Downhole tool
CA 2546358 C · Owner: Churchill Drilling Tools Limited · Inventors: Churchill, Andrew Phillip
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A downhole tool (10) comprises a body (12) defining a bore. The body includes a valve arrangement (18) including flow ports (24) in the wall of the body. The ports may be opened or closed. In addition a variable flow restriction , (30) is provided in the bore (14) the degree of restriction tending to , decrease as flow across the restriction increases. The variable flow restriction may be utilised to actuate the valve arrangement.
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 November 17, 2004 and granted January 15, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 17, 2024.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- 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.