US4654065A — Quasi-containerless glass formation method and ap…

Claim 1

Independent Claim 127 words

A method of forming a glass rod from a precursor rod comprising performing in a microgravity environment the steps of: heating a selected short section of said precursor rod in a first furnace to form a first self-supporting molten zone therein; heating a second selected short section of said precursor rod in a second furnace to form a second self-supporting molten zone of said rod which initially is contiguous with and part of said first molten zone; gradually moving said first and second furnaces apart to form an extended molten zone; and cooling the central portion of the extended molten zone at a sufficient cooling rate to a temperature below the glass transition temperature to form a rod of glass in the increasingly widening gap forming therebetween.

Claim 2

Independent Claim 127 words

A method of forming a glass rod from a precursor rod comprising performing in a microgravity environment the steps of: heating a selected short section of said precursor rod in a first furnace to form a first self-supporting molten zone therein; heating a second selected short section of said precursor rod in a second furnace to form a second self-supporting molten zone of said rod which initially is contiguous with and part of said first molten zone; gradually moving said first and second furnaces apart to form an extended molten zone; and cooling the central portion of the extended molten zone at a sufficient cooling rate to a temperature below the glass transition temperature to form a rod of glass in the increasingly widening gap forming therebetween.

Claim 3

Dependent Claim 51 words

The method of claim 1 including the further steps of: clamping the glass formed between said molten sections; removing one of said furnaces from one end of said rod; and pulling the clamped glass section away from the remaining furnace so as to draw a fiber from the molten section therein.

Claim 4

Dependent Claim 20 words

The method of claim 2 including the further steps of gripping said fiber and winding the fiber on a reel.

Claim 5

Dependent Claim 38 words

A method as in claim 1 in which said first and second furnaces are rotated in reverse directions with respect to each other as they are gradually moved apart to aid homogenization of the melt as it forms.

Claim 6

Dependent Claim 32 words

A method as in claim 1 in which the two ends of the said glass precursor rod are rotated relative to each other to aid homogenization of the melt as it forms.

Claim 7

Dependent Claim 40 words

A method as in claim 1 in which said first and second furnaces are traversed back and forth with respect to each other as they are moved apart to aid in achieving uniform distribution of a dopant by zone leveling.

Claim 8

Dependent Claim 43 words

The method of claim 1 wherein each of said molten zones is formed by first heating said short section to a temperature near the melting point in a pre-heating primary furnace region and then melting the pre-heated section in a trim furnace region.

Claim 9

Independent Claim 166 words

A method of preparing a glass rod from a reluctant glass--forming composition which comprises: preparing a precursor rod comprising a first axial section formed of a good glass former, a second axial section formed of a reluctant glass former and a third axial section between said first and second sections formed of a transitional composition gradually changing from a good glass former to a reluctant glass former; heating a short portion of said precursor rod at said first section in a furnace disposed in a microgravity environment to form a molten zone; moving said rod and said furnace relative to one another to gradually move said rod through said furnace and thereby move said molten zone through said second and third sections along said rod and cooling the area of said rod behind said molten zone to a desired undercooling temperature at a desired rate so as to produce glass from said reluctant glass-forming composition, said moving and cooling steps being performed in a microgravity environment.

Claim 10

Independent Claim 166 words

A method of preparing a glass rod from a reluctant glass--forming composition which comprises: preparing a precursor rod comprising a first axial section formed of a good glass former, a second axial section formed of a reluctant glass former and a third axial section between said first and second sections formed of a transitional composition gradually changing from a good glass former to a reluctant glass former; heating a short portion of said precursor rod at said first section in a furnace disposed in a microgravity environment to form a molten zone; moving said rod and said furnace relative to one another to gradually move said rod through said furnace and thereby move said molten zone through said second and third sections along said rod and cooling the area of said rod behind said molten zone to a desired undercooling temperature at a desired rate so as to produce glass from said reluctant glass-forming composition, said moving and cooling steps being performed in a microgravity environment.

Claim 11

Dependent Claim 38 words

The method of claim 8 including the further steps of: clamping the resulting glass rod at said first section and pulling said rod away from said furnace so as to draw a fiber from the molten section thereof.

Claim 12

Dependent Claim 20 words

The method of claim 9 including the additional steps of gripping said fiber and winding the fiber on a reel.

Claim 13

Dependent Claim 24 words

The method of claim 8 wherein said good-glass former is a silica-based composition and said reluctant glass former is halide or telluride based composition.

Claim 14

Dependent Claim 18 words

The method of claim 8 wherein said furnace includes a primary heating region and a trim heating region.

Claim 15

Dependent Claim 116 words

Apparatus for making a rod of glass from a glass precursor rod in a microgravity environment comprising: a first furnace for heating a first short section of said glass precursor rod to a first melted state zone; a second furnace for heating a second short section of said glass precursor rod adjacent to said first short section of rod to a second melted state zone which is contiguous to said first melted state; and means for gradually separating said first and second furnaces along with said first and second melted state zones to leave an increasingly longer molten zone adapted to be cooled to form a rod of glass in between said separating melted state zones.

Claim 16

Dependent Claim 116 words

Apparatus for making a rod of glass from a glass precursor rod in a microgravity environment comprising: a first furnace for heating a first short section of said glass precursor rod to a first melted state zone; a second furnace for heating a second short section of said glass precursor rod adjacent to said first short section of rod to a second melted state zone which is contiguous to said first melted state; and means for gradually separating said first and second furnaces along with said first and second melted state zones to leave an increasingly longer molten zone adapted to be cooled to form a rod of glass in between said separating melted state zones.

Claim 17

Dependent Claim 26 words

Apparatus as in claim 13 and further comprising means for rotating said first and second furnaces in opposite directions to aid a more homogenous resulting rod.

Claim 18

Dependent Claim 42 words

Apparatus as in claim 13 and further comprising means for traversing said first and second furnaces back and forth over said rod to aid in homogenization of a dopant or other desired component or characteristic of said rod of glass being formed.

Claim 19

Dependent Claim 17 words

Apparatus as in claim 13 comprising further means to draw said rod of glass into a fiber.

Claim 20

Dependent Claim 45 words

Apparatus as in claim 16 and further comprising: means for removing one of said furnaces from one end of said fiber; and reel type means for winding said glass fiber onto said reel type and for continuing to draw fiber from the remaining melted zone.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-03-30	1990-09-29	1991-03-31	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-03-30	1994-09-29	1995-03-31	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-03-30	1998-09-29	1999-03-31	$7700.00	Window Closed / Lapsed

Quasi-containerless glass formation method and apparatus

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag