Method of producing an internally-smooth, externally ribbed tube from extrudable plasic and apparatus for carrying out the method
CA 1331080 C · Owner: Unicor Gmbh Rahn Plastmaschinen · Inventors: Rahn, Horst
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In the production of plastic tubes or pipes which are internally smoothwalled but have peripheral ribs externally in particular from extrud-, able, more especially thermoplastic plastic such as PVC a good filling, of the cavities in the moving mold which are provided to form the ribs is achieved in that said cavities are filled with the molten plastic first at a distance from the separating plane of the moving mold and last in the region of said separating plane.
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
- Granted August 2, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 2, 2011.
- 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.