Abstract: An enclosure structure for housing switchgear apparatus (such as circuit breakers) is fabricated from a pair of sheet metal panels that are held in precisely-spaced upstanding relationship by a plurality of metal cross-struts of U-shaped cross-section which mechanically interlock with apertured portions of the panels and are held in such position by triangular-shaped metal gussets which overlap and are bolted to adjacent portions of the cross-struts and panels. The cross-struts are provided with longitudinally protruding tangs at each end that are slip-fitted into and interlock with slot apertures in the panels. The width dimension of the finished enclosure structure is precisely controlled by positioning tabs on the ends of the cross-struts that are offset from the associated tangs and are drawn into abutting relationship with the inner surfaces of the respective panels when the structure is bolted together.

Abstract: Circuit interrupter switchgear including a drawout unit mounted within an enclosure and operable between engaged and disengaged positions by means of a drive means having a two-way position actuated drive clutch. The position actuated drive clutch has an engaging means that is responsive to a sensing means for selectively engaging and disengaging a torque source with the drive means according to predetermined positions of the drawout unit.

Abstract: Draw-out circuit breaker apparatus is taught with an interphase barrier for metal enclosed switchgear. The interphase barrier includes a unitary member which is mounted on wheels so that it may be partially withdrawn when the circuit interrupter draw-out element is withdrawn thus allowing pivotal shutter members to be moved into position in front of the spouts or bottles of the high voltage terminals of the metal enclosed system. When the movable draw-out element is reinserted in its fully connected position the barrier moves flush with the previously described spouts as the shutters rotate upwardly and downwardly to accommodate insertion of the terminals of the movable circuit breaker into the complementary stationary high voltage terminals.