Patent GB-1476204-A (GB)
Title: Apparatus and method for use for coil tying
IPC: H02K15/04
Filed: 1974-07-19
Abstract: 1476204 Tying up end turns of coil windings GENERAL ELECTRIC CO 19 July 1974 [7 Aug 1973] 32067/74 Heading B8G [Also in Division B3] The invention relates to an apparatus, Fig. 1, for lacing the end turns 14, 16 of coils extending from a core 17 and in which, as the core 17 is rotated in steps by a shaft 18, a reciprocating cord tube 24 operating in conjunction with a lacing hook stitches or ties cord about the upper end turns 14. The cord tube 24 receives cord from a supply 13. There is a further cord tube (not shown) for the lower end turns 16, this further cord tube receiving a cord 69 (not shown) from a further supply.  According to the invention, when a cord lacing operation is completed, cord pullers 26, 27 are advanced to grip the cords 68, (69) and exert a pulling action on them away from the turns 14, 16; there being control means for providing a signal either at a predetermined time after a new tying cycle has commenced or after a predetermined number of stiches of a new tying cycle have been completed, the pullers 26, 27 including a mechanism for releasing their grip on the cords 68, (69) when a signal is provided by said control means. Fig. 2 shows a portion of a cord puller comprising a plunger 57 in a cylinder 64, the cylinder 64 having a slot 67 acting as a clamping anvil edge for a cord when the plunger 57 is moved along the cylinder 64. In Fig. 3, showing the upper pulling means 26 only, a piston rod 37 has moved a slide block 36 to the right, the slide block 36 carrying a cord puller 26 and associated means 30, 49, 52, 54, 57, 59 for actuating the plunger 57 in the cylinder 64. In this right hand setting of the puller 26 the cord 68 can be caught in the slot 67. Fig. 4 shows how the piston 52 has now been extended to force the plunger 57 along the tube 64 and so cause the cord 68 to be gripped in the slot 67. The piston rod 37 is then actuated to pull the slide block 36 to the left and so cause the closed puller 26 to exert a pulling action on the cord 68, the piston 52 remaining extended during this pulling period to ensure that the cord 68 remains clamped in the puller 26. During retraction of the rod 37, a cutter 62 on the puller 26 severs the portion of the final cord segment that had extended between cord puller 26 and the laced end turns on the last core which was laced. The final cord segment 68 however, continues to be held by cord puller 26; and this segment extends from the cord puller to the cord tube 24. Thereafter, the core which has just been laced is removed from the shaft 18; and an unlaced core is positioned in its place. Stitching of the end turns of the new core is then commenced, with the new core indexing after the formation of each stitch. As the new core starts indexing, the cord segment 68 becomes taut. However, before the cord tension becomes sufficiently great to pull the cord segment 68 free from the cord puller 26, or sufficiently great to interfere with proper, indexing of the core being laced; the cylinder 49 is vented, for example by a valve which connects conduit 30 to atmosphere. This allows the compressed spring 59 to force piston rod 52 to return to a position within the cylinder 49 and so release the cord 68. The signal for the cord to be released may be generated by a flag on the shaft 18 passing a fixed sensor.