Hydraulic pump jack drive system for reciprocating an oil well pump rod
CA 2255603 C · Owner: Ring, Curtis P. · Inventors: Grabill, Les; Schultz, Glenn; Ring, Curtis P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A hydraulic pump jack drive system (1) for reciprocating an oil well pump rod (6). The drive system comprises at least one hydraulic well head cylinder (2) a reversible flow hydraulic pump (7), and a master cylinder (8). The master cylinder has a free floating master piston (11) and at least one fixed bulkhead. The master cylinder also has a working fluid chamber (16) hydraulically connected to the hydraulic well head cylinder and at leat two master piston drive chambers (17, 18) hydraulicallly connected to the hydraulic pump. The hydraulic well head cylinder and the working fluid chamber are filled with a working fluid and define a working fluid system while the master piston drive …
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 May 27, 1998 and granted February 20, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 27, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 27, 2020.
- 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.