Metering device
AssigneeOil-Rite Corporation
InventorDonald G. Gruett
Life of this patent
Estimating the term…
Abstract
The metering device for a liquid medium comprises a cylinder and a piston operatively disposed therein to define a metering chamber ahead of the piston. The outlet end of the cylinder is open and closed by check valve means. The piston is driven forwardly through a working stroke to force the liquid medium in the metering chamber out of the chamber and past the check valve means. The piston breaks the plane of the open end of the cylinder on each working stroke to preclude entrapment of air in the metering chamber and thus provide for more accurate metering.
Claims8
In a metering device for a liquid medium a housing having an inlet and an outlet for the liquid medium, a cylinder in said housing and having an open end communicating with the housing outlet, check valve means in said housing and biased to close the open end of the cylinder, a piston operatively disposed in the cylinder and forming therewith a metering chamber ahead of the piston, means to conduct the liquid medium from the inlet to the metering chamber, and means to drive the piston forwardly through a working stroke to force the liquid medium in the metering chamber out of the chamber and past the check valve means forward the housing outlet, said piston breaking the plane of the open end of the cylinder to completely evacuate the metering chamber on each working stroke to generally preclude entrapment of air in the chamber and thus provide for more accurate metering of the liquid medium.
Dependencies are inferred from the claim text.