Patent ID: 6612468
Filing Date: 2003-09-02
Classification: B05B

Abstract:
A foam dispenser comprising a combined liquid pump and air pump for mounting at the top of a container of foamable liquid, the liquid pump having a liquid cylinder and a liquid piston defining between them a liquid chamber, the air pump having an air cylinder and an air piston defining between them an air chamber, and the liquid piston and air piston being reciprocable together in their respective cylinders by the action of a pump plunger which carries said pistons;an air inlet valve and liquid inlet valve being provided for the air chamber and liquid chamber respectively; an air discharge passage and a liquid discharge passage leading from the air chamber and the liquid chamber respectively, the air discharge passage and liquid discharge passage meeting one another for combinations of pumped flows of air and liquid and passing to an outlet passage and foam discharge opening of the dispenser by way of a permeable foam regulation element; and wherein the pump plunger comprises a core sleeve in surrounding relation to the outlet passage, a foam discharge nozzle, defining said foam discharge opening, and an outer cap shroud having an outer skirt which extends down and connects fixedly to the air piston adjacent a peripheral seal of the air piston so as to define an internal cap chamber above a roof of the air piston and enclosing the air inlet valve and the outer cap shroud has one or more external vent openings separate from the foam discharge opening to admit air to the cap chamber for drawing into the air chamber through the air inlet valve.