Downhole pump of constant differential hydraulic pressure
CA 2108531 C · Owner: Exxon Production Research Company · Inventors: Miller, Mark A.; Fox, James D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A combination low-pressure, high-pressure hydraulic pump which allows a constant differential pressure is disclosed. This pump features dual concentric pistons, each with its own chamber. The pistons reciprocate together at low pressures; as the system pressure increases, a spring resists the stroke of the low pressure piston so, that ultimately only the smaller, high pressure piston reciprocates.
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 October 15, 1993 and granted June 5, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 15, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 15, 2015.
- 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.