Positive clutch with dual releasing cams

Claim 1

A clutch for use in power-operated hospital beds and like service for selectively coupling two aligned shafts in driving engagement comprising a driving member fixed near the end of one of the shafts for rotation thereby and comprising a hub having at least a pair of opposed radially projecting lugs, a driven member fixed near the end of the other shaft in facing relation to said driving member, a pair of opposed clutch dogs pivoted to the driven member on axes transverse of the rotational axis and swingable thereon in planes radial to said driving member from an engaged position at which the dogs intercept the lugs of the driving member, and a disengaged position at which the said lugs rotate freely without striking the dogs, spring means urging said dogs inwardly to intercept said lugs, an actuator on said driving shaft shiftable axially thereof and having a pair of opposed axially spaced cam surfaces which are separated by an intervening dwell surface, each of said dogs having a follower finger adapted to follow said cam surfaces and said dwell surface of said actuator as the same is shifted axially of said driving shaft thereby to effect engagement of the clutch dogs with said driving lugs and to effect disengagement thereof when said follower fingers are located at said intervening dwell surface, and means for shifting said actuator axially of said driving shaft.