the small size configuration.
As a preference, the length of the central beam (4) is
less than the width of the telescopic chassis (1) .
Figure 3 for its part depicts the telescopic chassis
(1) at its maximum size corresponding to a spacing of
35 80 cm. The sliding extensions '{5, 6) are deployed, the telescopic chassis (1) is opened out to ' its maximum extent. This telescopic chassis (I) allows the user easily to adapt to the species of seed being sown (beetroot, corn, etc.) while allowing the minimum

- 5 -spacing between the work tools (2) to be adjusted. The width of the telescopic chassis (1) is therefore adaptable. To make it easier to alter the spacing between the work tools (2), the telescopic chassis (1) 5 is controlled from the cab of the tractor, for example hydraulically, pneumatically or electrically.
The telescopic chassis {1) is moved around, during work and during transport, by a tractor (not depicted) in a
10 direction and sense of forward travel indicated by the arrow (A) . The central beam (4) has a coupling frame (7) allowing it to be attached to the tractor. In the exemplary embodiment of the figures, the agricultural implement (3) is a planter comprising six work tools
15 (2) advantageously distributed at regular intervals along the telescopic chassis (1}. It allows seeds to be planted individually in six clearly defined rows. The telescopic chassis (1) is positioned substantially horizontally and substantially at right angles to the
20 direction of forward travel' (A). The telescopic chassis
(1) also supports wheels (8) intended to rest on the
ground and mechanisms for driving the distribution. The
telescopic chassis (1) is symmetric with respect to a
vertical mid-plane (12) substantially parallel to the
2 5 direction of forward travel (A) . It comprises a first extension (5) which is intended to slide in the left-hand part of the central beam (4) with respect to the direction of forward travel (A) . It also comprises a second extension (6) which is intended to slide in the
30 right-hand part of the central beam (4) with respect to the direction of forward travel. (A).
The work tools (2) are mounted on the chassis (1), in a known way, via respective deformable parallelograms 35 (9) . As a result, the work tool (2) is free in the heightwise direction and can faithfully follow the unevenness of the ground, thereby remaining parallel to the ground. In the case of a planter, each planting element has a hopper (10) that constitutes a supply of

- 6 -
seeds, a distribution system and a planting device. The distribution system allows the seeds to be taken one by one from the hopper (10) and delivered into the drill at uniform intervals. The planting device creates a 5 furrow at a determined depth in which the seed is placed and then earthed over. Each planting element further comprises a gauge wheel for controlling the planting depth and a weighting device for pressing the seeds down into the furrow. The-planting element may be 10 equipped at the front with a device for clearing away debris.
According to an important feature of the present invention, the length of each sliding extension (5, 6)
15 is substantially equal to the length of the said central beam {4}. By virtue of this great length of the sliding extensions (5, 6), the rigidity of the telescopic chassis (1) is improved. The length of the central beam (4} is substantially shorter than that of
20 the telescopic chassis in its smallest-size position. Figure 4 depicts the telescopic chassis (!) in horizontal section with a small size corresponding to a spacing of 45 cm. Each sliding extension (5, 6) has an outer end (13) and an inner end (14) . The length of a
25 sliding extension (5, 6) therefore corresponds to the distance between the outer end (3) and the inner end (14) . It may be noted that the outer end {13) extends beyond the central beam (4) while the inner end (14) extends inside the central beam (4). The outer end (13)
3 0 of a respective sliding extension (5, 6) lies on one side of the vertical mid-plane (12) while the inner end (14) lies on the other side of the vertical mid-plane (12) of the telescopic chassis (1). Advantageously, the outer end (13) and the inner end (14} of a
3 5 corresponding sliding extension (5, 6) always extend- on a different side of the vertical mid-plane (12).
Figure 5 depicts the telescopic chassis (1) in horizontal section with its maximum size corresponding

