Process for producing plastic pipes having oval cross- sectional shape
CA 1088720 A · Owner: Sekisui Kagaku Kogyo Kabushiki Kaisha · Inventors: Iida, Noboru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing a plastic pipe having an oval crosssectional shape with a high dimensional precision which comprises conduct-, ing a roughly shaped plastic pipe having an oval cross-sectional shape which is in the softened state and composed of a large-diameter portion a, small-diameter portion and transitional portions connecting them to each other, to a cooling tank while its shape is adjusted by being passed through a forming tube with its large-diameter portion down; cooling the form-adjusted plastic pipe in the cooling tank by dipping the large-diameter portion or both the large diameter portion and a part of the transitional portions contiguous thereto in a cooling bath, and …
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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 November 4, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 4, 1997.
- 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.