Title of Invention

A NIPPER UNIT OF A COMBER

Abstract

The invention relates to a nipper unit (1) of a comber comprising a nipper frame (8) having a lower cushion plate (12) which can be moved to and fro by a drive element (10, G) by means of at least one swivel arm (2a) which is swivellably mounted about the axis (5) of a circular comb (4) rotatably mounted underneath the nipper unit (1) in the machine frame (MG). To simplify the drive of the nipper unit of a comber and to keep the distance (a) between the covering circle of the comb segment (7) and the nipper lip (13) constant, it is proposed that the free end of the swivel arm (2a) swivellably mounted about the circular comb axis (5) is fixedly connected to the nipper frame (8),

Full Text

DRIVE OF A NIPPER UNIT OF A COMBER The invention relates to a nipper unit of a comber comprising a nipper frame having a lower cushion plate which can be moved to and fro by a drive element by means of at least one swivel arm which is swivellably mounted about the axis of a circular comb rotatably mounted underneath the nipper unit in the machine frame. DE-4216485 discloses and describes a nipper unit which executes a to and fro movement by means of swivel arms. In this situation, the swivel arms which are connected rotationally movably to the nipper frame, form a four-bar linkage. As a result, the nipper lip of the lower cushion plate moves away from the covering circle of the circular comb segment during movement in the direction of the detaching roller and approaches this covering circle again during its backward movement into a rear position. In this rear position the nipper unit is closed where the fibre tuft projecting over the nipper lip is presented to the circular comb segment for combing out. As can be deduced from the flow diagram in the literature "The short staple spinning mill - The Textile Institute", vol. 3 - ISBN 3-908.059-01-1, on page 31, the circular comb for combing out the fibre tuft is already in engagement during the backward movement of the nippers. This has the result that the depth of in-feed of the circular comb segment in the presented fibre tuft during the combing out process does not run exactly constantly. However, in order to obtain a combing-out result which is optimal as far as possible, it is necessary for the fibre tuft projecting from the closed nippers to be gripped almost completely by the circular comb segment. This can only be partly achieved with this drive arrangement of the nipper unit. In order that there are no collisions between the circular comb segment and the lower cushion plate, an exact mechanical coupling is required between the drive of the nipper unit and the circular comb. This means that individual control of the circular comb to adapt to specific technologies is not possible with this drive arrangement or is only possible to a very limited extent. It can also be deduced from this publication that the upper cushion plate which is swivellably mounted on the nipper frame by means of swivel arms is moved by means of spring struts connected to the drive. The spring struts are controlled by means of an eccentric drive to control the movement sequence of the upper cushion plate or to achieve an optimal nipping effect. In addition, the time of opening and closing the nippers and the switching safety of the feed is controlled by means of the position of the spring struts or their eccentric drive. This device gives an optimised nipping effect and good scope for adjustment in connection with this drive device of the nipper unit but is a relatively expensive and cost-intensive design. A drive arrangement of a nipper unit is known from DE-PS 231 797 where a lower cushion plate is fixedly connected to a lever whose swivel axis is located underneath a circular comb. In this case a hinge rod acts at the rear end of the nipper frame, this being connected to two levers which can be rotated about an axis. These levers carry rollers at their ends which are guided on respectively one driven cam plate. The movement sequence of the nipper unit is controlled by means of these cam plates. A disadvantage with this design is that the distance from the nip to the covering circle of the circular comb segment does not remain constant during the combing-out process since the swivel axis of the swivel arm of the lower cushion plate is located far below the circular comb axis. It is now the object of the invention to create a simplified drive of a nipper unit where in particular the distance between the nipper lip of the lower cushion plate and the covering circle of the comb segment of the circular comb remains constant during the entire combing process. The object of the invention is solved by fixedly connecting the free end of the swivel arm swivellably mounted about the circular comb axis to the nipper frame. On the one hand, this ensures that the combing-out relationships remain constant during the entire combing process and collisions between the circular comb segment and the lower cushion plate are prevented. In