Patent GB-718913-A (GB)
Title: Improvements in or relating to die ripping and polishing machines
IPC: B24B5/48
Filed: 1952-03-07
Abstract: 718,913. Ripping and polishing of dies. RUDKIN & RILEY, Ltd., and TARRY, F. H. March 6, 1953, [March 7, 1952.] No. 6008/52. Class 60. A die ripping and polishing machine comprises a work - holding chuck 8, Fig. 1, arranged with its axis vertical, and a vertically disposed lap spindle 9 adapted to be reciprocated up and down from eccentric or cam means through the medium of a component between which and the spindle yieldable drivetransmitting means are arranged to cushion the impact of the lap upon the work. In the preferred embodiment, the spindle 9 is reciprocated by an eccentric mounted on the end of a shaft 32, Fig. 2, and connected by a strap 30 to a collar 26 in adjustable screw - threaded and lockable engagement with a sleeve 19 which embraces a reduced portion 9d of the lap spindle. Two springs 22, 25 interposed between the ends of the sleeve and abutments 18 and 24 on the lap spindle constitute the yieldable drive-transmitting means. The shaft 32 is rotated by toothed gearing 35, 36, a shaft 37 and a V-belt drive 42 from one end of the spindle 43 of a double-ended electric motor mounted in a casing 44. To enable the lap to move circumferentially around the die aperture, the lap shank is gripped in a collet 12 carried on a universally-mounted portion 9b of the lap spindle. The portion 9b passes through a hole in an arm 57, Fig 4, pivotally mounted at 73 in a carrier 56 and provided with a spring-pressed ball 76 which subjects the spindle to lateral pressure. This pressure may be varied by adjustment of a screw 79 against which the arm 57 is held by a spring 77. The carrier 56 is rotated at about 12 r.p.m. by worm and bevel gearing and a V-belt drive 65 from the shaft 37. The latter may also be engaged by a hand-lever operated clutch 48, Fig. 2, with a V-belt drive 47 for rotating the lap spindle. When the clutch is disengaged, the lap spindle is held against rotation by the engagement of a screwed pin 17 with one of a number of holes in a disc 14 with which the spindle is slidably keyed. The die holder includes an open-topped cylindrical bowl 81, Fig. 3, having recesses 81a of different diameters to receive different sized dies, and a clamping plate 82 which is tightened against the action of springs 83 by nuts 84 to hold the die. The holder may be locked against rotation by a lever 104 or rotated through worm and bevel gearing, a manually-operable clutch 102 and V-belt drives 96, 92 from the lower end of the spindle 43. An impeller pump 106 mounted on a shaft 89 pumps liquid abrasive from a reservoir 105 into a cup 85 above the work, the abrasive draining back to the reservoir through a conduit 107. For ripping, a compound having a coarse abrasive action is employed, whereas for polishing a relatively fine, e.g. diamond, powder is used. For non-circular die holes, the spindle 9 is reciprocated only while for circular holes it is both reciprocated and rotated. The chuck 8 can rotate in both directions and may or may not be rotated in the treatment of both circular and non-circular holes. Specification 650,213 is referred to.