Self-tapping, and self-tapping and self-drilling, rock bolts
CA 2095230 A1 · Owner: Gray, Peter Andrew · Inventors: Gray, Peter Andrew
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A self-tapping rock bolt comprises a discontinuous threaded profile (9) having a plurality of cutting edges (11) and at least one flute (13) extending along the length of the rock bolt. The cutting edges (11) are adapted to cut a threaded profile in the internal surface of a pilot hole so that the threaded profile (9) of the rock bolt interlocks therewith. The or each flute (13) is adapted to facilitate removal of material cut by the cutting edges (11). A preferred embodiment of the rock bolt includes an internal axial hole (25) to enable water to be injected through the rock bolt as the threaded profile is being cut. A selftapping and self-drilling rock bolt comprises the self-tapping rock …
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 October 29, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 29, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 29, 2013.
- 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.