Disc brake with automatic adjustment

Abstract

Disc brake with automatic adjustment incorporating a calliper (10) mounted so as to slide on a fixed support by way of at least one axial pillar, a brake actuator (34) acting directly upon a first friction component, and by reaction through the calliper, upon a second friction component, the brake actuator (34) incorporating a mechanical control (48-50-60) acting upon a hydraulic control piston (36) through an automatic adjustment device (66), the adjustment device (66) being formed by a screw and nut system (68-70), which has a pitch which allows reverse action, and is capable of being actuated by the hydraulic piston (36) beyond a predetermined travel of the latter, the adjustment device (66) incorporating a sleeve (104) firmly fixed in rotation to the nut (70) and cooperating with annular control piston (80) which is capable of moving so as to be sealed relative to the screw (68) and relative to the brake actuator (34), the control piston (80) immobilizing the sleeve (104) in rotation and in translation when the hydraulic pressure acting on the hydraulic control piston (36) reaches a predetermined value. The screw and nut system (68-70) is positioned between the mechanical control (48-50-60) and the control piston (80); in addition, the brake actuator (34) incorporates a device for resetting manually to zero (114), which is capable of acting upon the nut (70) of the screw and nut system (68-70) in order to reset the automatic adjustment device (66) to zero.