JP7626536B2 - Chuck - Google Patents

Description

The present invention relates to a chuck for a winding machine for receiving and fixing a winding tube for winding a yarn to form a package, as described in the preamble of claim 1.

The aforementioned chuck of a winding machine is known, for example, from DE 196 07 916 A1.

Such a chuck is preferably used in a winding machine for winding freshly spun synthetic yarn to form a package. For this purpose, several winding tubes are fitted one after the other onto the chuck, which is arranged so as to protrude into the winding machine. To clamp the winding tubes, the chuck has a clamping device. This clamping device has several clamping elements that can be guided radially outward. The clamping device is integrated into a clamping bush, which is held on a shaft carrier, which protrudes into the clamping bush. Furthermore, the clamping bush is driven and held at a distance from the shaft carrier, so that a circumferentially extending annular chamber is formed between the shaft carrier and the clamping bush. The clamping device formed on the clamping bush has several clamping elements. For clamping and unclamping, these clamping elements are each arranged between a spring and a pressure chamber. These pressure chambers can be connected together via an annular chamber to a compressed air source. At the open end of the clamping bush, a peripheral opening is formed between the collar of the shaft carrier and the end face end of the clamping bush. This peripheral opening is connected to an annular chamber inside the chuck and can be selectively closed by a sealing means. For this purpose, a sealing piston is guided in a sliding manner in the shaft carrier as the sealing means, so that it can be pressed against the sealing surface on the end face side of the clamping bush with a seal.

To clamp the tube and wind the yarn during operation, the clamping device is operated without pressure, so that the clamping elements are held in a radially outer position under the action of a spring and fix the tube that is fitted over the circumferential surface of the clamping bush. In this situation, the peripheral wall openings at the end faces of the clamping bush are open and the annular chamber between the clamping bush and the shaft carrier is connected to the periphery in order to vent all pressure chambers.

After the package has been completely wound on the winding tube and the clamping bush has been braked to change the package, the compressed air supply is activated, in which the sealing piston first closes the peripheral opening between the shaft carrier and the clamping bush, so that the compressed air flowing into the annular chamber between the shaft carrier and the clamping bush can be guided into the pressure chamber of the clamping device. In the clamping element, a pneumatic force against the spring is generated, which causes the clamping element to adjust, so that it releases the winding tube around the clamping bush. This process is repeated with each package change.

To move the sealing piston of the shaft carrier to close the peripheral opening, compressed air is introduced into the annular chamber of the sealing piston. At this point, the sealing piston has an additional seal, which allows the pressure build-up for moving the sealing piston. The sealing of the peripheral opening at the end face end of the clamping bush is therefore essentially dependent on the function of the sealing piston. The return of the sealing piston is therefore caused via a spring element, which does not return the sealing piston in the event of breakage.

The object of the present invention is therefore to improve the chuck described at the beginning so that the peripheral wall opening at the end of the end face of the clamping bushing can be closed with high reliability and reproducibility.

This problem is solved according to the invention in that the sealing means is formed by an elastic cavity seal, which can be expanded by compressed air.

Advantageous refinements of the invention are defined by the features and combinations of features recited in the dependent claims.

The invention has the special advantage that no movable, axially displaceable elements are present in the shaft carrier for sealing the peripheral opening. As sealing means, a fixedly arranged elastic cavity seal is used, which can be expanded by compressed air for sealing. In order to be able to close the relatively large gap width of the peripheral opening, movable elements are no longer necessary. Furthermore, exact centering of the shaft carrier and the clamping bush is no longer necessary. Due to the elasticity of the cavity seal, even in the expanded state, certain errors in the position of the clamping bush and the position of the shaft carrier can be compensated.

In order to allow a direct supply of compressed air to the cavity seal if necessary, a refinement of the invention is provided in which the annular cavity seal has a compressed air connection in the bottom area, which cooperates with an inlet hole in the shaft carrier. The compressed air supply is thus effected directly via the inlet hole in the shaft carrier.

A refinement of the invention in which the inlet hole is connected to an air supply passage in the shaft carrier, by which the annular chamber is connected to a compressed air source, is particularly advantageous. In that respect, one common compressed air connection can be used for the compressed air source used to unclamp the clamping element and to inflate the seal. Separate compressed air connections are therefore not required.

