GB544230A - Improvements in and relating to protective devices for torque transmission - Google Patents

Abstract

544,230. Overload-release clutches. SELFCHANGING GEAR CO., Ltd., and DURSTON, W. H. R. Aug. 30, 1940, No. 13662. [Class 80 (ii)] In a protective device for limiting the amount of torque to be transmitted by a coupling of the type in which devices yieldingly held in clutching engagement are adapted-to disengage automatically when overload occurs, the yielding elements are under pneumatic pressure applied to them collectively by means of a diaphragm or applied to each element separately through a cylinder and piston. The members a, b to be coupled are provided respectively with flanges c, e into which are inserted at spaced intervals socket members d', f'. The members f' are bored to receive a ball o which is adapted to enter a slot d of smaller size in the corresponding member d'. The flange e overhangs the flange c and has bolted thereto a ring g which extends over the slots d. The bolts e' for securing this ring, also secure to the flange e an annular chamber h fitted with an annular diaphragm k secured by a cover plate l, the chamber h' on the other side of the diaphragm being adapted to be supplied with compressed air or other medium through a valve t. An annular plate m carries or acts upon a number of plungers n adapted to engage the balls o. The cover l carries a number of small cylinders p each containing a piston and packing ring q serving to control outlet ports s, the rods r of the pistons being in contact with the plate m. Upon overload occurring, the balls are forced back, the pistons q uncover the ports s to release the air pressure and the diaphragm and plate m are returned under the action of springs u assisted by vents v. In a modification, the annular pneumatic chamber is replaced by a series of separate cylinders spaced equally around the flange. In place of balls, bull-nosed plungers may be used.