GB2043721A - Clamping chuck for a thread-winding machine - Google Patents

Abstract

A clamping chuck for use in a thread winding device, wherein a bobbin carrier (106) is removably mounted and held on an expandable chucking spindle (103) by means of swingable, elongate clamping elements (108) which are distributed about the outer circumferential mantle (104) of the chucking spindle (103) and move radially outwardly and inwardly of the mantle surface through openings (109) defining each clamping position. Two torque-producing forces (111, 112) are applied to each clamping element to cause it to swing into its clamping position outwardly of the mantle, preferably under a spring tensioned force, and another force (114) counteracts the torque-producing forces (111, 112) to return the clamping elements (108) into their retracted or release position below the mantle surface in order to change bobbin carriers. The force (114) is preferably produced by a compressed air operated annular piston ring which is slidably mounted about the chuck in an annular interspace between the spindle (103) and the mantle (104) so as to engage the clamping elements (108) which are mounted in common cages formed in the annular interspace, using a self-contained arrangement within the spindle for delivering the compressed air to the cylinder operating the piston ring. <IMAGE>

Description

SPECIFICATION Clamping chuck for a thread-winding machine A number of different chucking spindle constructions are known for securely locking bobbin carriers onto the carrying arm or winding shaft of thread winding machines. For example, so-called bartension chucks have a wide enlargement or an axially slidable cone mounted on the chucking shaft which co-operates with respect to a counter-cone arrangement. In securing the bobbin carrier to the chucking device, the counter-cone is moved radially outward by shifting the axially slidable cone thereby gripping the bobbin carrier thereabout.

However, such cone-type chucking spindles have the disadvantage that a slide fit is required between the chuck shaft and the cone. This slide fit is of a very complicated design since otherwise, after a relatively short operational period, jamming and rusting inside the slide fit would occur, thereby taking the entire chucking spindle out of operation.

In order to overcome these drawbacks found with cone-type chucking spindles, clamping elements that operate according to the so-called "freewheeling" or coasting principle having been developed.

An example of such a chucking spindle is disclosed in U.S. Patent No. 3,815,836. Such chucking spindles are especially advantageous in that the clamping elements thereof are self-locking so that even with the introduction of high torsional or braking forces the bobbins will remain securely clamped.

However, in spite of the mechanical advantages of such "freewheeling" chucking spindles, several operational difficulties have been encountered in their use. Since the mounting and removal of the bobbin carriers takes place by means of turning them by hand in orderto disengage the clamping elements of the device while simultaneously moving the carriers axially on or off of the chucking shaft, if several bobbin carriers are arranged in axial succession on a single chucking spindle, the rearmost bobbin carrier must be slid over all of the front clamping zones in order to mount or remove it. Hence, with great care the bobbin carrier must be constantly rotated by hand from the front to back of the chuck shaft as it is slid thereon and this process must be again repeated when it is removed.

The chucking spindle of the present invention has been developed in part to take advantage of the desirable self-locking features of the known "freewheeling" spindles, while at the same time avoiding the above-described disadvantages of conventional chucking spindles.

