Triple action mechanism for producing high reduction cups in a double

Abstract

This invention relates to apparatus adaptable for use on a double acting press for producing high reduction metallic cups of high quality. The double acting press is provided with a crankshaft having a pair of offset cranks for attachment to the outer punch holder and the redraw horn assembly to produce a time lag between the operation of the outer punch holder and the redraw horn assembly. The high reduction cupping apparatus comprises a housing having an opening extending vertically therethrough, a redraw horn assembly centrally mounted in the housing for reciprocation therein, a pair of vertically disposed redraw cushion cylinders positioned within and in the upper portion of the housing, said redraw cushion cylinder surrounding the upper portion of the redraw horn assembly, a cushion piston movably carried in each cushion cylinder, said redraw cushion pistons being in engagement with each other for cumulative pressure effects, a cylindrical drawn horn and pressure sleeve fitting around the redraw horn assembly and having its upper portion engageable by the lower redraw cushion piston, a pair of vertically displaced pressure ring cylinders positioned within the housing and around the redraw horn assembly immediately below the redraw cushion cylinder pair, each pressure ring cylinder carrying a pressure ring piston fitting around the draw horn, said pressure ring pistons being in engagement with each other for cumulative pressure effects, a pressure ring reciprocably carried in the lower end of the housing and fitting around the lower end of the draw horn, the lower pressure ring piston engaging and applying cumulative pressure to the pressure ring, an annular cutter fixedly mounted on the lower end of the housing and surrounding the lower end of the pressure ring, a stationary die holder positioned beneath the lower end of the housing, said die holder having a central vertically extending hole therethrough, concentrically located with the above parts, a blank and draw die mounted in the upper portion of the die holder concentrically with this aforementioned hole, said blank and draw die having an external diameter slightly less than that of the annular cutter so that a shearing action may take place therebetween, the inner diameter of the blank draw die being sized to receive the draw horn in the drawing operation, a redraw die mounted in the die holder concentrically with the hole in the die holder, said redraw die being sized to receive the redraw horn assembly in the redrawing operation.