Abstract: An arc stack for receiving a circuit breaker blade moveable between a closed position and an open position, includes a plurality of arc plates positioned substantially parallel to one another and arranged in a plurality of adjacent groups. Each of the groups includes one or more arc plates having substantially similar respective arc throats formed therein. The respective arc throats progressively decrease in size from group to group along the length of the arc stack in a direction extending away from the closed position of the blade. A connecting support maintains the plurality of arc plates substantially parallel to one another.

Abstract: For use in a trip unit, a transformer assembly is provided in a compact and cost effective form. The assembly includes a toroidal transformer between a pair of busses, and plastic retainers around a conductor which connects the busses. Each of the plastic retainers are molded as a plastic part which features: a flat portion separating the transformer axially from the adjacent bus, a tubular section attached to the flat portion which protrudes through the center of the transformer and serves to separate it radially from the bus, and a set of ribs protruding from the tubular, flat portions which serve to slightly penetrate the insulation material in the center of the transformer and grip the transformer to prevent it from rotating, and a lip protruding from the flat portion which causes the retainer to stop rotational motion relative to the bus.

Abstract: A molded plastic current limiting circuit breaker having for each pole, a stationary and movable contact separable upon occurrence of a current higher than a predetermined level. The stationary and movable contacts are positioned inside an over-molded magnet opening to greatly increase the magnetic repulsion force between them and rapidly accelerate their separation by concentrating the magnetic fields generated upon an occurrence of a high level short circuit. The over-molded magnet is composed of a plurality of steel plates grouped together and being over molded with a thermoplastic material. The thermoplastic material has grooves integrally formed therein for retaining insulator inserts that protect the thermoplastic material during separation of the stationary and movable contacts.

Abstract: A flush mounted indicating button assembly and operating button assembly each connected to a cover having a pair of holes which receive identical buttons of the assemblies. Each button includes a circular head portion having a flat top surface and a circular base portion having a lesser diameter than the head portion which has a flat bottom surface and defines a collar portion at the bottom of the head portion. The base portion of each bottom is provided with a circumferential channel adjacent the bottom surface which carries a retaining ring. The indicator button is positioned within the hole by a leaf spring member which is connected to the bottom surface of the cover and includes an opening shaped and dimensioned to permit passage of the base portion while preventing passage of the head portion of the button. The opening is in registration with the hole in the cover and a helical coil encircles the base portion intermediate the leaf spring member and the retaining ring.

Abstract: A rotary switch is provided by a molded knob having a circular top portion, a circular bottom portion and a circumferential flange between the top and bottom portion. The bottom portion includes a recess which is provided with a pair of crush ribs provided to secure a rotary switch pin within the recess. A circumferential channel is provided on the flange around the top portion of the knob with a stop tab provided in the channel. The molded knob is operatively associated with a top plate and a bottom plate, each plate including a plurality of apertures which receive a respective top portion of a molded knob. The bottom plate is provided with an offset portion which spaces the apertures in the bottom plate a predetermined distance from the apertures in the top plate, with dimples provided in the bottom plate to maintain a predetermined spacing of the plates at the locations of the apertures.