Rotary drill bits
CA 2030859 A1 · Owner: Barr, John D. · Inventors: Barr, John D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Improvement in or relating to rotary drill bits" A rotary drill bit comprises a bit body having a shank for connection to a drill string and a passage for supplying drilling fluid to the face of the bit, which carries a plurality of polycrystalline diamond preform cutting elements . In order to reduce bit whirl, the cutting elements are so disposed as to apply a resultant lateral imbalance force to the bit as it rotates during drilling and the gauge of the bit body is provided with low friction bearing pads to transmit said resultant lateral force to the sides of the borehole. Each low friction bearing pad includes an outwardly facing cavity which is connected to the passage by a chocked …
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 November 26, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 26, 2012.
- 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.