Hydraulic metering device
CA 2802901 C · Owner: Oil-Rite Corporation · Inventors: Gruett, Donald G.; Wech, Michael J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
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 an evacuation valve. 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 evacuation valve. A check valve located in the metering chamber moves from a closed to an open position on each working stroke to preclude entrapment of air in the metering chamber and thus provide for more accurate metering. The metering device may include means to regulate the length of the working stroke.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed February 12, 2004 and granted June 30, 2015. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 12, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 12, 2026.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.