Patent ID: 7195139

Claim:
A valve assembly that is suitable to dispense a chemical from an aerosol container that has a first region with a gas propellant and a second region with an active chemical, the valve assembly being of the type that can automatically transition from an accumulation phase where the gas propellant is received from the container, to a spray phase where the active chemical is automatically dispensed, the valve assembly comprising: a housing mountable on an aerosol container; a movable diaphragm associated with the housing and linked to a seal, the diaphragm being biased towards a first configuration; an accumulation chamber inside the housing for providing variable pressure against the diaphragm; a first passageway in the housing suitable for linking the first region of the aerosol container with the accumulation chamber; a fluid filter adjacent to an inlet to the first passageway inhibiting liquid stored in the container from entering the first passageway; an orifice plate disposed in the first passageway to regulate the flow of gas therethrough; a second passageway linking the second region with an outlet of the valve assembly; whereby when the diaphragm is in the first configuration the seal restricts the flow of the active chemical out of the valve assembly; and whereby when the pressure of gas propellant inside the accumulation chamber exceeds a specified threshold the diaphragm can move to a second configuration where active chemical is permitted to spray from the valve assembly.