Three-way hydraulic valve
CA 1290650 C · Owner: Gratzmuller, Claude Alain · Inventors: Gratzmuller, Claude Alain
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An open-center three-way hydraulic valve as applicable to hydraulic control circuits of electric circuit-breakers comprises an admission valve-head which is restored to the closed position by a first spring a drain valve-head which is displaced toward the closed position by a pilot valve, a second spring which is more powerful than the first and tends to close the drain valve-head, and a resilient semi-locking mechanism for retaining the drain valve-head in the open position in opposition to the second spring when the pilot jack is not under pressure.
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
- Granted October 15, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 15, 2008.
- 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.