GB2177729A - Winding device - Google Patents

Abstract

Retaining device having a drivable shaft (3) for accommodating a spool (8) having two flanges (10) running parallel to each other. There are secured to the shaft (3) two discs (4, 5) to bear against the external face of the two side-walls of the spool (8). These discs have, in the region of their internal faces (14) turned towards each other, bores (15) connected via lines (11) to a source of reduced pressure. Reduced pressure applied during winding holds the spool flanges from deflecting in words under the weight of wound material. <IMAGE>

Description

SPECIFICATION Coiling device The invention relates to a coiling device having a rotatable shaft for accommodating a spool or cylinder having a side-wall or flange at either end thereof running parallel to each other.

During the coiling of spools or cylinders, especially those formed from plastics material, the tension of the material to be coiled, which is necessary for accurate coiling, results in forces acting radially on the spool core. As the number of coil layers increases, these forces bring about a central sinking or a reduction in diameter of the spool core which, in turn, causes the two spool side-walls to be deflected inwards, the amount of deflection being greater, the greater is the length of the spool or cylinder. As a result of such a reduction of the spacing of the side-walls, the width of the coil layer becomes, disadvantageously, ever smaller towards the outermost coil layer.

There is already known, according to FR-PS 91 4 703, a retaining device for such flanged spools. This has two discs that can be pressed against the flanges of the spool and sit on a drivable shaft. Such a device does not, however, make it possible to achieve a uniform width for each coil layer of the spool.

The object of the present invention is to provide a coiling device that ensures a uniform width for each coil layer of the spool.

In accordance with the present invention, there is provided a retaining device for a spool or cylinder having a pair of spaced flanges thereon, comprising two discs which can be pressed against the outer faces of the flange of the spool or cylinder and which are mounted on a drivable shaft; the discs having bores in their opposing faces that can be connected to a source of reduced pressure.

The problem outlined above is solved according to the invention in that the discs have, in their opposing faces, bores that can be connected via lines to a source of reduced pressure. By means of these bores adjacent the side-walls or flanges of the spool or cylinder, the side-walls or flanges can be drawn by suction against the discs of the coiling device.

In this manner, regardless of the radial forces acting on the spool core, inwards deflection of the side-walls or flanges of the spool is reliably prevented and a uniform width is achieved for each coil layer. As soon as the coil has been completed, the vacuum can be disconnected for removal of the spool, the layers of the coil preventing any subsequent inwards deflection of the side-walls.

A preferred embodiment of the invention comprises providing on the opposing faces of the discs an annular groove into which the bores open. By means of such an annular groove, uniform suction can be applied to the side-walls or flanges of the spool over the entire circumference so that even in the case of strong radial forces acting on the spool core, a reliable fixing of the side-walls of the spool is ensured.

A further advantageous embodiment of the invention provides that the annular groove communicates via at least one bore running radially in the disc with an axial bore that runs in the longitudinal direction of the shaft and connects the radial bores of the two discs to each other. Such an arrangement of the connection lines to the vacuum pump prevents any possibility of damage or impairment of the lines and thus ensures a high degree of operational reliability.

Finally, a further preferred embodiment of the invention comprises providing a pair of sealing rings, one either side of each annular groove, which project beyond the face of the disc. Such a design ensures, even in the case of rough or unevenly worn surfaces on the side-walls of the spool, a close fit against the adjacent disc producing secure clamping of the spool.

The invention is described on detail below with regerence to an embodiment shown in the drawing.

A coiling device 1 is shown partially in longitudinal section and partially in side view and comprises a shaft 3 that can be set in rotation by a motor 2. Discs 4, 5 are mounted on the shaft 3 such that they are spaced from each other and the motor 2. At the free end of the shaft 3 there are provided a spacer 6 connected to the lefthand disc 4 and a tensioning nut 7. To push an empty spool 8 onto the shaft 3, the tensioning nut 7 is removed from the shaft and then the spacer 6 together with the lefthand disc 4 is pushed off the shaft 3. As soon as the spool 8 comprising the spool core 9 and two side-walls 10 running parallel to each other (for the sake of clarity shown only in the upper half) has been placed on the shaft 3, it is fixed by pressing the lefthand disc 4 against the spool 8. There is provided in each disc 4, 5 a bore 11 which runs radially and is sealed in the region of its outer end by a plug 12. In the radially inner end region there is formed a connection to an axial bore 13 running in the longitudinal direction of the shaft 3, which bore is connected, for its part, to a vacuum pump (not shown).

In the region of the internal face 14 of the two discs 4, 5 there is arranged an annular groove 15, each adjacent area being sealed by an O-ring 16.

As soon as the coiling operation begins, the annular groove 15 of the two discs 4, 5 is placed under vaccum, whereby the side-wall 10 of the spool 8 can be held close against the internal face 14 of the discs 4, 5 during the entire coiling operation. This ensures that the same width is achieved for each layer of the coiled material.

Claims (5)

1. A retaining device for a spool or cylinder having a pair of spaced flanges thereon, comprising two discs which can be pressed against the outer faces of the flange of the spool or cylinder and which are mounted on a drivable shaft; the discs having bores in their opposing faces that can be connected to a source of reduced pressure.

2. A device as claimed in Claim 1, wherein annular grooves are provided on the opposing faces of the discs into which the bores open.

3. A device as claimed in Claim 2, wherein each annular groove communicates via at least one bore running radially in each disc with a further bore provided axialiy is said shaft and connecting the radial bores of the two discs to each other.

4. A device as claimed in Claim 2 or 3, wherein a sealing ring is provided on either side of each groove, said sealing ring projecting beyond the face of the disc.

5. A device as claimed in Claim 1 which is substantially as herein described with reference to the accompanying drawing.