Powder-filled welded steel tube and method for the continuous manufacture thereof
CA 1304015 C · Owner: Rijnstaal B.V. · Inventors: Dackus, Ir. A.J.G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A powder-filled welded steel tube has a tube wall with a welded longitudinal seam and is wound into a coil for despatch. To reduce the risk that the seam opens when the tube is twisted e.g. on, uncoiling, the tube wall is provided with a continuous longitudinal groove. Preferably the groove is symmetrical and directed radially inwards. In the continuous manufacture of such tube a metal, strip is formed into an open channel powder is, introduced into the channel the channel is closed, and the edges welded to form a closed tube. The diameter is then reduced and the finished product is coiled. The longitudinal groove is rolled in continuously during the diameter reduction of the powder-filled …
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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
- Granted June 23, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 23, 2009.
- 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.