Avoidance of nickel sulfide stone in a glass melting process
CA 2013955 C · Owner: Ppg Industries Ohio, Inc. · Inventors: Knavish, Leonard Arthur
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Nickel sulfide stones are avoided during the melting of glass batch materials in a glass melting furnace by electrically maintaining oxidizing conditions near the bottom of the upstream portion of the melting furnace at a location upstream from the establishment of a spring zone. In one embodiment an anode is located against the bottom pool of the molten glass.
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 5, 1990 and granted August 16, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 5, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 5, 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.