Parking brake actuator

Abstract

A parking brake actuator comprising a screw (1), a guide sleeve (2) slidably connected to a resistance sleeve (3), and an actuator piston (4) and a working spring (5, 6) placed between the surfaces of a rack (16) connected to the resistance sleeve (3) and the guide sleeve (2), wherein a nut (7) with a non-self-locking thread is mounted on the screw thread (1) constituting a conical clutch (8) with the guide sleeve (2), wherein a ratchet mechanism comprising a pawl (9) and a rod (10) is attached to the resistance sleeve (3). The parking brake actuator is characterized in that the ratchet mechanism is a pneumatic actuator comprising a piston (11), a cylinder (12), and a piston rod (9) constituting a pawl. The cylinder (12) of this pneumatic actuator is connected to a channel (13) supplying compressed air from the compressed air supply system of the piston (4).The actuator is configured so that the pawl (9) immobilizes the gear (16) under the influence of compressed air pressure supplied through the channel (13) to the actuator.