High strength sucker rod coupling
CA 2109854 A1 · Owner: Ltv Energy Products Company · Inventors: Isom, Horace G.; Hermanson, Dean E.; Hallden, Donald F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A sucker rod coupling 10 having a high ultimate tensile strength resistance, to corrosion, and resistance to surface cracking arising out of a method of making the sucker rod coupling 10, which employs a five-step process of forming a coupling 10. First, a hollow cylindrical core 12 from a heat treatable steel isformed. Second a thin coating 18 of metallic alloy is applied to the outer surface of the core 12. Third, the core 12 is heat treated. Fourth threads 20 are partially, cut in the inner surface of the core 12. Fifth the threads 20 are cold worked to, transform the partially cut threads 20 into finished threads 20 and to place thethread roots 22 in compression.
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, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 24, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 24, 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.