A method for joining spirally wound thermoplastic pipes together
CA 2109582 C · Owner: Blomqvist, Gunnar · Inventors: Blomqvist, Gunnar
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a method for joining spirally wound thermoplastic pipes (1 2) of a hole profile together, characterized by the following steps: working the end surfaces (3 4) of the spirally wound thermoplastic pipes (1 2) into a, smooth step-formed surface; setting two thermoplastic pipes (1 2) end against end such that a smooth step-formed gap is formed between the end surfaces (3,4); applying a stainless steel band (5) over the gap and heating the steel band (5) to ca. 100 °C applying an extruder (6) with a rotating extruder head (6) and a cooled slide and smoothing organ (8) cooperating therewith inside the pipes (1, 2) to be joined together; heating the end surfaces (3 …
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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 12, 1992 and granted September 15, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 12, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 12, 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.