| 摘要 |
<p>A brake control arrangement (30) permitting normal service brake actuation through a brake linkage (10) and providing automatic brake actuation in case assisting fluid pressure decreases. During normal operation, sufficient assisting fluid pressure is supplied to a pressurizable chamber (42) to move an actuation piston (34) to its non-actuation position against the biasing force of a spring (36). When fluid pressure falls below the pressure needed to counteract the spring's biasing force, the spring (36) displaces the piston (34) to an actuation position relative to a surrounding housing (40) and, during its displacement, displaces a brake engagement plunger (32) to its brake engaged position. Movement of the utilizing apparatus may thereafter be provided by axially displacing an engagement member (48) against the actuation piston (34) so as to drive the actuation piston (34) to its non-actuation position. The engagement member (48) has an indentation (48b) which accepts displacement of the plunger (32) thereinto and permits subsequent brake actuation by the brake linkage (10). </p> |
