Closure
CA 2059667 A1 · Owner: Tabatabai, Seyed H. · Inventors: Tabatabai, Seyed H.; Tabatabai, Seyed H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A stop valve assembly comprises two closure members one for stopping substantive gas or liquid flow and the other to prevent leakage along a spindle section (33). Each member possesses a closure element in the form of a rigid disc-like member (9 or 34) of accurately predetermined thickness lying in a recess (1 or 3) formed round the end opening of a duct or around the spindle section and having exactly the same depth as the thickness of the disc. Over the disc outer surface (11), and the end face around the recess is located a flat annular deformable seal member (14 64); this, can be secured at in relation to the disc member so as to travel , with the disc member (9) as a stop valve or …
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 August 16, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 16, 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.