Patent attributes
An exemplary foam dispenser includes a housing, a container for holding foamable liquid and a foam pump in fluid communication with the container. The foam pump has a plurality of diaphragm pumping chambers wherein at least one diaphragm pumping chamber pumps liquid, and at least two diaphragm pumping chambers pump air. The foam pump includes a liquid outlet valve having a cracking pressure of at least about 5 pounds per square inch; and two or more air outlet valves having cracking pressure of less than about 5 pounds per square inch. A mixing chamber is located downstream of the plurality of diaphragm pumping chambers for mixing liquid and air to form a foamy mixture. A foam cartridge located downstream of the mixing chamber and an outlet is provided for dispensing foam.