PURPOSE: To remarkably improve the drawing speed of an optical fiber, by providing a connection tube to hermetically connect a resin-coating apparatus and a curing apparatus and a gas-supplying means to prevent the inhibition of resin-curing and combining the connection tube with the supplying means in a manner so as to exert a specific action.
CONSTITUTION: A coating apparatus 18 for primary coating is hermetically connected with its curing apparatus 23 through a connection tube 24. A coating apparatus 25 for the secondary coating is connected to its curing apparatus 26 in series. The coating apparatus 25 is hermetically connected to the curing apparatus 26 through a connection tube 30. For example, helium gas is used as a gas to inhibit the curing of an energy radiation curable resin. A helium gas-feeding tube 34 connected to a helium gas-supplying source is connected to the lower end of a cooling tube 19 to fill the transfer path of an optical fiber preform 11, an optical fiber 21, an optical fiber filament 35 and an optical fiber core wire 36 extending from a wire-drawing furnace 15 to an extension tube 31 with helium gas.
SAIGO TOSHIAKI
MATSUDA HIROO
SANO HIROAKI
