Improved polished rod for oil well pumping
CA 2213552 C · Owner: Borden, B. Michael · Inventors: Borden, B. Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An unproved polished rod for use in pumping a well has the characteristics of reducing inventory and warehouse space requirements. The polished rod is in the form of an elongated high-strength cylindrical metal rod of uniform external diameter and adaptable for reciprocation in an oil well stuffing box the exterior surface being adaptable to receive a clamp thereon by which the polished rod is reciprocated. The polished rod having male threaded end portions at opposed first and second ends either of which may be employed far threadable attachment to a female threaded upper end of a string of sucker rods suspended in a well. The first end portion having a thread of a first size for …
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 August 21, 1997 and granted August 8, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 21, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 21, 2019.
- 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.