Thermally stable glass tubing forming apparatuses

Patent metadata

Field	Value
Publication number	US-10399883-B2
Application number	US-201715402058-A
Country	US
Kind code	B2
Filing date	Jan 9, 2017
Priority date	Jan 15, 2016
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A bell positioning apparatus for glass tubing manufacturing includes a bell and a support connected to the bell. A bell positioning apparatus is attached to the support and configured to move the support and the bell with at least three degrees of freedom. The bell positioning apparatus includes a platform, a platform frame, and one or more frame legs. A frame leg dimensional stability apparatus maintains a temperature variation within 6.5° C. per meter of distance between each frame leg for an extended period of time, e.g. 4 hours.

First claim

The invention claimed is:

1. A bell positioning apparatus for a glass tubing manufacturing apparatus comprising:
a bell configured for a glass tube to be drawn over;
a support connected to the bell;
a frame with at least one frame leg, a platform and a support arm attached to the platform and the support, the support arm configured to move the support with at least two degrees of freedom;
a frame leg dimensional stability apparatus operatively coupled to the at least one frame leg and configured to maintain a deflection δ of the bell to less than 200 microns over a time period of 4 hours, wherein:
δ=(Δ T*L*CTE L ) *h/W;

ΔT is a temperature variation across a width of the at least one frame leg over a time period of 4 hours when the at least one frame leg is a single frame leg or a temperature variation between two frame legs over a time period of 4 hours when the at least one frame leg is more than one frame leg;
L is a length of the at least one frame leg;
CTE L is the coefficient of thermal expansion of the at least one frame leg;
h is a length of the support from a top of the platform to a bottom edge of the bell; and
W is the width of the at least one frame leg when the at least one frame leg is a single frame leg or a distance between two frame legs when the at least one frame leg is more than one frame leg.

2. The bell positioning apparatus of claim 1 , wherein the frame leg dimensional stability apparatus is configured to maintain a temperature variation within 6.5° C./m of a width or a thickness of the at least one frame leg over a time period of 4 hours.

3. The bell positioning apparatus of claim 1 , wherein the frame leg dimensional stability apparatus is configured to maintain a temperature variation between the at least one frame leg and at least one other frame leg of the frame to within 6.5° C./m of a distance between the frame legs over a time period of 4 hours.

4. The bell positioning apparatus of claim 1 , wherein the frame leg dimensional stability apparatus comprises a temperature control component selected from the group consisting of:
heating pads;
electrical resistance heating wire;
heating tape;
heated fluid directed across each frame leg;
heated fluid within each frame leg; and
heated fluid in which each frame leg is immersed.

5. The bell positioning apparatus of claim 4 , wherein the temperature control component is heating pads attached to each frame leg, and further comprising an enclosure surrounding the temperature control component and insulating each frame leg and the temperature control component from ambient temperatures during glass tubing manufacturing.

6. The bell positioning apparatus of claim 5 , further comprising insulation within the enclosure.

7. The bell positioning apparatus of claim 6 , wherein the frame leg dimensional stability apparatus comprises at least one temperature sensor, a temperature controller and a power supply, the at least one temperature sensor communicatively coupled with the temperature controller, the power supply communicatively coupled with the temperature control component and the temperature controller communicatively coupled with the power supply, wherein the temperature controller receives temperature signals from the at least one temperature sensor and provides instructions to the power supply to increase, decrease, or maintain an electrical current provided to the temperature control component.

8. The bell positioning apparatus of claim 4 , wherein the temperature control component is heated liquid in which each frame leg is immersed.

9. The bell positioning apparatus of claim 8 , further comprising a heating element within the heated liquid.

10. The bell positioning apparatus of claim 9 , wherein the frame leg dimensional stability apparatus comprises at least one temperature sensor, a temperature controller and a power supply, the at least one temperature sensor communicatively coupled with the temperature controller, the power supply communicatively coupled with the temperature control component and the temperature controller communicatively coupled with the power supply, wherein the temperature controller receives temperature signals from the at least one temperature sensor and provides instructions to the power supply to increase, decrease, or maintain an electrical current provided to the heating element.

11. A glass tubing manufacturing apparatus comprising:
a glass delivery tank with molten glass, the glass delivery tank having a bottom opening with an inner diameter;
a bell having an upper portion with an outer diameter, wherein a clearance is present between the inner diameter of the bottom opening and the outer diameter of the bell;
a support connected to the bell, the support extending up through the glass delivery tank to a bell positioning apparatus, the bell positioning apparatus comprising:
a frame having at least one frame leg, a platform and a support arm, the platform attached to the frame, the support arm attached to the platform and the support attached to the support arm, the bell positioning apparatus configured to move and position the bell relative to the bottom opening of the glass delivery tank; and
a frame leg dimensional stability apparatus comprising:
a temperature control component selected from the group consisting of heating pads attached the at least one frame leg; electrical resistance heating wire wound around a length the at least one frame leg, heating tape wound around the length of the at least one frame leg;
heated fluid directed across the at least one frame leg;
heated fluid within the at least one frame leg; and
heated liquid in which the at least one frame leg is immersed;
one or more temperature sensors located along the length of the at least one frame leg; and
a temperature controller communicatively coupled with the one or more temperature sensors; and
a power supply operable to heat the temperature control component;

wherein the one or more temperature sensors, temperature controller and power supply are configured to:
maintain a temperature variation within 6.5° C./m of a width or a thickness of the at least one frame leg over a time period of at least 4 hours; or
maintain a temperature variation between the at least one frame leg and at least one other frame leg of the frame to within 6.5° C./m of a distance between the frame legs over a time period of at least 4 hours.

12. The glass tubing manufacturing apparatus of claim 11 , wherein the temperature control component is the heating pads attached to the at least one frame leg, and further comprising an enclosure surrounding the temperature control component and insulating the at least one frame leg and the temperature control component from ambient temperatures during glass tubing manufacturing.

13. The glass tubing manufacturing apparatus of claim 12 , further comprising insulation within the enclosure.

14. The glass tubing manufacturing apparatus of claim 11 , wherein the temperature controller receives temperature signals from the one or more temperature sensors and provides instructions to the power supply to increase, decrease, or maintain an electrical current provided to the temperature control component.

15. The glass tubing manufacturing apparatus of claim 11 , wherein the temperature control component is the heated fluid in which the at least one frame leg is immersed.

16. The glass tubing manufacturing apparatus of claim 15 , further comprising a heating element within the heated fluid.

17. The glass tubing manufacturing apparatus of claim 16 , w

Assignees

• Corning Inc

Inventors

• Berkey Adam Charles
• Rhoads Randy Lee
• Weibel Matthew Scott

Classifications

• C03B17/04 Primary

  Forming tubes or rods by drawing from stationary or rotating tools or from forming nozzles · CPC title

• G05D23/19

  characterised by the use of electric means {(G05D23/1393 takes precedence)} · CPC title