Back to results
US 4,784,584 AGranted
Metering device
AssigneeOil-Rite Corporation
InventorDonald G. Gruett
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeOil-Rite Corporation
InventorDonald G. Gruett
Estimating the term…
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.
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 communciating 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, a second piston operatively disposed within the cylinder behind the first-mentioned piston and connected to the first-mentioned piston with a lost motion connection, and means to drive the second piston forwardly through a working stroke, said second piston during each working stroke engaging upon and driving the first-mentioned piston through a working stroke to force the liquid medium in the metering chamber out of the chamber and past the check valve means toward the housing outlet, said first-mentioned piston breaking the plane of the open end of the cylinder to completely evacuate the metering chamber on each working stroke to thereby generally preclude entrapment of air in the metering chamber and thus provide for more accurate metering of the liquid medium.
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
No related US applications are recorded in the indexed filing history.
With measuring chambers which expand or contract during measurement: of the piston type
Measuring volume, volume flow, mass flow or liquid level
Term ended 17 Jul 2007 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates to a metering device for the precision feeding of a liquid medium, even in relatively small or minute quantities.
Oil lubricants are among the many liquids which are at times metered. In a given instance, the feeding of too little oil may place a machine at risk. Too much oil may contaminate a product and contribute to pollution. Thus, accuracy in metering can be very important.
While accuracy in metering is generally desired, it is often difficult to attain. Air often gets into a feeding or metering system and becomes entrapped in the metering chamber. The entrapped air in the metering chamber will displace liquid medium in the measured quantity to render metering in minute quantities virtually impossible and in larger quantities inaccurate. It is generally an object of this invention to provide a metering device for a liquid medium wherein entrapment of air in the metering chamber is generally precluded to provide for more accurate metering even in minute quantities.
The drawings furnished herewith illustrate the best mode presently contemplated for the invention and are described hereinafter.
In the drawings:
FIG. 1 is a sectional view through an hydraulic metering device according to this invention;
Referring initially to FIGS. 1-4 of the drawings, the hydraulic metering device 10 of this invention is intended to be disposed in a liquid medium supply line. A pump, not shown, delivers the liquid medium to the metering device 10 in pressure pulses for metered flow to a user assembly, not shown.
The metering device 10 generally comprises a pair of opposed hollow fittings 11 and 12 which are threadedly engaged to form the housing 13 having a stepped cylindrical chamber 14. The female fitting 12 is provided with an inlet 15 and the male fitting 11 with an outlet 16. As shown in the drawings, the inlet 15 and outlet 16 may be axially aligned with the chamber 14 and to each other. One or more openings 17 place the fitting inlet 15 in communication with the chamber 14.
A cylindrical sleeve 18 is disposed in the chamber 14 generally adjacent to the outlet 16 and in abutting relation with the annular shoulder 19. The end of the sleeve 18 adjacent to the outlet 16 is tapered as viewed in section to provide a peripheral edge 20 that projects forwardly in the direction of the outlets at the inside diameter of the sleeve.