Abstract: An electric furnace extending method and apparatus for an optical fiber glass body alignment when connecting the extension use body and pulling member and making it possible to immediately start the extension after the fusing of the connection portion. A centering mechanism for centering the free end portion of the body and member on the furnace center side is provided between the furnace pipe of the electric furnace and grips of the extension use glass body and between the furnace pipe and the pulling member. The free end portion is centered by this centering mechanism, then the gripped sides of the body and member are fixed, the front ends of the two free end portions are abutted and fused and bonded at the highest temperature portion inside the electric furnace, then the highest temperature portion is moved to the extension portion of the glass body side and the extending of the glass body is commenced.

Abstract: An electric furnace extending method and apparatus for an optical fiber glass body alignment when connecting the extension use body and pulling member and making it possible to immediately start the extension after the fusing of the connection portion. A centering mechanism for centering the free end portion of the body and member on the furnace center side is provided between the furnace pipe of the electric furnace and grips of the extension use glass body and between the furnace pipe and the pulling member. The free end portion is centered by this centering mechanism, then the gripped sides of the body and member are fixed, the front ends of the two free end portions are abutted and fused and bonded at the highest temperature portion inside the electric furnace, then the highest temperature portion is moved to the extension portion of the glass body side and the extending of the glass body is commenced.

Abstract: An electric furnace extending method and apparatus for an optical fiber glass body alignment when connecting the extension use body and pulling member and making it possible to immediately start the extension after the fusing of the connection portion. A centering mechanism for centering the free end portion of the body and member on the furnace center side is provided between the furnace pipe of the electric furnace and grips of the extension use glass body and between the furnace pipe and the pulling member. The free end portion is centered by this centering mechanism, then the gripped sides of the body and member are fixed, the front ends of the two free end portions are abutted and fused and bonded at the highest temperature portion inside the electric furnace, then the highest temperature portion is moved to the extension portion of the glass body side and the extending of the glass body is commenced.

Abstract: An electric furnace extending method and apparatus for an optical fiber glass body alignment when connecting the extension use body and pulling member and making it possible to immediately start the extension after the fusing of the connection portion. A centering mechanism for centering the frame and portion of the body and member on the furnace center side is provided between the furnace pipe of the electric furnaces and grips of the extension use glass body and between the furnace pipe and the pulling member. The free end portion is centered by this centering mechanism, then the gripped sides of the body and member are fixed, the front ends of the two free end portions are abutted and fused and bonded at the highest temperature portion inside the electric furnace, then the highest temperature portion is moved to the extension portion of the glass body side and the extending of the glass body is commenced.

Abstract: An electric furnace extending method and apparatus for an optical fiber glass body alignment when connecting the extension use body and pulling member and making it possible to immediately start the extension after the fusing of the connection portion. A centering mechanism for centering the free end portion of the body and member on the furnace center side is provided between the furnace pipe of the electric furnace and grips of the extension use glass body and between the furnace pipe and the pulling member. The free end portion is centered by this centering mechanism, then the gripped sides of the body and member are fixed, the front ends of the two free end portions are abutted and fused and bonded at the highest temperature portion inside the electric furnace, then the highest temperature portion is moved to the extension portion of the glass body side and the extending of the glass body is commenced.

Abstract: An apparatus for producing an optical fiber porous glass preform using the VAD method which can stably produce a high quality optical fiber porous glass preform, wherein a target bar is only rotatably supported by a chuck and is not pulled upward, a lower tip of a soot body is detected by a laser and a photodetector, and a core burner and a cladding burner is lowered in response to the result detected. A tip position detecting drive and burners are synchronizingly lowered while the deposit of porous glass grows at the lower portion of the target bar.

Abstract: Disclosed is a process of producing an optical fiber preform having a step of charging a feedstock gas in an oxygen-hydrogen burner via an electrode and hydrolyzing the same in an oxygen-hydrogen flame to produce particulates containing charged glass particulates and a step of blowing the charged particulates onto a target comprised of a seed rod or a soot body formed on the seed rod so as to cause them to deposit on the target and build up as a soot body. Preferably, the process includes the further step of reducing the magnitude of the charge of the particulates in the burner along with an increase of the diameter of the target which is formed. More preferably, the process also includes the further step of making the position facing the burner across the target an opposite polarity from the charging polarity of the particulates ejected from the burner so as to electrically attract the particulates ejected from the burner.

Abstract: An optical fiber coating apparatus which has a left holder unit 13a and a right holder unit 13b, in the left holding space 12a and right holding space 12b defined in those units are housed a second layer die 16a, 16b, a first layer die 17a, 17b, and a nipple 18a, 18b in a superposed state. The second layer die 16a, 16b and the first layer die 17a, 17b and the nipple 18a, 18b have block shaped planar outer contour shapes and the holding space 12a, 12b housing these also has a block shaped planar outer contour shape. Since the outer shapes of the dies 16a, 16b and 17a, 17b and the nipple 18a, 18b and the holding space 12a, 12b are all block shaped, it is easy to perform the axial alignment of the holes 30, 31, and 32 through which the optical fiber passes by pressing the die 16a, 16b, the die 17a, 17b, and the nipple 18a, 18b against the reference surfaces 19, 21 of the left holding space 12a.

Abstract: In a heating furnace an optical fiber preform is heated and the optical fiber is drawn. The obtained optical fiber is cooled by a cooling gas in a cooling apparatus provided beneath the heating furnace, then a resin is coated on the outer circumference of this optical fiber by a resin coater. At this time, the blowing direction of the cooling gas blown out from the optical fiber inlet of the cooling apparatus is inclined exactly by a predetermined angle (.theta.) with respect to the axial line of the running optical fiber. As a result, even if no rise suppression gas is used, it is possible to prevent the cooling gas blown upward from the cooling apparatus from entering into the heating furnace and thereby to prevent the lowering of the quality of the optical fiber due to the adhesion of dust. Also, a cooling apparatus container enclosing the cooling apparatus is provided.