Composite filled hollow structure
CA 2248804 C · Owner: Greene, Robert H. · Inventors: Greene, Robert H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A filled hollow structure (10), such as a fence post which is constructed , with a hollow member (14) filled with a core (12) to increase its strength. One aspect of the structure is that the core material normal expands upon setting, so that, when hardening within the hollow member the expansion is , restrained by the hollow member and the core is formed into an integral structure with the hollow member. Further strength is added by constructing the hollow member of reinforced fiberglass with the fiberglass rovings oriented at an angle to the axis of the pipe and by using a hard coating (18) on the outside of the pipe.
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
- Filed March 29, 1996 and granted August 20, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 29, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 29, 2018.
- 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.