Abstract: A pump dispenser for liquids includes a finger operated piston and cylinder, a valve to allow liquid to enter the pump dispenser during a filling stroke, a chamber to receive said liquid and to store it under increasing hydraulic pressure during a discharge stroke, a spring for storing strain energy as the hydraulic pressure increases, a means for releasing the stored energy when the piston has travelled a predetermined distance relative to its cylinder and a discharge outlet through which liquid is discharged from the chamber as the strain energy is released.This application is a continuation in part of Application Ser. No. 604,744 which application was filed on Aug. 14, 1975, now abandoned, and is, in turn, a continuation of Application Ser. No. 528,642 filed on Dec. 2, 1974, now abandoned.

Abstract: A valve for a pressure pack primarily designed for dispensing powders in the absence of liquid. The valve has the usual housing, gasket, stem, spring and mounting flange components but the special problems of dispensing powders are overcome (a) by introducing a liquid film between the sealing surfaces; (b) by physically removing particulate material from the valve stem by wiping and (c) by providing a double seal between the pressurized contents of the can and the atmosphere. In a further modification, the valve stem is connected to or continuous with the dip tube.

Abstract: This invention relates to an aerosol dispensing device for dispensing a substance free from liquified propellant. The device comprises a main compartment provided with a dispensing valve which contains the substance together with pressurized propellant vapor for effecting dispensation, and a reservoir compartment containing liquified propellant and pressurized propellant vapor. A communicating valve is provided between the reservoir compartment and the main compartment. The valve is adapted to open and allow propellant vapor to pass from the reservoir compartment to the main compartment. In a preferred arrangement the valve opens when dispensation to the atmosphere of the substance in the main compartment causes the pressure of the propellant vapor in that compartment to fall below the pressure of the propellant vapor in the reservoir by a predetermined amount.

Abstract: An aerosol hairsetting preparation comprises a film-forming resin and a minor amount of a propellant dissolved in water and optionally a water-miscible organic solvent. The product is preferably dispensed from an aerosol can having two compartments connected by a gas valve, one compartment containing the product and the other containing propellant gas.