Plastic pipe having walls with lengthwise extending channels
CA 1045992 A · Owner: Wavin B.V. · Inventors: Van Dongeren, Jan P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Pipes of thermoplastic material comprising inner and outer walls which are interconnected by lengthwise extending connecting partitions which form channels of rounded crosssection, the ends of the channels being each separately closed by sealingly pressing the end walls of a channel against each other after these walls have been heated to a temperature above the plasticizing temperature of the plastic material.
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 January 9, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 9, 1996.
- 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.