According to the present invention there is provided a clamping chuckforathread-winding machine, for the reception of a removable bobbin carrier, wherein said chuck comprises a chucking spindle; a cylindrical mantle sleeve mounted concentrically about said spindle and having an inner diameter greater than an outer diameter of said spindle over at least a substantial portion of the total length of the chuck so as to define an annular cylindrical interspace between said sleeve and said spindle; a plurality of elongate clamping elements situated within said interspace and radially supported by the spindle with openings in said mantle sleeve for the radial passage therethrough of each clamping element, the clamping elements being arranged to swing in a substantially axial plane of the chuck, each clamping element having an outer clamping end which is movable radially of its sleeve opening between an extended position for gripping the bobbin carrier and a retracted position for releasing the bobbin carrier, an inner thrust end free to slide while supported by the spindle and a force directing slide cam edge between said outer clamping end and said inner thrust end, said cam edge being in sliding contact directly or via a projection with an opposing slide surface within the sleeve and spindle combination so as to provide a radially directed component of force; means for exerting two forces on each clamping element to cause a swinging movement into its extended clamping position, one force being applied in the area of said thrust end and the other force being applied in the area of the slide cam edge, each of said two forces being directed axially parallel of the chuck and opposite to one another and at a radially spaced distance from one another so that the two forces on the clamping element combine to exert a torque acting in the axial plane so as to swing the clamping element into its radially extended clamping position; and means for counteracting said two forces to return each of said clamping elements to its retracted position.Since, the means for counteracting the said two forces (hereinafter referred as the activating means) is formed as a part of the chucking spindle, no external aids are needed to slide the bobbin carrier on or off of the device and it is immaterial whether such sliding of the bobbin carrier is carried out manually or by machine. Furthermore, since the working elements of the actuating means are integrated as a part of the rotating chucking spindle, no imbalance problems can arise during and after operation of the device.

The arrangement of the present invention may conveniently adapted for use with chucking spindles with clamping elements which operate according to the "free-wheeling" or self-locking principle. Such an embodiment is especially desirable in that while all of advantages of the "freewheeling" principle are utilized, atime-consuming and impractical steady rotary and axial movement of the bobbin carrier about the chucking spindle is not required in order to remove or slide on the bobbin carrier which is a particular problem where several bobbin carriers are used on one long chucking spindle. As has been noted since the clamping force on these elements is unaffected by the present invention, their independent operation according to the "freewheeling" priciple is fully preserved.

If it is not desired to construct the chucking spindle according the "freewheeling" principle, the present invention can be used in other types of chucking spindles. For example, kidney-shaped clamping elements which are very simple to produce may be used. The clamping force exerted by such elements may be made dependent upon a spring force that will allow automatic adjustment for different forms and sizes of the bobbin carrier.

A lug formed on the actuate slide surface of the clamping elements may engage the actuating means and also serve as a stop both in the extended direction of the elements when no bobbin carrier is place about the chucking spindle and in the fulls retracted position of the clamping elements. Hence, in this simple mannerthefunctioning of the clampir g elements is always ensured.

Since, the clamping elements immediately abut the chucking spindle, it may be formed entirely in a cylindrical shape. Furthermore, in contrast to bar tension-type chucks, fewer elements are moved during the tensioning and releasing of the clamping elements, thereby making the production of such chucking spindles more economical and their security in operation greater.

A substantial facilitation in the assembling and a further increase in the functional security of the device is provided by arranging the clamping elements of the chucking spindle in a common cage.

This ensures that all of the clamping elements of a clamping place are operated simultaneously and uniformly, thereby achieving a coaxial relationship between the bobbin carrier and chucking spindle.

By providing a winding groove which cooperates with tie s-r:tL'ating means, the thrust component of ilas BCEUi;pjjili measls which is axially parallel to the r;xis oP QCic ChSuCking spindle may be transformed into a rotary movement with respect to said cage. This construction has the advantage that only one translational movement is performed by the actuating means and the necessary rotary movement is achieved through the construction of the actuating means itself.

It has been found that connecting the cage elements to the actuating means, which may be an annular piston ring slidably mounted about the chucking spindle, by means of axially parallel guide elements and forming the winding groove in the inner circumference of the piston ring for cooperation with a guide ball fixed to the outer circumference of the chucking spindle has proven to be successful as a manufacturing technique for transforming the axial movement of the piston ring into a rotary movement of the clamping elements.

The actuating means may be operated electrically, hydraulically, pneumatically or by similar suitable drive techniques. In the preferred embodiments described beiow, a pneumatically operated actuating means is used. In order to simplify the construction of the device, a torsion spring may be used to create a force which normally brings the clamping elements into their extended position. Hence, it is necessary that the actuating means exert thrust in only one direction of travel in order to bring the clamping elements into their released position.

