GB889035A - Improvements in and relating to control devices - Google Patents

Abstract

889,035. Gearing for stopping and starting machinery; epicyclic gearing. SOC. AUXILIAIRE D'INDUSTRIE (SADI) S.P.R.L. May 30, 1958 [June 3, 1957], No. 17389/58. Classes 80 (1) and 80 (2). Gearing for stopping machinery on overload comprises an input sun-wheel shaft 1 and output planetwheel shaft 5 and reaction ring 6 which is positively held for a predetermined number of revolutions under control of a delaying device 16 and thereafter is held frictionally by a torque limiter 7 which on overload slips, permitting rotation of the ring gear 6 and operation of a signal and stop device 35 of the driving motor. On starting, the ring 6 is positively held in one direction by one (29) of two oppositely-directed toothed plates 28, 29, which engage ratchet teeth 9, 10 on the casing. After a predetermined number of revolutions the delay device 16, described below, permits rotation of a shaft 22 and discs 23, 24 splined thereto whereupon balls 25, in helical cam grooves between the plates 23, 24 and 28, 29, move the latter axially, engaging the oppositelydirected ratchet clutch 9, 28 and disengaging the clutch 10, 29 thereby releasing the positive hold on the ring gear 6 in the reaction direction, the ring being then held by a member 7 frictionally between a fixed flange 9 and an axially-slidable adjustably spring-pressed flange 10. On overload the member 7 slips, permitting rotation of the ring 6 which breaks the drive. The ring 6 takes along a member 33, Fig. 4, which frictionally engages an eccentric cam groove 34 in the ring gear until an abutment 39 on the member 33 engages a piston 41, whereupon the member 33 slips and after half a revolution of the ring gear the abutment 39 moves under the piston 41 (Fig. 5, not shown), which engages a lip 37 on a member 35 rotation ally fixed to the member 33, and during the next half revolution, the abutment 39 rises, pushing up the piston 41 to the level of the member 35 which then rotates with the ring gear 6 until it abuts a stop 42, maintaining the piston in the stop position of the motor for that direction of rotation. On rotation of the input shaft in the opposite direction the ring gear and members 33, 35 are permitted a slight rotation by a lost-motion connection between the torque limiter 7 and ring gear to reset the stop device 35 before being held against rotation. The delay device 16 comprises a lug on the planet carrier 3 which turns a toothed pinion 16 carried by a member 21 fast with the shaft 22 through part of a revolution for each revolution of the carrier 3. Lugs 17, 18 on the pinion 16 engage recesses in plates 19, 20 and turn the latter until one of the lugs engages a smaller recess whereupon the whole device is locked solid to rotate the shaft 22. The signal may be a bell as a light which indicates that the motor is stopped.