Method for the production of bubble-free objects of quartz glass by drawing
CA 1071410 A · Owner: N.V. Philips Gloeilampenfabrieken · Inventors: Van Der Steen, Gerardus H.A.M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for producing quartz glass objects starting from a melt of silicon dioxide in helium-hydrogen atmosphere. The drawn objects after cooling, are first heated in the temperature range of 800-1400°C and thereafter at a temperature of at least 1600°C. The result is a considerable reduction in the number of bubbles if the last-mentioned heating step is continued for a sufficient time.
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
- Granted February 12, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 12, 1997.
- 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.