| 摘要 |
<p>1290750 Indicating failure of braking system BENDIX CORP 18 Aug 1970 [2 Sept 1969] 39648/70 Heading F2E [Also in Division H1] A differential pressure switch for indicating failure in one of the two halves of a split braking system, comprises two pistons 32, 34 loose in a bore 14 with a switch actuating cam 37 between them. Each piston 32, 34 carries a stop 74 which in the central position shown rests against a retainer 64, 65 urged by a spring 62, 63 against the end of the bore 14. When the brakes are applied the pressures in the two halves of the system are applied at ports 18 to the ends of the pistons. If the applied pressures are equal the assembly of pistons 32, 34 and cam 37 remains fixed. If one pressure is smaller the whole assembly is driven to the right or left, a button 40 of a switch riding up a slope 38 on to a flat 39 on the cam to close the switch and energize a warning lamp 44. When the brakes are released the trailing piston is returned to the position shown by the spring acting through the respective retainer and stop 74. The leading piston however, -having no restoring force, remains where it is, as does the cam 37 and therefore the switch remains closed. If, when the brakes are operated again, the failure has been overcome, the pressure returns the second piston and the cam to the central position.</p> |
