Thread-cutting screw
CA 2015382 C · Owner: Rommel, Erwin · Inventors: Dicke, Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A thread forming screw has a shaft with a head and a tip at opposite ends of the shaft. The screw also has a thread which starts at the tip and runs at least partially along the shaft towards the head of the screw. The thread has first and second opposing flanks facing the tip and the head of the screw respectively. The thread at least at, the tip of the screw, has recesses in at least the first flank thereof. The recesses, which form undulations in the thread have upper borders which form an edge on the thread and are asymmetrical with a deeper front face and a shallower rear mace in screw in direction of the 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 25, 1990 and granted May 22, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 25, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 25, 2012.
- 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.