Raise drill
CA 1080690 A · Owner: Smith International · Inventors: Alther, George A.
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 raise-type earth boring drills and more particularly, to rais drills having shock elements for absorbing bending loads passing through the drill. During a raise drilling operation, a tremendous amount of wear and stress is imposed upon the raise bit and upon the drive stem thereof. Removable drive stems are used to extend the useful life of the bit, but a certain amount of down time is still required to remove and replace the stem. This non-operating time is costly and it is preferable to obtain as long a running time as possible for each bit-stem combination. One area that has not been sufficiently explored in raise drilling is the area relating to …
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
- Granted July 1, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 1, 1997.
- 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.