Rotating piston for sucker rod pump
CA 2201954 C · Owner: Snow, Jerry M. · Inventors: Snow, Jerry M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A downhole sucker rod pump especially well adapted for use in pumping thick oils and oils containing particles of sand or rock includes helical grooves or apertures for producing an intermittent unidirectional rotation of the plunger without appreciably restricting the flow of oil through the pump. This rotation distributes wear more uniformly around the plunger. In a first embodiment helical apertures are provided in the cage portion at the upper end of the plunger. Because of their large axial extent these apertures collectively provide an outlet of large area for the oil and thus restrict the flow only slightly. Because of their inclination these apertures produce a torque on the cage …
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 April 4, 1997 and granted August 1, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 4, 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.