Dual element fuse
CA 2079772 C · Owner: Nor-Am Electrical Limited · Inventors: Morgan, Peter; Biasutti, Tony; Ruggiero, Mary A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electrical interruption device is disclosed in which a space efficient spiral spring activates current interruption. The spring is characterized by coils which wind continuously about and approach a central axis with, successive coils of the spring having reduced radius to pass axially through the center of an outwardly adjacent coil. The spring may further be made to assume a flat condition with the spring coils lying flat, nesting interposed between adjacent coils. Advantageously, the spiral spring is conical in shape and is tensioned in a reverse loaded configuration wherein the coils of one end of the spring are pulled axially inward, through and past the coils of other end. …
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 October 2, 1992 and granted May 19, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 2, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 2, 2014.
- 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.