Patent ID: 7358837

Claim:
A circuit breaker comprising: an arc chamber; separable contacts proximate said arc chamber; an operating mechanism structured to open and close said separable contacts; a trip unit cooperating with said operating mechanism to trip open said separable contacts; a molded enclosure comprising a first molded portion and a second molded portion; a plurality of thread cutting screws fastening said first molded portion to said second molded portion; and a plurality of machine screws, wherein said first molded portion and said second molded portion cooperate to form a plurality of exterior side walls, wherein said exterior side walls define an interior volume, wherein said interior volume encloses said separable contacts, said arc chamber and at least a portion of said operating mechanism, wherein said exterior side walls include a first wall portion proximate said operating mechanism and a second wall portion proximate said trip unit, wherein a first one of said machine screws is intermediate the first wall portion and the second wall portion of a first one of said exterior side walls, wherein a second one of said machine screws is intermediate the first wall portion and the second wall portion of a second one of said exterior side walls, and wherein said first and second ones of said machine screws hold said first molded portion to said second molded portion and restrict expansion of said first and second ones of said exterior side walls away from said interior volume.