Valve
CA 2106923 C · Owner: Halliburton Company · Inventors: Cox, Don C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A metal valve, has a body with flow passages and curved internal sealing surfaces and a valve member with a flow passage and external curved sealing surfaces. Both the body and valve member sealing surfaces axe curved as a portion of the involute of a circle and are sealingly engageable. The valve member is mounted in the body for rotation between open and closed positions permitting and preventing flow through valve.
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 September 24, 1993 and granted September 21, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 24, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 24, 2015.
- 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.