Patent ID: 6923346

Claim:
A foaming liquid dispenser comprising: a pump housing having a liquid pump chamber and an air pump chamber; a liquid supply passage communicating with the liquid pump chamber; a pump plunger mounted in the pump housing for reciprocating movement of the pump plunger relative to the pump housing, the pump plunger having an internal discharge passage extending through the pump plunger; a liquid pump piston and an air pump piston on the pump plunger, the liquid pump piston and the air pump piston being mounted in the respective liquid pump chamber and the air pump chamber for reciprocating movement between charge and discharge positions of the liquid pump piston and the air pump piston in the respective liquid pump chamber and air pump chamber; a first biased closed valve between the liquid supply passage and the liquid pump chamber, the first biased closed valve controlling a flow of liquid from the liquid supply passage to the liquid pump chamber and preventing a reverse flow of liquid; and, a second biased closed valve between the liquid pump chamber and the internal discharge passage, the second biased closed valve controlling a flow of liquid from the liquid pump chamber to the internal discharge passage and preventing a reverse flow of liquid.