Apparatus for fabricating a glass rod and method of same

An apparatus for fabricating a glass rod, comprising:

• a furnace;
• a feeding mechanism configured to feed a relatively large diameter glass preform into a furnace through a top portion thereof;
• a drawing mechanism configured to draw the glass preform from the furnace through a bottom portion thereof so that the relatively large diameter glass preform is drawn into a relatively small diameter glass rod;
• a controller configured to control a feed speed (V1) of the glass preform by the feeding mechanism and a drawing speed (V2) of the preform by the drawing mechanism so that a ratio (V2/V1) between the feed speed (V1) and the drawing speed (V2) becomes a value ((D/d)2) determined based on a diameter (D) of the glass preform and a target diameter (d) of the glass rod, wherein
• the controller comprises:
• a setting unit configured to set the feed speed (V1) of the glass preform to a constant value;
• an acquisition unit configured to acquire the diameter (D) of the glass preform for determining the drawing speed (V2) from a measured diameter data of the glass preform before being drawn at a diameter acquisition position defined with respect to a reference position of the furnace, wherein
• a distance from the reference position to the diameter acquisition position is defined so as to vary depending on a diameter fluctuation of the glass preform before being drawn in a longitudinal direction thereof.