GB731273A - Improvements relating to power-operated presses - Google Patents

Abstract

731,273. Friction clutches. TAYLOR & CHALLEN, Ltd. June 24, 1953 [June 25, 1952], No. 15944/52. Class 80 (2). A plate clutch for a power press is operated by a slidable control collar 22 through a link 23 connected to one arm of a bell-crank lever 24 the other arm of which is connected through a toggle link 25 to the presser plate (not shown), the fulcrum 26 of the lever 24 being on a sleeve 27 which is splined on the driving member 17 and the position of which is automatically adjusted by a ring 28 which is caused to screw along the member 17 as the clutch plates wear. A bevel-ended spring-loaded radial plunger 29 in the collar 22 co-operates with the toe 38 of a lever 33 which is mounted on the sleeve 27 and which has a lost-motion connection 39, 40 with a second lever 34 connected by a link 42 to plates 44 carrying a pawl 47 co-operating with a ratchet wheel 50 carried by the member 27 and rigid with a worm 51 engaging wormteeth 52 on ring 28. The levers 33, 34 are spring-urged clockwise against stops. When the clutch is correctly adjusted and the collar 22 is in its leftward clutch-engaged position, plunger 29 is pressed in by lever 33 but remains beneath the toe 38, as shown in Fig. 5. As the clutch plates wear, however, collar 22 has to move further to the left for clutch engagement until plunger 29 passes beyond toe 38 and springs outwards, as shown in Fig. 2, so that on the subsequent rightward disengaging movement of collar 22 the lever 33 is turned anticlockwise'until its toe 38 can ride over the plunger. The lever 34 is thus also turned anticlockwise, after the lost-motion 39, 40 has been taken up, and causes the ratchet wheel 50 to turn so as to cause ring 28 to screw along member 17 and move sleeve 27 slightly to the left. This adjustment is repeated on successive operations of the clutch until the relationship of Fig. 5 is restored.