Patent GB-288414-A (GB)
Title: Improvements in machines for forming the eyes in needles
IPC: B21G1/00
Filed: 1927-02-24
Abstract: 288,414. Hall & Co., Ltd., W., and Groves, J. H. Feb. 24, 1927. Milling-machines.-A machine for forming the eyes in needles comprises a pair of groove-forming disc-like milling-cutters 1, 2 arranged in the same plane and moved relatively to the blank so as to cut longitudinal grooves on opposite sides thereof, the eye being subsequently completed by piercing the web of metal left between the grooves. The cutters are mounted between a shoulder 5 and collar 6 on parallel shafts 3, 4, which are carried in split bearings in brackets 11, 12 on main slides 13, 14, moving on guides 15, 16. The front end of the cutter-spindles are tapered at 17 and run in adjustable conical bushes 18. The rear spindle bearing is also fitted with an adjustable conical bush 20, and a slidable bearing- sleeve 22 to which is keyed a worm-wheel 25 is carried on a reduced end of the spindle 3, the parts being retained in position by a nut 26. The worm wheels are driven by worms 27 mounted on a shaft 28 driven by a pulley 31 or from fast an loose pulleys. The main, slides 13, 14 are reciprocated by cams 38, 42 arranged in pairs on parallel camshafts 40, 43 driven by worm gearing from the shaft 28. In a modification, the cam shafts may be driven independently, of the shaft 28. The slides are returned by springs 52. Auxiliary slides 53 mounted on the main slides terminate at the inner end in a work-gripping jaw 54 provided with a V-slot 55 to engage a blank 56 and slotted at 57 to allow the passage of the tools. The auxiliary slides are pressed towards the blank by springs 58, the movement being limited by a stop plate 61. The wire blanks which may be fed by hand or automatically are arranged in holes in a carrier 64 which slides in a slot in the bed, and the carrier is moved to bring successive blanks into pcsition opposite the tools by means of a weight 65 acting in conjunction with an escapement device. The lower ends of the blanks rest on an adjustable horizontal guide member 70, which is slotted at the part 71 beyond the operative plane of the tools. One sic.e of the carrier 64 is provided with ratchet teeth 73 and the escapement device comprises a pawl 74 engaging at 75 with the teeth 73 and coacting with a trip lever 78 mounted on a plate 80 on the main slide. A check pin 76 carried by the auxiliary slide also engages the teeth 73 when the auxiliary slide is in its inner position. On withdrawal of the main slide on completion of an operation, the lost motion between the main slide and the stop 61 is first taken up and thereafter both slides move together. During the first part of the movement the point 81 of the trip lever rocks the pawl 74 which is thus disengaged from the teeth 73. At the same time the heel 83 is brought against the ratchet teeth. The pin 76 is then withdrawn, whereupon the carrier moves forward, the heel 83 then being lifted by an advancing tooth to return the nose 75 into engagement with the teeth after the required spacing movement. A fresh blank is then brought, into position opposite the tools while the finished blank falls through the slot in the guide 70 into a receptacle. On return of the slides to the inner position the pin 76 re-engages the rack teeth and holds the same against movement while the trip lever is returned past the projection 82 of the escapement pawl.