Solid state formation of saphire using a localized energy source
CA 2122387 A1 · Owner: Maxwell, Randolph E. · Inventors: Erikson, Carl E.; Scott, Curtis E.; Kaliszewski, Mary S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polycrystalline alumina bodies have been converted to sapphire by a solid state conversion process in which a localized energy source is used to heat only a portion of the body to a temperature above 1800°C. Using a laser as the energy source resulted in conversion to sapphire in less than an hour. The polycrystalline alumina bodies had a magnesia content below 50 wppm, an average grain size below 100 microns and a density greater than 3.97 g/cc.
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 28, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 28, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 28, 2016.
- 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.