Circuit breaker

In a circuit breaker including two electroconductive elements between which an arc may form, a molded insulated housing having a pair of opposing interior surfaces with each of said surfaces having an opposing formed recess extending along and close to the arc-path between said electroconductive elements, at least one of said electroconductive elements being supported from said molded housing, said molded housing being rigid and possessed of sufficient structural strength to be self-supporting, the improvement comprising the combination of

• a pair of composition sheets, each said sheet residing alongside a respective said opposing surface and held in place within a respective said formed recess, said composition sheets including material comprising a water-insoluble binder and an arc suppressing substance selected from the class consisting of the oxides and hydrates of aluminum and magnesium, said binder constituting at least ten percent of the composition;
• and
• a channel for providing electric arc cooling and quenching within said circuit breaker comprising an integral, generally U-shaped member forming a base and opposing side walls having a length from one end to an opposite end, said one end of said opposing side walls having extending widths thereby providing a pair of enlarged side wall surfaces for engaging with and being held by said composition sheets, each of said one end and said opposite end of said base being formed with an extending tab for engaging a molded feature of an interior surface of said molded housing, whereby said extending tabs and said composition sheets are adapted to space said channel away from said interior surfaces of said molded housing, thereby exposing surfaces of said channel not in contact with said sheets, said base having an arrangement of venting holes therein, and wherein
• said composition sheets physically contact said extending widths of said channel but physically do not engage a majority of said length of said channel
• whereby said composition sheets, in addition to having arc suppression characteristics, also support said channel away from said molded housing, thereby helping exhaust gases produced during arcing to vent both through said venting holes and along said exposing surfaces of said channel, said sheets further insulating said channel thermally from said housing.