Multi-stage check valve
CA 2240781 A1 · Owner: Parker-Hannifin Corporation · Inventors: Harding, Curtis F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A check valve includes an outer valve body and an inner poppet valve moveable relative to the valve body and spring-biased into a closed position. The inner poppet valve has first and second stage openings. The first stage preferably has a single relatively small through-hole into the chamber of the poppet valve while the second stage, preferably has multiple openings of a larger diameter. The first and second stage openings are spaced axially along the poppet valve with the first stage opening being, located closer to the valve head of the poppet valve than the second stage openings. In the closed position, fluid flow is blocked through both the first and second stage openings. 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 June 15, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 15, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 15, 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.