GB1593126A

GB1593126A - Double twist rope stranding machine

Info

Publication number: GB1593126A
Application number: GB18019/78A
Authority: GB
Original assignee: Schwermaschinenbau Kombinat Ernst Thalmann VEB
Current assignee: Schwermaschinenbau Kombinat Ernst Thalmann VEB
Priority date: 1977-07-07
Filing date: 1978-05-05
Publication date: 1981-07-15
Also published as: ATA259478A; DD131943A1; DE2824227C2; IT7824228A0; IT1095034B; AT361810B; DE2824227A1; DD131943B1

Description

(54) DOUBLE TWIST ROPE STRANDING MACHINE (71) We, VEB SCHWERMASCHINENBAU KOMBINAT ERNST THALMANN MAGDEBERG, 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 double twist stranding machine of tubeless construction having a plurality of spaced apart support stands each supporting a rotor shaft and drive transmission and having mounted therein rotatable wire guide members, a cradle being freely rotatably mounted between the support stands, the wires from the bobbins being guided in the opposite direction of pull-off to one end of the stranding machine where they are re-directed in the reverse direction and passed as a pretwisted bundle of wires over a sinusoidal curved path evenly disposed about the axis of the rotatable guides, to the other end of the stranding machine whereby they are twisted for the second time.

According to the present invention there is provided a double twist stranding machine comprising a plurality of spaced apart support stands each supporting a rotor shaft and drive transmission and having mounted therein rotatable wire guide members, a cradle being freely rotatably mounted between the support stands, all the cradles except the first having means for supporting a bobbin, the wires from the bobbins and being guided in the opposite direction of pull-off to one end of the stranding machine where they are redirected in the reverse direction and passed as a pre-twisted bundle of wires over a sinusoidal curved path evenly disposed about the axis of the rotatable guides, to the other end of the stranding machine where they are twisted for the second time, and whereby in order to produce the wire tension needed for twisting, each payout bobbin is associated with an adjustable bobbin brake, and provided on the cradle supported between the first two support stands is a wire guide pulley and, axially parallel therewith, a brake pulley braked by brake influenced by the wire tension, the wires entering the end cradle centrally being passed in a plurality of turns and in the form of an interacting loop around the said pulleys, and in that for onward guidance of the wires and for regulating the braking force, there is at one end of a brake lever mounted on the cradle, a roller, a further roller being provided on the lever at the pivot point of the brake lever, a device for sorting the wires being disposed in front of the guide pulley while behind the brake pulley there is a layer pulley and behind that a central closing die.

Furthermore, in order to compensate for individual wire tension generated by the individual bobbin brakes and in order to avoid too great a deflection angle for the wires, the relevant periphery of the payout bobbins is utilized as a wire guide element.

Preferably the guide pulley for improved guidance of the wires, has grooves on its periphery.

An emboidment of the invention will now be described, by way of an example, with reference to the accompanying drawings, in which: Figure 1 shows the double twist stranding machine in its entirety and in plan view; Figure 2 is a side view of a bobbin support cradle, partly in section; Figure 3 is a plan view of the bobbin support cradle shown in Figure 2; Figure 4 is a side view of the brake frame partly in section, and Figure 5 is a plan view according to Figure 4.

The double twist stranding machine shown in the drawings consists of a plurality of supports stands 1, 2, 3, 4, 5 and 6 in which are mounted rotors driven in synchronism by a motor 7 and which are at the same time constructed as single stage drive transmissions.

On the output shaft of each single stage transmission (not shown) are mounted wire guide cones 39. Located between each two oppositely facing wire guide cones 39 except the first two between stands 1 and 2 are bobbin support cradles 14, 15, 16, 17 and a brake support cradle 18 is located between the oppositely facing cones between stands 1 and 2, said cradles 14-18 being mounted for free rotation on the output journals 11 of the drive transmission, by means of bearing bushes 12 and bearings (not shown). In order to achieve vibration-free mounting of the bobbin support cradles 1417, a rubber ring 13 is inserted between the bearing bush 12 and the bore in the bobbin support cradle.Located ahead of the support stand 6 is an overtwisting device 8 in front of which is a fixed roller point 40 and behind which there is a pull-off capstan 9 and a take-up means 10.

