Valve control unit for hydraulic actuator
CA 2133267 C · Owner: Harada, Koichi · Inventors: Ono, Tomoaki; Sakai, Makoto; Tozawa, Shoji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A valve control unit includes a main hydraulic oil circuit and a pilot oil circuit. The main circuit includes a main pump a main valve downstream from said, main pump and a hydraulic actuator downstream from said main valve. The pilot oil circuit circulates pressurized pilot oil to control the main valve and includes a pilot oil pump, an automatic control switching valve downstream from the pilot oil pump amanual limit switching valve downstream from the pilot oil pump a manual control, switching valve downstream from the manual limit switching valve and a pilot oil, chamber downstream from said manual control switching valve. The pilot oil chamber is located near the main valve such that …
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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 September 29, 1994 and granted July 27, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 29, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 29, 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.