Protective structure for excavations
CA 2128005 C · Owner: Spencer, Dennis I. · Inventors: Spencer, Dennis I.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A protective panel (12) constructed, of a corrugated aluminum sheet (16) that has alternating, oppositely opening, longitudinal channels (18, 20). The end edges and the lateral edges of the sleet are rigidified respectively by a transverse (22) and longitudinal rigidifying members (24). Mounting stations (26) are located on one side of the protective panel (12) and are formed by transverse support plates (34) dial extend across the top of a selectd channel and that are reinforced by gusset webs (38) to create a beam section. A pair of opposed protective panels (12) are interconnected and retained apart by a plurality of spreader beams (14) extending between opposed mounting stations (26) to …
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 May 20, 1993 and granted July 31, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 20, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 20, 2015.
- 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.