Patent GB-154977-A (GB)
Title: Improvements in wire making machines
IPC: B21B1/20
Filed: 1919-09-01
Abstract: 154,977. British Thomson - Houston Co., (General Electric Co.). Sept. 1, 1919. Rolling.-In an electricallv-controlled wire-rolling machine, particularly intended for rolling sheathed resistance wire, a straight length of wire is passed back and forth between multi-grooved rolls, the under roll being lowered automatically after each double pass and the wire transferred to the next groove, being given a quarter turn at the same time, until the smallest groove is reached, after which the rolls are permanently opened and the transfer mechanism is put out of action. The wire is held by clamps 16 in carriages 17 supplied by rollers on guide-bars 19 which are carried on supports 82, movable transversely across the machine to effect the transference of the wire, for which purpose racks 81 on the supports 82 are engaged by pinions 80 on the axle of a ratchet wheel 84 which is given a step-by-step motion by a pawl 83 actuated by the lower roll in moving downward. At the end of the cross traverse the pawl 83 is held out of action by a finger 83<c> on a sliding bar 83<a> moved by the guide-bar 19. The partial rotation of the wire is produced by a stationary rack co-operating with a pinion carried by each clamp 16. The grooves are of V-section and the length of wire is held taut by cables 85 wound on drums 86 and tensioned by means of pistons in compressed-air cylinders 87. Each carriage 17 at the end of its inward travel rocks one of the frames B and moves the bar 38, thereby operating a valve admitting air to one side or the other of a piston in the cylinder 33. A sliding shaft 28 and clutch member 27 are thus moved, connecting one or other of the pulleys 24, 25 (driven by open and crossed belts from the main motor 20) with the worm shaft 26 driving the rolls through toothed gearing of ordinary kind. After each double pass of the wire the lower roll 12 is moved downward to open the rolls by means of rods 53 and eccentrics 51 on a shaft 40 which is clutched to a conveniently-placed wheel in the driving train by the action ci a magnet 50, which controls a valve admitting air to a cylinder 45 so as to operate a piston on a rod 44 which puts the clutch in. The excitation of the magnet 50 is controlled by contacts 69, 70 which are closed by the rocking of one of the frames B, acting in conjunction with a detent 77 on a bar 75, depressed when the roll 12 is lowered. The rod 44 and clutch are locked by an arm 58, which is pushed up, by means of a spring 59 and rod 60, behind the end of the rod 44, so holding the clutch for one complete revolution of the shaft 40, corresponding to the opening and closing of the rolls. The rod 44 is then released by means of a cam projection 63 on the shaft 40, acting on. the upper end of the arm 58. At the end of a series of passes, the rod 44 is released when the rolls are in the open position by the action of a magnet 65 and contacts 66, 67, the first stationary, the second mounted on one of the carriages 17. A toggle 65<a> is thus operated so as to bring a projection 65<g> into the path of the cam 63 after half a revolution. The rolls may be permanently opened at any time by means of a hand-operated switch 91. Fig. 12 is a diagram of the electrical connexions and Fig. 13 shows the tapered end of the wire as left after rolling, with a layer 97 of insulating material (such as magnesia) which should be a fairly good conductor of heat, between the wire and the metal sheath 96. The upper members of the frames B, which are engaged by the carriages 17, are made each with an inclined face, so that the reversals take place progressively sooner as the wire is traversed across the rolls, the result being the tapered end shown.