Wire twisting device

A device for twisting multi-stranded wires having a first twisting portion comprising a supply reel carrying the wire and a first flyer bow rotatable about the axis defined by its ends. A second twisting portion, downstream of the first portion, has a second flyer bow which rotates about the axis defined by its ends. Means are provided for drawing the wire through the first portion and into the second portion and onto a take up reel. The wire is twisted in each of the first and second portions. In a preferred form of the device, a wire divergence plate, having a plurality of holes, is provided downstream of the supply reel. A convergence die is located downstream of the plate and upstream of the upstream end of the first flyer bow. The strands of wire pass separately through the holes and are brought together when passing through the die.

This invention is directed to a device which is capable of twisting a 
plurality of wire strands; more particularly for twisting electrically 
conductive wires useful as communications cables, appliance wires, 
automobile wiring harnesses, and the like. 
The prior art devices comprise a plurality of wire supply reels on which 
the strands to be twisted are separately wound. There is a take up reel 
and a rotating flyer bow. As described in U.S. Pat. No. 4,087,956, the 
feed wires from the supply reels are converged and twisted when the flyer 
bow rotates about its axis. However, such devices suffer from certain 
defects; specifically, the wires passing along the flyer bow are likely to 
be damaged when the speed of the bow is increased. Under such 
circumstances, the wires will collide with the inner surface of the bows 
and become abraded as a result. Since the strands of wire are extremely 
fine, breakage can occur, with the resultant imperfections in the final 
product. 
Moreover, such prior art devices uniformly require a plurality of supply 
reels, one for each of the intended strands. Since many stranded wires are 
made up of a large number of such strands, the necessary provision of an 
equal number of reels becomes difficult, cumbersome, and prone to tangling 
and breakage. 
SUMMARY OF THE INVENTION 
The present invention is capable of providing a group of electrically 
conductive wires with double the number of twists of the resulting 
stranded wire when compared with prior art devices. Moreover, this can be 
accomplished without the necessity of increasing the speed of rotation of 
the flyer and, therefore, avoids the tendency of the prior art devices to 
cause breakage of the strands.

DETAILED DESCRIPTION OF THE INVENTION 
As can best be seen in FIG. 1, the device of the present invention 
comprises broadly first twisting portion 1 and second twisting portion 2. 
Traction means 3 pulls the wire from supply reel 9 through first twisting 
portion 1, through and into twisting portion 2 and onto take up reel 29. 
Both twisting portions are maintained in frames 4 and 4'. 
First portion 1 comprises bearings 5 and 5' by which main shafts 6 and 6' 
are mounted on frames 4 and 4', respectively. First flyer bow 7 is mounted 
on shafts 6 and 6' and adapted to rotate thereabout. Within the volume 
defined by the rotation of flyer bow 7, supply reel 9, flyer 11, wire 
divergence plate 24 and convergence die 13 are located. 
Referring more particularly to FIG. 2, supply reel 9 carries a plurality of 
strands 53 which are taken off and pass over guide pulleys 19, 20, and 21, 
all of which are mounted on arm 18. Rotator 17, having hollow 16 axially 
therethrough, is rotatably mounted on bearings in frame 10. Strands 53 
pass through hollow 16 and individually through holes 23, 23' and 23" in 
arm 22. Strands 53 then enter convergence die 13 through hollow 12 and 
thereafter are led around sheave 14. 
The rotation of flyer bow 7 puts a twist in strands 53 to form wire 54 
which passes along flyer bow 7, around sheave 15, and out through hollow 
12'. It is then led around guide pulleys 38 and 39 and into second 
twisting portion 2 through hollow 40. 
In a manner similar to that described with relation to first twisting 
portion 1, partially twisted wire 54 passes along second flyer bow 27, 
around guide sheave 42, through hollow 43 and enters traction means 3. 
Wire 54 passes around drive capstan 35 and capstan 36 in a loop and then 
around sheave 55, through traverser 34 and onto take up reel 29. As in the 
case of first twisting portion 1, a twist is given to wire 54 by the 
rotation of second flyer bow 27. The device is powered by motor 45 through 
various belts and pulleys in a manner well known in the art and adequately 
shown in the drawings. 
FIG. 3 is an enlarged perspective view of supply reel 9 and the associated 
portion of flyer 11. Strands 53 are taken off supply reel 9 and pass over 
guide pulleys 19, 20, and 21, which are mounted on arm 18. The other end 
of arm 18 is secured to rotator 17 through which strands 53 pass. 
As can be seen from the foregoing, the present invention permits a higher 
degree of twisting per unit length of the finished wire. This is because 
the twisting portions are cumulative and, for a given speed of wire 
movement and flyer bow rotation, introduce twice the number of twists as 
are obtainable by the prior art. In addition, the invention permits the 
use of a single supply reel, rather than the large number which have been 
used previously. This reduces breakage and tangling of the strands. 
In a preferred form of the device, the relative velocity of rotation of arm 
18 is such that it is substantially equal to the peripheral speed of take 
up reel 29. In this way, the tension on strands 53 is minimized. This is 
of importance because these strands are usually extremely fine and hence 
are easily broken. 
It will be appreciated that, in the present device, the wire is twisted a 
total of four times. A twist occurs at sheave 14, sheave 15, guide sheave 
41, and guide sheave 42. If the distances between successive sheaves are 
not equal, the wire will not be twisted unless the bow rotation rate 
relative to the wire speed is adjusted. Therefore, it is a particularly 
preferred form of the device to arrange the elements in a manner such that 
the distances between sheaves 14 and 15 and guide sheaves 41 and 42 are 
substantially equal. In this manner, an even twist is provided to the 
wire. 
If the floor space for the device is at a premium, it is desirable to place 
the second twisting portion on top of the first twisting portion. This 
enables the dual device of the present invention to be located in the same 
floor space as would be required for the single devices of the prior art. 
While only a limited number of specific embodiments have been expressly 
described, the present invention is, nonetheless, to be broadly construed, 
and not to be limited except by the character of the claims appended 
hereto.