| 摘要 |
A dispensing pump for dispensing product from a container serves as a container closure. The pump has a cylinder having an inner shell open at its rear end and closed at a forward end and an outer shell surrounding the inner shell and defining a cavity therebetween. A reciprocally mounted piston is in the inner shell and defines a pump chamber therewith. Inlet port means includes a passage in the outer shell for communication the container interior with the pump chamber during the suction stroke to permit product to pass through the inlet port into the cavity and then into the pump chamber. A vent replaces product removed from the container interior into the pump chamber with air. An outlet valve is provided for opening the outlet port during the compression stroke and for closing the outlet port during the suction stroke; and an inlet valve is provided for opening the inlet port during the suction stroke and for closing the inlet port during the compression stroke.
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