Cam for revolving dobby

Claim 1

A cam and dobby apparatus comprising, a dobby and an intermittent-motion drive shaft including longitudinally extending, oppositely positioned grooves; a cam and plate member, said cam being positioned between said intermittent-motion drive shaft and a head of a main connecting rod that is installed idling on said intermittent-motion drive shaft, said plate member having a peripheral edge that extends outwardly from a surface of said plate member and includes oppositely positioned notches therein, first and second spring biased key levers pivotally connected to the surface of said plate member, one of said key levers having a first end that can be received by and cooperates with one of said grooves to lock said cam in rotatable position with said intermittent-motion drive shaft, said key levers each having second free ends terminating adjacent to said notches, said second free ends being supported and protected by said outwardly extending peripheral edge of said plate member; and a drive pusher and a rotatably hinged auxiliary pusher mounted on a common axis, thereby superimposing said drive pusher on said auxiliary pusher, each of said drive and auxiliary pushers have a thrust tooth at one end thereof that can be received by either of said notches, first spring means urging one end of said auxiliary pusher towards a fixed support and said auxiliary pusher thrust tooth into engagement with one of said notches and, second spring means engaging a shoulder of said drive pusher to force said thrust tooth of said drive pusher into said notch to engage one of said key levers and to disengage said first end of said key lever from said groove of said shaft.