Valve assembly for metered dose dispensers

Abstract

A valve assembly for a metered dose dispenser is described. A metering chamber (70) is formed as a cavity within an elastomeric main body (42) that also includes a flexible, elastic wall (72) as an integral part. That wall (72) forms a common boundary between the metering chamber and a pressurised storage reservoir (40) and includes a first vent (50). An opposing wall of main body (42) includes a second vent. A valve stem (20) is movable via the second vent between depressed positions in which the inside of the metering chamber (70) is in communication with the outside via the valve stem (20) and extended positions in which it is not. As the valve stem is depressed, it bears on the boundary wall (72), causing it to flex and wrap around the inner-most most end (26) of the valve stem (20). This seals off the first vent (50) before the stem (20) reaches the threshold between its extended and depressed positions. The pressure within the canister (40) returns the valve stem (20) to its extended position.

Dependencies are inferred from the claim text.