Title of Invention	A FEED TROUGH PLATE
Abstract	The present invention relates to a feed trough plate (20, 30) for application in a feed device with a feed roll (6a) and a feed trough plate (201 30), characterized in that the feed trough plate comprises a support element (22, 32) resistant to bending and at least one gap-forming element (24, 34) attached to the support element (22, 32) the gap-forming element being elastically deformable.

Full Text

The present invention concerns the design of the so-called trough plate of a feed device or take-in device for application in a textile machine, in particular in a spinning (preparatory) machine. The terms "feed device11 and "take-in device" in this context are considered equivalent. For simplifying the description the term "feed device" only is used. This term, however, comprises the equivalent term "take-in device" Examples of spinning (preparatory) machines comprising feed devices are blowroom machines (such as cleaners and openers), cards, feed chutes, mixers and rotor spinning machines. The present invention, however, is not restricted to these application examples. State of the Art The feed trough plate of a spinning (preparatory) machine in most cases is designed as a rigid element. Examples are found in US-B-4"275'483, DE-A-42 00 394 and DE-A-44 39 564. Pedal lever trough plates also are known (compare FR-A-2'322,943, FR-A-2,322,942 and DE-Ut-92 18 341). Rigid feed trough plates are easy to manufacture and to install but present the disadvantage (particularly if the working width ranges from e.g. 1000 mm to 1500 mm or even more) that the clamping action is unevenly distributed across the working width if the lap or batt layer supplied is of uneven thickness, or of uneven density respectively, across the width. This disadvantage can be avoided if pedal lever trough plates are applied, for which, however, the manufacture as well as the installation are cost intensive. The present invention thus provides a feed trough plate for application in a feed device with a feed roll and a feed trough plate. The feed trough plate comprises a support element resistant to bending and at least one element forming a gap which is attached to the support element. The element forming a gap can be elastically deformable. The present invention comprises also a feed device with a feed trough plate of this type. The element forming a gap preferentially is elastically deformable in the longitudinal direction of the roll, in particular elastically deformable locally. The element can be elastically deformed locally in function of thick and thin places or of foreign matter in the lap or batt layer supplied. The present invention is explained in more detail in the following with reference to illustrated design examples. Fig. 1 shows a schematic view of a known card with sensors for regulating the sliver thickness (a copy of the same Figure from EP-A-799 915), Fig. 2 a schematic view of a sliver regulating device (also from EP-A-799 915), Fig. 3 a schematic view of a measuring device arranged at the feed roll (also from EP-A-799 915), Fig. 4 a cross-section of a new feed trough plate for a card according to Figures 1 through 3, and Fig. 5 a schematic illustration of the deformation of a feed trough plate according to Fig. 4. The example to be described in the following concerns the application of the present invention in a card. But from the introduction it will be clear that the same principles apply in other spinning machines. In Fig. 1 a revolving flat card known as such is shown, e.g. the card C50 produced by the applicant, in a schematic view. The fibre material is supplied into a feed chute 20 in the form of loosened and cleaned flocks, then is taken over by a licker-in 32 (Fig. 3) (also called taker-in) in the form of lap or batt, is transferred to a drum 40 (also called main drum) and owing to the cooperation of the drum with a set of revolving flats 52 is opened and cleaned. The flats of the set of revolving flats 52 with the help of a suitable drive system are guided along a closed path via deflecting rolls (in the direction of the main drum rotation, or in the opposite direction). Fibres from the web located on the drum 40 are taken off by a doffer 70 and formed into a fibre sliver 90 in a delivery arrangement 80 consisting of various rolls. This card sliver 90 is deposited in cycloid coils into a transporting can (not shown) by a sliver depositing device. An alternative design example of the card has been shown in EP-A-866 153. The present invention is applicable also to this alternative design. The contents of the EP-A-866 153 thus is considered an integral part of the present application. The sliver delivered by the card to the next processing step, e.g. a draw frame, is to be as uniform as possible. Thus a sliver regulating device is required. This is discussed in the following with reference to the Fig. 2. In Fig. 2a computer 4 is shown schematically with input and output signals. Input signals are supplied by two sensors B5 and B6 which are described in more detail in the following as well as signals representing among