Flow restrictor valve for a downhole drilling assembly
CA 2270856 C · Owner: Park, Steven · Inventors: Park, Steven; Fehr, James
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved drilling assembly of the type comprising a fluid driven motor a driveshaft operatively connected with the motor a housing for enclosing the driveshaft and an annular flow passage defined between the driveshaft and the housing for circulating drive fluid therethrough. The improvement comprises a drive fluid flow restrictor device comprising a constricted section in the annular flow passage an expanded section in the annular flow passage and a valve member positioned in the annular flow passage. The valve member is movable axially in the annular flow passage between the constricted section and the expanded section to define a flow restricting position and a normal flow position …
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 May 5, 1999 and granted August 27, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 5, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 5, 2021.
- 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.