Patent ID: 8196794

Claim:
A system for driving a self pierce rivet into a plurality of workpieces, the system comprising: a fixture having an aperture; a first die comprising: an anvil disposed along an axis, the anvil comprising: a first portion disposed in the aperture, and a second portion coaxially disposed with the first portion and extending away from the aperture; and a collar disposed in direct contact with the anvil and disposed about the axis, wherein the collar and anvil are provided as separate pieces wherein a groove is defined in a surface of the anvil, the groove being disposed between the anvil and the collar to partially separate an interior surface of the collar from the anvil; a second die; and an actuator disposed proximate the fixture, the actuator being configured to move the second die in an axial direction between a retracted position and an advanced position to axially drive the self pierce rivet such that the first die is spaced apart from the self pierce rivet; wherein the anvil and collar cooperate to reduce stresses and inhibit breaking of the first die.