Bidirectional hydraulic jar
CA 2182491 C · Owner: Gefro Oilfield Services As · Inventors: Bakke, Stig Erling
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A double-acting hydraulic striking tool wherein a hammer's (8) upper end (9) is rigidly connected to an upper piston (10), and wherein the hammer's (8) lower end (26) is rigidly connected to a lower piston (26). The pistons (10, 27), which can be displaced within a tubular housing (11) are adapted to open and close for a forced flow of liquid from the upper end (9) of the hammer (8) towards the lower end (26). The hammer (8) is activated for downwardly directed blows by pressing against the hammer's (8) upper end (9) with a resilient force causing, the lower piston (27) to close the liquid flow whereby the housing (11) is lifted hydraulically until the piston (27) opens for the liquid flow, …
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 February 9, 1994 and granted May 14, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 9, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 9, 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.