Clamp with workpiece locator

Claim 1

Apparatus for locating a workpiece of sheet material in a predetermined edgewise position, for holding the workpiece during the performance of a punching operation on the workpiece by a punch and for advancing the workpiece edgewise between successive punching operations, said apparatus comprising a support, a clamp on said support and having a pair of jaws, means for closing and opening said jaws to cause the jaws to grip and release said workpiece, means for moving said clamp on said support and in a direction parallel to one edge of said workpiece to enable advancement of said workpiece when said jaws are closed and to enable return of said clamp along and parallel to the edge of said workpiece when said jaws are open, means for temporarily holding said workpiece in a given position relative to said punch during the return of said clamp when said jaws are open, and a locator carried on said clamp for movement with the latter, said locator being movable relative to said jaws between (a) a projected position in which the locator is engageable by said one edge of said workpiece to locate the latter in a predetermined edgewise position with respect to said jaws preparatory to closing of the latter and (b) a retracted position in which the locator is spaced from said one edge of the workpiece to avoid being worn by such edge during the return of said clamp, and reversible power actuated means carried on said clamp for advancing said locator to said projected position preparatory to initial loading of said workpiece in said jaws and for returning said locator to said retracted position prior to the return of said clamp along said one edge of the workpiece, said reversible means being operable to move said locator between said projected and retracted positions while said clamp is in a stationary position on said support.