Sequentially activated multi-diaphragm foam pumps, refill units and dispenser systems
A foam dispenser includes a housing, a drive motor, and a foam pump. The foam pump includes a pump housing, and a molded multi-chamber diaphragm. The molded multi-chamber diaphragm includes a liquid pump diaphragm having a liquid pump stem and two or more air pump chambers each having an air pump stem. The length of the liquid pump stem is longer than the air pump stem. The foam pump further includes one or more outlet valves, a mixing chamber, an outlet for dispensing foam wherein the outlet is in fluid communication with the foam cartridge; and an actuator for sequentially actuating the liquid pump chamber and the two or more air pump chambers, wherein there is lost motion between the actuator and the liquid pump diaphragm.
1. A foam dispenser comprising:
a housing;
a container for holding fluid;
a drive motor;
a foam pump coupled to the drive motor;
the foam pump having
a liquid pump diaphragm having a liquid pump stem; and
two or more air pump chambers each having an air pump stem;
wherein the length of the liquid pump stem is a different length than each of the air pump stems;
the liquid pump diaphragm has a liquid pump chamber depth; and
the one or more air pump diaphragms have an air pump chamber depth;
wherein the air pump chamber depth is greater than the liquid pump chamber depth;
and
one or more outlet valves;
a mixing chamber downstream of the one or more outlet valves for mixing foamable liquid from the liquid pump chamber with air from each of the two or more air pump chambers;
an outlet for dispensing foam wherein the outlet is in fluid communication with mixing chamber; and
an actuator for sequentially actuating the liquid pump diaphragm and the two or more air pump diaphragms to dispense foam.
2. The dispenser of claim 1 comprising a retaining member on the liquid pump chamber stem and on the air pump stems.
3. The dispenser of claim 2 wherein the actuator comprises a wobble plate and wherein when the wobble plate moves in the direction of compression of the liquid pump chamber, the wobble plate moves a first distance without compressing the liquid pump chamber.
4. The dispenser of claim 3 wherein the wobble plate moves a second distance and compresses the liquid pump chamber.
5. The dispenser of claim 2 wherein the actuator comprises a wobble plate and wherein when the wobble plate moves as far as it goes in the direction of compression, the wobble plate fully compresses the liquid pump chamber.
6. The dispenser of claim 2 wherein the actuator comprises a wobble plate and wherein when the wobble plate moves as far as it goes in the direction of compression for each of the liquid pump diaphragm and the two or more air pump diaphragms, each of the liquid pump diaphragms and the two or more air pump diaphragms are fully compressed.
7. The dispenser of claim 1 wherein the volume of the liquid pump diaphragm is less than the volume of the two or more air pump diaphragms.
8. The dispenser of claim 1 further comprising at least three air pump diaphragms.
9. The dispenser of claim 1 further comprising a flow control valve for controlling the flow of liquid to the liquid pump diaphragm.
10. The dispenser of claim 1 wherein a volume of the liquid pump chamber is zero when the liquid pump chamber is compressed during operation.
11. A foam pump for a foam dispenser comprising:
a housing;
a molded multi-chamber diaphragm;
the molded multi-chamber diaphragm comprising:
a liquid pump chamber; and
two or more air pump chambers;
wherein the two or more air pump chambers have a first depth;
wherein the liquid pump chamber has a second depth;
wherein the first depth is greater than the second depth;
on or more inlet valves;
one or more liquid inlet valves;
one or more outlet valves;
a mixing chamber downstream of the outlet valve for mixing foamable liquid from the liquid pump chamber with air from each of the air pump chambers; and
an outlet for dispensing the mixture of foamable liquid and air in the form of a foam.
12. The pump of claim 11 wherein the liquid pump chamber has a pump chamber stem and the two or more air pump chambers have air pump chamber stems, and wherein length of the liquid pump chamber stem is greater than the length of the air pump chamber stems.
13. The pump of claim 11 further comprising a wobble plate coupled to the motor for compressing and expanding the liquid pump chamber and the two or more air pump chambers, wherein the wobble plate fully compresses the liquid pump chamber and the two or more pump chambers.
14. The pump of claim 13 wherein the wobble plate moves a first distance in the compression direction of the liquid pump chamber without compressing the liquid pump chamber.
15. The pump of claim 13 wherein the wobble plate moves a first distance in the expansion direction of the liquid pump chamber without expanding the liquid pump chamber.
16. The pump of claim 13 wherein the wobble plate moves, the two or more air pump chambers compress or expand by the same amount as the amount of travel of the portion of the wobble plate connected to the two or more air pump chambers.
17. The dispenser of claim 11 wherein a volume of the liquid pump chamber is less than the volume of the two or more air pump chambers.
18. A foam dispenser comprising:
a housing;
a container for holding a foamable liquid;
a sequentially activated pump comprising:
a liquid pump chamber;
the liquid pump chamber having a liquid pump stem; and
two or more air pump chambers;
the two or more air pump chambers having air pump stems;
wherein the length of the liquid pump stem is different than the length of the air pump stems;
a foamable liquid inlet valve;
two or more air inlet valves;
one or more outlet valves;
a mixing chamber downstream of the one or more outlet valves for mixing foamable liquid from the liquid pump chamber with air from each of the air pump chambers;
a foam outlet; and
an actuator that compresses and expands the liquid pump chamber and the two or more air pump chambers in a sequential order.
19. The foam pump of claim 18 wherein the liquid pump stems length is greater than the length of the two or more air pump stems.
20. The foam pump of claim 18 , wherein the liquid pump chamber has a liquid pump chamber depth and the two or more air pump chambers have an air pump chamber depth; and wherein the air chamber depth is greater than the liquid pump chamber depth.