Title of Invention

GRATE BAR

Abstract

The invention relates to a grate bar for a cleaning device of a spinning preparation machine, particularly for a blow room machine or carding machine, with a free surface, which can be advanced to an opener roller of the spinning preparation machine, and with a setting surface, which adjoins a delimiting straight line that delimits the free surface while being located upstream with regard to the direction of rotation of the opener roll. A first half-plane, which originates from the delimiting straight line and which is tangent to the free surface, and a half-plane, which originates from the delimiting straight line and which is tangent to the setting surface, contain a cutting edge.

Full Text

GRATE BAR The present invention relates to a grate bar for a cleaning device of a spinning preparation machine, particularly for a blow room machine or a carding machine, with a free surface which can be advanced to an opener roller of the spinning preparation machine and with a setting surface which adjoins a delimiting straight line that delimits the free surface upstream in relation to the direction of rotation of the opener roller, wherein a first half-plane which originates from the delimiting straight line and which is tangent to the free surface and a half-plane which originates from the delimiting straight line and which is tangent to the setting surface contain a cutting edge. The invention further relates to a cleaning device for a spinning preparation machine, particularly for a blow room machine or carding machine with an opener roller. In the short staple spinning mill, particularly when natural fibres such as cotton or mixtures containing natural fibres are being spun, it is necessary to clean the fibre material before it is supplied to a spinning machine. Raw cotton, for example, typically contains between 3% and 8% impurities such as sand, dust, husks and other impurities. These impurities should be removed as completely as possible, whilst as few good fibres as possible should be lost from the raw cotton and the remaining fibres should be damaged as little as possible by the cleaning process. However, it basically holds that the higher the degree of cleaning, both the loss of good fibres and the impairment of the fibres increase. The raw cotton is usually supplied to the spinning mill in compressed bales. In this case, the undesirable dirt is firmly embedded in the raw cotton. In order to now remove this, it is necessary to open the raw cotton into increasingly finer flock and further into single fibres since the binding of impurities to the fibre material can only be sufficiently reduced in this way. In the spinning preparation lines usually used today, a plurality of successively arranged cleaning devices are provided. Cleaning devices of the type described here comprise peripheral or rotating opener units. Peripheral opener units comprise, for example, spiked feed lattices. Rotating opener units on the other hand include pin rollers, porcupine cylinders, porcupine separating rollers, carding rollers, scutcher beaters, needle bar flyers and needle bar rollers. Said opener units are subsequently designated uniformly as opener rollers. The opening, also called resolving, of the fibre material transported along the opener roller is effected by the mechanical action of the driven opener roller on the fibre material. As a result of this mechanical action, contaminants are loosened from the fibre material at the same time. The opened or resolved fibre material together with the loose contaminants contained therein is now passed by a shell-like grate arranged on the opener roller. In this case, some of this fibre material is removed through the grate to the outside for example, as a result of gravitation force, centrifugal force or by an air flow. Compared to the non-cleaned fibre material that is supplied, this portion of the fibre material removed through the grate, also called waste material, contains a high proportion of contaminants. By this means, the fibre material not passed through the grate is ultimately cleaned. However, the waste material contains a certain fraction of fibre material which is undesirable but unavoidable. Grates are segments which typically surround a quarter to three quarters of the opener roller. It is also possible to assign a plurality of segments to the opener roller. Grates consist of a plurality of individual angular grate elements ultimately forming a shell. In addition to slitted sheets, perforated sheets, angular bars and blades, grate bars having a triangular cross-section are primarily used today as grate elements. The cleaning effect of the cleaning device depends in particular on the fraction of the waste material from the total fibre material supplied. At the same time, the amount of waste material can be adjusted by varying the geometric arrangement of the grate bars. Thus, commonly used cleaning devices have an actuator to vary the distance of the grate bars from the opener roller and also the setting angle of the individual grate bars. It is also known to increase the waste material by