Environmentally secure polished rod liner head
CA 2114307 C · Owner: Borden, B. Michael · Inventors: Page, Ricky Don; Borden, Brian Craig; Borden, B. Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An environmentally secure polished rod liner head is provided for use on a polished rod employed in an oil well pumping system for vertically reciprocating a string of sucker rods the polished rod extends through a stuffing box the polished rod liner head having a body with a passageway therethrough receiving the polished rod a, polished rod liner removably secured to the lower end of the body and encompassing the polished rod, bolts extending laterally through the upper end of the body to secure the body to a polished rod so that the polished rod liner is reciprocated with the polished rod and a closure member within the body passageway above the polished rod liner biased to close in the …
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 January 26, 1994 and granted August 26, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 26, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 26, 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.