Double-acting accelerator for use with hydraulic drilling jars
CA 2113458 C · Owner: Weatherford Technology Holdings, Llc · Inventors: Evans, Robert W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A double acting accelerator (1) includes a mandrel (2) arranged in a housing (3) for sliding longitudinal movement. A pair of pistons (89), (111) are positioned radially between the housing (3) and mandrel (2) to form a substantially sealed chamber (88) longitudinally therebetween. Movement of the mandrel (2) in a first direction urges the first piston (89) toward the second piston (111), thereby greatly increasing the pressure of fluid in the chamber (88). Movement of the mandrel (2) in a second, opposite direction urges the second piston (111) toward the first piston (89) to, likewise greatly, increase the pressure of fluid in the chamber (88). Thus a, large amount of energy is stored in …
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 July 2, 1992 and granted September 23, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 2, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 2, 2014.
- 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.