摘要 |
A pressure operated switch device in which switch operation is effected by movement of the diaphragm in response to a fluid pressure difference across it, permanent magnets (40, 41) hold the diagphragm assembly (10) against switch operating movement until a reset device (45) is operated to release the diaphragm assembly from the magnets. A further permanent magnet (32) assists snap action and movement of the diaphragm assembly against the plungers of microswitches (20, 21), mounted on a bracket (25) which limits diaphragm movement against the plungers. A return spring (36) biasses the diaphragm assembly against the permanent magnets (40, 41). |