GB1593352A - Twisting machine for twisting together strands of elongate material - Google Patents

Description

(54) TWISTING MACHINE FOR TWISTING TOGETHER STRANDS OF ELONGATE MATERIAL (71) We, VEB SCHWERMAS CHINENBAU-KOMBINAT ERNST THALMANN MAGDEBURG, a body corporate organised and existing under the laws of the German Democratic Republic, of 20 Marienstrasse, 3011 Magdeburg 11, German Democratic Republic, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a twisting machine for twisting together strands of elongate material.

Twisting machines are known which operate without untwisting and have pay-out spools which are arranged either coaxially of or axially parallel to the centre axis and/or tangentially to the periphery of the twisting machine rotor and the wires are guided to the twisting station from the individual pay-out spools via a guidance system, such as guide rollers, nipples and tubes.

The twisting together of soft wires such as copper and aluminium takes place almost exclusively on basket-type twisting machines which operate without untwisting.

Various constructions of such twisting machines are known, whereby they differ in particular in the arrangement and mounting of the spools on the twisting rotor. Thus, there are twisting machines on which the spools are mounted interchangeably in axially parallel manner to the rotor axis or tangentially on the rotor periphery. In the third construction form, the spools are placed concentrically and successively on the twisting machine axis. In this case, the spools cannot be changed without dismantling the twisting machine and/or the twisting rotor. The latter twisting machine must be considered as the latest design and consequently constitutes a prototype for further designs, although the apparatus according to the invention can also be used on other known twisting machine types.

A twisting machine is known in which the pay-out spools are mounted successively and concentrically on a hollow shaft and are associated in pairs with a wire removal arm.

The wire removal arm removes the wire from the full spool of the pair of spools and feeds it via guide pulleys to the interior of the hollow shaft where it is fed by tubes arranged coaxially in the shaft to a rotary lay plate and from there to the closing die. A closing die secures the converging wires and terminate the twisting about their longitudinal axis. Thus, each individual wire is twisted once about its longitudinal axis during each revolution of the rotor. The zone between the inner guide pulley and the closing die is the torsion zone for the individual wire and this can be of considerably varying length, even for the single wire, due to the arrangement of the spools.

However, the length of the twist is only part of the torsion zone, and has different magnitudes due to the varying distances of the spools from the closing die. If the wire to be twisted comprised a completely homogenous structure and a completely identical cross-section over its entire length, the torsion (twisting) of the wire would be uniform over the length of twist. However, as the wire frequently has cross-sectional variations due to flaws and overlaps, whilst the characteristics of its structure are not always identical, there is also a variation in its section modulus. Thus, at its weak points (flaw or constrictions) the wire is twisted several times. This leads to wire cracks, which occur particularly frequently if there are bending stresses due to deflection.

Similar conditions also occur with the other known twisting machines operating without untwisting and in which the torsion zone is longer than the length of twist.

According to the present invention there is provided a twisting machine for twisting together strands of elongate material, including a rotary lay plate located upstream of a closing die in the direction of movement of the elongate material, and rollers carried by said rotary lay plate, each roller being located between the rotary lay plate and the closing die and positioned as close to said die as is possible so that a strand to be twisted can be passed around a single said roller through a looping angle of 2 z radius or less before passing to the closing die and so that the distance between the pay-off point of each roller and the stranding point of the die is as small as possible, said roller limiting the self-twist in the strand to the length of strand between the roller and the closing die.

According to an embodiment of the invention, in order to shorten the distance between the rollers and the centre axis of the cable and the consequently necessary restriction of the roller width, guide pulleys are associated with the rollers in order to prevent the wire crossing on the rollers.

Another possibility of reducing the torsion zone comprises positioning the rollers so close to the closing die that the pay-out angle of the "'ire. relative to the twisting axis, is 90", the intake side of the closing die having a curvature of 9() , the torsion zone eommellcing in the area of the curvature and terminating at the closing die.

Some embodiments of the invention will now he described, by way of examples. with reference to the accompanying drawings, in which : Figure I is a side view, partly in section, of a twisling machine according to the present invention with spools mounted conccntrical- ly on a hollow shaft, Figure 2 its a section view of the rotary lay plate and the closing die of the machine of Figure 1, Figure 3 is a front view of the rotary lay plate shown in Figure 2, F4ere 4 is another embodiment of a rotary lay plate, Figttre 5 is a section through a rotary lay plate with compression rollers positioned in front of it ftrming the closing die, 1;jgtiro 6 is a front view of the compression rollers of Figure 5, and Figure 7 is a section of a further embodi nient of the rotary l;iy plate and the closing die partly in section.

The twisting machine shown in Figure 1, comprises a hollow rotatable shaft 12 mounted in bearing supports 11, on which shaft 12 spools 13 arranged in pairs are concentrically and successively positioned.

A wire removal arm 2 with guide pulleys 14, 15, 16 is arranged on the hollow shaft 12 between each pair of spools 13. The wires 9 from the spools 13 are fed to a rotary lay plate 5 by means of a wire guidance system 4 which comprises individual tubes extending in an axially parallel manner within the hollow shaft 12. The lay plate 5 is rotatable with the shaft 12. For each wire 9, except the core wire, a roller 1 is provided, mounted by means of a mounting support 7 at the front end of the lay plate 5. Wire 9 is placed around said roller 1 with the looping angle of approximately 2n radians. From there the wire 9 passes into a closing die 3 where the wires 9 are twisted together.

