Cam and door assembly

Claim 1

In a bulk material container of the type having a discharge opening defined by a frame shaped to form an annulus having a surface in the plane of the opening, and a closure plate shaped to overlay said opening and annular surface, said plate adapted for slidable movement transverse to one end of said frame into the overlay position, a closure assembly comprising: bracket means movably mounted adjacent to said one end of the frame for carrying a sealing gasket to 1. pressurably engage one face of said closure plate when the latter is slidably moved and positioned to the overlay position, or 2. to pressurably engage said one end surface of the frame when said closure plate is entirely removed; and cam means mounted proximate each of two opposite sides of said frame and adjacent to said one end surface for alternately camming said closure plate and bracket means when in different camming positions, said cam means maneuverable to at least a first and a second position, said first position characterized by said cam means urging the other face of said closure plate into pressurable contact with the annular surface of said opening frame while causing said bracket means and sealing gasket to locate out of contact with said closure plate, and said second position characterized by said cam means out of contact with said closure plate while urging said bracket means and sealing gasket into pressurable contact with said one face of the closure plate, so that when the cam means is in the latter position said closure plate may be slidably withdrawn from the overlay position while said sealing gasket is urged to pressurably contact the closure plate, thus blocking leakage of material from said container around the closure plate and the end of said frame over which the plate is being slidably withdrawn.