DEVICE FOR ELONGATING GLASS ROD AS MATERIAL SUCH AS OPTICAL FIBER MATRIX

摘要

PURPOSE:To provide a high-quality elongated rod having a good outer diameter accuracy by a method wherein a measurement is made on the temperature and outer diameter of a heated glass rod and the glass rod is elongated when its outer diameter is larger than the elongated outer diameter by pulling. CONSTITUTION:The gas burner 7 on the heater truck 6 is ignited, the truck 6 is moved to heat the glass rod 3 held by the chuck 12 of the truck 6 and the chuck 16 of the traction truck 15, the temperature of the rod 3 is measured by the thermometer 11 moving with the truck 6, the signal of measured temperature is output to the comparator 19 installed on the control circuit 17 on the traction device 14 and the signal is compared with the predefined temperature signal. When the temperature of the rod 3 gets equal to the predefined temperatue range, the outer diameter of rod 3 is measured by the instrument 12 and its signal is output to the comparator 18 on the circuit 17 to be compared with the predefined outer diameter signal. If the outer diameter of the rod 3 is larger than that of the elongation, the circuit 17 outputs a control signal to the truck 15 so that the truck runs to elongate the rod 3.