chuck

Abstract

Chuck of a winding machine for receiving and fixing spools and for winding threads into spools, with a projecting axle carrier (2) and a clamping sleeve (1) held on the circumference of the axle carrier (2), the clamping sleeve having a clamping device (5) on its circumference for fixing the spools (32), the clamping device (5) having several slidable clamping elements (6) each arranged between a pressure chamber (12) and a spring (9), the pressure chambers (12) being connectable to a compressed air source via an annular chamber (14) formed between the axle carrier (2) and the clamping sleeve (1), the annular chamber (14) being connected to the environment at an inner end face (19) of the clamping sleeve (1) by a shell opening (18) formed between the clamping sleeve (1) and a collar (28) of the axle carrier (2), and the shell opening (18) being slidably on the axle carrier (2). designed sealing piston (21) can be closed,which acts to seal the jacket opening (18) with a seal (22) on a sealing surface (20) of the clamping sleeve (1), characterized in that the sealing piston (21) has a centering projection (23) on an end face facing the end end (19) of the clamping sleeve (1), which projects into the clamping sleeve (1) when the sealing piston (21) is in contact with the sealing surface (20), so that the clamping sleeve (1) is centered in its position relative to the axle carrier (2).

Description

[0001] The invention relates to a chuck of a winding machine for receiving and fixing spools and for winding threads into spools according to the preamble of claim 1.

[0002] Such a chuck for a winding machine is known, for example, from DE 196 07 916 A1.

[0003] These chucks are used in winding machines for winding preferably freshly spun synthetic yarns into bobbins. For this purpose, several bobbin cases are mounted one after the other on the chuck, which is cantilevered in the winding machine. To clamp the bobbin cases, the chuck has a clamping device with several radially extending clamping elements. The clamping device is integrated into a clamping sleeve, which is held on a shaft carrier, with the shaft carrier projecting into the clamping sleeve. The clamping sleeve is also driven and held at a distance from the shaft carrier, so that a circumferential annular chamber is formed between the shaft carrier and the clamping sleeve.

[0004] The clamping device formed on the clamping sleeve has several clamping elements arranged between a spring and a pressure chamber for clamping and releasing. The pressure chambers can be connected to a compressed air source via the annular chamber.

[0005] At the open end of the clamping sleeve, a shell opening is formed between a collar of the axle carrier and a face end of the clamping sleeve. This opening is connected to the annular chamber inside the chuck and can be selectively opened and closed by means of a sealing piston located on the axle carrier. For this purpose, the sealing piston is guided slidably on the axle carrier and can be moved against a sealing surface on the face of the clamping sleeve by means of a seal.

[0006] For tensioning the spools and during operation for winding the threads, the clamping device is operated without pressure, so that the clamping elements are held in a radially outer position by the action of the springs and fix the spools mounted on the circumference of the clamping sleeve. In this situation, the sealing piston on the axle carrier is held in an open position, so that the annular space between the clamping sleeve and the axle carrier is connected to the environment via the shell opening for venting all pressure chambers.

[0007] Once the coils are wound onto the spool sleeves and the clamping bushing has been braked to change the coils, a compressed air supply is activated. First, the sealing piston closes the opening between the axle carrier and the clamping bushing, directing the compressed air flowing into the annular space between the axle carrier and the clamping bushing into the pressure chambers of the clamping device. A pneumatic force opposing the force exerted by the springs is generated at the clamping elements, causing them to adjust and release the spool sleeves from the circumference of the clamping bushing. This process is repeated for each coil change.

[0008] With very long, projecting chucks, it has been observed that the load on the coils shifts the chuck sleeve relative to the axle carrier. This causes a displacement of the gap forming the annular chamber, so that, particularly when stationary, the inner end face of the chuck sleeve is held eccentrically to the axle carrier. This can lead to irregularities in the sealing of the sleeve openings, which promote wear of the seals or even cause leaks.

[0009] DE 30 39 064 A1 also describes a chuck for winding machines for holding a coil carrier, consisting of a clamping mandrel and a cylindrical shell with through-holes. The clamping elements consist of clamping pins that are guided linearly and radially movable in the through-holes of the shell and are supported on clamping elements that rise wedge-shaped in the axial direction.

[0010] US Patent 4,175,712 A discloses a clamping spindle arrangement in which a removable coil holder is slid onto the clamping spindle. An actuating device serves to move the coil holder clamping elements into their retracted position when a change of the coil holder is desired.

[0011] The object of the invention is therefore to further develop the generic chuck in such a way that, regardless of the length and load of the chuck bushing, the coil sleeves can be loosened by a supply of compressed air.

