AIR FOAM PUMP WITH SHIFTING AIR PISTON

摘要

A manually operated liquid foaming dispenser is attached to a bottle of liquid and pumps and mixes both the liquid and air to create a foam from the liquid and to dispense the foam. The dispenser includes a pump housing containing an air pump chamber and a liquid pump chamber, and a pump plunger that is manually reciprocated in both the air pump chamber and the liquid pump chamber. An air piston and a liquid piston are mounted on the plunger and are reciprocated by the plunger in the respective air pump chamber and liquid pump chamber. The air piston is mounted on the pump plunger for relative movement of the air piston on the plunger that enables an interior volume of the air pump chamber to be vented to an exterior environment of the dispenser on manual reciprocation of the pump plunger.