Drill bit inserts enhanced with polycrystalline diamond
CA 2132283 C · Owner: Keshavan, Madapusi K. · Inventors: Russell, Monte E.; Liang, Dah-Ben; Keshavan, Madapusi K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A drill bit has means at one end for connecting the bit to a drill string and a plurality of inserts at the other end for crushing the rock to be drilled. The, inserts have a cemented tungsten carbide body partially embedded in the drill bit, and at least two layers at the protruding drilling portion of the insert. The outermost layer contains polycrystalline diamond and particles of carbide or carbonitride of elements selected from the group consisting of W Ti, Ta, Cr, Mo, Cb, V, Hf and Zr. The remaining layers adjacent the polycrystalline diamond layer are transition layers each comprising a composite containing diamond crystals, particles of tungsten carbide and particles of titanium , …
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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 September 16, 1994 and granted November 21, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 16, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 16, 2016.
- 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.