| 摘要 |
912,862. Automatic circuit - breakers; switches held set and freed mechanically; thermal switches. MIDLAND ELECTRIC MANUFACTURING CO. Ltd. March 14, 1961 [March 14, 1960], No. 8839/60. Class 38 (5). An overload responsive switch has a bimetallic element 15 which serves both as a release means for effecting tripping of main contacts 11, 13, and as an auxiliary contact member which engages a co-operating auxiliary contact 23 when the current through the switch approaches the value at which main contacts are tripped. In the arrangement shown, the element 15 is heated by a coil 16 and deflects to move a trip-bar 14 to release a spring-biased arm 12 carrying the main moving contacts. Before the arm 12 is released, the element 15 engages the contact 23 to complete a circuit, e.g. for an alarm. The switch is closed by a push-button 19 and may be manually released by a further push-button 18 which acts on the trip-bar 14. |
