Volumetric metering device

摘要

A metering device meters and dispenses of a known volume of a liquid product. The metering device includes a receptacle and a moveable slug sized to fit within the receptacle, leaving a remaining volume within the receptacle equivalent to a desired amount of a liquid product to be dispensed. Application of a vacuum at the outlet end draws the known volume of liquid product out of the receptacle and causes the moveable slug to move from a first position at the inlet end of the receptacle to a second position at the outlet end of the receptacle. At the same time, additional liquid product is drawn in via the inlet aperture. When the vacuum is removed, the slug returns through the additionally drawn-in liquid product back to the first position.

主权项

1. An apparatus comprising:
a substantially cylindrical receptacle defining a cavity and including an inlet end having an inlet aperture and an outlet end having an outlet aperture; and a slug sized to fit within the cavity in a first position at the inlet end of the receptacle and sized to create a first known volume within the cavity equivalent to a desired amount of a liquid product to be dispensed, the slug further sized to move within the cavity from the first position to a second position at the outlet end of the receptacle upon application of a vacuum to the outlet aperture, wherein a second known volume of the liquid product substantially equivalent to the first known volume of the liquid product is drawn into the cavity via the inlet aperture as the first known volume of the liquid product is dispensed and the slug moves toward the outlet end of the receptacle; the slug further including at least one product bypass sized to permit the second known volume of the liquid product to flow toward the outlet end of the receptacle such that the slug moves from the second position through the second known volume of the liquid product and returns to the first position at the inlet end of the receptacle when application of the vacuum to the outlet aperture is removed.