Polyolefin coupler for joining polyolefin pipe
CA 2066919 C · Owner: Stafford, Trevor George · Inventors: Ewing, Lindsay; Stafford, Trevor George
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A coupler 10 consists of a length of cross-linked polyethylene pipe having a spiral groove 16 cut in its outer surface and another spiral groove cut in its inner surface. A heating element 18 is wound in the groove. The coupler is expanded mechanically so as to have an easy fit over the ends of polyethylene pipes 12 14. The heater element 18 is, energised and the coupler shrinks and forms fusion welded joints between itself and the pipes. No preparation of the pipe ends is necessary because the serrated inner surface cuts through the oxidised skin and bonds to material beneath the skin. The coupler is especially advantageous in large sizes of 500 mm or above. Instead of an electric heater, …
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 23, 1992 and granted May 6, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 23, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 23, 2014.
- 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.