Back gauge warning system for shears and the like

Claim 1

In a shear or the like having frame means, means defining a generally horizontal support surface along which a workpiece may be moved preparatory to shearing the workpiece, cutter means supported by said frame means and having a cutting edge movable between a first position spaced above the plane of said support surface and a second position spaced below the plane of said support surface so as to shear a workpiece underlying said cutting edge when moved from its said first to its said second positions, back gauge means disposed rearwardly of said cutter means and movable with said cutting edge, said back gauge means being disposed to provide a stop against which the leading edge of a workpiece may abut to establish a predetermined length of the workpiece to be sheared by said cutting edge, said frame means defining a receiving area below said cutter means and said back gauge means to receive severed portions of workpieces which may progressively stack up, and drive means operative to effect selective movement of said cutter means and back gauge means between their said first and second positions; the combination therewith comprising safety means operatively associated with said frame means and adapted to detect the presence of stacked severed workpiece portions at a predetermined height in said receiving area below said cutter means and said back gauge means, said safety means including means for providing a signal when the stack of severed workpiece portions in said receiving area reaches said predetermined height such that an operator is notified to remove severed workpiece portions from below said cutting means and back gauge means before said stack reaches a height sufficient to be engaged by said back gauge means.