Threaded coupling
CA 1291880 C · Owner: Larsson, Kenneth L. · Inventors: Larsson, Kenneth L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention refers to a threaded coupling for percussion drill rods having a diameter of 30 - 40 mm comprising an external rod thread and an internal sleeve thread, the longitudinal section of said threads having continuously curved tops and bottoms. In threads of the type mentioned above it is desirable to be able to tighten them to a relatively high degree because otherwise the thread coupling loosenes when used in hydraulic percussive drilling machines of a high frequency. Significant for the thread coupling of the present invention is that the pitch (S) is 7 - 11 mm, the radii of curvature (R1 - R4), at least for the portions of the tops and bottoms located immediately …
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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
- Granted November 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 12, 2008.
- 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.