摘要 |
(Case No. 7079) A parking brake, primarily for use with railway vehicles, including a friction clutch associated with a fast-travel nut which is locked by the clutch against rotation on a threaded spindle connected to a brake head, under a force exerted by a plurality of stacked Belleville-type disc springs. The spring load may be overcome by air pressure acting on respective faces of a plurality of serially connected pistons, which, in effect releases the fast-travel nut for free spinning to thereby accommodate axial displacement of the spindle during normal service application and release of the brakes. |