Method and device for manufacturing a cable

BACKGROUND OF THE INVENTION

The present invention relates to a method for manufacturing a cable having one or more wire-layers positioned around a core in which the wires run according to a three-dimensional serpentine pattern and in which the wires are fixed in their position by a wrapping or sheath applied after the wires are properly positioned. Such rnethods are generally known (see German Pat. No. 610,650, 682,267 and 631,629). According to these known methods, a number of wires are guided to a lay-nipple through a lay-disc. The lay-disc performs a rotating movement in alternating directions of approximately 360° so that the single wires are laid around the core by a repeatedly alternating S or Z lay. This lay forms a three-dimensional serpentine pattern, i.e. a serpentine pattern running according to a cylindrical plane and, therefore, being three-dimensional. The wave length or pitch of the lays is determined both by the angular ₄θ velocity of the lay-disc and by the velocity of movement of the core.

SUMMARY OF THE INVENTION

The object of the invention is to provide a novel method for the manufacture of a cable whereby it is possible to achieve a short wave length in an incomplex manner.

According to the invention, the above object is achieved by manufacturing a mat from wires running parallel to each other in a serpentine pattern and in the direction of the cable. The mat is folded over the core in such a way that the wave tops of one edge fit into the troughs of the other. The mat is then fixed in this position.

The manufacture of a mat from wires running in a serpentine pattern is effected by leading each wire through a wire bending device and then guiding all the wires, bent in the desired pattern, towards each other in such a manner that a mat is formed. According to another embodiment of the invention, the mat is manufactured from a layer of straight wires running parallel to each other, said layer being deformed into a wave form, transverse to its plane, after which the waves are bent into a common plane. This latter method simplifies the invention since only one bending device is needed for deforming the wires into a wave form and since the bending of same can be achieved with a common guide device for all wires. In accordance with this second embodiment of the invention, the wires are kept in a parallel relation by means of cross wires or straps, such as weft wires or transversely adjusted sealing strips. The weft wires are advantageously arranged at mutual distances from each other in such a manner that with the deformation in wave form, the weft wires are at positions where a number of wave tops appear. This simplifies the bending operation.

Another object of the invention is to provide a device for carrying out the methods enumerated above. In accordance with the invention, the device consists of a pair of meshing gears or cages for deforming a layer of parallel wires, a guide block for bending the deformed wires into a plane, guide means for guiding to the layer of wires, or mat, a core to be enclosed, a guide device for folding the mat over the core, and a device for closing the layer folded over the core. The device for bending the deformed mat consists of a flat sleeve having an entrance section in the form of a parallelogram, the entrance section passing gradually to an exit section in the form of a flat rectangular passage.

The closing device, well known in the art, helically folds a strip of material over the wire-wound core. However, this device may also consist of an extrusion device for providing a closed sheath around the layer.

In addition, it is possible to press the folded mat into shape by the means of a clamping strap such as that described in U.S. application Ser. No. 789,819, filed Jan. 8, 1969. The clamping strap gives the advantage that the wave tops, which protrude slightly after being folded, are bent in the cylindrical plane. Said strap can be driven, if necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified schematic side elevation of the cable winding machine of the present invention.

FIG. 2 is a top elevation of the device shown in FIG. 1.

DESCRIPTION OF THE INVENTION

With reference to FIGS. 1 andl 2, a layer or mat of parallel wires 1 is deformed into a serpentine pattern 3 between toothed elements 2 which mesh together. Thus, each wire takes on a serpentine wave shape wherein the waves lie in parallel vertical planes. A guide block 4 receives the deformed mat and serves to bend, or flatten, the waves in such a manner that they become planar as indicated at 7 in FIG. 2. The mat of waved wires then meets a cable or core 6 and is folded over the core 6 in a bent guide plate 5 in such a way that the wave tops of one edge fit into the troughs of the other. The above operations result in a closed sheath having substantially the same appearance as a sheath obtained with a prior art lay-disc rotating in alternate directions. However, the wave length may here be made considerably shorter. This is indicated at 8.

It should here be noted that the guide block 4 serves to flatten and make planar the deformed unit of wires by means of its particular shape. More particularly, the guide block 4 consists of an entrance section in the shape of a parallelogram. The top and bottom sides of the parallelogram are positioned to form sharp angles with the direction in which the planar pattern of wires is deformed by the meshing gears 2 and the entrance section smoothly transforms into a rectangle moving in the direction toward an exit section. In this manner, the guide block 4 tends to rotate the plane of each serpentine patterned wire by 90°. _Λ

The cable obtained in the above-outlined manner then runs through an extrusion device 9 and leaves some having a sheath 10 thereover. As an alternative to or in addition to the extrusion device 9, a strap 12 may be helically folded over the wires, said strap 12 serving to maintain the layers of wire in place. As is best seen in FIG. 2, the strap 12 is helically applied to the wire-covered core in a wire frame 13, said frame 13 capable of being driven by means not shown.

3,545, 3

As seen in FIG. 2, the mat may be provided with weft wires 11 positioned along the wires 1 at the wave tops thereof.

There has been described a method and a device for winding a multi-wire cable, the cable comprising a plu- ₅rality of three-dimensional serpentine wires housed on a central core. It should be understood that the description given above is for exemplary purposes only and that there are many modifications and alterations which will become apparent to those skilled in the art and which can be iq practiced without departing from the spirit and scope of the invention.