Mounted on the cradles 14, 15, 16, 17 are pay-out bobbins 19 which are each provided with an adjustable bobbin brake 20. Each bobbin brake 20 consists of a bake lever 24 which carries rollers 22, 23 and 26. The axis of the roller 26 forms at the same tme the pivot axis of the brake lever 24. Connected to the other end of the brake lever 24 which does not carry a roller is an adjustable thrust spring 41. Mounted at the other end of the cradle and extending over the entire height of the bobbin 19 is a pull-off roller 21 over which the wire 27 is pulled and passed via rollers 22, 23 into the axial centre of the rotating wire guide cone 39.The wires 27 pulled off the payout bobbins 19 and arriving through the axial centre as a bundle of wires 28 are passed over a roller 25 and over the winding periphery of the next payout bobbin 19 to the roller 26 and thence into the axial centre. Tfiis guiding of the wire takes place over all the payout bobbins except the first.

Thus, virtually whatever winding diameter of the payout bobbins 19 is available can be used asa wire guiding element. Since the peripheral speed of the payout bobbins 19 in relation to their winding diameter corresponds to the linear speed of the wire pulled off, guidance of wire is particularly favourable since on the one hand, for the same speeds between wire and bobbin winding, no negative friction influences can occur and because, on the other, the deflection angles for the wires guided around the payout bobbins 19 can be kept really small. The result is a high degree of matching of the wire pull rates in the individual wires 27 of the wire bundle 28.Mounted between the wire guide cones 39 of the support stands 1 and 2, in the same way as the bobbin support cradles, is a brake support cradle 18 on which a guide pulley 30 and a brake pulley 31 are disposed in axially parallel relationship. The guide pulley 30 has on its periphery grooves for guiding the individual wires 27. So that the wires 27 which arrive as a wire bundle 28 enter in isolated and orderly fashion into the grooves in the guide pulley 30, a sorting guide arrangement 29 is mounted upstream of the guide pulley 30, on the brake support cradle 18. The periphery of the brake pulley 31 is engaged by a brake which consists of a brake lever 34 having rollers 32 and 33 mounted thereon. The axis of the roller 33 at the same time constitutes the point of rotation of the brake lever 34.An adjustable thrust spring 42 engaging the brake lever 34 permits adjustment of the desired braking force. Located behind the brake pulley 31 and provided on its periphery with slotted nipples 35 is a layer pulley 36 behind which there is a central closing die 37. The wire bundle 28 running into the centre of the brake frame 18 is divided by the sorting arrangement 29 into the individual wires 27 and these are guided into the grooves in the guide pulley 30. Having been sorted, the wire bundle 28 is passed in several windings around the guide pulley 30 and the brake pulley 31 in the form of a crossed-over loop, after which the wires pass over rollers 32, 33 to the layer pulley 36 in which the wires 27 of the bundle of wires 28 are guided individually over the nipples 35 and are combined with one another again in the central die 37.From here, the wire bundle 28 passes over guide rollers 38 disposed on the periphery of the rotor to the outer guides of the wire guide cone 39. In the region between central die 37 and guide roller 38 the first twisting process occurs in known manner. The already stranded wire bundle 28 passes in a curved path resembling a sinusoidal curve around the payout bobbins 19 and across the rotary axis to the end of the stranding machine where it is guided along the central axis and to the fixed roller point 40. The second twisting operation (of the double twist pattern) takes place between rotor and the said fixed point.

