| 摘要 |
<p>A fluid metering system (10) includes a housing (12) having a piston chamber (14) with first and second spaced ends, at least one housing inlet passage (40), and at least one housing outlet passage (42). The housing inlet (40) and outlet passages (42) communicate with the piston chamber (14). A piston (16) is disposed in the piston chamber (14) for reciprocal movement between the first and second ends (31, 33) of the piston chamber (14) to alternatingly define first and second volumes (48, 50) therein. At least one first slot (52), and at least one second slot (54) are formed on the outer surface of the piston (16), and extend from respective ends of the piston toward the respectively opposite ends. The first slot (52) has an opening that is in communication with the first volume (48), and the second slot (54) has an opening in communication with the second volume (50). The piston (16) is rotatable within the piston chamber (14) to alternatingly bring one of the first or second slots (52, 54) in registration with the housing inlet passage (40), while simultaneously bringing the other of the first or second slots (52, 54) in registration with the housing outlet passage (42). As the piston reciprocates between the first and second ends (31, 33) of the chamber, fluid is alternatingly dispensed from the first and second volumes (48, 50).</p> |
