| 摘要 |
A fluid dispenser pump actuated manually to dispense a metered quantity or "dose" of fluid each time it is actuated. The pump has a pump body containing a pump chamber and a return spring resiliently urging the pump towards its rest position and returning it automatically to the rest position after each actuation. The pump chamber has an outlet value that is urged towards a closed position by the pressure from the fluid while the pump is being actuated, and is opened mechanically by a valve control element at the end of actuation. Once the full dose has been prepared, the outlet valve is kept in the open position while the fluid is expelled from the pump chamber. This prevents the flow of fluid from closing the outlet valve again before the full dose of fluid has been expelled.
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