Ported gate valves, method and apparatus
CA 2079488 A1 · Owner: Clifford, Walter A. · Inventors: Clifford, Walter A.; Clifford, Walter A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved gate valve comprising spaced parallel housing walls having axially aligned apertures therethrough and constituting a housing; sleeves removably coupled to the housing walls and defining an annular space therebetween; a gate plate in sliding contact with the sleeves reciprocable between open and closed positions and defining a primary seal to atmosphere between the gate plate and sleeves; packing located adjacent to the upper edges of the housing walls through which the gate plate reciprocates between open and closed positions and defining a secondary seal to atmosphere between the gate plate and the packing; and means associated with the periphery of the housing walls to …
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 5, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 5, 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.