Dust seal high performance breaker

Claim 2

In a circuit breaker having a housing and a handle extending outwardly from the housing, the improvement comprising sealing means engaging said handle to establish a seal between said handle and housing, an arc chamber gas vent in said housing, and a dust seal across said vent for closing off said vent against the entry of dust into said housing while permitting gases to exhaust to atmosphere from said housing through said vent.

Claim 3

Apparatus according to claim 1 wherein said dust seal comprises a movable flap.

Claim 4

Apparatus according to claim 1 wherein said sealing means comprises at least one rigid support member having a central aperture through which said handle passes, and a sealing member supported in said housing by said support member, said sealing member having a central aperture with its edges in sealing contact with said handle.

Claim 5

Apparatus according to claim 3 wherein said support member and sealing member apertures are rectangular.

Claim 6

Apparatus according to claim 3 wherein said housing is provided with a groove, the outer edges of said support and sealing members being received in said groove.

Claim 7

Apparatus according to claim 3 wherein said sealing member is made from a flat strip of silicone rubber.

Claim 8

Apparatus according to claim 6 wherein said support member is made from a flat strip of phenolic material.

Claim 9

Apparatus according to claim 7 including a second support strip of plastic material on the side of said sealing member remote from said phenolic strip.

Claim 10

A dust seal high performance circuit breaker comprising a housing, said housing having a first aperture, a handle extending through said first aperture, first sealing means in said aperture establishing a first seal between said housing and said handle, said housing have a second aperture, and dust seal means on said housing for sealing said second aperture against the entry of dust into said housing while permitting gases to exhaust from said housing through said second aperture.

Claim 11

A dust seal high performance circuit breaker comprising a housing, said housing having a first aperture, a handle extending through said first aperture, first sealing means in said aperture establishing a first seal between said housing and said handle, said housing have a second aperture, and dust seal means on said housing for sealing said second aperture against the entry of dust into said housing while permitting gases to exhaust from said housing through said second aperture.

Claim 12

A circuit breaker according to claim 9 wherein said dust seal means comprises means normally closing off said second aperture but movable in response to an overpressure in said housing to open said second aperture.

Claim 13

A circuit breaker according to claim 10 wherein said dust seal means comprises a flap resiliently biased closed but pivoted to open upon a rise in pressure within said breaker housing.

Claim 14

A high performance circuit breaker for use in potentially explosive atmospheres comprising a housing, said housing having a first aperture, a handle extending through said first aperture, sealing means in said first aperture establishing a seal between said housing and said handle, said housing having a second aperture, and flame arresting means on said housing for preventing contact arc flames from being blown out of said housing through said second aperture.

Claim 15

A high performance circuit breaker for use in potentially explosive atmospheres comprising a housing, said housing having a first aperture, a handle extending through said first aperture, sealing means in said first aperture establishing a seal between said housing and said handle, said housing having a second aperture, and flame arresting means on said housing for preventing contact arc flames from being blown out of said housing through said second aperture.

Claim 16

A circuit breaker according to claim 12 wherein said flame arresting means comprise a fine mesh screen extending across said second aperture.

Claim 17

A circuit breaker according to claim 13 wherein said screen has an effective mesh size no larger than 30 mesh.

Claim 18

A circuit breaker according to claim 13 wherein said screen comprises a single layer wire mesh having a mesh size of about 60 mesh.

Claim 19

A dust seal high performance circuit breaker comprising a housing, said housing having a first aperture, a handle extending through said first aperture, first sealing meaNs in said aperture establishing a first seal between said housing and said handle, said housing having a second aperture, and dust seal means on said housing for sealing said aperture against the entry of dust into said housing while permitting gases to exhaust from said housing through said second aperture, said dust seal means comprising means normally closing off said second aperture but movable in response to an overpressure in said housing to open said second aperture, said dust seal means comprising a flap resiliently bias closed but pivoted to open upon a rise in pressure within said breaker housing, said flap comprising a strip of plastic turned over at one end, said circuit breaker housing including a groove adjacent said second aperture receiving said turned over end of said flap.

Claim 20

A dust seal high performance circuit breaker comprising a housing, said housing having a first aperture, a handle extending through said first aperture, first sealing meaNs in said aperture establishing a first seal between said housing and said handle, said housing having a second aperture, and dust seal means on said housing for sealing said aperture against the entry of dust into said housing while permitting gases to exhaust from said housing through said second aperture, said dust seal means comprising means normally closing off said second aperture but movable in response to an overpressure in said housing to open said second aperture, said dust seal means comprising a flap resiliently bias closed but pivoted to open upon a rise in pressure within said breaker housing, said flap comprising a strip of plastic turned over at one end, said circuit breaker housing including a groove adjacent said second aperture receiving said turned over end of said flap.

Claim 21

A circuit breaker according to claim 16 wherein said flap is made of resilient plastic.