Valve assembly for pressurized dispensers

Claim 1

In a valve assembly for a pressurized dispenser, said assembly comprising a mounting member a center boss on said mounting member, said boss having a top wall with inner and outer faces and a side wall, a sealing gasket within said boss and engaging the inner face of said top wall, a hollow valve shell within said boss and having an open upper end surrounded by a rim having inner and outer sides, said shell being secured within said boss, a valve member within said shell, spring means urging said valve member into engagement with said gasket, a valve stem having therein an outlet path, said stem being connected to said valve member and having a portion protruding through said gasket and top wall, a dispensing tip mounted on the protruding portion of said stem and having an underside facing the outer face of said top wall, and a fluid passage through said tip opening into the underside thereof for the delivery of gassing fluid to said dispenser; the improvement comprising an annular shoulder having an inwardly facing annular surface on the outer face of said top wall, and surrounding said stem, and an annular flange having an outwardly facing annular surface on said underside of said dispensing tip outwardly of the opening of said fluid passage to said underside, said shoulder and flange surfaces making substantially fluid tight engagement when said tip is urged into contact with said top wall against the action of said spring means, said flange surface being arranged to be urged outwardly against said shoulder surface to increase said fluid tight engagement in response to pressure of gassing fluid delivered through said fluid passage to said underside of said tip.