Plunger and seal for well pump
CA 2219956 C · Owner: Starks, Jimmy A. · Inventors: Starks, Jimmy A.; Edwards, Billy Joe
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A plunger or travelling valve and seal for a well pump and an oil well pump in particular, which plunger includes a mandrel of selected length, at least one plastic sleeve fitted with at least one metal insert mounted on the mandrel for sealing the mandrel in a pump barrel and a ball and seat valve provided on at least one end of the mandrel. The plunger may include fibre rings and ring holders and is seated inside a conventional pump barrel and the plastic sleeve serves to seal the plunger as the plunger reciprocates in the barrel. The plastic seal is typically constructed of ultra-high molecular weight polyethylene with one or two flanged, typically brass inserts tightly, mounted 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 October 31, 1997 and granted August 14, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 31, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 31, 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.