Screw threaded fastener and fastening system
CA 2228673 C · Owner: Doneddu, Mark · Inventors: Roberts, David James Alexander; Doneddu, Mark
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A screw threaded fastener (103) has an elongate shank (122) with a drilling tip (104) at one end and a head (123) at the other end. A screw thread extends along at least a part of the length of the shank. The trailing flank (116) of the thread subtends an angle relative to the axis of the fastener which approaches 90° and is greater than the angle subtended by the leading flank (115). The screw is for use in fixing sheets of material to thin metal battens (5) and the angle between the trailing flank (116) and the adjacent thin metal section (18) of the batten, being reduced in comparison to a conventional thread form, lessens the distorting effect of the thread on the batten under …
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 February 3, 1998 and granted November 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 3, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 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.