Method and apparatus for manufacturing ribbed pipe
CA 2039736 C · Owner: Holso, Paul · Inventors: Holso, Eino; Holso, Paul; Jarvenkyla, Jyri
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method and apparatus for manufacturing ribbed pipes, wherein a formable mass in a plastic state is extruded into a substantially cylindrical forming space of a corrugator (12) said forming, space being delimited by forming means i.e. moulds, (17), movable in the production direction of the apparatus and having grooves on the inner surface thereof for forming rib flanges (10), and a stationary kernel (16) forming the inner surface of the pipe and, wherein the mass formed as a pipe (18) in the forming space is cooled. In accordance with the invention the, ribbed pipe (18) is cooled from the inner surface of the pipe with the kernel (16) which extends an essential …
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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
- Filed October 23, 1990 and granted July 26, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 23, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 23, 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.