Drive mechanism for multiple plungers

Claim 1

IN an apparatus of the character described, the combination of: a fixed structure; a power-actuated rotary structure adjacent the fixed support structure; a plurality of longitudinally extending guideways mounted on the rotary structure and spaced circumferentially thereof; a corresponding plurality of longitudinally extending plungers mounted in the guideways respectively, each of said plungers having a working end and a trailing end; fixed cam means on the fixed structure positioned concentrically of the series of plungers and forming two opposite continuous cam walls; two follower means mounted on the trailing ends of the respective plungers in moving contact with said two cam walls respectively, said cam walls being shaped to reciprocate the plungers in said guideways in the course of each revolution of the rotary structure; a corresponding plurality of first die means mounted on the leading ends of the plungers respectively for movement therewith; a corresponding plurality of second die means paired with the first die means respectively and mounted on the rotary structure in alignment with the first die means for cooperation therewith to process successive workpieces; means to feed successive workpieces to said pairs of dies; means to remove the successive processed workpieces; said guideways and corresponding plungers being of complementary noncircular cross-sectional configuration to prevent rotation of the plungers on the axes; and a pair of cooperating engagement means incorporated in each of said guideways in engagement with the periphery of the corresponding plunger to oppose rotation of the plunger on its axis in opposite rotary directions respectively, said two-cooperating engagement means being preloaded against each other to keep the plungers from rotating on their axes and in doing so to minimize backlash between the plungers and the corresponding guideways.