In the subsequent twisting device 8, the stresses brought about by the twisting process are compensated. Via the pull-off means 9, the twisted material passes to take-up means 10. By reason of the wires being guided over the winding diameters of the payout bobbins 19, the individual wires 27, in conjunction with the bobbin brakes, are given a relatively even pull even before they enter the brake frame 18, this even pull which is necessary to the quality of the stranded material is further enhanced by the common braking of all the wires 27 which run through and onto the brake pulley 31. By locating the roller 32 on the brake lever 34 and by virtue of the wire guidance arrangement described, an automatic control is achieved even in the case of over 50% variation in working distance, within a small range of tolerances. This in turn gurantees a good quality in the first twisting stage (single twist). Subsequently, the pull in the twisted bundle of wires is kept constant, whicn in turn in conjunction with the satisfactory quality first twist, produces a second twist (double twist) of high quality.

Furthermore, reducing the number of direction changing points and having a favourable angle of deflection are factors which reduce susceptibility to trouble and which ensure a saving on roller material.

WHAT WE CLAIM IS: 1. A double twist stranding machine comprising a plurality of spaced apart support stands each supporting a rotor shaft and drive transmission and having mounted therein rotatable wire guide members, a cradle being freely rotatably mounted between the support stands, all the cradles exept the first having means for supporting a bobbin, the wires from the bobbins being guided in the opposite direction of pull-off to one end of the stranding machine where they are re-directed in the reverse directon and passed as a pretwisted bundle of wires over a sinusoidal curved path evenly disposed about the axis of the rotatable guides, to the other end of the stranding machine where they are twisted for the second time, and whereby in order to produce the wire tension needed for twisting, each payout bobbin is associated with an adjustable bobbin brake, and provided on the cradle supported between the first two support stands is a wire guide pulley and, axially parallel therewith, a brake pulley braked by a brake influenced by the wire tension, the wires entering the end cradle centrally being passed in a plurality of turns and in the form of an interacting loop around the said pulleys, and in that for onward guidance of the wires and for regulating the braking force, there is at one end of a brake lever mounted on the cradle, a roller, a further roller being provided on the lever at the pivot point of the brake lever, a device for sorting the wires being disposed in front of the guide pulley while behind the brake pulley there is a layer pulley and behind that a central closing die.

2. A double twist stranding machine as claimed in claim 1, in which to match the wire tensions produced by the individual bobbin brakes and in order to avoid too great an angle of deflection of the wires, the relevant winding periphery of the payout bobbins is utilized as a wire guide element.

3. A double twist stranding machine as claimed in claim 1 or claim 2, in which the layer pulley has on its periphery evenly distributed slotted nipples for guiding the wires.

4. A double twist stranding machine as claimed in any preceding claim, in which the guide pulley has grooves on its periphery for the guidance of the wires.

5. A double twist stranding machine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. satisfactory quality first twist, produces a second twist (double twist) of high quality. Furthermore, reducing the number of direction changing points and having a favourable angle of deflection are factors which reduce susceptibility to trouble and which ensure a saving on roller material. WHAT WE CLAIM IS:

1. A double twist stranding machine comprising a plurality of spaced apart support stands each supporting a rotor shaft and drive transmission and having mounted therein rotatable wire guide members, a cradle being freely rotatably mounted between the support stands, all the cradles exept the first having means for supporting a bobbin, the wires from the bobbins being guided in the opposite direction of pull-off to one end of the stranding machine where they are re-directed in the reverse directon and passed as a pretwisted bundle of wires over a sinusoidal curved path evenly disposed about the axis of the rotatable guides, to the other end of the stranding machine where they are twisted for the second time, and whereby in order to produce the wire tension needed for twisting, each payout bobbin is associated with an adjustable bobbin brake, and provided on the cradle supported between the first two support stands is a wire guide pulley and, axially parallel therewith, a brake pulley braked by a brake influenced by the wire tension, the wires entering the end cradle centrally being passed in a plurality of turns and in the form of an interacting loop around the said pulleys, and in that for onward guidance of the wires and for regulating the braking force, there is at one end of a brake lever mounted on the cradle, a roller, a further roller being provided on the lever at the pivot point of the brake lever, a device for sorting the wires being disposed in front of the guide pulley while behind the brake pulley there is a layer pulley and behind that a central closing die.