enlarging the gap with between the ' bars. However, an extremely complex actuator is required for this purpose so that this method for increasing the waste material is only suitable to a limited extent in practice. Cleaning devices comprising an opener roller and grate bars can be configured as independent cleaning machines, for example, as coarse cleaners or fine cleaners, or as part of a spinning preparation machine such as, for example, of a mixing machine or a carding machine which primarily serve other purposes. Thus, such a cleaning device can be disposed in the feed chute or in the licker-in zone of a carding machine. In the latter case, for example, the licker-in (taker-in) of the carding machine is used as an opener roller in the sense of this application. EP 0 381 859 discloses a spinning preparation machine, i.e. a coarse cleaner comprising a cleaning device of the type of interest here. The disclosed cleaning device comprises an opener roller fitted with beater pins for opening the supplied fibre material into flocks and a plurality of grate bars arranged in groups on the circumference of the opener roller. A grate bar disclosed in EP 0 381 859 has a free surface arranged opposite to the circumferential surface of the opener roller and a setting surface pointing towards the feed direction of the fibre material. The free surface and setting surface are each configured as flat, i.e. two-dimensional. Furthermore, they have a common transition line which runs in a delimiting straight line. A first half-plane originating from the delimiting straight line and which is tangent to the free surface and a second half-plane originating from the delimiting straight line and which is tangent to the setting suri'ace form an edge in the mathematical sense, namely in the sense of three-dimensional geometry (stereo geometry), which extends to infinity on both sides relative to the longitudinal direction of the grate bar. That part of this mathematically defined edge which extends along the delimiting straight line between the free surface and the setting surface defines a cutting edge in the physical sense. The first half-plane and the second half-plane thus contain the physical (real) cutting edge. The actual separation between the cleaned fibre material and the waste material which contains a large proportion of impurities takes place at the cutting edge. The grate bar also has a third surface which is configured as flat, A so-called three-edged grate bar is thus disclosed. The distance of the grate bar with respect to the opener roller and their angle of attack, also called setting angle, can be varied by an actuator. For example, if the fraction of waste material relative to the total fibre material supplied is to be increased, the grate bars can be brought nearer to the opener roller and/or set more steeply. In both cases, the waste material and therefore the cleaning effect can be effectively increased. Said parameters are set so that a balanced ratio is established between cleaning effect and loss of fibre material suitable per se for further processing. Thus, not the maximum but the optimum waste material is set. However, the device shown has the disadvantage that particulariy when the grate bars are set steeply and/or moved close to the opener roller to achieve the optimum waste material, the fibre cleaning is accompanied by severe damage to the cleaned fibre material provided for further processing. Fibre damage is understood, for example, as kinking, starting to break or breakaway of a fibre. Such fibre damage is undesirable since it is disadvantageous for the quality of the end product produced in a spinning mill. The need for an improved cleaning effect without increasing the fibre damage has increased continuously over the last decades since the average degree of contamination of the raw cotton supplied to the spinning mills has increased over the same period. The problem is further exacerbated by the fact that the average size of the dirt particles has decreased over the last decades which is why these are more strongly bound in the fibre material. For this reason, the optimum waste material has also increased in many cases and this cannot always be achieved with the conventional scope for adjustment of the cleaning devices. No adjustment of the gap width between the grate bars is provided in EP 0 381 859. The fraction of waste material could certainly be increased in a relatively fibre-protective manner by such scope for adjustment but retrofitting of such a scope for adjustment is not possible in the disclosed device with justifiable design expenditure. It is thus the object of the present invention to provide a grate bar and a cleaning device which can give an improved cleaning effect for the same fibre damage or lower fibre damage for the same cleaning effect. In this case, the gap width between the grate bars should remain the same. The object is achieved by a grate bar and a cleaning device having the features of the independent claims. A grate bar according to the invention has a free surface which is configured as three-dimensional. It differs from the three-edged