Yielding strata bolt
CA 2432835 C · Owner: Minova Australia Pty Limited · Inventors: Fergusson, Jeffrey Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention discloses a rock bolt having a tendon (1,201) which is able to yield and thereby control movement of unstable rock strata into which the bolt is installed. The tendon has a portion which is provided with a grout slippage mechanism preferably in the form of a tube (8) whieh surrounds the tendon. A two part grout anchor (10 100, 200) is clamped to the tendon. The grout anchor is embedded in grout and is therefore essentially immovable. The tendon passing through the anchor is worked and thereby dissipates energy. The tendon can be either a multi-strand cable (1) or a solid bar (200). Various forms of anchor (10 200) are disclosed with either complementary recess(es)(14) …
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 20, 2003 and granted February 8, 2011. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 2025.
- 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.