Patent ID: 8898940

Claim:
An exit sign ( 10 ) comprising: an explosion-proof housing ( 12 ), said housing comprising a first chamber ( 44 ) and a second chamber ( 46 ) within the housing separated by a divider wall ( 46 ); a front cover ( 14 ) attached to said housing and defining an interface between said housing and said front cover, said interface defining a vent path for gases within said housing to exit said housing, and said front cover and said housing defining a heat sink for cooling said gases exiting said housing through said vent path; a bottom plate ( 34 ) attached to said housing and defining an interface between said housing and said bottom plate, said interface defining a vent path for gases within said housing to exit said housing, and said bottom plate and said housing defining a heat sink for cooling said gases exiting said housing through said vent path; a window ( 35 ), disposed in said bottom plate, containing a clear glass or plastic window pane ( 37 ) and located proximate to said first chamber of said housing, wherein a volume of said first chamber, a housing wall thickness surrounding said first chamber, a divider wall thickness, and a window pane thickness are arranged and designed according town expected internal explosion pressure within said first chamber; wherein a volume of said second chamber, a housing wall thickness surrounding said second chamber, and a divider wall thickness are arranged and designed according to an expected internal explosion pressure within said second chamber; a generally planar sign panel ( 16 ) having a first edge which is coupled to said housing at said window; an indicium ( 22 ) disposed on said sign panel; a plurality of light emitting diodes ( 32 ) disposed within said second chamber of said housing and directed to shine light through said window into said sign panel; and at least one floodlight ( 17 , 18 ) comprising one or more light emitting diodes ( 60 ) directed to illuminate a region in proximity with said exit sign.