addition, this makes it possible that the drive of the circular comb can be individually controlled and is no longer directly dependent on the drive of the nipper unit It is further proposed that at least one further swivel arm connected to the nipper frame by means of a swivel joint is provided, said arm being coupled to the drive element which is in communication with the drive. For problem-free transmission of the drive movement it is further proposed that the further swivel arm is embodied as two-membered and is provided with a swivel joint. It is furthermore proposed that an upper cushion plate is arranged on the nipper frame, mounted by means of lateral swivel arms, wherein the swivel arms are each hinged on a spring strut which can swivel about an axis and the axis of the swivellable spring struts is arranged fixedly in the machine frame underneath the nipper unit. With this device it is possible to dispense with separate control of the upper cushion plate via the spring struts. This means that by suitably mounting the spring struts, the closing and opening movement of the upper cushion plate can be triggered or controlled by the movement of the nipper frame. This means that a separate drive is no longer necessary to execute this movement. Advantageously, the axes of the spring struts, seen in the direction of material flow, are arranged behind the circular comb axis and underneath the detaching rollers following the nipper unit. In order to adapt, for example, the movement of the upper cushion plate to certain circumstances (fibre material, lap thickness etc.) it is proposed that the bearing of the axis of the spring struts is fixed so that it is adjustable in the machine frame transverse to the longitudinal direction of the axis. In order to be able to make precise adjustments, the adjusting device for the bearing is preferably provided with adjustment marks. The spring struts can consist of compression springs guided in cylinders. In order to especially be able to adjust a minimal distance between the nipper lip of the lower cushion plate and the covering circle of the comb segment of the circular comb, it is further proposed that means are provided to change the length of the front swivel arm. If the swivel arms are detachably affixed to the nipper frame by means of fixing means, it is possible to adjust this described minimal distance by inserting or by removing spacer plates. Existing manufacturing tolerances can thus also be compensated. In order to introduce the to and fro movement of the nipper unit, it is proposed that the drive means for the further (or rear) swivel arm is suitable for converting a continuous movement produced by a main drive into a discontinuous movement. It is preferably proposed that this discontinuous movement should be embodied as adjustable. The drive means can also be embodied in the form of a driven cam plate which is connected rotationally fixedly to a shaft driven continuously by the main drive. It would also be feasible to execute the drive of the nipper unit by means of a separate single drive motor where its angle-of-rotation control is coupled to the control of the main drive motor or a means driven by the main drive motor. It is further proposed that at least one further arm is connected to the nipper frame by means of a swivel joint which is mounted with its other end rotationally movably on an eccentric which is in drive communication with a drive. This makes it possible to have a simple drive design where the eccentric disk can also be driven discontinuously to suitably adapt the movement sequences. Further advantages of the invention are shown and described in detail with reference to the following exemplary embodiments. In the figures: Figure 1: is a schematic side view of a nipper unit of known design Figure 2: is a schematic side view of a nipper unit according to the invention Figure 3: is a simplified diagram according to Figure 2 with a drive arrangement Figure 4: is a further exemplary embodiment according to Figure 3 with a cam plate drive Figure 5 is a simplified diagram according to Figure 2 with a further embodiment of a drive arrangement. Figure 1 shows a nipper unit 1 which is swivellably mounted by means of the crank arms 2, 3. In this case, two crank arms 2 are swivellably mounted respectively at the side of a circular comb 4 on its circular comb shaft 5. The other end of the swivel arm 3 (two can also be provided) is mounted rotationally fixedly on a nipper shaft 10. The opposite free end of the swivel arm 3 is rotationally movably connected to the nipper frame 8 by means of a shaft 9. The nipper unit 1 substantially consists of a lower cushion plate 12 fixedly connected to the nipper frame 8 and an upper cushion plate 14 (in some cases also called nipper blade) which is affixed to two swivel arms 15,15'. These swivel arms are attached to the nipper frame 8 so that they can be swivelled about a swivel axis 16. The swivel arms 15, 15' are connected to respectively one spring strut 18 which in turn is mounted on a drive