Screw driver
CA 1069737 A · Owner: Phillips Screw Company · Inventors: Simmons, Frederick A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The screw driver is adapted for mating and driving engagement with a recess in the end of the screw which comprises a shank portion and a recessed engaging portion formed at one end of the shank portion. The recessed engaging portion comprising a central core and a plurality of blades radiating from the core. The surfaces of the lower end of the blades are provided with projections. In certain embodiments it is, the intermediate walls between pairs of adjacent blades which, have a concave configuration providing sharp edge at the lower end of each of the intermediate walls.
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
- Granted January 15, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 15, 1997.
- 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.