| 摘要 |
A liquid dispenser comprising a dispenser body, a check valve, a pressure regulating valve, and a pump piston. The dispenser body has a generally cylindric inner surface defining at least part of a pump chamber, an intake port for fluid communication with a source of liquid, an intake liquid flow path providing fluid communication between the intake port and pump chamber, a discharge port, and a discharge liquid flow path providing fluid communication between the pump chamber and discharge port. The check valve checks fluid flow from the pump chamber to the intake port. The pump piston has a head at its inner end reciprocally slidable within and in sealing engagement with the pump chamber between first and second positions. A vent passageway is defined at least in part by both the dispenser body and pump piston for venting air from the fluid receiving cavity. The dispenser body and pump piston are shaped and configured for opening the vent passageway when the pump piston is in its second position and for blocking the vent passageway when the pump piston is in its first position. When air is in the fluid receiving cavity, movement of the pump piston from its first position to its second position opens the vent passageway to permit air to vent therethrough and prime the pump.
|
