Aerosol valves

Claim 1

A dispensing device for dispensing metered fluid doses from an aerosol container, the device comprising a valve body at least partially defining a generally cylindrical metering chamber, and an inlet duct having a uniform diameter including a continuous annular upper section adjacent to the metering chamber and a lower section having an opening through the wall thereof, a valve stem slidably moveable within the metering chamber and the inlet duct of said valve body, said valve stem comprising a first, upper portion having an outlet duct and constituting a discharge tube and a second, lower portion positioned within the metering chamber adjacent to the inlet duct, first sealing means between said first stem portion and the valve body at a discharge end of the metering chamber, and second sealing means on said second stem portion for sealing engagement with said inlet duct, said first and second sealing means adapted to have (a) an operative position in which the first sealing means closes the discharge end of the metering chamber, the outlet duct is closed and the second sealing means is positioned within the metering chamber to open the inlet duct to receive fluid to be dispensed, (b) a dispensing position in which the upper stem portion is displaced into the metering chamber to communicate the outlet duct with the metering chamber and with the second sealing means in engagement with the inlet duct to seal off a predetermined quantity of fluid in the metering chamber for dispensation, and (c) a filling position in which displacement of the lower stem portion is such that said second sealing means passes completely through and out of the annular upper section of the inlet duct providing a passageway for the charging fluid which is unobstructed by said second sealing means.