grate bars known from the prior art in that the free surface is no longer arranged in a two-dimensional plane. The three-dimensional configuration of the free surface can produce an effect similar to that as if the spacing of the grate bars had been increased. An actual increase in the spacing of the grate bars is thus no longer necessary to improve the waste material behaviour. Thus, with the geometry of the cleaning device remaining otherwise unchanged, an increased fraction of the supplied fibre material can be eliminated between the grate bars without the cutting edge needing to be brought into a position which would bring about increased fibre damage. It is neither necessary to bring the grate bars closer to the opener roller nor to swivel the grate bar so that the cutting edge would act more aggressively on the fibre material. Overall, an improved cleaning effect can be achieved with unchanged fibre damage, or lower fibre damage with an unchanged cleaning effect. A grate bar according to the invention can be built in during the manufacture of any spinning preparation machine with a corresponding cleaning device. It is also possible to retrofit grate bars according to the invention in existing spinning preparation machines. For this it is merely necessary to provide the grate bars according to the invention with fixing sections which correspond to the existing fixing sections on the spinning preparation machines. Usually these fixing sections are provided on the front sides. The free surface is advantageously fomied on the side of the first half-plane facing the second half-plane. All the sections of the free surface thus lie either in the first half-plane defining the cutting edge or on the side of this half-plane pointing towards the centre of the cross-section of the grate bar, at least one section of the free surface projecting from the first half-plane. By this means the same effect can be achieved as if the spacing between adjacent grate bars were increased considerably but with a considerably lower design expenditure. In a preferred embodiment, the free surface adjoining the delimiting straight line comprises a first flat section which lies in the first half-plane. This gives a high stability of the cutting edge. The free surface adjoining the first flat section preferably comprises a second flat section which is inclined at an angle a with respect to the first half-plane in the direction of the second half-plane. The angle a preferably has a value between 15° and 40° and the first fiat section comprises 30% to 70%, preferably 40% to 60% of the entire area of the free surface. Such a geometry of the free surface leads to a high mechanical stability of the grate bar and is relatively simple to produce. The free surface can consist exclusively of the first flat section and the second flat section. In a further preferred embodiment, the free surface adjoining the second flat section comprises a third flat section which is inclined at an angle p with respect to the first half-plane in the direction of the second half-plane. By this means, improved guidance or easier sliding of the fibre material to be eliminated can be achieved. In this case, the first flat section can comprises 15%-50%, preferably 25%-40% and the second flat section can comprise 15%-50%, preferably 25%-40% of the entire area of the free surface. The angle a can preferably have a value between 3° and 10° and the angle (3 can have a value between 15° and 50°. The free surface can consist exclusively of said three flat sections. Alternatively, further sections can adjoin the third flat section. Preferably at least one edge formed by two of said flat sections has a rounding or a bevel. This also ensures improved guidance of the material to be eliminated. The free surface can preferably comprise at least one convexly curved section. Such curved sections are more complex to manufacture but the removal of the fibre material to be eliminated can thus be facilitated. A said convexly curved section can directly adjoin the delimiting straight line. In this case, said convexly curved section can comprise 30% to 70%, preferably 40% to 60%, of the entire area of the free surface. Particularly low fibre damage can be achieved by this means. In a further embodiment, a said convexly curved section can adjoin the first flat section. In this case, the first flat section preferably comprises 30% to 70%, preferably 40% to 60% of the entire area of the free surface. This results in particularly good guidance of the fibre material at the side of the free surface facing away from the cutting edge. The setting surface is preferably configured as flat, A flat setting surface in particular counteracts any possible blockage of the grate bar arrangement. In a particularly preferred embodiment, the first half-plane and the second half-plane enclose an edge angle y between 30° and 80°, preferably between 45° and 65°. Good mechanical stability of the grate bar can be achieved by this means. The grate bar is preferably formed as an extruded profile bar. Such a profile bar can be produced simply and inexpensively. In this case, the