Detail Z shown on Figure 1 can be as shown in Figures 2 to 5 which illustrate possible alternative designs of the area from the lay plate 5 up to and including the closing die holder 17. Thus, according to Figure 2, a roller 1 is provided for each wire 9 to be twisted (with the exception of the central core wire), each roller 1 being mounted at the front end of the lay plate 5 by means of a mounting support 7. Wire 9 passes through the lay plate 5 through a guide nipple 18 and is placed once round the associated roller 1 and is then inserted into the opening of the closing die 3. The closing die 3 and closing die holder 17 are located so close to the rollers 1 that the freedom of rotary movement of the latter is just ensured.The rollers 1 are laterally bounded by guide plates 6 which are in turn fixed to the associated mounting support 7 and prevent the wire 9 from sliding off the roller 1. In order to reliably prevent the wire 9 from crossing over on the roller 1, a guide pulley 8 can be arranged on an extended mounting support 7 about which is placed wire 9 with a looping angle which is smaller than 2 z radians and is consequently then placed around the roller 1 with a looping angle which is also smaller than 2 z radians. This is shown in Figure 4.

According to Figures 5 and 6, the closing die 3 is formed by pressure rollers 10 which press on the wires 9, which has the advantage that both end points A and C of the torsion zone are precisely defined.

According to a further constl uction shown in Figure 7, the rollers I are located so close to the closing die 3 that the pay-out angle from each roller 1 is 9() and the intake edge of the closing die 3 is rounded in such a way that an nre of 9()O is formed. The length of the torsion zone according to the inveii- tion is characterised by the distance of the pay-out A from roller 1 to twisting station C.Thus, in all the described embodiments, the torsion zone is reduced to such an extent that a multiple twisting of the individual wire 9 about its longitudinal axis beyond the torsion zone is no longer possible, even if there are so-called weak points. Thus, the frequency of wire cracking is greatly reduced and the shutdown times of the twisting machine are also reduced.

WHAT WE CLAIM IS: 1. A twisting machine for twisting together strands of elongate material, including a rotary lay plate located upstream of a closing die in the direction of movement of the elongate material, and rollers carried by said rotary lay plate, each roller being located between the rotary lay plate and the closing die and positioned as close to said die as is possible so that a strand to be twisted can be passed around a single said roller through a looping angle of 2 z radians or less before passing to the closing die and so that the distance between the pay-off point of each roller and the stranding point of the die is as small as possible, said roller limiting the self-twist in the strand to the length of strand between the roller and the closing die.

2. A twisting machine as claimed in claim 1, in which a guide pulley is associated with each other.

3. A twisting machine as claimed in claim 1 or claim 2 in which the rollers are mounted on support members extending from the rotary lay plate.

4. A twisting machine as claimed in claim 3 when dependent upon claim 2, in which the guide pulleys are mounted on extensions of the support members.

5. A twisting machine as claimed in any preceding claim, in which the inlet end of the closing die is arranged so close to the rollers that the pay-out angle of the strands is 90" relative to the longitudinal axis of the machine, the inner edge of the inlet end of the closing die being curved over an arc of 90".

6. A twisting machine as claimed in any preceding claim, in which each roller is located between fixed lateral material deflectors.

7. A twisting machine for twisting together strands of elongate material, substantially as herenbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. pay-out A from roller 1 to twisting station C. Thus, in all the described embodiments, the torsion zone is reduced to such an extent that a multiple twisting of the individual wire 9 about its longitudinal axis beyond the torsion zone is no longer possible, even if there are so-called weak points. Thus, the frequency of wire cracking is greatly reduced and the shutdown times of the twisting machine are also reduced. WHAT WE CLAIM IS:

1. A twisting machine for twisting together strands of elongate material, including a rotary lay plate located upstream of a closing die in the direction of movement of the elongate material, and rollers carried by said rotary lay plate, each roller being located between the rotary lay plate and the closing die and positioned as close to said die as is possible so that a strand to be twisted can be passed around a single said roller through a looping angle of 2 z radians or less before passing to the closing die and so that the distance between the pay-off point of each roller and the stranding point of the die is as small as possible, said roller limiting the self-twist in the strand to the length of strand between the roller and the closing die.

2. A twisting machine as claimed in claim 1, in which a guide pulley is associated with each other.

3. A twisting machine as claimed in claim 1 or claim 2 in which the rollers are mounted on support members extending from the rotary lay plate.

4. A twisting machine as claimed in claim 3 when dependent upon claim 2, in which the guide pulleys are mounted on extensions of the support members.

5. A twisting machine as claimed in any preceding claim, in which the inlet end of the closing die is arranged so close to the rollers that the pay-out angle of the strands is 90" relative to the longitudinal axis of the machine, the inner edge of the inlet end of the closing die being curved over an arc of 90".

6. A twisting machine as claimed in any preceding claim, in which each roller is located between fixed lateral material deflectors.

7. A twisting machine for twisting together strands of elongate material, substantially as herenbefore described with reference to the accompanying drawings.