STRANDING MACHINE

Abstract: A machine for symmetrical stranding of at least two wires includes wire magazines in a number corresponding to the number of wires, from which magazines the wires are fed out. Rotatably arranged about an axis of rotation (38) is a flyer (31) having outwardly directed bow-shaped or semi-circular arms (32, 33) connected, on one hand, with a tubular, motor-driven drive sleeve (36) rotatable about the axis of rotation and, on the other hand, with a runner sleeve (43) which is freely rotatable about the axis of rotation (38). Each arm (32, 33) has a plurality of wire guides (34, 35) for controlling a wire (26'', 20'') along the arm concerned (32, 33) between the drive sleeve (36) and the runner sleeve (43). A first wire magazine (10) is arranged around the axis of rotation (38) and inside the path of rotation of the arms (32, 33). A first wire (26'') is led downwards and through first control means (27, 28, 48) and the drive sleeve (36) to the wire guide (34) of a first arm (32). A second wire magazine (25) is provided outside the path of rotation of the arms (32, 33). A second wire (20'') is led downwards through second control means (21, 22, 23, 45, 46) and the drive sleeve (36) to the wire guide (35) of a second arm (33). Provided on the runner sleeve (43) on the axis of rotation is a stranding point (47) for stranding together the wires and a non-rotatable outfeed means (45, 49, 50) stationary in space and adapted to receive the standed wires.

Description: STRANDING MACHINE The present invention relates to a stranding machine for symmetrical stranding of two wires, especially insulated wires for telecommunication, said stranding machine in¬ cluding at least two wire-storing magazines, for instance in the form of creels or drums provided with end walls, the wires being fed out from said magazines by per se known means. Machines for stranding telecommunication wire are pre¬ viously known, the wire being fed out from a wire drum in that the drum is set in rotation when the wire is drawn off from it. When the machine is to be stopped the drums must be braked, which is an inconvenience since the braking takes a relatively long time at the same time as the wire is sub¬ jected to varying stretching forces which cause the wire cross-sectional area to be changed and consequently give rise to electrical resistance variations along the wire. Varying stretching forces can also be caused by snarls on the wire, by overcrossing wire turns wound on a drum, by varying acceleration forces on a drum depending on different mass-moments of inertia in the drum when it contains varying ' amounts of remaining wire and consequently also varying unwinding radii. Stranding machines are known where the wire magazines consist of rotary drums, as described above, as well as fixed wire magazines in, the form of stationary drums or creels. In stranding wire by means of such machines there are - in addition to the above-mentioned variation in re¬ sistance - also other unbalances for the stranded wire be¬ cause the wires come from magazines of different principal design (i.e. stationary and. rotary drums respectively), since the wires have different tensions and distortions when they arrive to the point where they are stranded. This means that the wires, the form of which is helical after stranding, have different helices, i.e. they have different helix O PI diameters and different lead. In the extreme case, one wire may for instance be practically straight while the other wire is wound around. This gives not only resistive unbalances but also capacitive unbalances in the stranded wire. This again leads to inferior quality in the tele¬ communication. The object of the ^ invention is to provide a stranding machine for wires in which the teletechnically sensitive, resistive and capacitive unbalances have been reduced to a minimum and an entirely symmetrically stranded wire with two or more parts is obtained. The object of the invention is realized by the pro¬ vision of: a flyer, which is rotary about an axis of rotation and includes a number of outwardly directed, generally bow- shaped or semicircular arms corresponding to the number of wires, each arm being connected at one end with a tubular drive sleeve rotatable about the axis of rotation and driven by a motor, and connected at its other end with a runner sleeve which is freely rotatable about the axis of rotation, each arm including a plurality of wire guides for leading and controlling a wire along the arm concerned between the drive sleeve and the runner sleeve; a first wire magazine arranged around the axis of ro- tation and. inside the path of rotation of the arms, said magazine including a support and first control means pro¬ vided on the underside of the support for leading the wire through the drive sleeve and to the wire guide of a first arm; a second wire magazine arranged outside the path of rotation of the arms , said magazine including a support and second control means provided on the underside of said support for leading the wire through the drive sleeve and to the wire guide of a second arm; a stranding point for stranding together the wires, provided in the runner sleeve on the axis of rotation; and a non-rotary outfeed means stationary in space and adapted to receive the stranded wires- O PI In a second embodiment ' of the invention each wire magazine includes a support with a fixing plane for sup¬ porting a wire drum at one end wall thereof and a means projecting at the other, free end wall of the drum outside the end wall and provided with a trumpet-shaped opening, said means extending through the centre of the drum and out on the other side thereof in order to guide the wire right through the drum to the support. In a third embodiment of the invention the axis of ro- tation is inclined relative to the vertical line and the first wire magazine is mounted for