Wedge mechanism

A mechanical wedge mechanism comprising:

• a base member having a first contact surface;
• an output member having a second contact surface, the output member being supported with its second contact surface opposing the first contact surface of the base member, for motion along an axis which varies the separation between the first and second contact surfaces;
• a wedge member disposed between the first and second contact surfaces, having third and fourth non-parallel contact surfaces, the third contact surface of the wedge member being opposed to and conforming with the first contact surface of the base member and the fourth contact surface of the wedge member being opposed to and conforming with the second contact surface of the output member;
• the wedge member being supported for movement along an axis substantially perpendicular to the axis of movement of the output member;
• a thin constant thickness shim comprising at least one full layer of elastomeric material disposed between and contacting at least one contact surface of the wedge member and either the first contact surface of the base member or the second contact surface of the removable wedge member so that the relative motion between these contact surfaces is accommodated by internal shear said elastomeric layer;
• and
• said thin elastomeric layer having a length l in a dimension parallel to the motion of the wedge, a width w in a dimension normal to the motion of the wedge, and a thickness t in a third dimension, such that a ratio of l/t and a ratio of w/t are both greater than approximately 10.