Cylindrical helical seamed tube and method and apparatus therefore
CA 2285510 A1 · Owner: Akins, Edward A. · Inventors: Harms, George; Akins, Edward A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A cylindrical helical seamed metal tube wherein the seam thereof is at an angle of between 1 and 25 degrees with respect to the axis of the tube. A method of making the tube comprises the steps of continuously feeding the metal strip into a tubing former to form the metal strip into a helical tube with the leading and trailing edges juxtaposed the, feeding such that the strip longitudinal axis is at a substantially constant acute angle with respect to the tube longitudinal axis, of between 1 and 25 degrees. After the tube is substantially formed applying pressure on at least the leading edge, leading portion, trailing edge and trailing portion in the direction of the cylindrical wall such …
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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 October 6, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 6, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 6, 2021.
- 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
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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.