other data the speed of the card sliver at the delivery arrangement (Va) and various data such as e.g. set values of the sliver weight. The basic principle of conventional sliver regulating is based on two measures, namely on a "long term regulation" and on a regulation" with a "short term supplement" at the intake where deviations are to levelled out at the time moment in which the material is taken in. As can be seen from Fig.1 a sensor B5 arranged at a feed trough plate 6B scans the irregularities in the weight of the lap or batt being taken in. These correspond to the movements of the pivotably mounted feed trough plate relative to the feed roll 6A (compare also Fig. 3). The sensor B5, as shown in Fig. 1, supplies a signal depending on the cross-section to the computer. By means of the signal 7 acting via a control device 8 the electronic unit influences the drive motor (not shown) and hence the rotational speed of the feed roll 6A. The sensor B6 also shown in the Fig. 1 scans the card sliver being delivered and transmits an electrical signal 2 which depends on the sliver weight to the regulating device (the computer) 4. A measured current value is supplied as an input signal 2 to the computer 4 independently of the delivery speed and is compared with the value of the sliver weight pre-set in the electronic unit, compare also Fig. 2. The rotational speed of the feed roll is influenced correspondingly by the control device in such a manner that the sliver weight at the delivery arrangement is maintained constant. The sensor B5 transmits measuring values which are used in the computer 4 for the "short term supplement" whereas the sensor B6 transmits measuring values which are used in the computer 4 for effecting a "long term regulation". The last mentioned regulation is of no consequence for the present invention and thus is not discussed further here. Details concerning this regulation can be found in the EP-A-799 915. The feed trough plate 6B according to Fig. 3 is a rigid element (resisting bending). It extends over the whole length of the roll 6A, i.e. over the working width of the machine. The lap supplied is inserted into the converging gap between the trough 6B and the roll 6A whereupon owing to the rotation of the roll 6A it is transferred to the opening roll (licker-in or taker-in) 32. The feed trough plate 6B is pressed by a pressure spring 6C against the roll 6A the rotational axis being arranged at a fixed location in the machine frame (not shown). The trough plate 6B is mounted pivotable about the axis 6D. If Variations occur in the fibre mass (density and/or thickness) of the lap fed the trough plate is pressed by the spring 6C to a greater or lesser extent towards the roll. A displacement sensor (not shown) is provided for scanning the deviations in the position of the trough plate 6B. An alternative for the displacement sensor is shown in EP-C-275 471. Such sensors are well suited for scanning lap thickness changes in the direction of lap transport. The working width of a conventional card is of the order of about 1000 mm -the working width of the feed device with the roll 6A and of the trough plate 6B thus must be at least as wide. Card, or roller cards respectively, are known the working width of which is larger (e.g. 1300 mm, 1500 mm or even 2000 mm) -compare e.g. EP-A-866 153. A feed trough plate 6B of great bending stiffness is not suitable for scanning unevenness of the lap thickness over the full working width. If the thickness of the lap presents substantial unevenness across the working width, the trough plate 6B "floats" on the thickest place of the lap, or on a foreign body carried along in the lap. In this zone the lap is pressed hard against the feed roll 6A whereas less thick zones are clamped relatively loosely. This can cause disturbances as the roll 32 possibly jerks whole "bundles" (instead of individual fibres) from the insufficiently clamped zones of the lap. Furthermore the "measurement" supplied by the displacement sensor no longer is representative of the average thickness of the lap present in the gap between the trough and the roll. This undesirable effect can be remedied by using a "pedal trough plate" (e.g. i?552!^0£i^^"Ut"9218^l)^which solution is less simple in its overall lay out, however. An advantageous alternative is shown in Figures 4 and 5. The feed trough plate 20 according to the Fig. 4 comprises a support member 21, a hollow profile of considerable bending stiffness 22 and curved gap-forming member 24 which co-operates with the feed roll 6A (Fig. 3, not shown in the Fig. 4). The support element 21 is provided with a rotatory bearing 25 (indicated schematically merely) to permit pivoting about the axis 6D (Fig. 3). The profile 22 is provided with a protrusion for taking up a pressure spring concerns in particular the gap-forming element 24 which is described in the following. The element 24 is formed in one piece with the profile 22 and extends over the full length of the profile 22 which corresponds to the working width. The elongated element 22 is provided with a "root zone" 26 merging into a protrusion 28 