Concrete column forming tube
CA 1307910 C · Owner: Foehrenbach, Charles D. · Inventors: Foehrenbach, Charles D.; Rummage, Tony F.; Cunningham, Mccleery B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract Of The Invention A concrete column forming tube is provided for receiving poured concrete therein to produce a concrete column and which is characterized by producing improved surface characteristics on the concrete column including a matte finish without seam lines of the forming tube. An improved flexible cylindrical liner is positioned in a generally friction-fit relationship within an elongate rigid cylindrical tube constructed of partially-overlapped spirally-wound plies of paper adhered together and defining an inside wall surface having spiral seam lines thereon. The improved flexible liner is constructed of a convolutely-wound paperboard layer secured at butted edges 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 September 29, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 29, 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.