In order to obtain a sealing of the peripheral opening directly inside the clamping bush, a refinement of the invention is provided in which a cavity seal is arranged in a circumferential groove on the peripheral surface of the shaft carrier, facing the peripheral wall of the clamping bush. Thus, the radially acting sealing of the peripheral opening is realized directly on the peripheral surface of the shaft carrier. Furthermore, the possibility of centering the clamping bush on the shaft carrier arises when sealing the peripheral opening by the cavity seal.

Alternatively, however, it is also possible to arrange the cavity seal in the end wall of the collar of the shaft carrier, facing the end end of the clamping bush. In this way, axial sealing of the peripheral wall opening is achieved.

Depending on the size of the sealing gap between the shaft carrier and the clamping bush, various types of cavity seals are possible. A first variation of the cavity seal has an expandable sealing profile, by means of which sealing gaps of more than 3 mm can be closed. This allows relatively large sealing gaps to be filled.

Alternatively, however, a variation is also available in which the cavity seal is formed by an expandable seal profile, by means of which a seal gap of less than 3 mm can be closed. In this variation of the cavity seal, the seal profile is implemented by stretching the contour essentially exclusively with compressed air.

The sealing effect is further improved by a refinement of the invention in which the cavity seal has at least one outer sealing lip in the sealing profile. However, preferably, several sealing lips are used, so that the smallest possible pressure loss can be achieved when the clamping device is released.

An embodiment of the chuck according to the present invention and further advantages of the present invention are described in more detail below with reference to the accompanying drawings.

1 is a schematic vertical cross-sectional view showing an embodiment of a chuck according to the present invention. FIG. 2 is an enlarged schematic view of the sealing means of the embodiment shown in FIG. 1 in an open position; FIG. 2 is an enlarged schematic view of the sealing means of the embodiment shown in FIG. 1 in a closed position; FIG. 11 is an enlarged view showing a schematic view of a sealing means according to another embodiment.

Figure 1 shows a schematic longitudinal section of an embodiment of a chuck according to the invention, for example for use in a winding machine for winding a yarn on a number of bobbins. The chuck has a drive shaft 3, which is rotatably supported in a hollow cylindrical shaft carrier 2 by means of a number of bearings 4. At its end, not shown in Figure 1, the drive shaft 3 is connected to an electric drive. At its end projecting from the shaft carrier 2, the drive shaft 3 is non-rotatably connected via a hub 15 to a hollow cylindrical clamping bush 1. The projecting piece of the shaft carrier 2 projects into the open end of the clamping bush 1 to support the drive shaft 3.

A clamping device 5 is arranged on the circumferential surface of the clamping bush 1. This clamping device 5 has an outer clamping sleeve 7 and a number of clamping elements 6 arranged between the clamping bush 1 and the clamping sleeve 7. In this embodiment, each clamping element 6 is formed by a radially movable clamping piece 10 and an axially movable piston 8, in which the clamping piece 10 is guided via a wedge-shaped guide surface. The clamping piece 10 protrudes into the opening 11 of the outer clamping sleeve 7, and the piston 8 has a number of cutouts 38 distributed on the circumferential surface in order to accommodate the clamping pieces 10.

A piston 8, which is guided in the axial direction for adjusting the clamping piece 10 in the radial direction, is arranged between a spring 9 and a pressure chamber 12, which is formed between the clamping sleeve 7 and the clamping bush 1. The piston 8 is supported on a stop 17, which is fixedly connected to the clamping bush 1 via the spring 9. In the situation illustrated in FIG. 1, the clamping element 6 is shown in a clamping position, in which the clamping piece 10 is held in the clamping position extended by the piston 8 using the spring 9. To release the winding tube 32, a pressure medium, preferably compressed air, is applied to the piston 8 on the side located opposite the spring 9 via the pressure chamber 12, so that the piston 8 moves against the spring 9 in the direction of the stop 17. This causes a wedge-shaped guide surface to move, so that the clamping piece 10 can move radially inwards. For sealing against the pressure chamber 12, the piston 8 has a number of seals on the pressure side, which respectively cause a seal between the piston 8 and the clamping bush 1 and between the piston 8 and the clamping sleeve 7.

The clamping elements 6 adjacent to the clamping bush 1 in the longitudinal direction are identically constructed, and the end faces of the pistons 8 to which pressure is applied face each other at a distance and define a pressure chamber 12. The winding tube 32 is thus clamped by two adjacent clamping elements 6. For release, both pistons 8 of adjacent clamping elements 6 are simultaneously controlled by the pressure chamber 12. For this purpose, the pressure chamber 12 is connected to the annular chamber 14 formed between the clamping bush 1 and the shaft carrier 2 via a through-hole 13 provided in the peripheral wall 31 of the clamping bush.

