Improvements in and relating to hand brakes for motor vehicles, more particularly lorries and omnibuses

摘要

775,533. Vehicle handbrakes. MASCHINENFABRIK AUGSBERG-NURNBERGAKTGES. Sept. 23, 1955 [Sept. 30, 1954], No. 27165/55. Class 103 (1). In a spring servo-operated handbrake, particularly for lorries and omnibuses, it is arranged that the release of the hand lever locking pawl 17 and the movement of the pawl 18 from its position shown in Fig. 3 to that in Fig. 5, causes spring operation of a valve 29 which opens to atmosphere the space below a diaphragm 39 in a valve chamber at one end of the spring servo-cylinder. The diaphragm is thus flexed upwardly by the fluid pressure holding off the brake in the space 44 to the left of piston 46, thus shutting off the supply port 33 and allowing air in the cylinder to escape through port 40. Slack in the brake rigging is thus quickly taken up by the expansion of main springs 53, 55 and the brake may be fully applied by a single movement of the hand lever 2. Air is also released from the right to piston 63 which is moved to the right by springs 65 so that balls 68 leave a groove 67 and the rod 67 is effectively locked to the sleeve 59.