- 7 -
to a spacing of 80 cm. Each extension (5, 6) has a guiding length, which corresponds to the length that remains inside the central beam (4), substantially equal to at least half the length of this central beam 5 (4). The guiding length is great. The rigidity of the telescopic chassis (l) is therefore significantly improved even when this chassis is opened out to the maximum extent. According to an additional advantage, the first sliding extension (5) and the second sliding
10 extension (6) remain nested one inside the other inside the central beam (4) irrespective of what spacing has been set. The rigidity is thus increased by virtue of the inner ends (14) of the slicing extensions (5, 6) which remain nested one inside the other. Deformation
15 of the telescopic chassis (1) is thus reduced.
The sliding extensions (5, 6) , on the one hand, slide in the central beam (4) and, on the other hand, slide one inside the other. They are therefore hollow. The 20 sliding extensions (5, 6) have sections of corresponding shapes but different sizes allowing them a telescopic piling. Each end of the central beam (4) has skids (22) making it possible to guide the corresponding sliding extension (5, 6) . These skids
2 5 (22) encourage the sliding extensions (5, 6) to slide
in the central beam (4) . In the exemplary embodiment depicted, the cross section of the central beam (4) and of the sliding extensions (5, 6) is square. To achieve a chassis (1) of small size, the dimensions of the 30 square sections of the two extensions (5, 6) differ. According to Figures 4 and 5, the dimensions of the cross section of the first extension (5) are greater than the cross section of the second extension (6). The second extension (6) slides in the first extension (5).
3 5 The extensions (5, 6) slide in the central beam (4), so
the square cross section of the central beam (4) is larger than that of the extensions (5, 6). The internal cross section of the central beam (4) is substantially equal to the external cross Section of the first

- 8 -
extension (5) . The internal cross section of the first extension (5) is substantially equal to the external cross section of the second extension (6) . A minimal clearance is needed to ensure the extensions (5, 6) 5 slide properly. By virtue of the difference in cross section, the sliding extensions (5, 6) pile up optimally inside the central beam (4) and the telescopic chassis (1) can have a minimal size.
10 As can be seen from Figure 1, the telescopic chassis
(1) carries four work tools (2) that can move along the
central beam (4). Each sliding extension (5, 6) carries
one work tool (2) . It is therefore possible to see two
central work tools (2A) , two intermediate work tools
15 (2B) and two outer work tools (2C). in the remainder of
the description and to allow for a better understanding
thereof, the qualifier {A, B or c) is added after the
reference numeral of the term designated as the
central, intermediate or outer one. An outer work tool
20 (2C) is connected to a respective sliding extension (5,
6) and the intermediate and central work tools (2B, 2A)
are connected to the central beam {4} via a respective
sleeve (20) . Each sleeve (20) slides on the central
beam (4) according to the spacing set. The work tools
25 (2) are connected to one another by tie rods (21) .
These tie rods {21} are longitudinal rods the cross
section of which allows them to have tension applied to
them. Each tie rod (21) is provided with holes for
adjusting the spacing between the work tools (2} . The
3 0 desired spacing between the work tools (2) is obtained
by virtue of an opening stop (23} and/or a closing stop
' (24) .
According to another feature of the invention, the 3 5 extensions (5, 6) slide in the central beam (4) via a single cylinder (15) . The cylinder (15) comprises a body (16) and a rod (17). The cylinder (15) is preferably built into the hollow telescopic chassis (1). Advantageously, the body (16) is connected to the

- 9 -first sliding extension (5) which has a larger cross section, and the rod (17) is connected "to the second sliding extension (6) of smaller cross section. The body (16} is connected to the first extension (5) by 5 means of a first articulation (18) the axis of which is substantially vertical, and the rod (17) is connected to the second extension (6) by means of a second articulation (19). The articulations (18, 19) are in the vicinity of the outer ends (13) of the extensions 10 (5, 6) . Thus, the cylinder (15) is deployed or retracted until each tie rod (21) comes up against the opening stop (23) or against the closing stop (24). The position of the opening or closing stops (23, 24) is altered to suit the desired spacing. In the exemplary 15 embodiment depicted, the range of adjustment of the spacing between two adjacent rows is great. The spacing can vary between 4 5 and 80 cm, with a minimum setting of 43 cm.
20 To convert from a small spacing (Figure 2) to an intermediate spacing or to the maximum spacing (Figure 3), the telescopic chassis (5) is deployed by means of the cylinder (15). The latter is deployed and gradually drives the outer work tools (2C), the intermediate work
25 tools (2B) and the central work tools (2/A) . To do that, the telescopic chassis (1) is preferably held clear of the ground by means of the three-point hitch of the tractor. The sliding extensions (5, 6) connected to the cylinder (15) slide out of the central beam (4) until
30 the outer tie rods (21C) are resting against the opening stops (23C). The tie rod (21C) is connected to the corresponding sliding extension (5, 6) . Thanks to the opening stop (23C), the desired spacing between the outer work tool (2C) and the intermediate work tool
3 5 (2B) is obtained. When the outer tie rods (21C) come into abutment, it is the intermediate work tools (2B) with their respective sleeve (20B) which slide along the central beam (4) as the cylinder (15) deploys. The intermediate work tools (2B) therefore move, away from

