Method for producing a steel pipe using a high density energy beam
CA 2175169 C · Owner: Shiozaki, Tsuyoshi · Inventors: Ono, Moriaki; Shiozaki, Tsuyoshi; Nagahama, Yutaka
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for producing a steel pipe using a high density energy beam, comprises the steps of: (a) forming a steel strip having two edges into a cylindrical form so that the two edges face each other; (b) preheating the two edges of the steel strip to a temperature of a melting point or less by applying a high frequency electric current to the two edges; (c) pressing the two edges of the steel strip against each other by using squeeze rolls to form a joint portion; (d) irradiating a high density energy beam sufficient to fuse a full thickness of the steel strip to a portion adjacent to a squeeze point to weld the joint portion; and (e) controlling an upset using the squeeze rolls enough to …
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 26, 1996 and granted November 16, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 26, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 26, 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.