Method of manufacturing long tubes having small diameters
CA 2013068 C · Owner: Furugen, Munekatsu · Inventors: Furugen, Munekatsu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of manufacturing a long tube having a small diameter, such as a tube for use in a heat exchanger by, cold works. A plug drawing using a pressurized lubricating oil of 500kgf/cm2 or more accompanied by the reduction in wall-thickness is adopted as at least the final cold work. In the case where a tube having desired dimensions is not obtained by this plug drawing, the subsequent free-loaded drawing is conducted.
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 March 26, 1990 and granted November 15, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 26, 2012.
- 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.