- 10 -the vertical mid-plane (12) until the intermediate tie rods (21B) come up against the corresponding opening stops (2 3B) . Next, it is the two central work tools (2A) with their respective sleeve (20A) that move away 5 from the vertical mid-plane (12) until the central tie rods (21A) come up against their stop.
When closing up, the rod (17) is retracted into the body (16) of the cylinder (15) and the widthwise size
10 of the telescopic chassis (1) is reduced. In this case, it is the closing stops (24) that are used. When converting to a shorter spacing, the work tools (2} move closer'together and each one also moves closer to the vertical mid-plane (12) . In the figures, the
15 spacing between the various work tools (2) is uniform. There is no need for all the work tools (2} to be equidistant from one another. It is also possible to conceive of a non-uniform distribution of the work tools (2) on the telescopic chassis (1) to suit the
20 requirements specific to a particular crop or particular terrain. It is also possible to add a work tool in the vertical mid-plane (12).
In a particularly advantageous manner, the coupling
25 frame (7) is attached only to the central beam (4) at
the vertical mid-plane (12) . The respective sleeves
(2 0) of the central and intermediate work tools (2A,
2B) can therefore get even closer to the vertical mid-
plane (12) by sliding under the coupling frame (7). A
3 0 design such as this for the frame/beam connection makes
it possible to reduce the widthwise size of the
telescopic chassis (1) to 2.50 metres with a spacing of
4 3 cm. Set up in. this way, the telescopic chassis (1)
can be transported by road, being connected to the
3 5 three-point hitch of the tractor. This connection also
allows additional equipment of the fertilizing device
type to be added to the central work tools (2A) .
Fitting a fertilizing device such as this onto the
telescopic chassis (1) allows fertilizer to be spread

- 11 -
and seeds planted in a single pass. To do that, a burying coulter (26) is mounted at the front of the work tool (2). The burying coulter (26) of the central work tool (2A) advantageously slips under the coupling 5 frame (7) when the telescopic chassis (1) is retracted. The burying coulters (26) are depicted only on the left-hand part of. the planter with respect to the direction of forward travel (A) . For the fertilizer to be brought up close to the seeds, the burying coulter 10 (26) is offset sideways with respect to the work tool (2). The planter is therefore equipped with a hopper in which granules are stored and with conveying devices to the burying coulters.
15 Advantageously, a wheel (8) is mounted on each intermediate sleeve (2 OB) . The wheels (8) therefore move along with the intermediate work tool (2B) . They are mounted offset sideways relative to the intermediate work tool (2B). As a result, the seeds are
20 not sown in the tracks left by the wheels (8) . The frame/beam connection allows the intermediate sleeves (2 OB) carrying the wheels (8) to move as close as possible to the vertical mid-plan^ (12).
25 In order to sow the seeds with a constant spacing, the distribution speed is adapted to the speed of forward travel of the planter. Thus, the planter wheels (8) drive a gearbox (11) which transmits motion to the planting elements via a drive far (27) . The gearbox
3 0 (11) is arranged substantially in the vertical mid-plane (12) of the telescopic chassis (1) . Siting the gearbox (11) centrally allows a petter distribution of the torque transmission to the six planting elements. The design of the drive bar (27) is also telescopic and
35 retractable. It has to drive the various work tools (2) irrespective of the spacing set; between them. This spacing varies from 43 to 80 cm. The drive bar (27) is advantageously parallel to the telescopic chassis (1) . It is made up of male elements (28) which slide in

