GB724101A - Improvements relating to the manufacture of cables, ropes and the like - Google Patents

Abstract

724,101. Rope stranding machines. ROZIERES, J. A. L. Oct. 16, 1951 [June 9, 1951], No. 24161/51. Class 109. In an apparatus for making wire ropes or cables in which wires or strands are twisted together and in which normal residual elasticity in the rope is nullified by backtwisting the rope, a device is interposed between the backtwister and a winch feeding a take up reel, which, in response to residual elasticity remaining in the rope, occasioned by local departures from normal elasticity, varies the rotary speed of the take-up winch or of the backtwister relative to the twisting device so as to compensate for such variations of residual elasticity. As shown, wires from reels 2 are stranded together in a conventional stranding device 1 from which the strand passes to a backtwister 9 rotating in the opposite sense to the strander 1, both strander 1 and backtwister 9 being 'driven through suitable gearing from an electric motor 18. The backtwister 9 comprises a pair of rolls 11 and 12 about which the strand makes idle turns. From the backtwister the strand is drawn over pulleys 26, 27 and 28 by the winch 23 and is taken up on a reel 25. The pulley 28 is carried by an axle 29 mounted for rotation in a bearing 31. Any elasticity remaining in the strand causes the pulley 28 to rotate about its vertical axle 29 so bringing a contact member 32 mounted thereon into contact with either of members 33 or 34 depending upon the sense of the rotation and so completing an electric circuit operating an electric motor 35 causing the motor to rotate in one sense or another depending upon which of members 33 or 34 is contacted by the member 32. The motor 35 drives the outer cage 36 of a differential gearing through which the winch 23 is driven from the main motor 18 through shafts 24 and 37. The speed of rotation of shaft 24 and therefore of the winch 23 is varied relatively to the speed of the backtwister 9, and therefore the speed at which the strand is drawn through the apparatus is varied so altering the number of backtwists applied at 9 relatively to the twists applied at I to nullify the residual elasticity. When the finger 32 breaks contact with either of the members 33 or 34 the motor 35 stops and the shafts 24 and 37 again rotate at the same speed. In a modification the differential gearing can be interposed between the strander 1 and backtwister 9. The axle 29 may be replaced by a deformable silk or nylon strand. The pulleys 26, 27 and 28 may be arranged horizontally. Instead of the motor 35 an electromagnetic brake acting upon the cage 36 may be operated through the contacts 32, 33 and 34, the shaft 24 in this case operating at a higher speed with the brake off than is necessary to correct normal elasticity and the braking effect would cause variations in the reduction of speed of the shaft 24 to obtain the desired result.