Abstract: In the manufacture of bundles of at least ten twisted pairs or quads of electric wires, a compact design of the first twisting stage and a servicable guiding system for guiding the pairs from the first twisting stage to the twisting closer of the second twisting stage is obtained by having at least two groups of SZ-twisting devices in the first twisting stage, the rotating twisting heads of the two stages radially staggered and the guide pulleys of the respective inner twisting head which are arranged at the transition from the first to the second twisting stage provided with several guiding grooves for the twisting units so that they can guide twisted units from both the inner and outer twisting heads.

Abstract: In order to eliminate tension variations in the metal wires in the operation of a tubular accumulator SZ twisting machine for the ceander shaped application of elements on a core the length l.sub.0 of the cylindrical tube arranged between a stationary and an oscillating perforated disc satisfies the condition:l.sub.0 .gtoreq.100D.sup.2 /bwhereD=the outside diameter of the tube, andb=the period of the ceander-shaped twist. The new twisting machine is particularly useful for stranding twisting elements of an optical cable on a core.

Abstract: The driving device for the twisting head of an SZ stranding machine assures short switching times with little equipment even for a multi-step change of the rotary motion by associating with one or both magnetic clutches of the twisting head either one driving shaft rotating at changing speed, or at least two driving shafts revolving at constant speed and each having a magnetic clutch for coupling rotation to the twisting head clutch.

Abstract: For fixing the reversal points of the twist direction in SZ twisted elements of electric cables and lines to be twisted, a device is provided which runs along in sections with the continuously moved material to be twisted and includes clamping tongs for gripping the twisted assembly and an associated device for joining the elements to be twisted together. The clamping tongs and the joining device are arranged between the stationary twisting tool and the following stationary torsion stopper. The device for joining the elements to be twisted together preferably comprises rotatable clamping tongs which may be arranged between two non-rotating clamping tongs.

Abstract: An S-Z twisting machine including a twisting disc operated reversibly at the speed n.sub.1 and a tubular accumulator driven with the lower speed n.sub.2. The elements to be twisted which are applied to the tubular accumulator via an aperture guide disc, are preferably conducted through a further aperture guide disc which is rigidly connected to the tubular accumulator near its center to insure that the loops before and behind the further guide disc are equal per unit length of the tubular accumulator.

Abstract: So as to be able to perform layer-wise SZ twisting of twisting elements of electric cables by means of a twisting plate with changing direction of rotation, the twisting plate is preceded at a distance by a twisting head which revolves with constant speed and direction of rotation. The twisting plate itself is provided with guide holes for guiding the twisting elements, which holes are arranged on at least two concentric pitch circles. Advantageously, the twisting plate has, besides a central guide hole, six guide holes on a first pitch circle and twelve guide holes on a second pitch circle. The distance between the twisting head and the twisting plate should be greater than the length of a section with the same twisting direction in the finished twisted material.

Abstract: To be able to correct irregularities in the length of lay, which result from the reversal of the twisting device in SZ twisting devices with very large storage capacity, a post-twisting device is arranged after the SZ twisting device, the post-twisting device including a retwisting disc with an equalization section in the back thereof. The length of the equalization section is at least five times the resulting length of lay; the speed of rotation of the post-twisting device is equal to the difference between two successive speed steps of the SZ twisting device and direction of rotation of the post-twisting device is changed in the same rhythm as the rotary motion of the SZ twisting device.

Abstract: SZ twisting of stranding elements of electric or optical cables and lines is accomplished by means of twisting apparatus which consists of a twisting section defined by a first and a second twisting point within which at least one twisting head is arranged. The twisting head includes at least one deflection pulley or deflection roller which is stationary in the circumferential direction of the material to be twisted and with which the material to be twisted is in contact over part of the circumference. The axis of the deflection pulley or deflection roller is set at an angle to the axis of the tautly conducted material to be twisted. The inclination of this axis can be varied at intervals and the location of the deflection pulley or deflection roller relative to the material to be twisted can be changed at intervals. By setting the axis at an angle, a force component in the tangential direction which leads to a twisting of the material to be twisted, is exerted on the material to be twisted.

Abstract: For the SZ twisting of cable conductors with a sector-shaped conductor cross section which are not pre-twisted, stationary control guides for the conductors are provided and a twisting device is disposed immediately after the twisting closer with the distance between the engagement point of each control guide at a cable conductor and the first point of engagement with the material to be twisted of the twisting device tensionally gripping the material to be twisted from the outside made smaller than or at most equal to the length of lay of the material to be twisted. In addition, the free distance between the twisting device and the nearest device gripping the material to be twisted in a torsion-proof manner is very much larger than the length by which a longitudinal section of the twisted material is advanced during an interval of constant direction of rotation of the twisting device.

