| 摘要 |
A reversing switch comprises a mounting plate assembly with a hub extending forwardly through a wall of an explosion proof enclosure. A shaft is journaled for rotational and axial movement in the hub. A stationary contact assembly includes four circumferentially spaced contacts. A moveable contact assembly includes four circumferentially spaced contacts mounted on the shaft. The shaft extends through an external operator member at the forward end of the hub. The operator member is connected to the hub by a groove and flange arrangement preventing fore and aft movement but enabling rotational movement about the hub. A pair of forwardly extending side walls each with a transverse guide slot are connected to the operator member. A handle member with a pair of combined lever and cam arms is connected to the operator member and the shaft. A pair of bosses on the lever and cam arms are seated in the guide slots and there is a pivotal connection between the shaft and portions of the lever arms offset eccentrically from the bosses. The bosses act as moveable fulcrums moving in the guide slots in response to forward and backward swinging movements of the handle. A pair of cam surfaces on the handle engage the operator member and supplement the action of the levers in moving the shaft.
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