grate bar can have a hollow profile. The overall weight of the grate bar can thus be kept low. In a cleaning device according to the invention, at least one grate bar according to the invention is associated with the opener roller whereby the advantages according to the invention are achieved. Advantageously, the at least one grate bar is pivotally mounted about an axis which runs parallel to the axis of rotation of the opener roller. The fraction of eliminated material can thus be simply adjusted. The grate bar can particularly preferably be pivoted such that the angle 5 of a tangential plane of the opener roller running through the delimiting straight line to the first half-plane can have negative values. The angle 5 then has negative values when the tangential plane needs to be turned into the first half-plane by a rotation in the clockwise direction. When the angle 5 is set to negative values, the fibre-damaging effect of the cutting edge is substantially reduced. The grate bar is preferably pivotally mounted such that the angle 5 can be adjusted at least in a range of-5° to +30°, preferably of-15° to +45°. The elimination of material can be influenced over a wide range by this means. The axis of the at least one grate bar can preferably be adjusted with regard to the distance from the opener roller. This results in another possibility for variation. Further advantages of the invention are described in the following exemplary embodiments. In the figures: Figure 1 is a schematic cross-section through a spinning preparation machine with a cleaning device; Figure 2 is a partial view of the cleaning device; Figure 3 is a perspective view of a grate bar according to the prior art; Figures 4 to 7 each show an exemplary embodiment of a grate bar according to the invention in cross-section; Figure 8 is a partial view of a cleaning device according to the invention with a negative free angle of the grate bar; Figure 9 is a partial view of a cleaning device according to the invention where the free angle of the grate bar has a positive value. Figure 1 shows a coarse cleaner 1 as an example of a spinning preparation machine with a cleaning device. This has a driven opener roller 2 which rotates in the direction of rotation DR about the axis of rotation 8 and is fitted with beater pins 6 in the usual manner. The outer ends of the beater pins 6 move on the beating circle 7. The coarse cleaner 1 has an inlet 4 for supplying fibre material FMsup to be cleaned and an outlet 5 for the cleaned fibre material FMci. The supplied fibre material FMsup is in the form of fibre flocks FF which are transported by a delivery air flow. In this case, the delivery air flow is guided around the opener roller 2. As a result of the mechanical action of the beater pins 6 on the fibre flocks FF, these are continuously refined. At the same time, dirt material is released from the fibre flocks FF. A large part of this dirt material passes with a part of the fibre flocks FF as waste material AG through the intermediate spaces between the grate bars 10 into a collecting tray 3. Figure 2 shows an enlarged view of three grate bars 10 which are associated with the opener roller 2. The fibre flocks FF are opened by the opener roller 2 and entrained on its circumference. However, contaminants and a part of the fibre flocks FF are eliminated outwards between adjacent grate bars 10 as waste material AG. The waste material AG is separated from the further transported fibre flocks FF at the transition of the free surface 11 to the setting surface 12. The grate bars 10 shown here have a triangular cross-section and originate from the prior art. However, such grate bars 10 are not only used in coarse cleaners, as in the example described here, but also in other cleaning devices on other spinning preparation machines. The grate bars 10 have a cutting edge 19 at their end directed in the opposite direction to the direction of rotation DR. In this case, the grate bars 10 are each pivotally mounted about an axis 9. The possible pivoting movement is indicated by a curved double arrow. The continuous line indicates a position of the grate bars 10 which brings about a relatively small amount of waste material AG. The dot-dash line, on the other hand, indicates a position in which the waste material AG is substantially increased. In the latter case, however, the respective cutting edge 19 of the grate bar 10 acts extremely aggressively on the fibre flocks FF passing by. This gives rise to appreciable damage to the cleaned fibre material FMci. Another possibility for adjustment of the grate bars 10 and the cutting edges 19 is indicated by means of the rectilinear double arrow. The distance of the pivot axis 9 from the opener roller 2 can thus be varied. The amount of dirt elimination can also be influenced by this means. A relatively complex actuator, not shown, is required for the pivoting or displacement of the grate bars 10 and therefore the respective cutting edge 19. Figure 3 shows a perspective view of a grate bar 10 in a Cartesian x-y-z coordinate system. The grate bar 10 has a free surface 11 which is located completely in