Method and apparatus for forming a porous glass preform
CA 2034772 C · Owner: Schirmer, William, Iii · Inventors: Schirmer, William, Iii; Abbott, John S.; Bertz, Mark Charles
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for rapidly forming a porous glass preform is provided in which an array of burners is oscillated along a path parallel to the longitudinal axis of the preform. Unlike existing soot deposition techniques, the oscillation amplitude is limited so that each burner deposits soot on only a portion of the preform, e.g. 20% of the preform. By controlling inter-burner variability and the air flow in the burner-array/preform region preforms, having substantially uniform axial properties are obtained notwithstanding the fact that different burners are used to laydown different parts of the preform.
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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 January 23, 1991 and granted October 23, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 23, 2013.
- 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
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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.