Cementing plug
CA 2239748 C · Owner: Ryll, Robert Lawrence · Inventors: Reid, Colin George; Ryll, Robert Lawrence
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A cementing plug has a plurality of body segments which are secured together, preferably by adhesive to form a plug body. Elastomer wipers are clamped between the body segments. This cementing plug may be readily made shorter or longer in length with an increased or decreased number of wipers. Elastomer covers only the wipers and not the plug body.
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, 1998 and granted February 11, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 5, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 5, 2020.
- 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.