Stock feeder for punch presses

Claim 1

In a pneumatic feeder for advancing stock into the work station of a punch press or the like; said feeder including: a frame; a feed slide mounted on said frame for reciprocating movement through feed and non-feed strokes; stock gripping means carried by said feed slide; a first fluid motor means for actuating said feed slide; a second fluid motor means for actuating said stock gripping means; and conduit means defining a pair of separate fluid conducting lines that are respectively connected to said first and second fluid motor means: a slide valve for controlling the operation of said first and second fluid motor means; said slide valve including means defining a smooth plate surface, said surface having at least three ports formed therein, two of said ports being disposed respectively at the ends of said pair of fluid conducting lines and one of said ports effectively defining an exhaust port; a valve cup member having an end face defining a smooth valving surface, said end face of said cup member being recessed, said cup member being movable back and forth between two operative valving positions while said smooth plate and valve cup surfaces are in mutual sliding engagement; conduit means adapted to continuously supply pressure fluid to a chamber formed in said slide valve so as to bias said valve cup member against said plate surface whereby when said valve cup member is in a first one of its said two operative positions one of said two fluid conducting lines is exposed to the pressure fluid in said valve chamber while the other of said fluid conducting lines is connected through said recessed end face of said valve cup member to said exhaust port, and vice versa when said valve cup member is shifted to the second one of its said two operative positions; a control plunger adapted to be operated in response to the operation of said punch press; and coupling means adapted to effectively couple said control plunger and said valve cup member whereby said valve cup member may be shifted between its said two operative positions in response to the movement of said control plunger.