In the longitudinal direction of the clamping bush 1, the clamping device 5 has a number of clamping elements 6, each of which is identically designed and in which the respective pressure chamber 12 is connected via a through-hole 13 to the pressure chamber 14 or to a pressure chamber 35 in front of the clamping bush 1. The annular chamber 14 is connected to an air supply channel 34 in the shaft carrier 2 via a number of passages 33 on the periphery of the shaft carrier 2. The air supply channel 34 can be formed, for example, by holes in the shaft carrier 2. The air supply channel 34 is connected to a controllable compressed air source 39 (FIG. 2).

At the free end of the chuck, a cover 16 is fixedly held on the clamping bush 1. The cover 16 is dimensioned so that the pressure chamber 35 formed in the clamping bush 1 at the end is closed by the cover 16.

At the opposite end, the clamping bush 1 has a free end face 19 which is flange-shaped and forms a sealing surface 20 on the outer side. Between the end face 19 of the clamping bush 1 and the shaft carrier 2 which has a flange 28 opposite the end face 19, a peripheral opening 18 is formed. The peripheral opening 18 connects the annular chamber to the periphery for degassing the pressure chamber 12. A sealing means 21 is associated with the peripheral opening 18 at the flange 28 of the shaft carrier 2, by which the peripheral opening 18 is selectively held open or closed.

To further explain the sealing means 21 arranged on the flange 28 of the shaft carrier, reference is further made to FIG. 2, which shows an enlarged view of a portion of the peripheral wall opening 18 between the clamping bush 1 and the shaft carrier 2. The following description therefore applies to both figures.

A circumferential groove 25 extending annularly is formed on the end wall 27 of the flange 28 of the shaft carrier 2. A hollow chamber seal 22 is disposed in the circumferential groove 25. The hollow chamber seal 22 has a compressed air connection 23 at the bottom of the circumferential groove 25. The compressed air connection 23 is connected to an air supply passage 34 inside the shaft carrier 2 via an inlet hole 26.

The cavity seal 22 faces a seal surface 20 provided on the end face end 19 of the clamping bush 1. In this embodiment, the cavity seal 22 has an expandable seal profile 24. The seal profile 24 is annular and is expanded by compressed air supplied by the compressed air connection 23.

1 and 2, the cavity seal 22 is shown in a stationary state without pressure. In this operating condition, several winding tubes are usually clamped around the chuck in order to wind several threads in parallel around the winding tube to form a package. In this condition, the peripheral wall opening 18 between the shaft carrier 2 and the clamping bush 1 is open, so that the pressure chamber 12 is evacuated. The clamping element 6 of the clamping device 5 is held in the clamped position via a spring force.

At the end of the winding process, the drive shaft 3 is braked together with the clamping bush 1 so that the fully wound package can be removed from the chuck. Compressed air is then supplied from the compressed air source 39 and introduced via the air supply channel 34. The compressed air reaches the cavity seal 22 from the air supply channel 34 through the inlet 26. The cavity seal 22 is expanded by the compressed air so that the seal profile 24 unfolds and closes the sealing gap at the peripheral opening 18. In this case, the cavity seal 22 rests against the sealing surface 20 provided at the end face end 19 of the clamping bush 1. This situation is illustrated in FIG. 3, which shows the part shown in FIG. 2 in a merely modified operating situation. In so far as this is concerned, the explanation for FIG. 2 also applies to FIG. 3.

After the peripheral opening 18 is closed by the cavity seal 22, a positive pressure is generated in the pressure chamber 12 of the clamping device 5, which moves the piston 8 against the spring 9 and thus the tube 32 is released. The full package is now removed from the chuck and replaced by a new empty tube. As soon as the empty tube is fitted over the peripheral surface of the chuck, the compressed air supply is stopped, which relaxes the cavity seal 22 and opens the peripheral opening 18. The annular chamber 14 is connected to the periphery and the pressure chamber 12 is evacuated. The clamping piece 10 is now held in a tight position by the spring tension.