A preferred embodiment has a means for sealing the ends of the compressed air-carrying annular gap between the chucking spindle and carrying arm, which sealing means consists of an annular piston ring mounted for axial r:lovement in the machine frame whicn is actuated by the compressed air supply prior to the air being supplied to the actuating means for the clamping elements. This arrangement has the advantage that no wear of the sealing elements is experience during operation of the tread winding machine since it is only engaged when the bobbin carri r and chucking spindle are at a standstill.

A choke may be placed in the compressed air feed line in order to create a time lag in the air pressure build up between the resulting subdivisions of the line. In this manner, the sealing elements may be operated first before air is supplied to the actuating means for the clamping elements. Hence, no air leakage will occur so that all of the clamping elements of the chucking spindle will operate simultaneously.

As a final point, in order to prevent the bearings which support the chucking spindle upon the carrying arm from having their lubricantforced out when compressed air is introduced to release the clamping elements, the air is preferably simultaneously supplied at substantially equal pressure from both sides of the bearings. Hence, the compressed air does not flow through the bearings in orderto reach the individual actuating means for the clamping elements and no lubricant is thereby dragged away. In addition, no special sealing of the bearings from the compressed air is necessary.

In the accompanying drawings: FIGURE 1 is a schematic view in axial cross-section of an embodiment of a chucking spindle arrange ment,taken through a partial segment of the spindle shaft with circumferential drive; FIGURE 2 is a schematic view in axial cross-section through a chucking spindle shaft of another embodiment of the invention.

FIGURE 1 illustrates only the centre portion of the chucking spindle assembly in a schematic axial cross-section. On a machine frame 1, (see FIGURE 2) there is rotatably fastened about a projecting carrying arm 2 (again as shown in FIGURE 2) the particular chucking spindle 103 shown in FIGURE 1. At several axially separated positions of the mantle sleeve 104 of the chucking spindle 103, there are arranged clamping positions 105 so as to carry the spool or bobbin sleeve 106 on which the thread material 107 is spooled or wound.

The individual clamping positions 105 each consist essentially of a clamping element 108 having an elongate structure which at its pushing or thrust end 1081 is supported on the spindle 103 and which at its other end, the clamping or gripping end 1082, is radially passed through or positioned to move out wardlythrough an opening 109 in the mantle sleeve 104. The mantle sleeve 104 has a larger diameter than the spindle 103 and is arranged concentrically and coaxiallythereto so as to provide an intermediate annular space between the spindle 103 and the sleeve 104 for insertion of the clamping elements 108 which lie essentially in one axial plane, i.e. a plane extending through the axis of the spindle 103.

Each clamping element 108 is also free to swing or pivot for movment in the opening 109, i.e. between an extended position to secure the spool or bobbin sleeve 106 to the chuck and a retracted position in which the spool or bobbin sleeve 106 is released from the chuck.

By means of a thrust element 110 arranged to slide in the annular space between the spindle 103 and the mantle sleeve 104, a pushing force is exerted on the thrust end 1081 of the clamping element 108 in the axial direction of the chuck as illustrated by the arrow 111. As a result of this thrust or pushing movement 111, the clamping end 1082 of the element 108 moves outwardly from the opening 109 due to the fact that the slide edge connecting the thrust end 1081 and clamping end 1082 of the clamping element 108 slides along the opposing slanted surface of the mantle sleeve 104 with a radially directed component of movement.Two forces are thus imposed on the clamping element 108 to achieve the desired extended clamping or gripping movement: first, the thrust force 111 at the thrust end 1081, and second, the opposing force 112 against the slide edge where it comes in sliding contact with the slanted surface of the mantle sleeve 104. These two forces 111 and 112 run axiallyparal- lel with reference to the chuck axis but in opposite directions and are spaced at a radial interval from each other; therefore, these two forces exert a tor queorturning moment on the clamping element 108 in the axial plane, as illustrated by the arrow 113.

