Patent ID: 6384518
Filing Date: 2002-05-07
Classification: F16D,H01L

Abstract:
A controlled collapse joint for selectively controlling the relative motion of two bodies, the joint comprising:an outer member concentrically mounted on an inner member for relative motion about or along an axis; the outer member having an inner wall; the inner member comprising a piezoelectric cylinder having inner and outer walls, the piezoelectric cylinder being radially deformable in response to a voltage difference between the inner and outer walls of the cylinder; the outer member mounted on the piezoelectric cylinder with the inner wall of the outer member and the outer wall of the piezoelectric cylinder engaging each other in an initial interference fit to frictionally couple the inner and outer members and resist relative motion of the two members; means for mounting the outer member to a first body; means for mounting the inner member to a second body; a voltage source having terminals for generating a voltage difference across the terminals; first and second electrical connections for applying the voltage difference generated by the voltage source between the inner and outer walls of the piezoelectric cylinder to radially deform the piezoelectric cylinder and thereby vary the interference fit from the initial interference fit to an operating interference fit; the first electrical connection electrically connecting one terminal of the voltage source to the outer wall of the piezoelectric cylinder and the second electrical connection connecting the other terminal of the voltage source to the inner wall of the piezoelectric cylinder; and a control system operatively connected to the voltage source for selectively setting the voltage difference applied to the piezoelectric cylinder.