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

1. 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 liquid pump diaphragm in fluid communication with the container; and

a plurality of air pump diaphragms;

a mixing chamber for mixing foamable liquid from the liquid pump diaphragm with air from the plurality of air pump diaphragms;

a foaming cartridge in fluid communication with the mixing chamber;

an outlet for dispensing foam wherein the outlet is in fluid communication with the foaming cartridge; and

an actuation mechanism to sequentially activate the liquid pump diaphragm and the plurality of air pump diaphragms;

wherein the sequential operation of the liquid pump diaphragm and the plurality of air pump diaphragms is such that the liquid pump diaphragm pumps at least a partial dose of liquid into the mixing chamber prior to the plurality of air pump diaphragms pumping one or more doses of air into the mixing chamber;

wherein the actuation mechanism is configured to releasably connect to a drive system that is permanently attached to a dispenser; and

wherein the actuation mechanism sequentially activates the liquid pump diaphragm and the plurality of air pump diaphragms when the refill unit is connected to the dispenser and the drive system is activated to dispense foam.

2. The refill unit of claim 1 wherein the dose of foam dispensed from the outlet has a volume between about 2.1 ml and 70 ml of liquid.

3. The refill unit of claim 1 wherein the at least a partial dose of liquid pumped from the liquid pump diaphragm has a volume between about 0.1 and about 1.0 ml of liquid.

4. The refill unit of claim 1 wherein the actuation mechanism includes a wobble plate and a pin, wherein the pin releasably connects to the drive system that is permanently attached to the dispenser.

5. The refill unit of claim 1 wherein the pump outlet of the foam pump is on a longitudinal axis and the liquid pump diaphragm and the air pump diaphragm are concentric about the longitudinal axis.

6. The refill unit of claim 1 wherein the foamy mixture comprises an air to liquid ratio of between about 7 to 1 and about 10 to 1.

7. The refill unit of claim 1 wherein the foam pump further comprises a plurality of walls for directing the liquid and air into the mixing chamber in opposing directions.

8. The refill unit of claim 7 wherein the plurality of walls are non-linear.

9. A refill unit for a foam dispenser comprising:

a container for holding foamable liquid;

a foam pump connected to the container;

the foam pump having a plurality of diaphragm pumping chambers wherein at least one diaphragm pumping chamber pumps liquid, and at least two diaphragm pumping chambers pump air;

a mixing chamber located downstream of the plurality of diaphragm pumping chambers for mixing liquid and air to form a foamy mixture;

a foaming cartridge located downstream of the mixing chamber; and

an outlet for dispensing foam;

a plate connected to the plurality of diaphragm pumping chambers;

the plate configured to engage with a drive system that is permanently secured to the foam dispenser when the refill unit is installed in the foam dispenser and disengage with the drive system when the refill unit is removed from the foam dispenser;

wherein movement of the plate causes at least a partial dose of liquid to be pumped into the mixing chamber, followed by of a first dose of air being pumped into the mixing chamber, followed by a second dose of air being pumped into the mixing chamber.

10. The refill unit of claim 9 wherein the foam dispensed from the outlet has a volume between about 2.1 ml and 70 ml of liquid.

11. The refill unit of claim 9 wherein the at least a partial dose of liquid being pumped into the mixing chamber has a volume between about 0.1 ml and 1 ml of liquid.

12. The refill unit of claim 9 wherein the foam pump further comprises a plurality of walls for directing the liquid and air into the mixing chamber in opposing directions.

13. A refill unit for a foam dispenser comprising:

a container for holding foamable liquid;

a sequentially activated multi-diaphragm foam pump including:

a housing;

a liquid pump portion secured to the housing;

the liquid pump portion having:

a liquid inlet; a liquid inlet valve; a liquid pump diaphragm; a liquid outlet valve; and a liquid outlet;

an air pump portion secured to the housing;

the air pump portion having:

a first air inlet, a first air inlet valve, a first air pump diaphragm and a first air outlet; and

a second air inlet, a second air inlet valve, a second air pump diaphragm and a second air outlet;

a mixing chamber in fluid communication with the liquid outlet, the first air outlet and the second air outlet;

wherein the liquid pump diaphragm pumps a shot of liquid into the mixing chamber;

wherein the first air pump diaphragm pumps a shot of air into the mixing chamber to mix with the liquid to form a liquid air mixture; and

wherein the second air pump diaphragm pumps a shot of air into the mixing chamber to mix with the liquid air mixture to form a foamy mixture; and

a pump outlet for dispensing the foamy mixture;

a plate connected to the liquid pump diaphragm, the first air pump diaphragm, and the second air pump diaphragm;

the plate configured to engage with a drive system that is permanently secured to the foam dispenser when the refill unit is installed in the foam dispenser and disengage with the drive system when the refill unit is removed from the foam dispenser;

wherein movement of the plate causes the shot of liquid to be pumped from the liquid pump diaphragm into the mixing chamber, followed by the shot of air to be pumped from the first air pump diaphragm into the mixing chamber, followed by the shot of air to be pumped from the second air pump diaphragm into the mixing chamber

a foaming cartridge in fluid communication with the pump outlet; and

an outlet for dispensing foam wherein the outlet is in fluid communication with the foaming cartridge.

14. The refill unit of claim 13 wherein the plate engages with the drive system by a pin.

15. The refill unit of claim 13 wherein the plate engages with the drive system by a hook and loop connection.

16. The refill unit of claim 13 wherein the plate engages with the drive system by a magnetic connection.

17. The refill unit of claim 13 wherein the foam dispensed from the outlet has a volume between about 2.1 ml and 70 ml of liquid.

18. The refill unit of claim 13 wherein the shot of liquid pumped from the liquid pump diaphragm has a volume between about 0.1 ml and 1 ml of liquid.

19. The refill unit of claim 13 wherein the pump outlet of the foam pump is on a longitudinal axis and the liquid pump diaphragm and the air pump diaphragm are concentric about the longitudinal axis.

20. The refill unit of claim 13 wherein the sequentially activated multi-diaphragm foam pump further comprises a plurality of walls for directing the liquid and air into the mixing chamber in opposing directions.