Butterfly valve
CA 2013164 C · Owner: Tomoe Technical Research Company · Inventors: Yamamoto, Takeshi; Tanaka, Toshiharu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A butterfly valve is described including : a valve, body made from synthetic material and having an internal cylindrical fluid passage; a movable disk valve disposed in the valve body for controlling the opening and closing of the fluid passage ; a seated ring made from elastic material inserted between the valve body and the disk valve for closing the fluid passage when the disk valve is in a closed position ; a shaft hole formed in the valve body into which a stem is inserted ; a shaft cylinder formed to extend ouwardly from an outer circumference of the valve body in correspondence with the shaft hole, the stem being inserted into the shaft cylinder and holding the valve axially 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 March 27, 1990 and granted August 30, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 27, 2012.
- 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.