Drilling
CA 2013804 C · Owner: De Beers Industrial Diamond Division (Pty) Limited · Inventors: Stewart, Aulette; Clark, Ian Eric
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A rotatable crown for a rotary drill comprising a working end and an opposite end for engagement in a drill rod stringer or, adaptor coupling, the working end having a cutting face and a plurality of discrete, spaced, elongate cutting elements located in the cutting face, each cutting element: (1) being of square or rectangular cross-section; (2) presenting a cutting point which is defined by a corner of the element;, (3) having a longitudinal axis which extends behind the cutting face; and, (4) being made of thermally stable abrasive compact. The crown has particular application for the drilling of substrates having a compressive strength of at least 180MPa such as Paarl granite, Norite …
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 April 4, 1990 and granted November 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 4, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 4, 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.