rotation about the axis of rotation. In a fourth embodiment the first support is so de- ■ signed that the drum in the first wire magazine is suppor- ted with its central point on the axis of rotation and such that that the centre of gravity of the support is located at a distance from the axis of rotation in order to take a stable bottom position under the influence of the force of gravity and thus keep the support in a position which is stationary in space. . The .invention will now be -described in more detail with reference to the accompanying drawing which is a partly sectioned side view of a stranding machine according to the inve ' ntnion. In the drawing a first wire magazine is designated by 10. This comprises a drum 11 with flanges 12 and 13. The flange 13 rests on a support 29 which is provided with means for controlling and retaining the drum in the desired posi¬ tion. Arranged on the top of the free flange 12 of the drum is a disc 15 which is rotary relative to the flange and has a rounded periphery which extends outside the upper flange 12 of the drum 11. Above the rotary disc 15 is a plurality of radially outwardly directed elastic wires 16 which project outside the edge of the disc 15. The wires 16 are attached to a centre portion 17 which is shaped as a flange on a tube or a sleeve 18 which is connected with the drum 11 and passes through the centre of the drum. OMPI The arrangement of the disc 15 and the elastic wires 16 is usually called a "whisker type disc" which, when a wire 26 is pulled off from the drum, guides the wire outside the upper flange 12 of the drum at the same time as it is set in rotation by friction from the wire. The elastic wires 16 successively intercept the wire as it travels around the disc 15 and bring thus about a soft stretching and braking of the wire 26. The wire is led from the "whisker type disc" to a trumpet-shaped opening 19 in the upper end of the sleeve 18. During unwinding the wire will thus sweep around the rounded outer edge of the opening 19 and into the centre and through the center of the drum towards the support 29. Arranged in the support 29 are two pulleys 27, 28 over which the wire 26 is led in S-fashion. The pulleys constitute a _ braking means to give the wire a certain stretch. The wire ' is then guided further on via a pulley 48 to the stranding device which will be described in more detail below. Thus, in the manner described above the wire part 26' leaving ' the first wire magazine 10 will have a certain tension and also a certain torsion because it has been turned- one revolution in response tp each unwinding re¬ volution. In the drawing 25 designates a second wire magazine which is built up in the same manner as the first wire • magazine 10. The designations 11 - 13, 15 - 19 stand for details which are identical with the details of the first wire magazine 10 having the same designations. The second support 14 is equal to the support 29. Considering the identical buildup of the two wire magazines 10 and 25 it is easily understood that the wire 20' leaving the second magazine 25 has the same tension and the same distortion as the wire 26 ' from the first wire magazine 10. A condition therefor is that the drum 11 of the first magazine is essentially stationary in space. This will be obtained in a manner to be described in more detail below. The device for the symmetrical and similar stranding of the two wires will now be described in more detail. GMH The stranding of the wires is obtained by means of a rotary so-called flyer 31 which has two arms 32 and 33. In the device described by way of example the flyer has two arms because two wires are to be stranded. If more wires are 5 to be stranded the flyer has as many arms as the number of wires. Arranged on the arms 32 and 33 is a number of wire guides 34 and 35, respectively, in the form of small pulleys. The lower ends of the arms are fixedly connected with a 10 tubular drive .sleeve 36 which is rotatable in a bearing house 37 arranged around an axis of rotation 38. The drive sleeve has at- its lower end, which projects outside the bearing house 37, a belt pulley 39 by means of which the flyer 31 can be rotated by means of a belt drive 40 from a 15 motor 41. The bearing house 37 is fixedly connected with a support 42 resting on the ground. The upper ends of the bow-shaped arms 32, 33 are connected with a tubular,-rotary runner sleeve 43 which is rotatable about the same axis of rotation 38 as the flyer 31 20 and the drive sleeve 36. The runner sleeve is borne in an . upper bearing house 44. • From the description it is apparent that the motor 41 rotates the rotary unit 36 - 31 - 43 borne in the bearing • houses 37 and 44, The. speed of rotation may amount to about 25.1500 rp . The other wire .20 coming from the other wire magazine 25 is led via pulleys 21 and 22, which are similar to the pulleys 27 and 28, and further on via a pulley 23. The wire part 20' is led on a pulley 45 fixed on the 30 support 42 into the hollow space of the drive sleeve 36 and further on via a pulley 46 arranged on the drive sleeve 36 to the above-mentioned wire guides 35 along the arm 33. Via the uppermost wire guide 35 the second wire part 20' ' tra¬ vels into the inner hollow of the runner sleeve 43 to a 35 stranding point 47 where it is stranded with the first wire part 26 ' « . The first wire part 26' is led further via the wire guides 34 on the arm 32 so that the wire part 26'' after the uppermost wire guide 34 is led to the stranding point 47 where it meets the other wire part 20'', as described above. After the stranding point 47 the stranded wires 20' ' och 26 ' ' are guided to a pulley assembly 45 which is attached to the upper bearing house 44 and consequently stationary in space. The assembly includes two successive pulleys 49 and 50 which may have several tracks so that the stranded wires will travel more than one turn over them