Abstract: A bounce- and weld- resistant contact assembly includes a pair of spaced contact plates with facing contacts on their ends. A switch blade is rapidly movable into and out of engagement with the contacts. The contacts are convexities coined into the plates which add no mass to the plates. Thus, the natural frequency of the plates is maximized and the magnitude of oscillation of the plates, when the contacts are rapidly engaged by the blade, is minimized. Legs on leaf springs act against concavities formed in the plates opposite the convexities. The legs conformally nestle in the convexities so that their frictional engagement therewith and the spring force co-act to quickly damp the high frequency, low magnitude oscillations of the plates. The low mass coined contacts also permit close spacing of the plates to maximize magnetic forces thereon due to current flow therethrough. These forces aid the spring and the leg-concavity friction in quickly damping oscillations of the plates.

Abstract: A high voltage circuit interrupter is enclosed within an integral insulating housing that includes an operating mechanism enclosing portion, an insulator portion, and a muffler portion. The integrally formed insulating housing is formed to provide a groove in one interior wall of the operating mechanism enclosing portion and a similar groove is formed on the housing cover immediately opposite the groove in the wall so that a portion of the operating mechanism can ride in the grooves thereby eliminating certain internal metallic components. The operating shaft of the interrupter is hexagonal in cross section thereby eliminating the need for special machining, keys, and cross pins to attach operating levers to the shaft. Operating triggers having round bearing surfaces are inserted over the ends of the hexagonal shaft to provide a smooth running bearing fit with openings in the housing wall. A unique locking arrangement is utilized to lock the lever arm of the operating mechanism to the hexagonal shaft.