Fan housing assembly

Claim 1

In a fan housing assembly comprising a generally rectangular hollow box having an open side, a bottom wall and a top wall, said open side having a predetermined vertical open dimension, an exhaust fan mounted inside said hollow box, baffle means mounted in said hollow box, said baffle means partially surrounding said fan, outlet means penetrating a wall said box so that air may be exhausted from said box, an orifice pan arranged to partially close said open side to restrict air flow into said hollow box, said orifice pan having a circular opening in alignment with said exhaust fan, and a ventilating grille attachable to said orifice pan to form a closure for said open side, the improvement in which said orifice pan has outwardly extending fingers spaced apart with respect to each other along one edge thereof, the edge of said orifice pan opposite said one edge being spaced from said one edge a distance greater than said predetermined vertical open dimension of said open side, said bottom wall of said box having slots therein spaced apart a distance equal to the distance between said fingers and being adapted to receive said fingers, and top wall of said box having pairs of inwardly extending detents adapted to receive said opposite edge of said orifice pan, said opposite edge of said orifice pan further having cut out portions located so that when said orifice pan is in its engaged position, a tool can be inserted therein to disengage said orifice pan from said fan housing box, whereby said orifice pan can be easily removed from said open side of said hollow box to permit easy entry for servicing and cleaning said fan.