ThIr torque rotates or pivots the clamping element loa so that it is forced outwardly of the mantle sleeve 104 in a radial direction, thereby securely clamping or gripping the bobbin sleeve carrier 106.

The clamping movement of the element 108 imparted by the applied torque is equivalent to the forcing of a wedge between the spindle 103 and the spool or bobbin sleeve 106. The amount of the torque can be readily adjusted so as to accomodate winding spools or bobbins of various sizes and weights, e.g. by selecting a suitable spring means or the like to exert the required force 111 against the thrust element 110.

In order to release each clamping position, it is necessary to exert a force in the direction of the arrow 114 by means of another thrust element (not shown) which counteracts and over-balances the preselected spring force or the like 111 causing the clamping element 108 to drop radially inwardly away from the inner surface of the spool or bobbin sleeve 106. This counteracting thrust element is Preferably applied as indicated against the striking edge of a lug, this striking edge lying approximately in a plane perpendicular to the spindle axis.

Instead of striking this lug with a thrust element, it may also be connected by a lever arm to a piston actuated by pneumatic pressure or the like. However, since a plurality of two or more clamping elements are often preferably arranged at the same axial position around the circumference of the spindle, the thrust element acting with the force 114 is most easily constructed as a ring projection on an annular piston head sliding in the space between the mantle sleeve 104 and the spindle 103. Each lug is thus contacted by such a ring projection at the same instant as the common piston is moved axially in the direction 114.

In the further embodiment of a chucking spindle arrangement according to FIGURE 2 the carrier arm 2 is fastened to project from the machine frame 1. On this carrier arm 2, the chucking spindle 203 is rotatably mounted by insertion of bearing bodies 3, i.e.

suitably positioned bearing elements on which the spindle 203 is supported for rotation. Between the carrier arm 2 and the spindle 203, an annular gap 4 is present and extends over most of the length of the spindle. This annular gap 4 is again connected via several radially arranged channels 4.1 with a distributor channel 4.2. It is also preferred in this embodiment to arrange the connecting channels before and after the bearing bodies 3, this arrangement preventing the lubricant of the bearings from being washed out by a one-sided airflow therethrough.

At a plurality of axially spaced positions along the circumference of the chucking spindle 203, the clamping positions 205 are arranged with the specific clamping elements 208. These clamping elements may carry one or several bobbins or spools so that their number and arrangement are determined by the number and length of the bobbin carriers being inserted onto a chucking spindle.

Each clamping element 208 is inserted into the intermediate annular space formed by the spindle 203 and the mantle sleeve 204, thereby providing each of the clamping positions 205. A convexly arced or bowed slide cam edge 2083 of the clamping element 208 is positioned in the mantle sleeve opening 204 for contact with the opposing sliding surface 2091 of said opening, the clamping element in this case being shown in its retracted or non-clamping position. By means of the thrust force exerted in the axial direction by a thrust element 210 on the cammed thrust side 2081 of the clamping element 208, the extendable gripping end of the element 208 is moved radially outwardly of the opening 209 to come in gripping contact with a bobbin tube or sleeve (not shown) mounted about the mantle sleeve 204.This axial movement of the thrust element 210 into the clamping or gripping position is effected by the spring force of the spring 215. By means of a peg-shaped enlargement of the clamping element 208, which forms the thrust side 2081, the swinging or pivoting movement of the clamping element 208 in the intermediate space between the outer circumference of the spindle 203 and the inner circumference of the mantle sleeve 204 is accomplished substantially without any radial play.

