Threaded joint for oil well pipes
CA 2132767 C · Owner: Yamamoto, Miyuki · Inventors: Nagasaku, Shigeo; Yamamoto, Miyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A threaded joint for oil well pipes has excellent leaktightness and a high disconnect torque and can withstand repeated make-ups. At the time of make-up the load flanks (1), of the male and female threads contact each other either the, crest surfaces (3) or the root surfaces (4) are contacting and the other of the two pairs of surfaces has a gap and a gap of, at most 0.03mm exists between the stab flanks (2) of the male and female threads.
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 September 23, 1994 and granted June 2, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 23, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 23, 2016.
- 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.