to obtain an equalization of any irregularities in the stranding before they leave the stranding machine to be carried to the de¬ sired winding device in the form of a drum or the like. It appears from the figure that the axis of rotation 38 is somewhat inclined. The purpose of this is to impart to the first wire magazine 10 a position which is stationary in space and is established in the following way. The centre of gravity of the drum 11 is, as appears from the figure, situated on the axis of rotation 38. This condition prevails independently of the amount of wire on the-drum. The support 29, -however, is eccentric relative to the axis of rotation 38 in that its body, ith respect to the figure,is situated to the righ ; of the axis of rotation 38. The support 29 is pivotally supported by a bearing 52 on the drive sleeve 36. The centre of gravity of the support 29 for the first maga- zine 10 has been designated, by 53 and with respect to the figure it is to the. right of the axis of rotation 38. It is easily seen that the centre of- gravity .53 under the influ¬ ence of the force of gravity tends to take its lowermost position in space, i.e. that shown in the figure, and thus exert a stabilizing torque around the axis of rotation 38. The friction torque caused in the bearing 52 during the rotation of the drive 36 is much less than the sta¬ bilizing torque resulting from the position of the gravity centre 53 and therefore the first wire magazine 10 will take the stable position shown in the figure, possibly with small oscillations around it. It is quite clear that it is possible to vary the stretch of the stranded wire by arranging braking means on the pulley pairs 21 - 22 and 27 - 28, respectively, for the wires 20 and 26. It is likewise possible to increase the lead of the stranded wires by increasing " the unwinding rate of the wires or reducing the number of revolutions of the flyer and reduce the lead by an inverted operation. The above embodiment of a stranding machine has been suggested as an example of a device according to the in¬ vention. It is quite clear to anyone skilled in the art that it is possible to modify the device for stranding three or more wires symmetrically by arranging three wire maga¬ zines and three arms in the flyer or the greater number of wire magazines and arms corresponding to the number of wires. The wire magazines can to this effect be placed outside as well as inside the flyer in a manner appropriate to the particular case. Also other embodiments of the in¬ vention can be realized by anyone skilled in the art within the scope of the appended claims. OM?I

Claims: CLAIMS 1. A stranding machine for symmetrical stranding of at least two wires, especially insulated wires for telecom¬ munication, including wire-storing magazines corresponding to the number of wires, such as creels or drums provided with end walls, the wires being fed out from said magazines by per se known means, comprising: a flyer (31) , which is rotary about an axis of rotation (38) and includes a number of outwardly directed, generally bow-shaped or semicircular arms (32, 33) corresponding to the number of wires and being each at one end (32', 33') connnected. with a tubular drive sleeve (36) rotatable about the axis of rotation and driven by a motor (41) , and con¬ nected at its other end (32 11 , 33' * ) with a runner sleeve (43) which is freely rotatable about the axis of rotation (38) , each arm (32, 33) including a plurality of wire guides (34, 35) for leading and controlling a wire (26'', 20'') along the arm concerned (32, 33) between the drive sleeve (36) , and the runner sleeve (43) ; a first wire magazine (10) arranged around the axis of rotation (38) and inside the path of rotation of the arms (32, 33) t said magazine including a support (29) and first control means (27, 28, 48) provided at the underside of the support (29) for leading the wire (26 11 ) through the drive sleeve (36) and_ to the wire guide (39) of a first arm (32); a second wire magazine (25) arranged outside the path of rotation of the arms (32, 33), said magazine including a support (14) and second control means (21, 22, 23) provided on the underside (14) of said support (14) for leading (45, 46) the wire (20) through the drive sleeve (36) and to the wire guide (35) of a second arm (33); a stranding point (40) for stranding together the wires, provided in the runner sleeve (43) on the axis of rotation (38) ; and a non-rotary outfeed means (45, 49, 50) stationary in - _ z. h O PI space and adapted to receive the stranded wires. 2. A machine as claimed in claim 1, w h e r e i n each wire magazine (25) includes a support (14) with a fixing plane for supporting a wire drum (11) at one end wall 5 (13) thereof, a means projecting at the other free end wall of the drum outside the end wall (12) and provided with a trumpet-shaped opening, said means extending through the centre of the drum (11) and out on the other side thereof in order to conduct the wire (20, 26) right through the drum 10. (11) to the support (14, 29). 3. A machine as claimed in claim l or 2, w h e r e - i n the axis of rotation (38) is inclined relative to the vertical line and-the first wire magazine (10) is mounted for rotation about the axis of rotation (38) . 15 4. A machine as claimed in claim 3, w h e r e i n ' the support (29) is so designed that the drum (11) is sup¬ ported with, its central point on the axis of rotation (38) and the support (29) is so designed that its centre of gra¬ vity (53) lies at a distance from the axis of rotation (38) 0 in order to take a stable bottom position under the in¬ fluence of .the force of gravity and thereby to keep the support (29) in a stationary position in space. OMPI

Inventors: BARUD LENNART, LARSSON ANDERS, BARUD, LENNART, LARSSON, ANDERS
Applicants: KABMATIK AB
Application year: 1982
Main classification: H01B13
IPC codes: D07B3, H01B13