Hydraulic control valve system with load sensing priority
CA 2255991 C · Owner: Hamkins, Eric P. · Inventors: Hamkins, Eric P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A hydraulic fluid is supplied from a tank to a plurality of actuators by a variable displacement pump which produces an output pressure that is a constant amount greater than a pressure at a control input. A mechanism senses the greatest pressure among the workports to provide a first load-dependent pressure and a second load-dependent pressure which is greater than the first load-dependent pressure when the pump operates a maximum flow capacity. Each valve section includes a pressure compensating valve which controls the fluid flow to the associated actuator in response to a pressure differential between the metering orifice and either the first or second load-dependent pressures. When the …
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 December 14, 1998 and granted March 18, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 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.