Glass manufacturing – Processes of manufacturing fibers – filaments – or preforms – With measuring – controlling – sensing – programming – timing,...
Reexamination Certificate
2000-03-08
2004-06-01
Hoffman, John (Department: 1731)
Glass manufacturing
Processes of manufacturing fibers, filaments, or preforms
With measuring, controlling, sensing, programming, timing,...
Reexamination Certificate
active
06742363
ABSTRACT:
This patent application claims priority based on a Japanese patent application, H11-067366 filed on Mar. 12, 1999, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a glass rod manufacturing method and a glass rod manufacturing apparatus that can manufacture a straight glass rod.
2. Description of Related Art
FIG. 1
shows a conventional glass base material first elongating apparatus
400
. A glass base material
102
, which is a base material of an optical fiber, is usually elongated by the glass base material first elongating apparatus
400
. This reduces the diameter of the glass base material
102
, to produce a glass rod
106
. The glass rod
106
has a diameter from 3 mm to 5 mm larger than the most convenient diameter to draw an optical fiber. The most convenient diameter for drawing an optical fiber is 30 mm to 80 mm.
A glass base material first elongating apparatus
400
comprises a heating furnace
100
that heats the glass base material
102
, a hanging mechanism
105
that supplies said glass base material
102
to the heating furnace
100
, and a drawing chuck
104
that holds and elongates the heated glass base material
102
. To elongate the glass base material
102
, the glass base material first elongating apparatus
400
supplies the glass base material
102
to the heating furnace
100
using hanging mechanism
105
. Here the glass base material
102
is heated to approximately 2000° C. The first elongating apparatus
400
then holds the glass base material
102
by the drawing chuck
104
, and draws the glass base material
102
from the heating furnace
100
downward continuously to form a glass rod
106
.
FIG. 2
shows a configuration of a conventional glass lathe
110
. The glass rod
106
made by the glass base material first elongating apparatus
400
undergoes secondary elongation by the glass lathe
110
to produce a preform
107
. At this time, the diameter of the glass rod
106
is reduced to prescribed diameter. The glass lathe
110
comprises chucks
118
and
119
that hold the glass rod
106
, a tail stock
116
which moves the chuck
119
, and a heating source
122
which heats the glass rod
106
. One side of the chuck
118
is fixed, and the other side of the chuck
119
movable. A traction force can be applied to the chuck
119
. The glass rod
106
, which is held by the chucks
118
and
119
, is heated by the heating source
122
. The heated glass rod
106
is elongated by moving the tail stock
116
which pulls the glass rod
106
. The result is, the diameter of the glass rod
106
reduces to become the prescribed diameter
There was the possibility of manufacturing bent glass rods
106
when using a conventional glass base material first elongating apparatus
400
to elongate the glass base material
102
. One of the causes of manufacture of bent glass is when the elongating axis of the glass base material first elongating apparatus
400
, along which the glass base material
102
being elongated, are not vertical. Conventionally, the elongating axis of the glass base material first elongating apparatus
400
is adjusted by setting the plumb bob on the glass base material first elongating apparatus
400
and adjusting the elongating axis to be parallel to the string which is connected to the plumb bob. However, this method of using the plumb bob cannot adjust the axis which connects the hanging mechanism
105
and the drawing chuck
104
that actually hold the glass base material
102
.
Also, when using a conventional glass lathe
110
to elongate the glass rod
106
to manufacture the preform
107
further problems often arose. These problems included variation in the diameter of the preform
107
because the amount of gas provided to the heating source
122
and the speed of moving the tail stock
116
differed for each preform
107
produced.
When elongating a bent glass rod
106
, which is made by a conventional glass base material first elongating apparatus
400
, to make a preform
107
by the glass lathe
110
, the diameter of the preform
107
varied. When manufacturing optical fibers by drawing a preform
107
with a varying diameter, the diameter of the optical fibers produced also varies. This makes it difficult to manufacture an optical fiber of high quality.
SUMMARY OF THE INVENTION
As stated, it is an object of the present invention to provide a glass rod manufacturing method and a glass rod manufacturing apparatus that can solve the problems outlined above. The object of the present invention can be achieved by the combinations of features described in the independent claims of the present invention. The dependent claims define further advantageous embodiments of the present invention.
According to the first aspect of the present invention, a method for manufacturing a glass rod, which is a parent material of an optical fiber, can be provided such that said method comprises: adjusting a vertical inclination of a standard rod having a predetermined straightness; and heating and elongating a base material, which is a parent material of the glass rod, along an axis of the standard rod, the vertical inclination of which is adjusted, to generate the glass rod.
A method for manufacturing a glass rod can be provided such that the base material is elongated with a furnace which heats the base material, a hanging mechanism which supplies the base material to the furnace, and an elongating mechanism which pulls the base material heated by the furnace along the axis of the standard rod to produce the glass rod, and wherein the adjusting the vertical inclination includes: holding the standard rod by the hanging mechanism; and adjusting a vertical inclination of the standard rod held by the hanging mechanism to be a vertical direction.
A method for manufacturing a glass rod can be provided such that the adjusting the vertical inclination further includes: holding the standard rod by the elongating mechanism; and adjusting a vertical inclination of the standard rod held by the elongating mechanism to be a vertical direction.
A method for manufacturing a glass rod can be provided such that the adjusting the vertical inclination further includes: holding the standard rod by both of the hanging mechanism and the elongating mechanism; and adjusting a vertical inclination of the standard rod held by both of the hanging mechanism and the elongating mechanism to be a vertical direction.
A method for manufacturing a glass rod can be provided such that the base material is elongated with a furnace which heats the base material, a hanging mechanism which supplies the base material to the furnace, and an elongating mechanism which pulls the base material heated by the furnace along the axis of the standard rod to produce the glass rod, and wherein the adjusting the vertical inclination includes: holding the standard rod by the elongating mechanism; and adjusting a vertical inclination of the standard rod held by the elongating mechanism to be a vertical direction.
A method for manufacturing a glass rod can be provided such that the adjusting the vertical inclination further includes: holding the standard rod by the elongating mechanism; and adjusting a vertical inclination of the standard rod held by the hanging mechanism to be a vertical direction.
A method for manufacturing a glass rod can be provided such that the adjusting the vertical inclination further includes: holding the standard rod by both of the hanging mechanism and the elongating mechanism; and adjusting a vertical inclination of the standard rod held by both of the hanging mechanism and the elongating mechanism to be a vertical inclination.
A method for manufacturing a glass rod can be provided such that the base material is elongated with a furnace which heats the base material, a hanging mechanism which supplies the base material to the furnace, and an elongating mechanism which pulls the base material heated by the furnace along the axis of the standard rod to produce the glass rod, and
Hirasawa Hideo
Sakashita Mitsukuni
Shimada Tadakatsu
Yamamura Waichi
Hoffman John
Pillsbury & Winthrop LLP
Shin-Etsu Chemical Co. , Ltd.
LandOfFree
Straightening a glass rod for use in making an optical fiber... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Straightening a glass rod for use in making an optical fiber..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Straightening a glass rod for use in making an optical fiber... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3356758