Expired Canadian patentCanada
Wellhead production blowout preventer ram
CA 2177629 C · Owner: Farquharson, Keith D. · Inventors: Farquharson, Keith D.; Lam, Tony M.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The rubber layer on the ram is reinforced at the sealing areas by forming ribs on the ram core. The ribs function to resist extrusion of the rubber layer when the blowout preventer is subjected to high pressure from the well.
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 29, 1996 and granted September 21, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 29, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 29, 2018.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 29, 1996
GrantedSeptember 21, 1999
Term endedMay 29, 2016
Patent numberCA 2177629 C
Classification (IPC)E21B33/06
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.