PURPOSE: To provide a drawing method so that, especially, even a large-size optical fiber preform can be easily drawn.
CONSTITUTION: Both ends of the optical fiber preform are provided with dummy bars in one body, and each dummy bar is inserted to the respective engaging member, engaged, and fixed with pins. The engaging member is held with chucks disposed above and under the heating furnace and the preform is heated and drawn. This method features in that the difference between the outer diameter of the dummy bar inserted to the engaging member and the inner diameter of the engaging member is 0.2 to 4mm and that the length of the dummy bar in the inserted part in the engaging member is 50 to 150mm. It is more preferable to further fix the engaging member and the dummy bar with bolts. Thus, a large-size preform can be drawn without bending, and moreover, this process can be performed while the height of the equipment is suppressed.
OGA YUICHI
DANZUKA TOSHIO
MUKAI KATSUZOU
