GB214334A - Improvements in safety clutches adapted for use with power presses, shearing and other machines - Google Patents

Abstract

214,334. Rhodes, C. J., and Berry, G. W. Jan. 20, 1923. Operating clutches for power presses, shearing- machines, &c. wherein a crank or other shaft is to be arrested at intervals. A trigger carried by a resiliently-mounted rocking bracket is normally in engagement with a manually-operated member adapted to withdraw the trigger from the path of a rotatable declutching-abutment, upon which withdrawal the bracket rocks to free the trigger and permit it to obstruct the abutment and absorb the shock of impact. As applied to a segmentalkey clutch of the kind described in Specification 180,523, the key has an arm h normally engaged by a trigger f slidably mounted in a bracket l pivoted at l<1> to a frame d. On actuation of manual or pedal means to raise a rod a, a catch e, engaging by its slot g a pin h<1> on the trigger f, draws down the trigger against an adjustable spring i to free the arm h for clutch engagement. The bracket l immediately tilts under the action of an adjustable spring k until arrested by an abutment l<2>, thereby disengaging the trigger from the catch e, which is normally prevented from following the tilting movement under the pressure of an adjustable spring r by the hooked end of a slide p. The clutch is thus automatically released at the end of one revolution, the spring k cushioning the impact. Bv means of the bolt- and-slot connection q, the slide p can be so moved as to allow the parts e, h<1> to remain in engagement, when the ahaft j will continue to rotate so long as the pedal &c. is actuated. In a modification designed to reduce the depth of the device, the spring k is arranged to act horizontally on the back of the bracket l above its pivot l<1>, and the spring r is replaced by a tension spring connected to the rocking arm b and an extension of the catch e below its pivot e<2>.