eccentric 21 by means of an axis 20. Seen in the direction of material flow, a pair of detaching rollers 24 is provided behind the nipper unit. These detaching rollers 24 are driven by means of a drive train 25 shown schematically by a gear unit G which is driven by a motor M. The motor M is controlled by means of a control unit ST. The nipper shaft 10 is driven by a partial region of the gear unit G1 which is constructed to convert a continuous rotational movement produced by the motor M into a discontinuous rotational movement. For the sake of completeness, it may also be mentioned that a feed roller 27 is rotatably mounted inside the nipper unit 1 which executes a discontinuous rotational movement by means of a drive not shown in detail to transport the supplied lap W in sections. The eccentric 21 and also the circular comb shaft 5 are also driven by the gear unit G as shown schematically by the drive connections 30, 31. In the position shown in Figure 1 the nipper unit 1 is in a rear position where the nippers are closed and the lap W is nipped by means of the cushion plate 14 or 12. The fibre tuft FB projecting over the nip is then gripped by the comb segment 7 of the circular comb 4 and combed out. The swivel arm 3 is then swivelled to the left by means of the nipper shaft 10 whereby the nipper unit 1 is swivelled around the swivel arm 2 in the direction of the detaching rollers 24. In this swivelling process the nipper unit opens and enters into a front position where the combed-out fibre tuft FB is placed on the end E of the nonwoven V. As a result of the reversing movement of the detaching rollers shown schematically, the end of the fibre tuft FB comes into cooperation with the end E of the fibre nonwoven V at the nip K of the detaching rollers 24 whereby the fibres 1 not retained in the nipper unit 1 are drawn out of the lap. In general during this process a fixed comb is also in engagement but this is not shown for reasons of clarity. In the detachment process which has already been described, the ends of the fibre tuft FB are covered with the end E of the fibre nonwoven V whereby a so-called soldering takes place as soon as the nip K was passed. After the detachment process which has been described, the nippers return to the position shown in Figure 1 whereby a further combing-out process is started. Figure 2 shows the design of the drive arrangement for a nipper unit 1 claimed according to the invention. The nipper unit 1 is also swivelled about a circular comb shaft 5 of a circular comb 4 by means of swivel arms 2a attached on both sides of the circular comb during its movement to and fro. In contrast to the known exemplary embodiment from Fig. 1 the swivel arm 2a is fixedly connected to the nipper frame 8. This has the result that the distance a between the nipper lip 13 of the lower cushion plate 12 and the covering circle H of the comb segment 7 remains constant during the nipper movement. In order to be able to adjust this distance a, the swivel arms 2a are formed from respectively two parts 2a\ 2an which are detachably connected to one another by means of fixing elements, for example, screws 22. The upper part 2aM is fixedly connected to the nipper frame 8. The connection point 17 is shaped so that corresponding spacers 19 can be inserted between the part pieces 2a' and 2a" which serve to adjust the distance a. "This is only one of the possible designs for varying the length of the swivel arm 2a and thus the distance a. Further designs are possible. It would also be feasible to provide a continuous adjustment of the swivel arm 2a. In contrast to the exemplary embodiment in Figure 1, the rear swivel arm 3a is executed as two-membered with arms 3a' and 3a" which are swivellably connected to one another by means of a hinge 3b. The other end of the arm 3a" is mounted swivellably on the shaft 9 of the nipper frame 8. At the end opposite to the hinge 3b the arm 3a' is fixed on a clamping hub 32 which in turn is connected rotationally fixedly to the nipper shaft 10. As is indicated schematically, the clamping hub 32 is executed in two parts 32, both parts being connected to one another by means of fixing means not described in detail, whereby the rotationally fixed connection to the shaft 10 is produced at the same time. The drive of the detaching rollers 24,, the circular comb shaft 5 and the nipper shaft 10 corresponds to the drive of the design already described in Figure 1 and thus is not explained in further detail here. In contrast to the exemplary embodiment in Figure 1, the swivel arms 15a, 15b, which are connected to the upper cushion plate 14 are swivellably mounted underneath the feed roller 27 by means of the axis 16a. As a result of this arrangement, the feed roller 27 can be inserted or dismantled without any problems. A spring strut 18a equipped with a compression spring F acts on the free ends of the swivel arms 15a, 15b. The other end of the spring strut 18a is swivellably mounted on an axis 34 which is fixed in the machine frame MG. In the example shown, the