Spark plug with ring shaped ground electrode
CA 2044622 C · Owner: Johnson, James E. · Inventors: Johnson, James E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Spark plug for an internal combustion engine having a metal shell (20) enclosing a ceramic insulator (16) containing a conductive centre electrode (18) having a bottom end (58) exiting from the insulator. The bottom end of the centre electrode is spaced apart from a groud electrode ( 12) attached to the metal shell by at least one support member or mounting post (38) . The ground electrode is ring/openring shaped and its interior diameter ranges from equal to the exterior diameter of the centre electrode to a multiple of the size of the interior diameter of the centre electrode. Fig. 1
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 13, 1990 and granted December 26, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 13, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 13, 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.