[0012] This problem is solved according to the invention by the fact that the sealing piston has a centering projection on an end face facing the end face of the clamping sleeve, which projects into the clamping sleeve when the sealing piston is in contact with the sealing surface.

[0013] Advantageous embodiments of the invention are defined by the features and combinations of features of the respective dependent claims.

[0014] The invention has the particular advantage that the clamping bushing on the circumference of the axle carrier is brought into a predefined centered position before each sealing of the sleeve opening. This ensures that the sealing surface on the clamping bushing is always aligned with the seal held on the sealing piston. Furthermore, the position of the clamping bushing on the circumference of the axle carrier is stabilized, thus facilitating the removal of the full coils. The overpressure within the clamping device required to relieve the clamping elements remains constant throughout the entire changeover period until new coil sleeves are pushed on, so that the clamping elements remain in a radially retracted position.

[0015] To ensure a uniform position of the clamping sleeve relative to the axle carrier around its circumference, the sealing piston is advantageously designed in an annular shape, with the centering projection forming a continuous closed ring or circumferentially with individual axially aligned parting lines. This allows the clamping sleeve to be radially displaced around its entire circumference relative to the axle carrier.

[0016] In order to ensure the engagement of the centering projection of the sealing piston even with larger relative displacements of the clamping sleeve, a further development of the invention is preferably implemented in which the clamping sleeve has a circumferential inner phase opposite the centering projection of the sealing piston, which interacts with the centering projection.

[0017] To accommodate the seal, the sealing piston has an axially offset circumferential groove on the end face of the centering projection, ensuring a secure hold for the seal. An offset between the end of the centering projection and the seal held in the circumferential groove provides pre-centering before the seal comes into contact with the sealing surface of the clamping sleeve. However, to ensure sufficient effectiveness, this offset is limited to a maximum of 2 mm.

[0018] To prevent any contact between the sealing piston and the clamping sleeve during rotation of the chuck, a spring is provided between the axle carrier and the sealing piston, holding the sealing piston in an open position. This ensures that the opening between the clamping sleeve and the axle carrier remains open at all times when the clamping sleeve rotates, and that the pressure chambers of the clamping device are vented.

[0019] Only if the clamping sleeve for changing the full coil is completely braked can the sealing piston be moved into a closed position via a compressed air actuator. For this purpose, a guide end of the sealing piston is guided within an annular space formed in the axle carrier, whereby the annular space can be connected to the compressed air source.

[0020] An embodiment of the chuck according to the invention, as well as further advantages of the invention, are described in more detail below with reference to the accompanying figures.

[0021] They represent: Fig. 1 schematically a longitudinal section of an embodiment of the chuck according to the invention Fig. 2 schematically an enlarged representation of the sealing piston of the exemplary embodiment from Fig. 1 in an open position Fig. 3 schematically an enlarged representation of the sealing piston of the exemplary embodiment from Fig. 1 in a closed position

[0022] In Fig. Figure 1 schematically shows a longitudinal section through an embodiment of the chuck according to the invention, as used, for example, in a winding machine for holding several bobbins and for winding threads. The chuck has a drive shaft 3, which is rotatably mounted within a hollow cylindrical axle carrier 2 by several bearings 4. The drive shaft 3 is coupled to an electric drive at one end (not shown). At the end projecting from the axle carrier 2, the drive shaft 3 is non-rotatably connected to a hollow cylindrical clamping sleeve 1 via a hub 15. The projecting section of the axle carrier 2 extends into an open end of the clamping sleeve 1 to support the drive shaft 3.

[0023] A clamping device 5 is arranged around the circumference of the clamping sleeve 1. This clamping device comprises an outer clamping sleeve 7 and several clamping elements 6 arranged between the clamping sleeve 1 and the clamping sleeve 7. In this embodiment, each clamping element 6 is formed by a radially displaceable clamping block 10 and an axially displaceable piston 8, on which the clamping block 10 is guided via a wedge-shaped guide surface. The clamping block 10 projects into an opening 11 of the outer clamping sleeve 7. The piston 8 has several notches 38 distributed around its circumference to accommodate multiple clamping blocks 10.

