| 摘要 |
<p>1486937 Mechanical switches J D KINNEAR 6 Dec 1974 [7 Dec 1973] 52788/74 Heading H1N [Also in Division H2] A manually operated switch for isolating the battery in a battery operated vehicle has an electromagnetically operated blocking means to prevent the switch from being closed in the event of a contactor in the motor control system (see Division H2) being welded closed. The electromagnet 128, Figs. 1, 9 is connected across the fixed contacts 16, of the switch as by wires 130, 132 and if current passes through a weldedclosed contactor the electro-magnet operates to pivot a lever 138 against the action of a return spring 136 so that its end 142 engages over a hole 144 beneath a plunger 72 attached to the moving contact cross bar 46 and prevents movement of the switch actuator 48, 50. A fixed pair of tubular contacts 16, Fig. 4 comprise tulip connectors 26 retained by ring springs 32 and aligned axially by flared ends 24 for engagement and disengagement by bridging tubular contacts 44 mounted on the conductive cross-bar 46. The tubular contacts 44 are slidably guided on insulating rods 38 extending between a housing wall 40 and the fixed contacts 16 and have ring ends (62) Fig. 6 (not shown) of material such as copper-tungsten or berylliumcopper to resist arcing. The switch actuator 48, 50 acts against a return spring 58 which urges a plunger 56 against a screw head 60 on the contact housing 14. The actuator 48, 50 is retained in the closed circuit positions by the arm 66 of a U-shaped spring latch 64 which engages in a goove 76 on the end of the plunger 72. The latch 64 is released by a push knob 82 attached to a slider 80 engageable with the latch 64 and urged outwardly by a spring 80. On release, the movable contacts 44 and crosshead 46 disengage from the fixed contacts 16 under the action of the spring 58.</p> |