a plane parallel to the x-y plane. The free surface 11 is therefore configured as two-dimensional and is delimited by a delimiting straight line 13 at its upstream end. Furthermore, the grate bar 10 has a setting surface 12 which adjoins the delimiting straight line 13 of the free surface 11. The half-plane 14 which originates from the delimiting straight line 13 and which is tangent to the free surface 11 and the second half-plane 15 which likewise originates from the delimiting straight line 13 but is tangent to the setting surface 12 together forni an edge in the mathematical sense. The delimiting straight line 20 between the free surface 11 and the setting surface 12 is contained in the delimiting straight line 13. The delimiting straight line 20 and the adjoining sections of the first half-plane 14 and the second half-plane 15 form the physically configured cutting edge 19 of the grate bar 10. The edge angle y which is also the edge angle y of the cutting edge 19 is enclosed by the first half-plane 14 and the second half-plane 15. Figure 4 shows an exemplary embodiment of a grate bar 10 according to the invention in cross-section in the y-z plane. A first flat section 11 a adjoining the delimiting straight line 13 runs inside the first half-plane 14. The second flat section 11b, however, is inclined with respect to the first half-plane 14 by the angle a in the direcfion of the second half-plane 15. Shown at the transition of the first half-plane 11a to the second half-plane 11b is an edge 16 which has a rounding. Figure 5 shows another grate bar 10 according to the invention which is also shown in cross-section, i.e. in the y-z plane. Here, the free surface 11 is divided into a first flat section 1 la, a second flat section lib and into a third flat section 11c. The first flat section 1 la is arranged in the first half-plane 14, as in the example in Fig. 4. The second flat section 1 lb is inclined by the angle a with respect to the first half-plane 14. The third flat section 11c, on the other hand, is inclined by the angle |5 with respect to the first half-plane 14. Figure 6 shows another example of a grate bar 10 according to the invenfion, where the free surface 11 comprises a curved section 11d which originates from the delimifing straight line 13 and at the transifion 17 goes over into a flat secfion lie of the free surface 11 without forming an edge. Figure 7 shows an exemplary embodiment of a grate bar 10 according to the invention in cross-secflon. A first flat section 11a originating from the delimifing straight line 13 is followed at the transifion 17 by a convexly curved secfion lid without forming an edge. Figure 8 shows the grate bar 10 described in detail with reference to Figure 5 and its relative arrangement with respect to the beafing circle 7 of the opener roller 2. The beafing circle 7 is shown in simplified form as a straight line. The angle 6, also called the free angle, of a tangenfial plane of the opener roller 2 running through the delimifing straight line 13 to the first half-plane 14 has a negative value since the imaginary tangential plane 18 must be turned in the clockwise direction to transfer this into the first tangential plane 14. In the position shown, the grate bar 10 causes extremely little fibre damage but as a result of the downwardly directed inclination of the third flat section 11c, a relatively large amount of dirt material can be eliminated. In Figure 9 the grate bar 10 from Figure 8 is pivoted in the anti-clockwise direction. The angle 5 itself thus has a positive value. The fibre-damaging effect of the grate bar 10 is increased compared with the position described in Figure 8. However, it is no greater than would be the case if a triangular grate bar known from the prior art were arranged in the same position. However, a higher elimination is ensured compared with the conventional grate bar. The present invention is not restricted to the exemplary embodiments shown and described. Modifications within the framework of the claims can be made at any time. For example, different grate bars according to the invention can be combined in a cleaning device. A combination of one or more grate bars according to the invention with conventional grate elements such as slotted sheets, perforated sheets, three-edged bars, angular bars or blades is also possible. It can furthemriore be provided that the grate bars of a cleaning device are adjustable individually, in groups or in their entirety. CLAIMS 1. A grate bar (10) for a cleaning device of a spinning preparation machine (1), particularly for a blow room machine or a carding machine, with a free surface (11) which can be advanced to an opener roller (2) of the spinning preparation machine (1) and with a setting surface (12) which adjoins a delimiting straight line (13) that delimits the free surface (11) upstream in relation to the direction of rotation (DR) of the opener roller (2), wherein a first half-plane (14) which originates from the delimiting straight line (13) and which is tangent to the free surface (11) and a second half-plane (15) which originates from the delimiting straight line (13) and which is tangent to the setting surface (12) contain a cutting edge (19), characterised in that the free surface (11) is configured as three-dimensional. 