[0024] The piston 8, which is guided axially for radial adjustment of the clamping blocks 10, is arranged between a spring 9 and a pressure chamber 12 formed between the clamping sleeve 7 and the clamping bushing 1. The piston 8 is supported by the spring 9 against a stop 17 that is fixedly connected to the clamping bushing 1. In the Fig. In Figure 1, the clamping elements 5 are shown in a clamping position in which the clamping blocks 10 are held in an extended clamping position by the pistons 8 via the spring 9. To release a coil sleeve 32, the piston 8 is pressurized on the side opposite the spring 9 via the pressure chamber 12 with a pressure medium, preferably compressed air, so that the piston 8 is moved against the spring 9 in the direction of the stop 17. This moves the wedge-shaped guide surface, allowing the clamping block 10 to move radially inwards. For sealing against the pressure chamber 12, the piston 8 has several seals on the pressurized side, each creating a seal between the piston 8 and the clamping sleeve 1, and between the piston 8 and the clamping sleeve 7.

[0025] The clamping element 6 adjacent to the clamping sleeve 1 in the longitudinal direction has an identical construction, with the pressurized end faces of the pistons 8 positioned at a distance from each other and defining the pressure chamber 12. Thus, a coil sleeve 32 can be clamped by two adjacent clamping elements 6. To release, both pistons 8 of the adjacent clamping elements 6 are actuated simultaneously by the pressure chamber 12. For this purpose, the pressure chamber 12 is connected via a passage 13 to the annular chamber 14 formed between the clamping sleeve 1 and the axle carrier 2.

[0026] In the longitudinal direction of the clamping sleeve 1, the clamping device 5 has a plurality of clamping elements 6, each of which is identical and in which a respective pressure chamber 12 is connected via a passage 13 to the annular chamber 14 or a pressure chamber 35 in the front part of the clamping sleeves. The annular chamber 14 is coupled via several channels 33 on the circumference of the axle carrier 2 to an air supply channel, which could, for example, be formed by a bore 34 in the axle carrier 2.

[0027] A cover 16 is firmly held against the clamping sleeve 1 at the free end of the chuck. The cover 16 is dimensioned such that a pressure chamber 35 formed at the end inside the clamping sleeve 1 is sealed by the cover 16.

[0028] At the opposite end, the clamping sleeve 1 has a free end face 19, which is collar-shaped and forms a sealing surface 20 on its exposed side. Between the end face 19 of the clamping sleeve 1 and the axle carrier 2, which has a collar 28 opposite the end face 19, a shell opening 18 is formed, connecting the annular chamber 14 to the surroundings. A sliding sealing piston 21 is associated with the shell opening 18 on the axle carrier 2, by which the shell opening 18 can be selectively held open or closed.

[0029] To further explain the sealing piston 21 held in the axle carrier 2, in addition to the Fig. 2. Referenced. In the Fig. Figure 2 shows an enlarged section of the jacket opening 18 between the clamping sleeve 1 and the axle carrier 2. The sealing piston 21 has a centering projection 23 on an end face facing the end 19 of the clamping sleeve 1, which is formed axially projecting from the sealing piston 21 in the direction of the clamping sleeve 1.

[0030] The clamping sleeve 1 has an internal inner phase 31 at the end face 19, which interacts with the centering projection 23 when the sealing piston 21 is displaced.

[0031] The sealing piston 21 is ring-shaped, so that the centering projection 23 forms a closed ring. However, it is also possible that one or more parting lines could be provided in the circumferential direction of the centering projection 23.

[0032] Radially offset from the centering projection 23, a circumferential groove 36 is provided on the free end face of the sealing piston 21, in which an annular seal 22 is held. The seal 22 extends axially to a maximum height of the centering projection 23. Preferably, an offset of max. 2 mm is formed between the seal 22 and the centering insert 23 in order to ensure that, upon axial displacement of the sealing piston 21, the centering projection 23 initially engages with the clamping sleeve 1.

[0033] Opposite the seal 22 on the sealing piston 21, a sealing surface 20 is formed on the end face 19 of the clamping sleeve 1, which cooperates with the seal 22 to seal the jacket opening 18.

[0034] The sealing piston 21 has a guide end 24 on the side opposite the seal 22, which is guided in an annular space 25 of the axle carrier 22. The annular space 25 can be connected to a compressed air source via a channel 33. An inner seal 39 and an outer seal 40 are provided on the circumference of the guide end 24, sealing the annular space 25 towards the sealing piston 21.

[0035] A recess 37 is formed in the central area of ​​the sealing piston 21, in which a spring 27 is arranged. The spring 27 is supported at one end by a holder 26, the holder 26 being attached to the axle carrier 2. At the opposite end, the spring 27 is supported against the sealing piston 21.

[0036] In the Fig. 1 and Fig. Figure 2 shows the chuck in an operating situation in which several spools are clamped around the circumference of the chuck and the chuck is ready to wind a thread. In this situation, the sealing piston 21 is pressed into the annular space 25 by the spring 27, so that the jacket opening 18 is open and the annular chamber 14 is connected to the environment to relieve the pressure chambers 12 of the clamping device 5. The clamping elements 6 of the clamping device 5 are held in the clamping positions by spring force.

