Patent ID: 8708200

Claim:
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; and 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, 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, and wherein 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.