Abstract: A high temperature pressure switch assembly for an explosion-proof enclosure used in hazardous atmospheres comprises an electrical control switch for a remote power source supplying electrical power to the enclosure, and a pressure responsive member which actuates the control switch to disconnect the power source in response to a small but abrupt pressure rise within the enclosure which indicates an explosion, severe electrical arcing or insulation pyrolysis therewithin.

Abstract: An isolation switch comprises a mounting plate with a hub adapted to extend forwardly through a wall of an explosion-proof enclosure. A shaft is journaled for axial movement in the hub. First and second stationary contact members are supported on the mounting plate. The first stationary contact member has input and output power contacts, and the second stationary contact member has first and second grounding contacts. Jumpers connect the output power contacts with the second set of grounding contacts. A moveable contact member is moveable by the shaft between a "closed" position connecting the input and output power contacts; and an "open and load-side-grounded" position disconnecting the input and output power contacts and connecting the output power contacts to ground through the grounding contacts. A handle assembly is eccentrically pivoted on the forward end of the shaft, is guided for forward and backward swinging movement, and has cam bosses guided for transverse movement relative to the shaft.

Abstract: 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.

Abstract: A reversing switch comprises a mounting plate assembly with a hub adapted to extend forwardly through a wall of an explosion proof enclosure. A shaft is journaled for both rotational and axial movement in the hub. A stationary contact assembly consists of a first set of four evenly circumferentially spaced contacts, each with a connecting terminal, mounted on an insulator base. A movable contact assembly consists of a second set of four evenly circumferentially spaced contacts mounted on an electrical insulating member connected to the shaft. Adjacent pairs of the movable contacts are interconnected. The shaft has an external handle with a unique cam and rotatable eccentric pivot connection for moving the shaft axially to engage or disengage the contacts when the handle is pivoted forward and backward a half turn, and for rotating the shaft to reverse the contacts when the handle is rotated a quarter turn.