Abstract: For SZ twisting power cable conductors with a sector shaped conductor cross section which are not pre-twisted, two twisting heads are used which form a stretched accumulator and are arranged, respectively, after or before a twisting closer and revolve synchronously with changing rotary motion. Ahead of the first twisting point, a positive guide is arranged for each cable conductor. The positive guides and the twisting heads are arranged at a distance as short as possible from the twisting points. In this manner, an exact twisting geometry of the twisted assembly in the vicinity of the reversal points of the twist direction is obtained.

Abstract: A method and apparatus for the layer-wise SZ twisting of electrical or optical cables in which, so that, in the manufacture of multi-layer cables, several stranded layers can be applied in one operation, the twisting elements are fed at points within a single stretched accumulator offset in the longitudinal direction and the speeds of rotation of the twisting heads are varied periodically in at least two increasing and decreasing steps with the distances of the twisting heads from each other adjusted, so that adjacent stranded layers have reversal points of the twist direction which are offset relative to each other.For applying a stranded layer, a twisting closer immediately followed by a rotating twisting head is provided at each feeding point.

Abstract: In apparatus for SZ twisting twist elements of electric cables so that twisted units, in which the distance between the reversal points of the twist direction is about 500 to 1000 m, can be manufactured with apparatus of relatively short overall length, the basically straight accumulator section of the SZ twisting machine is divided into several subsections arranged in different, preferably parallel planes and connected to each other by deflection devices. The devices provided for guiding and deflecting the material to be twisted make possible or ensure the rotation of the material to be twisted in the region of the individual subsections of the accumulator.

Abstract: For the layer-wise SZ-stranding of elements to be stranded about a core strand, the elements to be stranded are first temporarily cabled onto the core strand with a long lay and alternating direction of lay, subsequently roped down from the core strand by means of a first cabling disc and fed, parallel to the core strand, to a second, oscillating cabling disc by means of which the final stranding is accomplished. The two cabling discs advantageously form the end faces of a twisting cage which revolves with alternating direction of rotation, with the distance of a first twisting closer, into which the core strand and the elements to be cabled enter, from the first cabling disc and the distance of the first cabling disc from the second cabling disc larger than the distance of the twist reversal points in the finished stranded material.

Abstract: To provide symmetrical communication cables, especially wiring cables for telephone exchange installations, with connectors at the cable ends, in a simple manner, the individual groups of pairs of the cable core consist of a flat cable, which is formed into a group by twisting or torsioning. The pairs of each flat cable are connected to each other by means of flexible holding elements which are cemented or welded to the pairs on one side. In the manufacture of such a communication cable, the pairs of a group are first arranged along the generatrix of a cylinder and are temporarily secured in this configuration by means of a holding helix. The holding helix is cemented or welded to the surface of the pairs and subsequently cut open between two adjacent pairs in the same operation.

Abstract: In order to avoid troublesome length differences between the core and the outer layer in the S-Z twisting of five or more elements to be twisted, the average value of the input twist is chosen equal to the average value of the resulting S and Z twist.

Abstract: A twisting disk disposed within a torsioning section between two twisting points in the vicinity of the exit point of the torsioning section and which rotates with a direction of rotation alternating by sections in used to avoid over twisting of the twisting elements during the SZ-twisting of electrical cables.

Abstract: A method for reducing the electrical coupling in communications cables constructed of bundles in which in a first twisting stage of a two stage operation sections of opposite phase are formed in pairs in the twisted units and in the second twisting stage, adjacent twisted units are related to each other in such a manner that two adjacent twisted units always have the same number or approximately the same number of parallel sections of the same and opposite phase over their entire length. In one disclosed apparatus for carrying out this method an aperture disc, which is rotatable about the twisting axis and whose angular position is variable, is arranged in front of each twisting nipple in the first twisting stage.

Abstract: To localize a conductor break occurring in a conductor being twisted into a communications cable in a two stage twisting operation the faulty wire is first ascertained and the fault in that wire then subsequently located using a probe placed between the twisting apparatus and a take up drum, with the twisting process then stopped and the fault corrected. In one particular embodiment which is disclosed all wires are short circuited, for example, at the end of the twisted cable which is wound on the take up drum, the wires entering the twisting arrangement are divided into two groups of equal size with each of the groups connected to one end of an a-c voltage source symmetrical with respect to ground through high resistance series resistors with the voltage drop at the series resistors then detected to locate the faulty wire and the probing of the twisted structure done capacitively using a probe for determining the exact fault location.