Brake actuator apparatus and method for actuating a brake

A method for actuating a brake comprising the steps of:

• moving an abutment member to abut a piezo-electric device against a force transmission element operable for transmitting a brake actuating force, wherein the abutment member is moveable to cause the piezo-electric device to selectively abut against and disengage from the force transmission element, wherein the abutment member includes a first threaded portion in engagement with a first body member, and the abutment member moves by relative rotation between the abutment member and the first body member;
• expanding the piezo-electric device to apply a force between the abutment member and the force transmission element to move the force transmission element in a direction of brake actuation from a first position into a second position;
• moving a support member independently of the abutment member into abutment with the force transmission element to support the force transmission element in the second position, wherein the support member includes a second threaded portion in engagement with a second body member, and the support member moves by relative rotation between the support member and the second body member and wherein the support member and the abutment member are co-axially arranged;
• contracting the piezo-electric device;
• repeating the step of moving the abutment member;
• and
• expanding the piezo-electric device to apply the force between the abutment member and the force transmission element to move the force transmission element in the direction of brake actuation from the second position to a third position.

The method for actuating a brake according to claim 9 further comprising the steps of:

• moving the abutment member out of abutment with the force transmission element while the force transmission element is supported by the support member and the piezo-electric device is contracted;
• expanding the piezo-electric device to abut the abutment member on the force transmission element;
• moving the support member away from the force transmission element;
• contracting the piezo-electric device to cause the support member to support the force transmission element;
• and
• repeating the steps of moving the abutment member, expanding the piezo-electric device, moving the support member, and contracting the piezo-element to release the brake.