Safety valve for aerosol package

Claim 1

A valve structure for an aerosol package, comprising A. a cover member adapted to be installed in said package and having a central upstanding boss, a plurality of vertically elongate circumferentially arranged indentations in the exterior of the boss, the boss having an upper wall and a central opening in the wall, B. a hollow housing connected to said boss on the interior thereof and having a bore coaxial with the said central opening in the boss and means in the bore for communication with the interior of the package, C. a post mounted in the bore between the ends thereof and extending upward to the upper end of the housing and having a head with a downward facing valve seat on the head, the post mounting being provided with means permitting flow of pressurized product through said bore, D. an elastomeric diaphragm having a central perforation extending across the upper end of the housing with the post extending through the perforation, said diaphragm being held around its edges between the housing and the upper wall of the boss with the central portion of its upper surface around the central perforation engaged against the valve seat and adapted to press against said valve seat in a closed valve relationship due to internal pressure of pressurized product in the bore against the bottom surface of the diaphragm, E. an actuator member engaged over the exterior of the boss and adapted to be pressed downward to invaginate the central portion of the diaphragm that is engaged against the valve seat inward of the package to permit pressurized product to move upward past the valve seat, said actuator member comprising a plurality of exterior resilient fingers having enlarged bottom ends engaged in said indentations for limited vertically reciprocable movement while so engaged, an exterior orifice in said actuator member, an interior depending annular skirt having its lower edge coaxial with the opening in the boss and clearing the same, said lower edge being in engagement with the upper surface of the diaphragm but spaced from said head to provide an annular clearance chamber between the skirt and head during normal use of the valve structure, internal passageways between the clearance chamber and the external orifice including a vertical expansion chamber whereby any pressurized product entering the clearance chamber will pass through said internal passageways and emerge from said external orifice, downward pressure upon the actuator member serving to move the skirt edge against the upper surface of the diaphragm causing same to invaginate downward in an open valve relationship with the valve seat releasing pressurized product from said bore, release of said actuator member enabling internal pressure to return the invaginated portion of the diaphragm to its closed valve relationship and to stop the flow of pressurized product thereby raising the actuator member, and abnormal internal pressure of the package short of explosion pressure forcing the central portion of the diaphragm to invaginate upward and outward of the package into the clearance chamber and forcing the actuator member to move off the boss because of its said fingers being forced out of said indentations enabling the contents of the aerosol package to be expelled by way of said clearance chamber.