| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus for drawing glass preform capable of safely drawing a glass preform without causing fracturing of a flange or scratches due to rubbing on a telescopic top chamber while preventing abrasion due to oxidation of a carbon-made muffle tube.SOLUTION: The apparatus for drawing a glass preform comprises a glass preform suspension device, a heating furnace, a telescopic top chamber consisting of a multi-layered cylinder and a top chamber suspension device, in which a flange is fitted to the upper part of the outermost tube of the multi-layered cylinder, and in which the top chamber suspension device has a cylinder supporting member which supports the flange from below and a cylinder pulling up member which pulls up the cylinder supporting member. It is preferable that the multi-layered cylinder be made of glass, that a top lid is placed on the top of the multi-layered cylinder and that the top lid be not fixed to the multi-layered cylinder. It is preferable that the glass preform suspension device have an XY table and that a gas seal plate which can slide in XY directions be placed on the top lid. Moreover, it is preferable that the glass preform suspension device and the top chamber suspension device be fitted to one carriage. |
