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

A refill unit for a foam dispenser comprising:

• a container for holding foamable liquid;
• a foam pump secured to the container wherein the foam pump includes:
• a housing;
• a molded multi-chamber diaphragm;
• the molded multi-chamber diaphragm comprising:
• a liquid pump chamber;
• and
• three air pump chambers;
• an inlet valve;
• and
• an outlet valve
• a mixing chamber downstream of the outlet valve for mixing foamable liquid from the liquid pump chamber with air from each of the three air pump chambers;
• a foam cartridge in fluid communication with the mixing chamber;
• and
• an outlet for dispensing foam wherein the outlet is in fluid communication with the foam cartridge.

A foam dispenser comprising:

• a dispenser housing;
• a foam pump secured to the housing wherein the foam pump includes:
• a pump housing;
• a molded multi-chamber diaphragm;
• the molded multi-chamber diaphragm comprising:
• a liquid pump chamber;
• and
• two or more air pump chambers;
• a rotatable drive mechanism for sequentially compressing the liquid pump chamber and two or more air pump chambers;
• the rotatable drive mechanism coupled to a drive motor;
• a mixing chamber downstream of the liquid and air pump chambers for mixing foamable liquid from the liquid pump chamber with air from each of the three air pump chambers;
• a foam cartridge in fluid communication with the mixing chamber;
• and
• an outlet for dispensing foam wherein the outlet is in fluid communication with the foam cartridge.