- 12 -female elements (29). The internal cross section of the female element (29) corresponds to the external cross section of the male element (28) . Advantageously, the cross section is polygonal (square or hexagonal), with 5 no possibility of rotation. The drive bar (2 7) additionally comprises a sleeve (30) positioned between the central implement (2A) and the intermediate implement (2B) . This sleeve (30) ensures continuity of the drive between the female element (29) and the male 10 element (28) when the chosen spacing is substantially , at its maximum (80 cm). The internal cross section of the sleeve (30) corresponds to the external cross section of the female element (29) and is advantageously polygonal. 15
For better guidance of the lateral sliding of the intermediate sleeves (20B) on the central beam (4), the sliding extensions (5, 6) each have two tie rods (2-1C) , one tie rod (21C) being positioned at the front and the 20 other at the rear of the Corresponding sliding extension (5, 6) with reference to the direction of forward travel (A). With two tie rods (21C), the tensile force applied by the sliding extension (5, 6) to the intermediate sleeve (20B) is better distributed. 25
The central beam (4) and the two sliding extensions (5, 6) are positioned in the same plane perpendicular 'to the direction of forward travel (A) . The lengthwise size, in the direction of forward travel (A) , of the 3 0 telescopic chassis (1) is reduced. The telescopic chassis (1) is compact and its overhang is small.
The telescopic chassis (1) that has just been described is merely one exemplary embodiment and example of use 3 5 which does not in any way restrict the scope cf protection defined by the claims which follow. Various modifications remain possible, particularly as regards the construction of the various elements, or by substituting technical equivalents.

- 13 -
It is entirely possible to have a different number than six work tools distributed a long the telescopic chassis. A telescopic chassis with seven, eight or more 5 work tools also forms part of the scope of protection of the invention. The minimum and maximum sizes would then change.

- 14 -Claims
Variable-width telescopic chassis (1) for an agricultural implement (3), comprising a central beam (4) and, on either side, at least one sliding extension (5, 6) , the said telescopic chassis (1) supporting work tools (2) distributed with a defined and adjustable spacing, the said telescopic chassis (1) also having a reduced size when the spacing between the said work tools (2) is at a minimum, the said central beam (4) for its part having a length substantially similar to that of the said telescopic chassis (1) in its reduced-size position, characterized in that the length of each sliding extension (5, 6) is substantially equal to the length of the said central beam (4).
Telescopic chassis according to Claim 1, characterized in that it has a vertical mid-plane (12), and in that each sliding extension (5, 6) has an outer end (13) and an inner end (14), the said outer end (13) and the said inner end (14) always lying on a different side of the said vertical mid-plane (12).
Telescopic chassis according to Claim 1 . or 2, characterized in that the said sliding extensions (5, 6) remain nested one inside the other irrespective of the spacing defined between the said work tools (2).
Telescopic chassis according to any one of Claims 1 to 3, characterized in that it comprises a first sliding extension (5) and a second sliding extension (6), and in that the said sliding extensions (5, 6) have cross sections of correspondina shapes but different sizes.

- 15 -
5. Telescopic chassis according to any one of Claims
1 to 4, characterized in that the said sliding
extensions (5, 6) are moved relative to the
central beam (4) using a single cylinder (15).
6. Telescopic chassis according to Claim 5,
characterized in that the said cylinder (15) is
built into the said telescopic chassis (1) between
a first articulation (18) and a second
articulation (19) and has just one rod (17).
7. Telescopic chassis according to any one of Claims
1 to 6, characterized in that it has a drive bar
(2 7) made up of male elements (28) sliding in
female elements (29) , the said drive bar (27)
additionally comprising a sleeve (30).
8. Telescopic chassis according to Claim 7, characterized in that the said sleeve (30) allows the work tools (2) to be driven when the spacing is substantially at its maximum.
9. Telescopic chassis according to any one of Claims 1 to 8, characterized in that it comprises a coupling frame (7) attached to the said central beam (4) in the region of the said vertical mid-plane (12) .
10. Agricultural implement (3), characterized in that it comprises a telescopic chassis (1) according to any one of claims 1 to 9,
11. Agricultural implement according to Claim 10, characterized in that it is a seed drill.
12. Agricultural implement according to Claim 11, characterized in that it is a planter.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=1QBEKQCZVEOlMEFKDsmYiA==&loc=vsnutRQWHdTHa1EUofPtPQ==

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Patent Number

268511

Indian Patent Application Number

1773/MUM/2008

PG Journal Number

36/2015

Publication Date

04-Sep-2015

Grant Date

31-Aug-2015

Date of Filing

22-Aug-2008

Name of Patentee

KUHN S. A.

Applicant Address

4, IMPASSE DES FABRIQUES, F-SAVERNE,

Inventors:

#	Inventor's Name	Inventor's Address
1	MARICELLI GIANFRANCO	VIA MANDONOVO, 23 33075 MORSANO AL TAGL. TO (PN)
2	AUDIGIE JEAN-CHARLES	5 RUE DOBERMODERN, 67330 BOUXWILLER,

PCT International Classification Number

A01B73/00; A01C7/04

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	07/57267	2007-08-30	France