Solenoid device
CA 2004672 C · Owner: Patterson, David · Inventors: Patterson, Albert; Patterson, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved solenoid wherein the end of the armature within the first coils has a predetermined length of rigid nonmagnetizable material secured to it, and a second electrically, energizable coil being energizable in a manner opposite to that of the first coil, being secured to the other end of the length of non-magnetizable material so as to move therewith from a position adjacent the first coil when the arm is in extended position to one space therefrom when the arm is in retracted position. This coil provides magnetic repulsion between the two coils to produce good starting power for the armature when the first coil is energized as a result of repulsive magnetic forces created between …
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 December 5, 1989 and granted May 11, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 5, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 5, 2011.
- 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.