Food packing machinery with differential force-controlled packing action

Claim 1

In a food packing machine including rotary turret mechanism having a cake-forming cavity movable with the mechanism through a defined cake-forming zone in the machine, a piston holder mounted for reciprocation toward and away from an entrance to the cavity, and a piston having a work face for compressing material in said cavity mounted in the holder for reciprocation between a pair of limit positions relative thereto into and out of the cavity through such entrance, one of said limit positions occurring with the piston maximally extended relative to the holder, and the other occurring with the piston minimally extended relative to the holder, piston drive means comprising spring means operatively interposed in said holder between the piston and an end of said holder urging the piston toward its said one limit position relative to the holder, and cam means operatively associated with the holder for guiding the same toward the cavity with movement of the cavity toward the cake-forming zone, said cam means, in the cake-forming zone, being constructed to effect placement of the piston in its said other limit position with the piston's work face adjacent the cavity's entrance.