摘要 |
A metering fluid pump including a cylinder and a pumping piston movable therein, the cylinder being configured to define a liquid inlet chamber on one side of the piston and a liquid outlet chamber on the opposite side of the piston. A suction valve for the inlet chamber and a pressure valve for the outlet chamber open simultaneously when the piston is moving in a first direction to simultaneously pump liquid out of the outlet chamber and draw liquid into the inlet chamber. Both valves close when the piston is moved in a second reversed direction to transfer the liquid through a constricted conduit from the inlet chamber into the outlet chamber. In a second aspect of the invention an accumulator may be provided which receives liquid under pressure from the inlet chamber and which transfers the liquid into the outlet chamber when the piston is moved in the second direction and is at the end of its transfer stroke.
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