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A disposable pump for liquid dispensing includes a chamber in which pressure may be varied for pumping liquid from a compressible container to the chamber to a dispensing opening. The chamber encloses an inner valve that regulates liquid flow between the container and the chamber, and an outer valve

A disposable pump for liquid dispensing includes a chamber in which pressure may be varied for pumping liquid from a compressible container to the chamber to a dispensing opening. The chamber encloses an inner valve that regulates liquid flow between the container and the chamber, and an outer valve regulates flow of liquid between the chamber and the dispensing opening. The pump has a closed position where liquid is drawn from the container to the chamber by negative pressure in the chamber. To dispense, a volume of liquid is drawn from the chamber to the dispensing opening. The inner valve is a one-way valve openable to flow liquid in the dispensing direction when inner valve opening pressure acts in the dispensing direction, and closes for pressure acting in the opposite direction. The outer two-way valve opens to flow liquid in the dispensing or opposite direction.

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1. A disposable pump for a liquid dispensing system comprising a compressible container, the pump comprising: a housing forming a chamber and a dispensing opening, wherein the pressure in the chamber is varied for pumping liquid from the compressible container to the chamber, and further from the co

1. A disposable pump for a liquid dispensing system comprising a compressible container, the pump comprising: a housing forming a chamber and a dispensing opening, wherein the pressure in the chamber is varied for pumping liquid from the compressible container to the chamber, and further from the compressible chamber to the dispensing opening;an inner valve enclosed by the housing, the inner valve being configured for regulating a flow of liquid between the container and the chamber; andan outer valve enclosed by the housing, the outer valve being configured for regulating a flow of liquid between the chamber and the dispensing opening,wherein the pump assumes a closed position, in which a volume of liquid is drawn from the container to the chamber by a negative pressure created in the chamber and the outer valve, and a dispensing position, in which a volume of liquid is drawn from the chamber to the dispensing opening,wherein the inner valve opens for a flow of liquid in the dispensing direction at an inner valve opening pressure acting in the dispensing direction and closes for any pressure acting in a direction opposite to the dispensing direction,the outer valve opens for a flow of liquid in the dispensing direction at an outer valve opening pressure,said inner valve and said outer valve being arranged on a regulator which is fixedly arranged in the housing, wherein the regulator comprises a stem extending in a straight, single longitudinal extension between the inner valve and the outer valve such that, as the pump transfers from the dispensing position to the closed position, and a negative pressure is created in the chamber,a pressure difference between the container and the chamber will cause the inner valve to open so as to allow liquid to pass from the container to the chamber, and a pressure difference between the dispensing opening and the chamber will cause the outer valve to remain open to allow liquid to be sucked back in the direction opposite the dispensing direction from the dispensing opening to the chamber, andwherein when the pump is in the dispensing position, the outer valve assumes a tilted position in the chamber, and when the pump is in the closed position, the outer valve assumes a symmetrical position in the chamber, a center of the outer valve being closer to a wall of the chamber when the outer valve is in the tilted position relative to when the outer valve is in the symmetrical position. 2. The pump according to claim 1, wherein, as the pump transfers from the dispensing position to the closed position, the outer valve will remain open to allow liquid or air to be sucked back from the dispensing opening to the chamber, and then, as the closed position is reached, seal between the chamber and the dispensing opening. 3. The pump according to claim 1, wherein the inner valve opening pressure is less than the outer valve opening pressure, such that the outer valve will close before the inner valve as the negative pressure in the chamber is leveled out. 4. The pump according to claim 1, wherein the inner valve, when in a closed position, has a contact area with the housing which is greater than the contact area of the outer valve with the housing, when in a closed position. 5. The pump according to claim 1, wherein the outer valve, when in a closed position in the chamber, is circumferentially compressed in relation to an uncompressed state of the outer valve, and a difference between a diameter of the chamber at a location being in contact with the outer valve when in the closed position, and a diameter of the outer valve when in the uncompressed state, is between 0.09 and 0.20 mm. 6. The pump according to claim 5, wherein the outer valve, when in the closed position in the chamber, is circumferentially compressed in relation to the uncompressed state of the outer valve, and the difference between the diameter of the chamber at the location being in contact with the outer valve when in the closed position, and the diameter of the outer valve when in the uncompressed state, is between 0.10 and 0.20 mm. 7. The pump according to claim 6, wherein the outer valve, when in the closed position in the chamber, is circumferentially compressed in relation to the uncompressed state of the outer valve, and the difference between the diameter of the chamber at the location being in contact with the outer valve when in the closed position, and the diameter of the outer valve when in the uncompressed state, is between 0.10 and 0.15 mm. 8. The pump according to claim 1, wherein the inner valve, when in a closed position in the chamber, is circumferentially compressed in relation to an uncompressed state of the inner valve and a difference between a diameter of the chamber at a location circumferentially compressing the inner valve and a diameter of the inner valve when in said uncompressed state is between 0.20 and 0.35 mm circumferential direction. 