METERING PUMP FOR DISPENSING LIQUID

摘要

A pump for metering a liquid is disclosed comprising a flexible tube conn ected to a container with a pressure relief valve located in the flexible tu be. A housing defines an aperture for receiving the flexible tube with a com pression surface located adjacent to the aperture. A reciprocating member ha s a sealing element and a pumping element. A drive moves the sealing element for pinching the flexible tube against the compression surface upstream fro m the pressure relief valve for trapping liquid between the sealing element and the pressure relief valve. The drive moves the pumping element for colla psing the flexible tube against the compression surface for pumping the trap ped liquid to discharge a metered quantity of the liquid from the pressure r elief valve.