| 摘要 |
<p>The automatic change over switch is activated by pressure differential, utilises a cambered compressed coil spring, and may be used on a compressed air feed to effect the switch to a reserve supply. A hollow casing has two inlets and one or more outlets, accommodating a sliding piston obturator which reciprocates axially to seal off one or other of the inlets. Initial piston movement is caused by pressure differential at the inlets, being terminated by a bistable coil spring. In a permanent state of compression, the spring traverses a central diametric piston bore, and acts to assist a particular piston movement once a central dead point is passed. One of the spring end mountings may be adjustable, the piston bore may take a conical venturi form, and compressible seals may be employed.</p> |