2. The grate bar (10) according to the preceding claim, characterised in that the free surface (11) is formed on the side of the first half-plane (14) facing the second half-plane (15). 3. The grate bar (10) according to any one of the preceding claims, characterised in that the free surface (11) adjoining the delimiting straight line (13) comprises a first flat section (11a) which lies in the first half-plane (14). 4. The grate bar (10) according to the preceding claim, characterised in that the free surface (11) adjoining the first flat section (11a) comprises a second flat section (11b) which is inclined at an angle a with respect to the first half-plane (14) in the direction of the second half-plane (15), 5. The grate bar (10) according to the preceding claim, characterised in that the angle a has a value between 15° and 40° and the first flat section (11a) comprises 30% to 70%, preferably 40% to 60% of the entire area of the free surface (11). The grate bar (10) according to claim 4 or 5, characterised in that the free surface (11) adjoining the second flat section (lib) comprises a third flat section (11c) which is inclined at an angle p with respect to the first half-plane (14) in the direction of the second half-plane (15). The grate bar (10) according to the preceding claim, characterised in that the first flat section (11a) comprises 15% to 50%, preferably 25% to 40% and the second flat section (lib) comprises 15% to 50%, preferably 25% to 40% of the entire area of the free surface (11). The grate bar (10) according to claim 6 or 7, characterised in that the angle a has a value between 3° and 10° and the angle (3 has a value between 15° and 50°. The grate bar (10) according to any one of claims 4 to 8, characterised in that at least one edge (16) fonned by two of said flat sections (11a, lib, 11c) has a rounding or a bevel. The grate bar (10) according to any one of the preceding claims, characterised in that the free surface (11) comprises at least one convexly curved section (lid). The grate bar (10) according to claim 10, characterised in that a said convexly curved section (lid) adjoins the delimiting straight line (13), wherein said convexly curved section (lid) comprises 30% to 70%, preferably 405 to 60%, of the entire area of the free surface (11). The grate bar (10) according to claim 10, characterised in that a said convexly curved section (lid) adjoins the first flat section (11a) wherein the first flat section (11a) comprises 30% to 70%, preferably 40% to 60% of the entire area of the free surface (11). The grate bar (10) according to any one of the preceding claims, characterised in that the setting surface (12) is configured as flat. The grate bar (10) according to any one of the preceding clainns, characterised in that the first half-plane (14) and the second half-plane (15) enclose an edge angle y between 30° and 80°, preferably between 45° and 65°. The grate bar (10) according to any one of the preceding claims, characterised in that this is formed as an extruded profile bar. The grate bar (10) according to any one of the preceding claims, characterised in that this comprises a hollow profile, A cleaning device for a spinning preparation machine (1), particularly for a blow room machine or carding machine, with an opener roller (2), characterised in that at least one grate bar (10) according to one of the preceding claims is associated with the opener roller (2). The cleaning device according to the preceding claim, characterised in that at least one grate bar (10) is pivotally mounted about an axis (9) which runs parallel to the axis of rotation (8) of the opener roller (2). The cleaning device according to the preceding claim, characterised in that the at least one grate bar (10) can be pivoted such that the angle 5 of a tangential plane of the opener roller (2) running through the delimiting straight line (13) to the first half-plane (14) can have negative values. The cleaning device according to the preceding claim, characterised in that the at least one grate bar (10) can be pivoted such that the angle 5 can be adjusted at least in a range of-5° to +30°, preferably of-15° to +45°. The cleaning device according to any one of the claims 17 to 20, characterised in that the axis (9) of the at least one grate bar (10) can be adjusted with regard to

Documents:

5030-CHENP-2007 FORM-3 20-10-2014.pdf

5030-CHENP-2007 AMENDED CLAIMS 20-10-2014.pdf

5030-CHENP-2007 CORRESPONDENCE OTHERS 04-03-2014.pdf

5030-CHENP-2007 ENGLISH TRANSLATION 20-10-2014.pdf

5030-CHENP-2007 EXAMINATION REPORT REPLY RECIEVED 20-10-2014.pdf

5030-chenp-2007-abstract.pdf

5030-chenp-2007-claims.pdf

5030-chenp-2007-correspondnece-others.pdf

5030-chenp-2007-description(complete).pdf

5030-chenp-2007-drawings.pdf

5030-chenp-2007-form 1.pdf

5030-chenp-2007-form 26.pdf

5030-chenp-2007-form 3.pdf

5030-chenp-2007-form 5.pdf

5030-Chenp-2007-Petition 137 for AF3.pdf

5030-Chenp-2007-Petition 137 for vertification.pdf