On the side of its sliding edge 2083, the clamping element 208 has a nose 2084 adapted to be contacted and moved axially of the spindle by a ring piston 217 acting to release the clamping tension or force when the piston 217 moves to the left as shown in FIGURE 2. The contacting surface 2171 of ring piston 217 lies in a plane normal to the spindle axis, extending between the spindle 203 and the mantle sleeve 204, and can be moved in direct opposition to the chuck engaging movement of the thrust element 210 by using a suitable force transmitting means. For example, a pneumatic ring piston and cylinder unit is preferably used to transmit force sufficient to counteract and overbalance the spring force of spring 215 in releasing each clamping element, i.e. to retract each element 208 to its release or non-clamping position.The front side of the ring piston 217, which fills the space between the spindle 203 and the mantle sleeve 204, thus forms the release actuating contacting surface 2171.

For each clamping element 208, a cage 218 is formed consisting of the ring piston 217 and thrust element 210 as one piece such that its end faces or walls, facing the clamping element, form the boundary of the cages.

The ring piston 217 is loaded by a pressure medium from the annular gap 4 via the connecting channel 5 and a cylindrical space 6. The space 13, which is used for driving or actuating the ring piston 217 and which cooperates with this piston 217 to form the piston-cylinder unit 216, is closed in radial direction by the mantle sleeve 204 which consists of individual segments whose total length corresponds to the spindle 203. In axial direction, the space 6 is preferably limited by another ring piston 217 such that at least two sets of clamping elements are acted upon by the same pressure-actuated system.

At the end of the chucking spindle 203 attached to the machine the annular space or gap 4 is capable of being closed or sealed off by additional ring pistons 7 which is movably arranged on the machine frame 1 or on the carrier arm 2. On the face of the ring piston 7, opposite the rotating spindle 203, an O-ring 8 is constructed as a sealing member which can be pushed by the piston 7 against the end of the spindle 203 and withdrawn again so as to close off or open up the annular space 4.

The annular space 9 associated with the ring piston 7 is supplied with a pressure medium via the bores 4.3 from a central supply channel 4.4. The fluid such as compressed air can be supplied through the channel 4.4 as required by using any conventional control valve means. The piston 7, is held in its initial open or retracted position by a plate spring 10, so that the pressure medium is free to escape from the annular gap 4 and the remainder of the pressurized system. When compressed air or other pressurizing fluid is supplied through the supply channel 4.4, part of the pressurized stream is directed through the bores 4.3 into the annular space 9 to actuate the pistons 7, thereby sealing off the annular space 4 and permitting the other pressurized stream to act through the distributor channel 4.2.A choke 11 provides a transition point between the feed or supply channel 4.4 and the distributor channel 4.2.

In order to achieve a uniform outward movement of the clamping elements, it is desirable to distribute several engaging springs 215 about the circumference of each ring 210.

It is also possible to form ring 310 and piston 217 as one structural element in which an opening is madeforthe reception of the clamping elements 208. In this embodiment, the spring-tensioned ring 310 and annularpiston 217 are combined to create the cage 218 for the reception of clamping elements 208, this cage simultaneously functioning as a thrust element for the actuating means. Radial openings or slots with two end walls extend through this onepiece ring piston from spindle 203 to sleeve 204 to receive the clamping elements 208. Hence, in this manner, the structural parts necessary for the operation of the clamping elements are reduced to a minimum.

Claims (16)

