Dovetail thread coupling for expandable tubulars
CA 2491300 C · Owner: Weatherford Technology Holdings, Llc · Inventors: Metcalfe, Paul David; Duggan, Andrew Michael; Simpson, Neil Andrew Abercrombie
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An expandable coupling arrangement for coupling first and second tubulars includes a male thread portion on an end of the first tubular and a female thread portion on an end of the second tubular. The thread portions comprise dovetail threads having flanks, roots and crests wherein the flanks are , inclined at an angle of greater than 10~.
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 July 3, 2003 and granted May 29, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 3, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 3, 2025.
- 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.