Brake self-acting lining wear adjuster - has opposed pistons unaffected by variation in clearance due to thermal expansion

摘要

The nut on the stud of the piston is held in contact with the conical bore of the adjuster by spring. When the pistons move apart slowly due to thermal expansion the nut rotates due to the rotation imparted to the adjuster by the pin sliding in the oblique slot in the extension of the piston. As the pistons resume their initial position the nut rotates back to its original position. When the brake is suddenly applied the friction ring restrains the adjuster and the nut is not rotated. When the brake is released the adjuster being now in contact with the nut rotates it to a new position.