The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 09, 1993
Filed:
Sep. 24, 1990
Kiyotaka Miura, Asa, JP;
Toshiharu Yamashita, Hachioji, JP;
Hoya Corporation, Tokyo, JP;
Abstract
In a method of manufacturing a preform for a nonoxide glass fiber, cladding and core glass materials are placed in a cylinder of an extrusion apparatus such that ground end faces of the respective cladding and core glass materials are in contact with each other and such that the cladding glass material is located adjacent a molding section of the extrusion apparatus. The cladding and core glass materials are heated within inert-gas atmosphere, to their respective temperatures equal to or below their respective sag points and equal to or above their respective crystallization start temperatures. An extrusion punch of the extrusion apparatus is pushed within the atmosphere, to extrude the cladding and core glass materials through a molding nozzle in the molding section while the cladding and core glass materials are in fusible contact with each other, thereby forming the preform of a core and cladding structure. The preform is gradually cooled within a liner connected to the molding section within the atmosphere. Alternatively, an over-cladding glass material may be placed in the cylinder such that the over-cladding material is located adjacent the molding section, and the cladding glass material is located between the over-cladding and core glass materials.