Internal shoe drum brakes for trailer vehicle - has greater braking force in one direction of drum rotation

摘要

The internal shoe drum braker for a trailer vehicle can be operated for parking as well as for service braking. They comprise a pair of brake shoes (66, 67) of which one is mounted on a carrier (68) for circumferential movement and an expanding device (53) which acts between the carrier and the other shoe. The brake shoe on the carrier abuts a stop when a predetermined expanding force is applied and the drum rotates in one sense. The braking force is greater when the drum rotates in one sense than in the other when the expanding force is less than the predetermined force. The brake allows reversal of the trailer vehicle.