1. Aclamping chuckforathread-winding machine, for the reception of a removable bobbin carrier, wherein said chuck comprises a chucking spindle; a cylindrical mantle sleeve mounted concentrically about said spindle and having an inner diameter greater than an outer diameter of said spindle over at least a substantial portion of the total length of the chuck so as to define an annular cylindrical interspace between said sleeve and said spindle; a plurality of elongate clamping elements situated within said interspace and radially supported by the spindle with openings in said mantle sleeve for the radial passage therethrough of each clamping element, the clamping elements being arranged to swing in a substantially axial plane of the chuck, each clamping element having an outer clamping end which is movable radially of its sleeve opening between an extended position for gripping the bobbin carrier and a retracted position for releasing the bobbin carrier, an inner th rust end free to slide while supported by the spindle and a force directing slide cam edge between said outer clamping end and said innerthrustend, said cam edge being in sliding contact directly or via a projection with an opposing slide surface within the sleeve and spindle combination so as to provide a radially directed component of force; means for exerting two forces on each clamping element to cause a swinging movement into its extended clamping position, one force being applied in the area of said thrust end and the other force being applied in the area of the slide cam edge, each of said two forces being directed axially parallel of the chuck and opposite to one another and at a radially spaced distance from one another so that the two forces on the clamping element combine to exert a torque acting in the axial plane so as to swing the clamping element into its radially extended clamping position; and means for counteracting said two forces to return each of said clamping elements to its retracted position.

2. A clamping chuck as claimed in Claim 1, including a thrust element arranged to be pressed in axial direction by a force transmitting means to act on the thrust end of said clamping element.

3. A clamping chuck as claimed in Claim 3, wherein the thrust is arranged to be pressed in axial direction by a resilient spring force acting on the thrust end of said clamping element to move it into the clamping position.

4. A clamping chuck as claimed in Claim 3, wherein said opposing slide surface is arranged to be pressed into the retracted position of the clamping element by an adjustable force transmitting means to counteract said spring force on said thrust element.

5. A clamping chuck as claimed in Claim4, wherein said force transmitting means is a pneumatic ring piston-cylinder unit.

6. A clamping chuck as claimed in claim 5, wherein said movable opposing slide surface is provided by the front face of the ring piston which is slidingly inserted in said annular interspace between the mantle sleeve and the spindle to form the pneumatic unit.

7. A clamping chuck as claimed in Claim 1 wherein said opposing slide surface is formed by one side of the opening of the mantle sleeve which contacts the slide cam edge of said clamping element as it lies on the edge of the sleeve opening, and wherein a thrust element exerting a thrust force to swing the clamping element into its clamping position is axially movable with reference to the chuck so that the clamping element is urged radially outwardly of the sleeve opening.

8. A clamping chuck as claimed in Claim 7, wherein the slide cam edge of the clamping element is in the form of a convex arc.

9. A clamping chuck as claimed in Claim 7 or 8 wherein the thrust element is pressed into the clamping position by a resilient spring force.

10. Aclamping chuck as claimed in any of Claims 7 to 9, wherein the thrust end of the clamping element as seen in its swinging plane is thickened with a peg shape in such a manner that the positioning of the clamping element between the outer circumference of the spindle and the inner circumference of the mantle sleeve as well as its swinging movement impa r;ted by the thrust element can be accomplished substantially without radial play.

11. A clamping chuck as claimed in any one of Claims 7 to 10, wherein said clamping element has a nose at the lower end of its sliding cam edge, said nose being arranged for contact with a tension releasing surface which is movable in axial direction and which is carried between said mantle sleeve and said spindle in a plane perpendicular to the chuck axis, and said tension releasing surface being engaged for movement in its axial direction by said means for counteracting the two torque producing forces, thereby returning the clamping element to its retracted position.

12. A clamping chuck as claimed in Claim 11, wherein said means for counteracting the torque producing forces includes a force transmitting pneumatic ring piston and cylinder unit.

13. A clamping chuck as claimed in Claim 12, wherein said tension releasing surface is the front face of said ring piston which occupies an axial segment of the interspace between the spindle and the mantle sleeve.

14. A clamping chuck as claimed in Claim 13, wherein the ring piston and the thrust element consist of one piece and form the facing end walls of a cage containing each clamping element.

15. A clamping chuck as claimed in Claim 14, wherein the cage is pressed on one side of a resilient spring force for movement into its clamping position and is pressed on the other side by pneumatic means into its retracted position for release of the bobbin carrier.

16. A clamping chuck substantially as herein described with reference to Figure 1 or Figure 2 of the accompanying drawings.