Patent ID: 7273333

Claim:
An apparatus for supporting a tool relative to a surface of a workpiece, the apparatus comprising: a base; a tool support coupled to the base and moveable along a translation axis relative to the base, the tool support being configured to be coupled to the tool, at least one of the base and the tool support being further configured to operatively position the tool relative to the workpiece for performing a manufacturing operation on the workpiece; a biasing device having a first portion operatively coupled to the base and a second portion coupled to the tool support, the first and second portions being moveably coupled and configured to apply a biasing force to the tool support to at least partially counterbalance a force exerted on the tool support along the translation axis by a weight of the tool coupled to the tool support, wherein the biasing device includes a pneumatic actuator; and a control valve coupled to the pneumatic actuator, the control valve being configured to adjustably control at least one of a magnitude and a direction of a biasing force applied to the tool support by adjustably controlling a pressure within the pneumatic actuator.