GB525515A - Improvements in or relating to driving mechanism for presses or other machines - Google Patents

Abstract

525,515. Clutches; gearing for stopping and starting presses &c. BRITISH UNITED SHOE MACHINERY CO., Ltd., GOULDBOURN, J., and KEALL, F. B. Feb. 27, 1939, No. 6369. [Class 80 (ii)] A one-revolution combined friction and positive clutch for a clicking press or other machine comprises a main shaft 10 carrying fixed to it a hub 12 with a sliding bolt 14 for actuating a friction clutch, and a pawl 16 for actuating a positive clutch for securing a driving flywheel 18 to the shaft 10. The bolt 14 is actuated by a manually movable tripping lever 50 and two cam blocks 52, 54 on the machine frame. The lever 50 carries a latching lever 56 with tail 57 engaged by a cam 58 on the hub 12 and a tripplate 59 co-operating with a trip-plate 60 on a lever 62. The pawl 16 is pivoted on a stud 41 on the hub and is urged outwards by a spring plunger 42 in the hub. The pawl carries an extension 45 engaging a cam 46 on the machine frame which allows the, plunger 42 to push the end of the pawl 16 into the path of teeth 48 on a ring 20 on the flywheel and positively clutch the shaft 10 to the flywheel. A light brake 72 is permanently applied to the shaft 10. Operation. Raising a starting rod 61 lifts the lower end of the lever 50 free of the bolt 14 which moves axially under spring pressure to turn a lever to tighten a friction band 24 and rotate the shaft 10. The cam 58 lifts the tail 57 to disengage trip-plates 59, 60 and a spring 63 restores the lever 50. As soon as the bolt engages the cam 52 it is pushed back to relieve the friction clutch to aid the engaging of the positive clutch. The extension 45 of the pawl 16 drops into a recess 47 and the pawl moves out and engages the teeth 48. The ring 20 of the flywheel is rotating faster than the hub 12. When the bolt 14 has passed the cam 52 the friction clutch is re-engaged and both clutches are operative until pawl extension 45 reaches the edge 49 of the cam 46 which pushes in the pawl and disengages the positive clutch. The friction clutch is disengaged as the end of the bolt 14 reaches the cam 54. The momentum of the parts restores the mechanism to the position shown in Fig. 2. The friction clutch may be disengaged after the positive clutch. Specification 22023/05, [Class 31], is referred to.