Mine roof support
CA 1069714 A · Owner: Fletcher Sutcliffe Wild Limited · Inventors: Wake, Malcolm; Bower, Lewis 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 comprises a plurality of hydraulically extensible chock legs articulated at upper ends to one or more roof beams and at lower ends to one or more base members, a shield pivotally connected to a rearward part of the base member and also pivotally connected to a rearward part of the roof beam with a permanently loaded force applying means reacting via the shield on the roof beam in such a manner that the, force applying means resists displacement of the roof beam and upon a sufficient fall in pressure in the chock legs restores, any displaced chock legs to a predetermined position.
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
- Granted January 15, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 15, 1997.
- 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.