protruding from the profile 22 and with a free edge 30. The thickness "d" of the element at the edge 30 is substantially smaller than the thickness "D" at the root zone. The thickness "d" is e.g. less than 5 mm (e.g. 2 to 4 mm) whereas the thickness "D" can be 8 mm or more. The cross-section of the element 24 is maintained constant as far as possible over its full length. The proportions of the element 24 and the material of this element are chosen in such a manner that the element 24 can be elastically deformed locally (in the sense of a limited zone relative to the full length) if in the local zone of the gap between the trough plate 20 and the roll 6A a particularly thick, or dense respectively, fibre group passes, whereas in other zones of the gap the fibre mass rather corresponds to an average value. This effect is shown schematically in the Fig.5. In Fig. 5 the feed roll 6A is shown and a feed trough plate 30 with a support member 32 (in the form of a bar) and a curved gap-forming element 34. The element 34 is mounted to the support member 32 via a leg 36. The holder for the support member 32 is not shown in Fig. 5 - it can be designed according to the Fig. 3, and the Fig. 4 respectively, of the present application or e.g. according to B^C-275471. The lap also is not shown in the Fig. 5 for the sake of simplicity. If the lap fed presents a certain average value of thickness a corresponding gap width SB results at (in the vicinity) of the free edge 38 of the element 34. If the fibre 1 mass of the lap is evenly distributed over the working width, the resulting gap width SB is substantially uniform over the full working width. If however, the lap contains a "thick place", this will sooner or later pass between the element 34 and the roll 6A and there will cause a local (locally limited) deformation of the element 34 which in Fig. 5 is indicated in an exaggerated manner with a "deformation zone" DZ. The fibre material thus also outside the deformation zone DZ remains sufficiently clamped between the element 34 and the roll 6A in such a manner that even if a thick place is present, the licker-in roll (not shown in the Fig. 5) must comb through a "fibre fringe" offered and can not just jerk fibre bundles from an insufficiently held fibre aggregate. The present invention of course is equally effective if a thin place passes, under condition that the element 34 is sufficiently pre-tensioned against the roll 6A. The (shearing) forces generated in the element 34 (Fig. 5), and 24 respectively (Fig. 4), by the clamped fibre mass must be transmitted from the elastic element 34, 24 to the support member 32, 22. As the support member (with respect to these forces) represents a rigid structure the forces generated in the elastic element are "integrated " at the support member. The above mentioned sensor (not shown) thus reacts to the force generated in the support member which results from all the forces generated in the elastic element. The present invention is not restricted to the application in connection with a regulating system - presence of a sensor is not mandatory. The inventive new feed trough plate thus can clamp laps of different thicknesses supplied to it effectively over the whole working width. Preferentially bodies of foreign matter (at least of larger dimensions) do not reach the elastic zone. A body of such type is e.g. clamped upstream from the elastic rim zone between the element 24 and the feed roll. As the element presents higher bending stiffness upstream from the rim zone, the reaction forces acting on the element 24 cause lifting of the element the pre-tension effected by a spring (not shown) being overcome, i.e. the feed trough plate as a whole pivots about the axis 25. This fact can be detected by a further sensor the output signal of which can be applied for stopping the lap supply, e.g. by stopping the drive of the feed roll. Simultaneously an alarm can be set off in order to attract the attention of the operator in such a manner that the defect can be corrected. The stopping sensor of course also can be formed by the displacement sensor in which arrangement a signal level value is to be pre-set in the signal processing device which represents an inadmissible displacement (= disturbance, possibly due to the presence of a body of foreign matter) The elastic rim zone (or the elastic rim strip) comprising the free edge can be of a small dimension transversely with respect to the working width (length of the profile), e.g. 10 mm to 20 mm, preferentially about 14 mm to 16 mm. In this manner the lap is clamped only in the zone in which a clamping action is desired, namely in the vicinity of the licker-in 32 (Fig. 3). The layout of the gap between the element 24 and the feed roll 6A (Figures 3 and 5) thus can changed compared to the current conventional design, namely in that at the "mouth" (where the lap enters the gap) is relatively wide, e.g. 10 mm to 20 mm, preferentially about 15 mm. The gap width at the licker-in (at the free edge of the trough plate) is relatively small, e.g. 0.1 mm, i.e. the minimum required for avoiding contact between the