Casing spacers
CA 2174407 C · Owner: Gray, Patrick H. Jr. · Inventors: Mcdonald, Stephen R.; Gray, Patrick H. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Casing spacers for isolating carrier pipe mechanically galvanically, and chemically from, pipe casings. The spacers may be attached using fasteners to pipe joint restrainers or other ring structures which encircle carrier pipe. The spacers are more efficient to install in the field provide, robust mechanical structure and physical stability which does not degrade over time provide, additional protection to the pipe joints and, because they may be attached to conventional structures instead of requiring an integral ring structure for encircling a pipe alleviate the, distribution and inventory problems encountered by conventional systems in which the casing spacer runners are attached to an …
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 April 17, 1996 and granted October 24, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 17, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 17, 2018.
- 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.