Patent ID: 7971883

Claim:
A combination comprising: a pallet configured to have a plurality of workholding assemblies attached thereto, the pallet being configured to be mounted to a base machine; and a failsafe workholding clamping assembly mounted to the pallet, the failsafe workholding clamping assembly comprising: a base; a draw bar operatively connected to the base for movement along an axis relative to the base between open and closed positions; a structure operatively connected to the base for movement along the axis relative to the base between open and closed positions; a driver that operatively extends between the base and the structure and applies a continuous driving force to the structure that tends to bias the structure toward its closed position; a force amplifier operatively extending between the structure and the draw bar, the force amplifier amplifying the driving force and applying a resulting amplified force to the draw bar to bias the draw bar toward its closed position; and a collet opener supported by the base and constructed and arranged to apply a force to the structure that counteracts the driving force with an opening force, thereby preventing the driver from biasing the draw bar toward the closed position.