| 摘要 |
1530887 Mechanical switches; snap-action CUTLER HAMMER WORLD TRADE Inc 19 Sept 1977 [26 Oct 1976] 38992/77 Heading H1N In an electric switch having a movable contact 24 co-operating with a fixed contact 20 under the action of switch operating means such as a snap-action cam follower 30, a separate safety disconnecting arrangement is provided to open the circuit in the event of the contacts 24, 20 being welded together. As applied to a double pole switch actuated by a trigger 14, a pair of parallel contacts 24 slide on a fixed support 10e of the casing and yielding supports comprising pivoted terminal connections 36 urged upwardly by tension coil springs 40. On movement of the trigger 14 the coupled slider 16 carrying a projection 16e moves against the action of a return spring 18 and causes cam follower 30 to snap endwise together with contact carrier 28. The cam follower 30 is resiliently held in the contact carrier 28 by a resilient arm 28g whereby on release of the trigger 14 and failure of the contacts 20, 24 to separate the follower 30 moves against the arm 28g so that its support legs 30e, 30f drop into holes 28h, 28j in the carrier 28 so that the ends 24b of the contact lift clear of the ends 36d of the terminals 36 whereby the terminals 36 are lifted by the springs 40 to open the circuit.
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