Hole punch quick-change die assembly with clamp system

Abstract

Embodiments of an punch machine and a quick-change die assembly are shown and described. The die assembly may be quickly installed and removed from the punch machine, without bolting or unbolting of either machine housing or the die assembly itself. The die assembly is slid into the machine through a hole in the machine housing and into a position which mates part of the die assembly with the push-bar. A clamp, with a handle outside the machine, is then pivoted against the die assembly. The push-bar is adapted to be self-supporting without being bolted to the die assembly, keeping the push-bar in place without manual adjustment and alignment. The die assembly preferably includes a die, pin retainer, and punch pins, and preferably includes a flexible, pivotal, or hinged pin strap to secure the pins to the retainer. The preferred die assembly includes a positioning system that biases the pin retainer with its pin heads out from the die a proper distance for easy and unobstructed sliding into the machine housing and into a channel of the bar that drives the die assembly. The preferred die assembly system includes a clamp system with a resilient or spring-biased pivot bar that pivots against the die assembly to maintain tight clamping even after wear of the clamp system.