A valve, a float shoe and a float collar for use in the construction of oil and gas wells
CA 2311362 A1 · Owner: Lucas, Brian Roland · Inventors: Giroux, Richard Lee
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A valve for use in the construction of oil and gas wells which valve , comprises means (12, 15, 24) responsive to hydrostatic pressure to close said valve, and frangible member to maintain said valve in an open position in which fluid can pass through said valve characterised in that said frangible , member comprises a shear ring (16) the arrangement being such that in use, when said valve is subjected to a predetermined hydrostatic pressure said shear ring will shear and thereby permit said valve to close.
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 November 24, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 24, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 24, 2020.
- 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.