Yieldable mine roof support
CA 2257865 C · Owner: Kennedy, John M. · Inventors: Kennedy, John M.; Kennedy, William R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A mine roof support (10) designed to extend vertically in a mine passageway. The support includes a containment structure (16) having at least two telescoping containment members (20, 22) freely telescopically movable relative to one another, and a filler material (18) introducible into the containment structure to form a column of material extending vertically in the passageway. Each containment member defines an interior space for receiving the filler material (18). The material is hardenable inside the containment structure to form a yieldable column whereby in the event of a mine convergence, the yieldable material yields while providing continued support and the telescoping …
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 January 22, 1998 and granted July 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 22, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 22, 2020.
- 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.