edge and the feed roll 6A. The lap in this arrangement is compressed relatively feebly between the element 24 and the roll 6A until it enters the gap between the elastic zone and the roll. The reaction forces exerted onto the feed trough plate thus to a great extent are generated in the elastic zone. In this manner also the traction exerted by the feed roll 6A acting onto the lap is reduced which possibly is to be compensated for by means of an additional transporting means (upstream from the feed trough plate). It may prove advantageous to provide an inlet plate directly upstream from the mouth of the gap in order to facilitate insertion of the lap into the gap. The support member 22 should be designed as a rigid element, in particular an element resisting torsion. For this purpose a hollow profile is the ideal form, which however, is not essential within the scope of the present invention. The feed trough plate can be pivoted as a unit about the axis 25 until it rests against a stop (not shown). In this arrangement the position of the clamping point (at the free edge of the element 24) can be adjusted relative to the licker-in 32 which for processing different fibre materials (of different staple length) can prove advantageous. The present invention also is not restricted to a particular variant in which the elastic element extends over the full working width. A plurality of elastic elements can be mounted onto a common support member. The preferred variant comprises an extruded profile in which the elastic element is incorporated in a unit. The elasticity of the gap-forming element can be adapted to the requirements by suitably choosing the material (e.g. Al-alloy, cast iron, steel), its thickness and its "width" which term here concerns the length of the element in the direction of fibre transport (i.e. the arc length of the element). The surface facing the roll 6A should be processed in such a manner that it presents non-clinging surfaces for fibres and that together with the roll forms a suitable gap profile. WE CLAIM : 1. A feed trough plate (20, 30) for application in a feed device with a feed roll (6a) and a feed trough plate (201 30), characterized in that the feed trough plate comprises a support element (22, 32) resistant to bending and at least one gap-forming element (24, 34) attached to the support element (22, 32) the gap-forming element being elastically deformable. 2. The feed trough plate (20, 30) as claimed in claim 1, wherein the gap-forming element (24, 34) is elastically deformable in the longitudinal direction of the roll (6a) 3. The feed trough plate (20, 30), as claimed in any one of the claims 1 to 3, wherein the gap-forming element (24, 34) is elastically deformable locally. 4. The feed trough plate (20, 30), as claimed in any one of the claims 1 to 4, wherein the gap-forming element (24, 34) is formed as a unit in one piece extending over the length of the roll (6a). 5. The feed trough plate (20, 30), as claimed in claim 5, wherein the gap-forming element (24, 34) is formed as a unit in one piece with the support element (22, 32). 6. The feed trough plate (20, 30), as claimed in any one of the claims 1 to 6, wherein the support element (22, 32) is designed as a hollow profile. 7. The feed trough plate (20, 30), as claimed in any one of the claims 1 to 7, wherein the support element (22, 32) is provided with holding device e.g. in the form of a bearing element co-operating with a pivoting axle. 8. The feed trough plate (20, 30), as claimed in any one of claims 1 to 7, wherein the gap-forming element (24, 34) is designed curved with a free edge extending longitudinally and with a longitudinal side attached to the support element (22, 32). 9. The feed trough plate (20, 30), as claimed in any one of the claims 1 to 8, wherein the thickness of the gap- forming element (24, 34) decreases in the direction of fibre transport. 10. The feed trough plate (20, 30), as claimed in any one of the claims 1 to 9, wherein the feed trough plate (20, 30) co-operates with a sensor (e.g a displacement measuring sensor or a force measuring sensor) to form a measuring device for the fibre mass present between the trough plate (20,30) and the roll (6a). 11. The feed trough plate (20, 30), as claimed in any one of the claims 1 to 10, wherein the element (24, 34) is elastic only in a rim zone presenting a free edge. 12. The feed trough plate (20, 30), as claimed in claim 11, wherein the rim zone in the direction of fibre transport presents a dimension of 10 to 30 mm. 13. A feed device with a feed roll and a feed trough plate (20,30) as claimed in any one of the preceding claims.

Documents:

2839-mas-1998 abstract duplicate.pdf

2839-mas-1998 claims duplicate.pdf

2839-mas-1998 description (complete) duplicate.pdf

2839-mas-1998 drawings duplicate.pdf

2839-mas-1998-abstract.pdf

2839-mas-1998-claims.pdf

2839-mas-1998-correspondence others.pdf

2839-mas-1998-correspondence po.pdf

2839-mas-1998-description complete.pdf

2839-mas-1998-drawings.pdf

2839-mas-1998-form 1.pdf

2839-mas-1998-form 26.pdf

2839-mas-1998-form 3.pdf

2839-mas-1998-other documents.pdf