Butterfly valve
CA 2043159 A1 · Owner: Miyairi, Kazuhiro · Inventors: Miyairi, Kazuhiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A T I O N, 1 . T I T L E O F T H E I N V E N T I O N A Butterfly valve, 2 . A B S T R A C T O F T H E I N V E N T I O N At the outer-periphery contact portion of a butterfly disk of a butterfly valve, the sealing area close to the shaft is formed smaller than other sealing areas. Thus, when the valve is closed by the butterfly disk, the outer-periphery contact portion of the butterfly disk almost simultaneously starts contacting a seat ring throughout the periphery because the area of the portion is smaller than other sealing areas. Therefore, the sealing effect for a long time is expected because the shaft is hardly scratched and the seat ring is hardly abraded. - 1 -
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 23, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 23, 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.