Patent ID: 7572340

Claim:
A device for adjusting a spacing between a chamber body and a leveling plate, the device comprising: a mounting stud configured to be mounted to the chamber body, the mounting stud including a stud threaded surface; a bushing capable of being fixed to the leveling plate, by a retaining member the bushing including a bushing threaded surface; and an adjustment screw extending through an opening in the leveling plate and having a first threaded surface threadingly engaged with the stud threaded surface of the mounting stud, and a second threaded surface threadingly engaged with the bushing threaded surface of the bushing, the adjustment screw not threadingly engaged with the leveling plate; wherein the threaded surfaces are configured, when the bushing is fixed to the leveling plate and the adjustment screw is turned, to cause the adjustment screw to move in a first direction with respect to the mounting stud at a first rate and the bushing to move in a second direction opposite from the first direction with respect to the adjustment screw at a second rate which is different from the first rate, and when the bushing is not fixed to the leveling plate and the adjustment screw is turned, to cause the adjustment screw to move in the first direction with respect to the mounting stud at the first rate with the bushing rotating with the adjustment screw.