Expired Canadian patentCanada
Box culvert without rib stiffeners
CA 2072036 C · Owner: Cier, Donald J. · Inventors: Musser, Samuel C.; Cier, Donald J.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A corrugated box culvert constructed from reinforced corrugated steel or aluminum sheets having very deep corrugations and generally having a uniform bending moment profile for the whole length of the culvert.
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 June 23, 1992 and granted September 14, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 23, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 23, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 23, 1992
GrantedSeptember 14, 1999
Term endedJune 23, 2012
Patent numberCA 2072036 C
Classification (IPC)E01F5/00
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.