Abstract: A machine for operating on sheet stock workpieces having stock grippers mounted on a work positioning carriage for moving the sheet stock workpiece along first and second relatively transverse paths in the plane of the stock to position the workpiece at predetermined positions relative to the machine tools. Work grippers are mounted on the work positioning carriage for adjustment relative to the carriage when the work grippers are released and the work grippers are automatically clamped against movement relative to the carriage when the work grippers are actuated to grip the stock.

Abstract: A punch press having a hydraulic actuator for extending and retracting the ram, a stripper sleeve coaxial with and guidably engaging the ram, and a hydraulically operated clamp encircling the stripper sleeve and normally in a release condition guidably engaging the stripper sleeve. Hydraulic fluid pressure supply apparatus is operable to a first condition supplying fluid pressure to the hydraulic ram actuator to move the ram forwardly, and a stripper clamp spring yieldably urges the stripper sleeve forwardly into clamping engagement with the workpiece as the ram is moved forwardly. The hydraulic fluid pressure supply apparatus is operable to a second condition supplying fluid pressure to the hydraulically operated clamp to clamp the stripper sleeve against movement and to also supply fluid pressure to the hydraulic ram actuator to move the ram to a return position while the clamp holds the sleeve against return movement.