Drill bit
CA 2098581 C · Owner: Sandvik Ab · Inventors: Hedlund, Jan-Gunnar; Asberg, Bengt
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a drill bit (10) for rock drilling pref-, erably a down-the-hole drill bit said drill bit (10) including a head (11) and, a shaft (12), said head (11) defining a cutting face (14) that carries a number of hard material button inserts (l5) having end portions extending outwardly of said cutting face (14), means (16 17) for transporting flushing, medium from the free end (13) of the shaft (12) to the cutting face (14) of the head (11), said means for transporting flushing medium including a central passage (16) extending from the free end (13) of the shaft (12) and terminating in the head (11) short of the cutting face (14) and at least one branch passage …
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 December 6, 1991 and granted October 8, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 6, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 6, 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.