Circuit breaker case structure

Claim 2

The structure recited in claim 1 wherein said sections of said inner case are formed with at least one wall portion trapped between said stationary contact and said baseplate.

Claim 3

The structure recited in claim 3 wherein the terminal which is connected to said electromagnetic device has a lateral projection and said sections of said inner case are formed with at least one wall portion trapped between said lateral projection and said baseplate.

Claim 4

The structure recited in claim 4 wherein said handle extends through said outer housing and into said inner case at one end of said inner case and said terminals extend through said baseplate at the opposite end.

Claim 5

The structure recited in claim 1 wherein each terminal includes an enlarged portion within said inner case and a stem extending through said baseplate, the inner case sections having wall portions trapped between the enlarged portion of each terminal and said baseplate to thereby restrain relative movement of the inner case sections relative to said baseplate, and said wall portions jointly surrounding said stems.

Claim 6

The structure recited in claim 6 wherein one inner case section has slots, arc grids received within said slots, the inner case section with said arc grid slots having its wall portion recEssed and the other inner case section having its wall portion projecting and mating with said recessed wall portion, the recessed wall portion facilitating assembly of said baseplate to the inner case having said arc grids by providing said terminals with ready, lateral access to the interior of the inner case without disturbing said arc grids during assembly of the circuit breaker.

Claim 7

The structure recited in claim 7 wherein said outer casing and baseplate are metallic and brazed to each other.

Claim 8

A circuit breaker comprising an outer housing, an inner case of electrical insulating material enclosed by said outer housing, a stationary contact within said inner case, a mechanism within said inner case and including a movable contact engageable with said stationary contact, an electromagnetic device for tripping said mechanism upon predetermined electrical conditions to open the contacts, a handle carried by said outer housing and extending into said inner case for operating said mechanism, said outer housing comprising a tubular casing open at one end and closed at the other end but for a hole through which said handle extends, and a baseplate closing the open end of said tubular casing, two terminals carried by said baseplate, one of said terminals being connected to said stationary contact and the other terminal being connected to said electromagnetic device, said inner case being divided into two sections along a plane generally parallel to the path through which said movable contact moves during opening and closing of said contacts to jointly define a space within which said mechanism is received, the inner case sections having, at one end, wall portions interfitting with said terminals and said baseplate to restrain movement of the inner case sections relative to said baseplate after said outer housing is placed over the inner cases and secured to said baseplate, and said terminals being generally disposed along said plane.

Claim 9

A circuit breaker comprising an outer housing, an inner case of electrical insulating material enclosed by said outer housing, a stationary contact within said inner case, a mechanism within said inner case and including a movable contact engageable with said stationary contact, an electromagnetic device for tripping said mechanism upon predetermined electrical conditions to open the contacts, a handle carried by said outer housing and extending into said inner case for operating said mechanism, said outer housing comprising a tubular casing open at one end and closed at the other end but for a hole through which said handle extends, and a baseplate closing the open end of said tubular casing, two terminals carried by said baseplate, one of said terminals being connected to said stationary contact and the other terminal being connected to said electromagnetic device, said inner case being divided into two sections along a plane generally parallel to the path through which said movable contact moves during opening and closing of said contacts to jointly define a space within which said mechanism is received, the inner case sections having, at one end, wall portions interfitting with said terminals and said baseplate to restrain movement of the inner case sections relative to said baseplate after said outer housing is placed over the inner cases and secured to said baseplate, and said terminals being generally disposed along said plane.

Claim 10

A multipole circuit breaker comprising a plurality of similar circuit breakers each constructed as recited in claim 1 except that said outer housing is large enough to enclose all of the inner cases and said baseplate is large enough to carry all of said terminals.

