Stamping die for producing smooth-edged metal parts having complex perimeter shapes

Abstract

A stamping die produces gears or other parts having quality tooth forms or the like from smooth edged metal blanks. A lower portion of the die includes a trim punch, whose perimeter shape corresponds to the shape of the desired part, and a vertically movable stripper plate surrounding the trim punch and having a recess for aligning the blank. An upper portion of the stamping die is vertically movable with respect to the lower portion, and includes a trim die. The trim die has a bore disposed therein complementary to the trim punch. A nest plate is affixed to the underside of the trim die, and has a tapered nest opening that aligns with the die bore. A controllably biased shedder passes through the bore and opening. During operation, a blank is first placed in the recess. A press ram subsequently descends, with the blank becoming sandwiched between the shedder and the trim punch, with a portion of the blank to be trimmed being left unsupported. The press ram then moves further downwards, with the trim punch in effect advancing into the bore and radiused cutting edges of the trim die trimming the blank. The trimmed scrap portions attempt to flow away from the trim punch, but are constrained by the nest plate, whose tapered shape causes the scrap portions to partially flow together, forming a scrap ring, which is removed from the trim punch via the stripper.