It should be explicitly stated here that the construction of the chuck is exemplary. Thus, for example, the shaft carrier 2 can be constructed integrally, i.e. in one piece, or can be constructed from several components. In particular, the flange 28 here can be formed from a separate component. The clamping element 6 shown is likewise exemplary. It is important here that compressed air is required for release, which is supplied via an annular chamber.

In the above-described embodiment, the radial sealing gap between the end face end 19 and the opposing cavity seal 22 at the peripheral wall opening 18 is sealed in the axial direction. However, it is also possible in principle to arrange the cavity seal 22 directly on the peripheral surface of the shaft carrier 2 and use it as a radial seal. In this regard, FIG. 4 shows some possible embodiments of another sealing means in the chuck. The embodiment shown in FIG. 1 is identical in the structure of the chuck to the embodiment shown in FIG. 1, so that the above description is referred to for the overall structure of the chuck, and only the differences are described here.

In FIG. 4, a circumferential groove 25 is arranged on the circumferential surface of the shaft carrier 2 in the clamping bush 1. A cavity seal 22 is held in the circumferential groove 25. The cavity seal 22 has a compressed air connection 23 at the bottom of the circumferential groove 25. The compressed air connection 23 is connected to the air supply passage 34 via an inlet hole 26. An annular cavity seal 22 is arranged in the circumferential groove 25. The cavity seal 22 has an expandable sealing profile 24 with a number of outer sealing lips 29. The sealing lips 29 in the cavity 24 are located against the peripheral wall 31 of the clamping bush 1 with a sealing gap of the peripheral wall opening 18. In the situation shown in FIG. 4, the cavity seal 22 is shown in an unloaded state, such that the peripheral wall opening 18 between the shaft carrier 2 and the clamping bush 1 is open.

In order to be able to carry out the unclamping of the clamping device 5, when compressed air is supplied, the hollow seal 22 stretches such that the sealing lip 29 seals the sealing gap of the peripheral wall opening 18 in the peripheral wall section 31 of the clamping bush 1. In this case, mainly only the stretching of the hollow seal 22 occurs. Such a hollow seal 22 can therefore only fill smaller sealing gaps, preferably < 3 mm. In contrast, the embodiment of the hollow seal 22 shown in FIG. 2 is suitable for filling and sealing larger sealing gaps in the range of more than 3 mm.

Claims (7)

A chuck for a winding machine for receiving and fixing a winding tube for winding a yarn into a package, the chuck having a protruding shaft carrier (2) and a clamping bush (1) held on the circumferential surface of the shaft carrier (2), the clamping bush (1) having a clamping device (5) for fixing the winding tube (32) on its circumferential surface, the clamping device (5) having a plurality of movable clamping elements (6), the clamping elements (6) being respectively arranged between a pressure chamber (12) and a spring (9), the pressure chamber (12) being arranged between the pressure chamber (12) and a spring (9), the clamping element (5 ... a chuck in which the chamber (12) is connectable to a compressed air source via an annular chamber (14) formed between the shaft carrier (2) and the clamping bush (1), the annular chamber (14) being connected to the periphery at an inner end face end (19) of the clamping bush (1) by a peripheral wall opening (18) formed between the clamping bush (1) and a flange (28) of the shaft carrier (2), the peripheral wall opening (18) being closable by a sealing means (21) arranged between the shaft carrier (2) and the clamping bush (1),
A chuck, characterized in that the sealing means (21) is formed by an elastic cavity seal (22), which is expandable by compressed air. The chuck according to claim 1, wherein the cavity seal (22) has a compressed air connection (23) in the bottom region, which cooperates with an inlet hole (26) provided in the shaft carrier (2). The chuck of claim 2, wherein the inlet hole (26) is connected to an air supply passage (34) in the shaft carrier (2), and the annular chamber (14) is connected to the compressed air source by the air supply passage (34). The chuck according to any one of claims 1 to 3, wherein the cavity seal (22) is arranged opposite the end end (19) of the clamping bush (1) on the end wall (27) of the flange (28) of the shaft carrier (2). 5. The chuck according to claim 1, wherein the cavity seal (22) is formed by an expandable seal profile (24) by which a seal gap of a peripheral wall opening (18) larger than 3 mm can be closed. 5. The chuck according to claim 1, wherein the cavity seal is formed by an expandable seal profile (30), by which a seal gap of the peripheral wall opening (18) of less than 3 mm can be closed. 7. The chuck according to claim 1, wherein the cavity seal (22) has at least one outer sealing lip (29) at a seal profile (30).

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