[0037] To remove the wound coils from the chuck at the end of a winding cycle, the drive shaft 3 is braked by the clamping sleeve 1. Compressed air is then supplied from a compressed air source, flowing first through the channel 33 into the annular space 25 and moving the sealing piston 21 towards the end face 19 of the clamping sleeve 1. The engagement of the centering projection 23 aligns the end face 19 of the clamping sleeve 1, centering it in its position relative to the axle carrier 2. The centering projection 23 of the sealing piston 21 and the inner chamfer 31 of the clamping sleeve 1 work together in this process. Subsequently, the sealing piston 21, with its seal 22, is pressed against the sealing surface 20 at the end face 19 of the clamping sleeve 1. The opening 18 between the clamping sleeve 1 and the axle carrier 2 is thus closed.

[0038] The compressed air introduced via the axle carrier 2 passes through the bore 34 and the channels 33 into the annular chamber 14. From there, the compressed air is guided further through the passages 13 into the pressure chambers 12 of the clamping device 5. This initiates the release of pressure on the clamping elements 6, whereby the pistons 8 are moved against the springs 9 and the clamping blocks 10 retract into an inner position. The coil sleeves 32, held on the circumference of the clamping sleeve 7, are free and can be pushed off the chuck. This situation is in the Fig.Figure 3 illustrates this. Centering the clamping sleeve 1 on the circumference of the axle carrier 2 ensures that the seal 22 rests uniformly against the opposite sealing surface 20 of the clamping sleeve 1 across its entire circumference. This stabilization has a particularly positive effect on the removal of the full coils, especially with very long, projecting chucks. Furthermore, the alignment of the sealing surfaces with respect to the seal achieves a high degree of tightness, so that the clamping device remains in the released position throughout the entire changeover period. This prevents premature and unwanted extension of the clamping blocks.

[0039] It should be explicitly mentioned here that the design of the chuck is exemplary. For example, the axle carrier can be manufactured as a single piece or using multi-part components. The clamping elements shown are also exemplary. Crucially, compressed air supplied via the annular chamber is required for release.

Claims

[1] Chuck of a winding machine for receiving and fixing spools and for winding threads into spools, with a projecting axle carrier (2) and a clamping sleeve (1) held on the circumference of the axle carrier (2), the clamping sleeve having a clamping device (5) on its circumference for fixing the spools (32), the clamping device (5) having several slidable clamping elements (6) each arranged between a pressure chamber (12) and a spring (9), the pressure chambers (12) being connectable to a compressed air source via an annular chamber (14) formed between the axle carrier (2) and the clamping sleeve (1), the annular chamber (14) being connected to the environment at an inner end face (19) of the clamping sleeve (1) by a shell opening (18) formed between the clamping sleeve (1) and a collar (28) of the axle carrier (2), and the shell opening (18) being slidably on the axle carrier (2) designed sealing piston (21) can be closed,which acts to seal the jacket opening (18) with a seal (22) on a sealing surface (20) of the clamping sleeve (1), characterized by , that the sealing piston (21) has a centering projection (23) on an end face facing the end face (19) of the clamping sleeve (1), which projects into the clamping sleeve (1) when the sealing piston (21) is in contact with the sealing surface (20), so that the clamping sleeve (1) is centered in its position relative to the axle carrier (2). [2] Chuck according to claim 1, characterized by , that the sealing piston (21) is ring-shaped and the centering projection (23) is formed circumferentially with or without radial separation joints. [3] Chuck according to claim 1 or 2, characterized by , that the clamping sleeve (1) opposite the centering projection (23) of the sealing piston (21) has a circumferential internal chamfer (31) which interacts with the centering projection (23). [4] Chuck according to any one of claims 1 to 3, characterized by, that the sealing piston (21) has an axially offset groove (36) on the end face of the centering projection (23) for receiving the seal (22). [5] Chuck according to claim 4, characterized by , that the offset between the end of the centering projection (23) and the seal (22) held in the groove (36) is a maximum of 2 mm. [6] Chuck according to any one of claims 1 to 5, characterized by , that a spring (27) acts between the axle carrier (2) and the sealing piston (21), which holds the sealing piston (21) in an open position. [7] Chuck according to any one of claims 1 to 5, characterized by , that the sealing piston (21) is guided with a guide end (24) opposite the seal (22) within an annular space (25) formed in the axle carrier (2), wherein the annular space (25) can be connected to the compressed air source.

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