Claim 11

A multipole circuit breaker comprising a plurality of similar circuit breaker units, an outer housing enclosing said units, each unit comprising an inner case of insulating material within said outer housing, a stationary contact within said inner case, a mechanism within said inner case and including a movable contact engageable with said stationary contact, an electromagnetic device for tripping said mechanism upon predetermined electrical conditions to open the contacts, a handle carried by said outer housing and extending into said inner case for operating said mechanism, said outer housing comprising a tubular casing open at one end and closed at the other end but for a hole through which said handle extends, and a baseplate closing the open end of said tubular casing, two terminals carried by said baseplate one of said terminals being connected to said stationary contact and the other terminal being connected to said electromagnetic device, said inner case being divided into two sections to jointly define a space within which said mechanism is received, the inner case sections having, at one end, wall portions interfitting with said terminals and said baseplate to restrain movement of the inner case sections relative to said baseplate after said outer housing is placed over the inner cases and secured to said baseplate, each inner case including an opening, and means extending through the openings in said inner cases for interconnecting said units, whereupon an overload in any one electromagnetic device of any one unit causes said means to trip the so interconnected unit.

Claim 12

A multipole circuit breaker comprising a plurality of similar circuit breaker units, an outer housing enclosing said units, each unit comprising an inner case of insulating material within said outer housing, a stationary contact within said inner case, a mechanism within said inner case and including a movable contact engageable with said stationary contact, an electromagnetic device for tripping said mechanism upon predetermined electrical conditions to open the contacts, a handle carried by said outer housing and extending into said inner case for operating said mechanism, said outer housing comprising a tubular casing open at one end and closed at the other end but for a hole through which said handle extends, and a baseplate closing the open end of said tubular casing, two terminals carried by said baseplate one of said terminals being connected to said stationary contact and the other terminal being connected to said electromagnetic device, said inner case being divided into two sections to jointly define a space within which said mechanism is received, the inner case sections having, at one end, wall portions interfitting with said terminals and said baseplate to restrain movement of the inner case sections relative to said baseplate after said outer housing is placed over the inner cases and secured to said baseplate, each inner case including an opening, and means extending through the openings in said inner cases for interconnecting said units, whereupon an overload in any one electromagnetic device of any one unit causes said means to trip the so interconnected unit.

Claim 13

In a circuit breaker including a meChanism, an electromagnetic device for tripping said mechanism, a pair of contacts and terminals for connecting the circuit breaker to a circuit, the improvement comprising an outer metallic housing formed by a tubular casing closed at one end by a baseplate, and an inner case of electrical insulating material enclosed by said outer housing, said inner case being snugly received within said tubular casing, said baseplate carrying two terminals, said inner case being trapped to said baseplate as a subassembly having mating portions locking said baseplate to said inner case.

Claim 14

In a circuit breaker including a meChanism, an electromagnetic device for tripping said mechanism, a pair of contacts and terminals for connecting the circuit breaker to a circuit, the improvement comprising an outer metallic housing formed by a tubular casing closed at one end by a baseplate, and an inner case of electrical insulating material enclosed by said outer housing, said inner case being snugly received within said tubular casing, said baseplate carrying two terminals, said inner case being trapped to said baseplate as a subassembly having mating portions locking said baseplate to said inner case.

Claim 15

The combination recited in claim 12 wherein said inner case includes bosses seated against a wall of said tubular casing opposite said baseplate.

Claim 16

A multipole circuit breaker comprising at least two circuit breakers constructed in accordance with claim 12 wherein said outer metallic housing is large enough to receive the inner cases, said baseplate is large enough to carry all of the terminals and close said tubular casing, an electrical insulating spacer between the inner cases, said spacer having compressible means thereon, a common trip rod extending between the mechanisms and rotatable upon the tripping of one mechanism to trip the other mechanisms, and a spring between the inner cases having one end hooked to said spacer and the other end hooked on said common trip rod and biasing said rod away from the tripping direction and against bearings formed in walls of the inner cases.

Claim 17

The structure recited in claim 14 and further including a projection extending from said trip rod limiting rotation of said trip rod by abutment with said spacer, said projection being trapped between inner cases so as to also limit axial movement of said trip rod.

Claim 18

The structure recited in claim 15 wherein said spacer has slots in its margins to permit said spacer to be moved out between the inner cases so as to hook said spring onto said spacer and then be moved back between the inner cases.