Stress measuring rock support device
CA 2200834 C · Owner: Bawden, William F. · Inventors: Hyett, Andrew J.; Bawden, William F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A stress measuring rock support device is provided such as a cable bolt or friction stabilizer which has an, internal longitudinal cavity such as a groove or a flat, section on the kingwire or a hollow core in the kingwire or the like. One or more rigid wires or filaments extend in such cavity and their ends are anchored at predetermined anchor points within the cavity. The other ends of the rigid wires or filaments are spring-loaded and are provided with movable actuators having electrical contacts which are in contact with a linear potentiometer and measure the displacement of the actuators resulting from the stretch of the cable. This is then correlated to measure the cable load or …
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 24, 1997 and granted May 2, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 24, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 24, 2019.
- 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.