Dispensing pump with positive shut-off

摘要

A container-mounted dispensing pump incorporates elastomeric duckbill valves for controlling the flow into and from the pump chamber. A mechanism within the pump employs hinged leaves which cooperate with the pump plunger to effect a pinching and closing one of the duckbill valves when the plunger is disposed in a depressed, shipping position. With the pump plunger held in the shipping position, the closed duckbill valve will preclude leakage of the container contents through the pump.