Patent ID: 7772832

Claim:
A manipulator for positioning a test head on a tester, the manipulator comprising: positioning means for three-dimensionally positioning the test head; a cradle connected to the positioning means and secured to the test head; a compensator loadable by a weight of the test head; the positioning means comprising a column and at least one lead screw extending in a vertical direction; the compensator being connected to the cradle and being moveable by the lead screw in the vertical direction; and the compensator comprising a driver cooperating with the lead screw and which is guided in the vertical direction on the column, and a spring element which is biased and supported by the driver, wherein the compensator includes a housing through which the lead screw extends and in which the spring element is disposed, wherein the housing comprises an inner sleeve and an outer sleeve connected to the inner sleeve, wherein the inner sleeve threadingly engages the outer sleeve, and the outer sleeve includes a lug.