Raising structure for manhole cover
CA 2038020 C · Owner: Claing, Jean-Louis · Inventors: Claing, Jean-Louis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The raising structure according to the invention is intended to raise a manhole cover to the level of the resurfacing new layer of asphalt. The raising structure comprises a pair of superposed concentric rings one of which is slightly smaller than the other one so that the outer diameter of the smaller one is slightly smaller than the inner diameter of the other one. The rings are maintained in a spaced relationship by a set of spacer legs disposed around the periphery of the inner ring. Each of the legs have one end secured to the outer periphery of the small ring and the outer end of the leg is secured to the inner periphery of the larger ring. The legs are characterized by at least one …
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 12, 1991 and granted August 8, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 12, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 12, 2013.
- 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.