| 摘要 |
A disposable pump for liquid dispensing includes a chamber in which pressure may be varied for pumping liquid from a compressible container to the chamber to a dispensing opening. The chamber encloses an inner valve that regulates liquid flow between the container and the chamber, and an outer valve regulates flow of liquid between the chamber and the dispensing opening. The pump has a closed position where liquid is drawn from the container to the chamber by negative pressure in the chamber. To dispense, a volume of liquid is drawn from the chamber to the dispensing opening. The inner valve is a one-way valve openable to flow liquid in the dispensing direction when inner valve opening pressure acts in the dispensing direction, and closes for pressure acting in the opposite direction. The outer two-way valve opens to flow liquid in the dispensing or opposite direction. |
