| 摘要 |
A load type circuit switch of the kind requiring a minimum time delay between the closing thereof and opening thereof is taught. The minimum time delay is utilized to allow a separate circuit clearing apparatus to completely interrupt overload current in the event the switch contacts are closed upon an overload. The time delay is provided by a removable manual spring charging handle which is collapsible or non-operable in one direction of movement. The handle is rectangularly shaped and is inserted in a rectangular opening in a movable hub of a spring charging mechanism. The handle is insertable into the rectangular opening in an orientation which is appropriate to allow charging of the spring for the closing operation. After the closing operation, attempted movement of the handle in the opposite direction will cause collapse thereof thus preventing recharging of the spring for a subsequent circuit breaker contact opening operation. In order to recharge the spring, the handle must be physically removed from the keyed opening rotated 180 degrees then reinserted so that movement in the other direction may take place. The minimum time delay is related to the time interval it takes to remove the handle, rotate it, and then reinsert it.
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