Fastener having primary and secondary threads
CA 2234860 C · Owner: Bechtel, Frank W. · Inventors: Bechtel, Frank W.; Barth, Gerald D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a fastener having a head, which may have having torque-absorbing ribs, and a shank, which is unitary with the head and which hasa primary thread formation and a secondary thread formation. The primary thread formation, which defines axially spaced threads along a generally cylindrical portion of the shank and along a tapered tip of the shank, has a generally uniform radial dimension along the generally cylindrical portion of the shank. The secondary thread formation which, defines axially spaced threads between some of the threads defined by the primary thread formation, originates at a region spaced axially from the distal end of the generally cylindrical portion of the shank terminates …
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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
- Filed April 15, 1998 and granted November 27, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 15, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 15, 2020.
- 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.