Abstract: Motor control centers have units or bucket assemblies with a spring-loaded front panel attached to a housing of the unit by a laterally extending metallic shaft that allows the front panel to pivot open about a long axis of the shaft. When closed, the bottom of the front panel slidably receives and is in abutting contact with the shaft which provides an electrical ground.

Abstract: Disclosed is a switching device for a tap changer comprising an input lever and an output lever rotatably attached to a shaft. The output lever is provided for making contact with a selected one of a first tap and a second tap. The output lever has a cammed surface at its base for securing a position of the output lever to make contact with the first tap and for preventing the output lever from rotating about the shaft. The device also includes a spring for pulling the output lever toward the input lever, and a clutch, rotatably attached to the shaft, which has a slot. A latching apparatus engages the clutch. The device further includes a pin which is fixedly attached to the input lever and disposed within the slot. The pin drives the clutch to engage the latching apparatus. In operation, after the input lever has been pulled away from the output lever by a predetermined angle, the pin drives the clutch to engage the latching apparatus, thereby freeing the cammed surface from the latching apparatus.

Abstract: A snap action operating mechanism for electrical switches and the like includes a hollow cylindrical housing closed at the ends. A rod extends through one end and is slidable within the housing, while the opposite end of the housing is connected to the switch to be operated. A trip bar projects radially outward in diametrically opposed directions from the rod through longitudinal slots in the housing. A pair of compression springs are disposed within the housing, one on each side of the trip bar. Latch units, each comprising a pair of pivoted latch members, alternately engage opposite ends of the housing to restrain movement of the housing in that direction. Thus, initial longitudinal movement of the rod in the direction of the engaged latch unit results in compression of one of the springs until the trip bar engages a camming surfaces on the engaged latch members, and rotates them clear of the housing. The housing is then accelerated rapidly by the energy stored in the compressed spring.