Lock cylinder with overload coupling

摘要

The core(4) rotates in a housing(2), and is locked by tumblers(5) to a bush(6) between it and the latter on taking the key out of the keyhole(3). On turning the core with a wrong key or a tool an overload coupling(7) uncouples an output member(8) from the core, and has a driving dog(16) sliding in the radial direction and engaging in the output member. The control lever(9) extends in the lengthwise direction of the cylinder(1) and rocks on the bush via a knife-edge(11) extending towards the housing. The lever end(12) furthest from the dos bears under overload against a ramp face(13) on the bush, so that when the latter turns on its axis the other lever end(13) thrusts the dog radially inwards against spring action(17), freeing it from engagement in the recess in the output member.