US Patent 10143339 Sequentially activated multi-diaphragm foam pumps, refill units and dispenser systems

An exemplary foam dispenser includes a housing, a drive motor and a foam pump operatively coupled to the drive motor. The foam pump is secured to the housing and the foam pump includes a housing and a molded multi-chamber diaphragm. The molded multi-chamber diaphragm includes a liquid pump chamber, two or more air pump chambers; and an outlet valve. A mixing chamber is included and located downstream of the outlet valve for mixing foamable liquid from the liquid pump diaphragm with air from each of the two or more air pump chambers. In addition, a foam cartridge and an outlet for dispensing foam are also included.