axis 34 is fixed on a bearing element 35 which in turn is detachably affixed to a holder 37 by means of screws 36. The holder 37 is fixedly connected to the machine frame MG. The connection between the bearing element 35 and the holder 37 is embodied as adjustable in relation to the holder 37 which was indicated by a double arrow. However, other designs are also feasible where the axis 34 is additionally attached as adjustable in the vertical direction. This adjustability of the axis 34 makes it possible to adjust the nipping forces at the nipper lip 13 which are applied by the action of the spring force of the spring F. In addition, the closure time of the nippers, for example, can be adjusted by means of the adjustability of the axis 34. It is also possible to compensate for an adjustment of the setting distance (smallest distance between nipper lip and nip of the detaching roller) by a displacement of the axis 34. This should have the result that the "nip force/nipper movement" relationships remain constant. In the position shown in Figure 2 the combing-out process of the fibre tuft FB by the comb segment 7 has already begun. As soon as the combing-out process has ended, the nipper unit 1 moves as a result of the action of the nipper shaft 10 by means of the gear section G1 in the direction of the detaching rollers 24 into a front position where the nippers are open. Since the swivel arm 2a is now fixedly connected to the nipper frame 8, it is necessary for the rear swivel arm 3a to be executed as two-part and to be provided with an additional hinge 3b. During the forward movement of the nippers 1, the piston 39 moves inside the spring strut 18a as far as a stop 40 which then hinders further displacement of the piston 39 inside the spring strut 18a. This means that in this position the length of the spring strut 18a is fixed by the axis 34 as far as the hinge 23. This has the result that from a certain swivel movement of the nippers 1 into its front position, the upper cushion plate 14 is raised from the nipper lip 13 of the lower cushion plate 12 and the nipper opens. As soon as the detachment process (as described in Figure 1 for example) has ended, the nipper 1 is again swivelled by means of the driven nipper shaft 10, into a rear position which is shown in Figure 2. During this swivelling process the piston 39 of the spring strut 18a is displaced in the direction of the hinge 23 and thus shortens the spring length of the spring F. During this process the upper cushion plate 14 is brought into the closed position with the lower cushion plate wherein the spring force produced by the spring F applies the nipping force in the area of the nipper lip 13. This device makes it possible to achieve a simple and inexpensive design of nipper drive where on the one hand the minimal distance a between the nipper lip 13 and the covering circle H can be optimally adjusted and kept constant and on the other hand additional drive elements for moving the upper cushion plate 14 can be dispensed with. Further examples for the drive of the two-membered swivel arm 3a are shown in simplified form in Figures 3 and 4. In these simplified diagrams individual parts are omitted for reasons of clarity as can be identified for example by comparing with Figure 2. In the example in Figure 3, the nipper shaft 10 is directly driven by a separate single motor M1. Located on the motor shaft M1 is an encoder E1 which registers the angle-of-rotation position of the motor shaft. The detaching rollers 24 and the circular comb shaft 5 are driven by a central gear unit G by means of the drive connections 25 or 31, as has already been described in Figure 2. The gear unit G is driven by a main motor M which also has an encoder EM arranged on its drive shaft. The drive of the auxiliary motor M1 is suitably controlled by means of the control unit ST which is connected to the encoders EM, E1. That is, the position of the angle of rotation of the drive shafts of the motors M, M1 are matched to one another. This has the result that the swivelling movement of the nippers 1 is coordinated with the rotational movements of the circular comb 4, or the detaching rollers 24. -• In contrast to Figure 2, Figure 4 shows an arrangement where a cam plate 42 is used instead of the additional gear section G1 to produce a discontinuous movement on the nipper shaft 10. The cam plate 42 sits on a shaft 43 which is fixedly mounted in the machine frame and is in drive communication with the gear unit G by means of the drive connection 45. The gear unit G is driven by a main motor M which is controlled by means of the control unit ST. In this case, the drive of the shaft 43 is continuous. A roller 46 which is fixedly connected to the nipper shaft 10 by means of an arm 47 runs on the cam plate 42. The roller 46 is held in contact on the periphery of the cam plate 42 by means of a spring F1. The two-armed lever 3a is likewise fixedly mounted on the nipper shaft 10 which transmits the drive to the hinge 9 of the nipper frame 8 by means of its hinge 