Optical fiber drawing furnace with a zig zag heating element
AssigneeSumitomo Electric Industries, Ltd.
InventorsIchiro Tsuchiya, Kohei Kobayashi, Hiroaki Ohta, Kazuya Kuwahara, Katsuyuki Tsuneishi, Hideo Miyaki, Yasuo Matsuda
Life of this patent
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Abstract
There is provided an optical fiber drawing furnace capable of drawing an optical fiber having small non circularity, which drawing furnace includes a muffle tube, in which an optical fiber preform is supplied, a heater surrounding the muffle tube, a plurality of electrode connecting portion extending from the heater, a plurality of electrodes connected to electrode connecting portions, and in conjunction therewith to an electric power source, and unifying means for unifying the temperature distribution along the circumferential direction.
Claims9
An optical fiber drawing furnace comprising:
- a muffle tube, into which an optical fiber preform is supplied;
- a cylindrical heater surrounding the muffle tube;
- a pair of support column portions which rise from the upper end of said heater at circumferential positions substantially equidistantly spaced from one another;
- four electrode connecting terminals and no more than four, two electrode connecting terminals extending perpendicularly from each of said support column portions and connecting to one another via a connecting element, the four electrode connecting terminals being arranged so that the angle between the adjacent terminals substantially equals 90°;
- an electric power source connected, via electrodes, to the four electrode connecting terminals;
- and
- two extension portions protruding upwardly from the heater to balance heat supplied by the pair of support column portions, and being disposed substantially equidistantly between said support column portions.
Dependencies are inferred from the claim text.