Automatic purging and easy dispensing aerosol valve system
Self-purging, low force opening, aerosol valve system with an orificed valve stem groove and gasket forming a first valve for product and propellant, or propellant, flow. A check valve element, biasing element and housing first opening form a second valve for product flow. Actuating the valve stem sequentially opens first valve and then second valve. After actuation, second valve closes before first valve, and propellant from housing second opening purges valve stem and actuator until first valve closes. No first valve closing return spring acts directly on valve stem, allowing easy opening. Gasket in stem groove and product and propellant flow fully close first valve after second valve closes. High solid and/or resin content products can be dispensed through an actuator with mechanical break-up insert.
1. A self-purging, low force opening, aerosol valve system for use with a container holding a product to be dispensed and a propellant gas, said aerosol valve system comprising in combination: a mounting cup, a valve housing captured by the mounting cup, a valve stem extending within and above said valve housing, a valve stem sealing gasket which cooperates with the stem to comprise a first valve of the aerosol valve system, a valve housing extension, and a check valve element and biasing element positioned within the valve housing extension; said valve housing having a first opening, and a second opening for entry of propellant gas from the container into the valve housing; said check valve element and said valve housing first opening comprising a second valve of the aerosol valve system; said valve stem having an internal channel for product dispensing, one or more orifices extending through the side wall of the stem for product and gas entry into the stem internal channel, and an annular groove in the stem side wall within which the stem gasket seats and seals said one or more orifices when the aerosol valve stem is not actuated; said valve housing extension having an opening therein for product in the container to enter the valve housing extension; said biasing element in the valve housing extension biasing said check valve element against said valve housing first opening when the aerosol valve is not actuated; said aerosol valve stem when actuated first unsealing said one or more stem orifices and only thereafter unseating said check valve element by action of the stem against the check valve element to allow product to enter the valve housing extension, valve housing, the one or more stem orifices and the stem internal channel; said aerosol valve system when actuation ceases resulting in the biased check valve element pushing the stem upwardly to close the said second valve to product flow, followed thereafter, before the first valve is closed, by stem separation from the check valve element and propellant gas flow through the housing said second opening and through the stem one or more orifices and internal channel to purge remaining product in the stem until said first valve is closed; said aerosol valve being further characterized by the absence of any return spring acting directly upon the valve stem to fully close the first valve or resist initially opening the first valve; and wherein the closing of the first valve is initiated by the check valve element biasing the valve stem upward followed, after separation of the check valve element and stem, by the gasket acting against the stem groove to assist in full closure of the first valve.
2. The aerosol valve system of claim 1 , wherein said check valve element comprises a check ball.
3. The aerosol valve system of claim 1 , wherein the valve housing extension is a separate member mounted to the valve housing.
4. The aerosol valve system of claim 1 , wherein said biasing element is a biasing spring.
5. The aerosol valve system of claim 1 , wherein said valve housing second opening extends through the side wall of the valve housing.
6. The aerosol valve system of claim 1 , wherein said one or more orifices through the stem side wall are positioned in the annular groove in the stem side wall.
7. The aerosol valve system of claim 1 , having an actuator mounted on the top of the stem, said actuator including a mechanical break-up insert at its nozzle.