3b. This design shows a simple possibility for converting the continuous drive movement delivered by the gear unit G into a discontinuous movement which is necessary for the to and fro movement of the nipper 1. A simijar drive arrangement can be deduced from DE-PS 231 797 which has already been described. Figure 5 shows another possibility of a drive arrangement for the nipper unit 1. In this case, an arm 52 is connected rotationally movably to the nipper frame 8 by means of a swivel joint 9. At the other end of the arm 52 said arm is fixed rotationally movably on an eccentric disk 50 by means of an eccentric. The eccentric disk 50 is driven by a motor M by means of a gear unit G via the drive connection 45 shown schematically. The circular comb 4 and the detaching rollers 24 are driven by means of this gear unit as has already been described in the previous examples. It is also feasible to provide other drive possibilities. CLAIMS A nipper unit (1) of a comber comprising a nipper frame (8) having a lower cushion plate (12) which can be moved to and fro by a drive element (10, G) by means of at least one swivel arm (2a) which is swivellably mounted about the axis (5) of a circular comb (4) rotatably mounted underneath the nipper unit (1) in the machine frame (MG), characterised in that the free end of the swivel arm (2a) swivellably mounted about the circular comb axis (5) is fixedly connected to the nipper frame (8). The nipper unit (1) according to claim 1, characterised in that at least one further swivel arm (3a) connected to the nipper frame (8) by means of a swivel joint (9) is provided, said arm being coupled to the drive element (10, G) which is in communication with the drive (M, M1). The nipper unit (1) according to claim 2, characterised in that the further swivel arm (3a) is two-membered and is provided with a swivel joint (3b). The nipper unit (1) according to any one of claims 1 to 3, characterised in that an upper cushion plate (14) is arranged on the nipper frame (8), mounted by means of lateral swivel arms (15a, 15b), wherein the swivel arms are each hinged on a spring strut (18a) which can swivel about an axis (34) and the axis (34) of the swivellable spring struts is arranged fixedly in the machine frame (MG) underneath the nipper unit (1). The nipper unit (1) according to claim 4, characterised in that the bearing (35) of the axis (34) of the spring struts (18a) is fixed so that it is adjustable in the machine frame (MG) transverse to the longitudinal direction of the axis (34). The nipper unit (1) according to claim 4, characterised in that an adjusting device (36) is provided for the bearing (35) with adjusting marks. The nipper unit according to claim 4, characterised in that the axis (34) of the spring struts (18a), seen in the direction of material flow, is arranged behind the circular comb axis (5) and underneath the detaching rollers (24) following the nipper unit (1). The nipper unit (1) according to any one of claims 4 to 7, characterised in that the spring struts (18a) consist of compression springs (F) guided in cylinders. The nipper unit (1) according to any one of claims 1 to 8, characterised in that means (17, 22) are provided to change the length of the front swivel arms (2a). The nipper unit (1) according to claim 9, characterised in that the front swivel arms (2a') are detachably affixed to the nipper frame (8) by means of fixing means (22). The nipper unit (1) according to any one of claims 1, 2 or 3, characterised in that the drive element (G1) is constructed such that a continuous movement produced by a main drive (G) is converted into a discontinuous movement. The nipper unit (1) according to claim 11, characterised in that means are provided for adjusting the discontinuous movement. The nipper unit (1) according to claim 11, characterised in that the drive element is a cam plate (42) which is connected rotationally fixedly to a shaft (43) driven continuously by the main drive (G). The nipper unit (1) according to claim 1 or claim 2, characterised in that the drive means is a drive motor (M1) whose angle-of-rotation control is coupled to the control (EM) of the main drive motor (M) or a means driven by the main drive motor. The nipper unit (1) according to claim 1, characterised in that at least one further arm () is connected to the nipper frame (8) by means of a swivel joint (9) which is mounted with its other end rotationally movably on an eccentric () which is in drive communication with a drive (G, M).

Documents:

2469-chenp-2005 abstract granted.pdf

2469-chenp-2005 claims granted.pdf

2469-chenp-2005 description(complete) gratned.pdf

2469-chenp-2005 drawings granted.pdf

2469-chenp-2005-abstract.pdf

2469-chenp-2005-claims.pdf

2469-chenp-2005-correspondnece-others.pdf

2469-chenp-2005-correspondnece-po.pdf

2469-chenp-2005-description(complete).pdf

2469-chenp-2005-drawings.pdf

2469-chenp-2005-form 1.pdf

2469-chenp-2005-form 18.pdf

2469-chenp-2005-form 26.pdf

2469-chenp-2005-form 3.pdf

2469-chenp-2005-form 5.pdf

2469-chenp-2005-pct.pdf