9. The pump according to claim 8, wherein the inner valve, when in the closed position in the chamber, is circumferentially compressed in relation to the uncompressed state of the inner valve and the difference between the diameter of the chamber at the location circumferentially compressing the inner valve and the diameter of the inner valve when in said uncompressed state is between 0.25 and 0.35 mm circumferential direction. 10. The pump according to claim 9, wherein the inner valve, when in the closed position in the chamber, is circumferentially compressed in relation to the uncompressed state of the inner valve and the difference between the diameter of the chamber at the location circumferentially compressing the inner valve and the diameter of the inner valve when in said uncompressed state is between 0.25 and 0.30 mm circumferential direction. 11. The pump according to claim 1, wherein the inner valve is substantially parabolic. 12. The pump according to claim 1, wherein the inner valve comprises a rim which is movable to and from sealing contact with the housing, said rim forming an angle α with the longitudinal axis of the pump, wherein the angle α is in the range 15-30 degrees. 13. The pump according to claim 1, wherein the outer valve has an outer shape at least partly following a contour of a sphere. 14. The pump according to claim 13, wherein the outer shape of the outer valve follows the contour of the sphere for forming at least half the sphere. 15. The pump according to claim 1, wherein the outer valve comprises a rim which is movable to and from a sealing contact with the housing, and said rim, when the pump is in the closed position, is confined between parallel housing walls and extending in parallel to said walls. 16. The pump according to claim 1, wherein a guide member extends along a circumference of the stem so as to symmetrically restrict movement of the stem. 17. The pump according to claim 16, wherein the guide member is formed from four bars arranged so as to form a cross with the stem at a center of the cross. 18. The pump according to claim 1, wherein a guide member is arranged on an outer side of the inner valve, the guide member extending transversely so as to confine bending of the stem to a portion of the stem extending outside the guide member. 19. The pump according to claim 18, wherein the guide member extends along a circumference of the stem so as to symmetrically restrict movement of the stem. 20. A disposable pump for a liquid dispensing system comprising a compressible container, the pump comprising: a housing forming a chamber and a dispensing opening, wherein the pressure in the chamber is varied for pumping liquid from the compressible container to the chamber, and further from the compressible chamber to the dispensing opening;an inner valve enclosed by the housing, the inner valve being configured for regulating a flow of liquid between the container and the chamber;an outer valve enclosed by the housing, the outer valve being configured for regulating a flow of liquid between the chamber and the dispensing opening; anda stem defined by a straight, single longitudinal extension between the inner valve and the outer valve, the stem being resilient and bendable sideways during pumping so as to resume an original shape of the stem after bending,wherein the pump assumes a closed position, in which a volume of liquid is drawn from the container to the chamber by a negative pressure created in the chamber, and a dispensing position, in which a volume of liquid is drawn from the chamber to the dispensing opening,wherein the inner valve opens for a flow of liquid in the dispensing direction at an inner valve opening pressure acting in the dispensing direction and closes for any pressure acting in a direction opposite to the dispensing direction,the outer valve opens for a flow of liquid in the dispensing direction at an outer valve opening pressure,said inner valve and said outer valve being arranged on a regulator which is fixedly arranged in the housing, such that, as the pump transfers from the dispensing position to the closed position, and a negative pressure is created in the chamber,a pressure difference between the container and the chamber will cause the inner valve to open so as to allow liquid to pass from the container to the chamber, and a pressure difference between the dispensing opening and the chamber will cause the outer valve to remain open to allow liquid to be sucked hack in the direction opposite the dispensing direction from the dispensing opening to the chamber. 21. A disposable pump for a liquid dispensing system comprising a compressible container, the pump comprising: a housing forming a chamber and a dispensing opening, wherein the pressure in the chamber is varied for pumping liquid from the compressible container to the chamber, and further from the compressible chamber to the dispensing opening;an inner valve enclosed by the housing, the inner valve being configured for regulating a flow of liquid between the container and the chamber;an outer valve enclosed by the housing, the outer valve being configured for regulating a flow of liquid between the chamber and the dispensing opening; anda stem extending between the inner valve and the outer valve, the stem being resilient and bendable sideways so as to resume an original shape of the stem after bending,wherein the pump assumes a closed position where the stem is straight, in which a volume of liquid is drawn from the container to the chamber by a negative pressure created in the chamber, and a dispensing position in which the stem is deformed sideways, in which a volume of liquid is drawn from the chamber to the dispensing opening,wherein the inner valve opens for a flow of liquid in the dispensing direction at an inner valve opening pressure acting in the dispensing direction and closes for any pressure acting in a direction opposite to the dispensing direction,the outer valve opens for a flow of liquid in the dispensing direction at an outer valve opening pressure,said inner valve and said outer valve being arranged on a regulator which is fixedly arranged in the housing, such that, as the pump transfers from the dispensing position to the closed position, and a negative pressure is created in the chamber,a pressure difference between the container and the chamber will cause the inner valve to open so as to allow liquid to pass from the container to the chamber, anda pressure difference between the dispensing opening and the chamber will cause the outer valve to remain open to allow liquid to be sucked back in the direction opposite the dispensing direction from the dispensing opening to the chamber.