A method of preparing a steel pipe, an apparatus thereof and a steel pipe
CA 2201166 C · Owner: Yorifuji, Akira · Inventors: Matsui, Hiroyuki; Ohnishi, Toshio; Tanaka, Nobuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for reducing a raw steel pipe obtained by a solid phase bonding pipe manufacturing method or a welding pipe manufacturing method is carried out by heating the steel pipe to a temperature in excess of 100 ·C and lower than 800 ·C before it is reduced, restricting the temperature of the steel pipe during a rolling operation to a level in a specific range controlling the , temperature difference of the steel pipe in the circumferential direction thereof at the inlet side of a reducing mill to be in a specific range and , also controlling the temperature of the steel pipe between the stands of the reducing mill. This enables the steel pipe to be reduced with a low load with the …
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 August 21, 1996 and granted November 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 21, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 21, 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.