Screw for use as a fastener in fibrous material such as wood
CA 2234040 A1 · Owner: Walther, Mirco · Inventors: Walther, Uli; Walther, Mirco; Walther, Thorsten
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The thread of a screw for use in fibrous material such as wood has V-shaped notches provided at the outer edge of selected thread portion. The cutouts are preferably arranged in pairs closely adjacent to each other so that, each cutout has the general configuration of the letter W. The cutouts do not penetrate the whole thickness of the thread. There are about three cutouts at each turn of the thread at a central length of the threaded stem of the screw. The cutouts facilitate the penetration of the screw into the material at the, same time reducing or preventing the loosening tendency or reducing the overall strength of the threaded portion as would be the case in previously, used thread …
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 3, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 3, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 3, 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.