Patent GB-474813-A (GB)
Title: Wire tying machine
IPC: B65B13/28
Filed: 1936-05-08
Abstract: 474,813. Wiring packages. HARVEY, H. May 8, 1936, No. 13079. [Class 45] A machine for tensioning, tying, and severing a placed wire about an article has wireseparating means adjacent each end of a twisting pinion to limit the length of the twist applied to the overlapping ends of the wire. Two forms of 'machine are described, (1) a portable machine adapted to be applied to individual articles and (2) a stationary machine having a work bench on which the articles to be wired are placed. The machines may be driven manually or by power, the portable machine being described as manually operated and the stationary machine as power driven. The portable machine has gripping dogs carried at the ends of arms 33, 34, Fig. 1, which are coupled by links 35, 36 to fixed pivots 37, 40 and by links 44, 45 to pivots 46, 47 on a slide 43 which is reciprocated to separate the grippers by a toggle action and thus apply tension to the wire. The arms 33, 34 pass through slots in a tube 55 housing a spring 50, Fig. 4, coupling the arms together so that the tensioning effort is automatically equally distributed between the two grippers. Each gripping device comprises a shoe 67 pivoted at 68 to the gripper arms and subject to the influence of a spring 69. A gripping dog 72 is slidable within the shoe 67, and is coupled by a thrust link 74 to the end of the gripper arm. The gripper is maintained open to facilitate the placing of the wire by a spring-urged pivoted latch 80 on the frame, which engages with a lug 79 on the shoe, the latch having an extension 83 with which the wire may engage during placing, to trip the gripping engagement with the wire. The wire 172 is led through the gripper 72, then into the twisting-pinion slot 91, round the package, back through the slot 91 and thence to the gripper on the other gripper arm. The twisting-pinion slot and the slots between the gripping dogs and their co-operating surfaces on the shoes 67 are so disposed when loading as to lie in the plane of the wire round the package and after the overlapping wires have been twisted together the ends are severed and the twisting pinion is rotated back a part of a revolution corresponding to the overtwist, in order to release the tie. The twisting pinion is supported by peripheral bearings 94, 95 and internal bearings 98, 99 screwed thereto, the engagement of the bearings 94, 95, 98, 99 extending only over a sector of the pinion so that the slot in the pinion is fully exposed in both the wire-loading and the wiredischarging positions. The wire having been positioned and secured in the grippers, the slide 43 is advanced to separate the grippers and tension the wire, the advance of the slide being effected by a dog 124, Fig. 3, engaging in a slot 125 in the slide and carried by an arm 123 which is carried by a link 121 hung on a fixed pivot 122 and actuated by a link 118 coupled to a quadrant 113 which swings about a shaft 114 as controlled by a handle 116. A second handle 106 mounted on a shaft 111 is geared to the quadrant 113 and carries a pawl 136 which is inoperative during movement of the handles to strain the wire, but which, on the return movement of the handles, is released to engage the teeth of a gear wheel 133 in order to rotate the twisting pinion. The wheel 133 has secured thereto a cam having concave faces adapted to be engaged by corresponding surfaces on a lever 153 which is urged by a spring 155 to tend to maintain the wheel 133 in one of two positions. The engagement of the pawl 136 with the wheel 133 is governed by a spring-urged arm 137 secured to the pawl and controlled by a cam 141 secured to the wheel 133. The pawl 136 has a cam surface 146 which is adapted to engage with a roller 147 so that a predetermined amount of overtwist may be imparted to the wires, the roller 147 causing the arm 137 to engage more deeply in the cam slots in the cam 141 during movement of the handle 106 to produce overtwist. On return movement of the handle 106 in a clockwise direction, the pawl 136 positively rotates the twisting pinion from the overtwist position to the discharge position, after which the release of the pawl from the roller 147 allows the arm 137 to ride out of the cam slot in the cam 141, thereby disengaging the pawl from the gear wheel 133. The position of the handle when the pawl disengages corresponds to the point in the cycle of operations at which the wire is severed and the cam which, at the same moment, is displaced from a position of full engagement with the lever 153, is thereupon rotated by the lever 153 to return the cam to full engagement with the lever 153 and thus to rotate the pinion to wire - loading position. To limit the length of the twist applied to the wires, pointed separators 166, Fig. 11, carried by the slide 43, are inserted between the superposed wires adjacent each end of the twisting pinion as the slide is advanced. Severing blades 165 are loosely coupled to the slide by lugs 163 and are urged downwardly by spring plungers 171 in such manner that the blades ride over the upper of the superposed wires on forward movement of the slide, but cut the same on rearward movement of the slide. The lost motion provided by the slot 125 ensures that the slide is not actuated on return of the handles 106, 116, until the twisting is complete. On actuation of the slide, the breaking of the toggle enables the spring 50 to return the slide and attached parts quickly to initial position. The stationary machine includes a bench 200, Figs 15, 17, having at the front edge a gap for a slotted twisting pinion 206 which is driven by gearing 222, 220 actuated by a toothed quadrant 219 controlled positively through a bell-crank 217 by cams 213, 223. The quadrant 219 is also coupled by a link 316 to pivoted arms 312 having cutting edges 332. A cam 291 engages a roller 293 on a bell-crank 278 to actuate a cross-head 275 connected through a spring 286 to a plunger 272 coupled by links 266, Fig. 16, to gripper arms 227, 229 in order to tension the wire. The gripping arms have pivoted dogs 242 which are automatically swung to open-jaw position by catches 246 when the arms are in retracted position but the placing of a wire in the left hand gripper trips the catch and allows the dog to close on to the wire. After placing the wire in the slot of the twisting pinion and leading it round the package 335 on the bench top 200 and again into the twisting pinion slot, the wire is inserted in the righthand gripper, the placing of the wire lifting a latch 257 to release the gripper dog 253 and causing the latch to actuate an arm 326 of a trip lever, whereupon a control shaft 328 is rocked to allow a one-revolution clutch to couple a continuously running motor shaft 321 to the cam shaft 210. The cam shaft has a cam 301, Fig. 18, operating linkage 305, 308 which projects wire separators 298 to a position 299 between superposed wires and, after the wires have been tensioned, twisted and severed, further projects the separators to a position 300 to eject the tie from the slot of the twisting pinion. The severing of the wires allows the compressed spring 286 to throw the gripper arms apart, whereupon a pin 338 on the gripping dog 253 engages a stop 337 and resets the gripping dog under the latch 257, this action causing the onerevolution clutch to be disengaged. The twisting pinion driving cam has a hump 336 to rotate the pinion backwards an amount corresponding to the overtwist prior to cutting and one or both of the arms 312 has a hook extension 332 to retain the wires in the twisting pinion slot until the cutting operation. A guard plate 341 is fitted at the front of the machine and serves to guide the wire into the slot of the twisting pinion.