Control change system for a hydraulic working vehicle
CA 2041614 C · Owner: Arii, Kazuyoshi · Inventors: Watanabe, Shiro; Arii, Kazuyoshi; Tsuji, Kazuhiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A control change system for a hydraulic working vehicle having a plurality of hydraulic actuators operable by control levers each shiftable to a plurality of control positions. This system includes a plurality of pilot-operated control valves for controlling pressure oil supply to the hydraulic actuators, respectively, pilot pressure generating valves for generating a pilot pressure in accordance with the control positions of the control levers and, a pilot pressure switching unit for receiving the pilot pressure from the pilot pressure generating valves and outputting the pilot pressure selectively to the control valves. The pilot pressure switching unit includes a plurality of spools …
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 1, 1991 and granted November 9, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 1, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 1, 2013.
- 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.