Claims
- 1. A method for heating, forming, and tempering a glass sheet comprising the steps of:
pre-heating the glass sheet to at least a first predetermined temperature; applying radio-frequency energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature; and cooling at least one outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet.
- 2. A method as set forth in claim 1 wherein said radio-frequency energy is a frequency within a range of about 0.1 GHz to about 2.0 GHz.
- 3. A method as set forth in claim 1 wherein said radio-frequency energy is a frequency of about 0.4 GHz.
- 4. A method as set forth in claim 1 wherein said step of cooling comprises directing at least one air stream at the at least one outer surface of the glass sheet.
- 5. A method as set forth in claim 1 including the step of quenching the glass sheet to produce a tempered-glass sheet.
- 6. A method as set forth in claim 5 wherein said step of quenching comprises applying at least one air stream to the at least one outer surface of the treated-glass sheet.
- 7. A method as set forth in claim 5 wherein said step of quenching reduces a temperature of the treated-glass sheet to a temperature within the range of about 400° F. to about 600° F.
- 8. A method as set forth in claim 1 wherein said steps of heating and cooling comprises providing at least one hollow electrode, applying radio-frequency energy from the electrode to the glass sheet, and applying at least one air stream through the electrode to the at least one outer surface of the glass sheet.
- 9. A method as set forth in claim 1 wherein the first predetermined temperature is a temperature in the range of about 900° F. to about 950° F.
- 10. A method as set forth in claim 1 wherein the second predetermined temperature is a temperature within a range of about 1150° F. to about 1250° F.
- 11. A method as set forth in claim 1 wherein said step of pre-heating of the glass sheet to at least the first predetermined temperature comprises heating with either infrared energy or convective energy.
- 12. A system for heating, forming, and tempering a glass sheet comprising:
a pre-heating section having at least one heat source positioned over and/or below the glass sheet and adapted to raise a temperature of the glass sheet to a temperature substantially at or above a softening temperature of the glass sheet; a heating/cooling section having at least one radio-frequency energy source positioned over and/or below the glass sheet and adapted to raise a temperature of the pre-heated glass sheet to a temperature substantially at or above a forming temperature of the pre-heated glass sheet; and a cooling section to maintain a desired temperature differential between a center and an outer surface of the glass sheet with the center having a higher temperature than a temperature of the outer surface, the heating and cooling combining to form a tempered-glass sheet.
- 13. A system as set forth in claim 12 wherein said at least one radio-frequency energy source emits energy having a frequency within a range of about 0.1 GHz to about 2.0 GHz.
- 14. A system as set forth in claim 12 wherein said at least one radio-frequency energy source emits energy having a frequency of about 0.4 GHz.
- 15. A system as set forth in claim 12 wherein said at least one radio-frequency energy source includes a bus bar having a plurality of electrodes extending therefrom toward the glass sheet, each of said electrodes having a terminal portion positioned as closely as possible to and in non-contacting relationship with an outer surface of the glass sheet and adapted to heat glass sheet.
- 16. A system as set forth in claim 12 wherein said at least one radio-frequency energy source includes at least one hollow electrode to apply the radio-frequency energy to the glass sheet and connected to a source of compressed air to apply the compressed air through said at least one hollow electrode as the glass sheet.
- 17. A system as set forth in claim 12 wherein said pre-heating section includes a series of selectively operable rollers that rotate in a desired direction to introduce the glass sheet into said pre-heating section and move the glass sheet through said pre-heating section in a particular direction.
- 18. A system as set forth in claim 12 wherein said heating section includes a series of selectively operable rollers that rotate in a desired direction to introduce the glass sheet into said heating/cooling section and move the glass sheet through said heating/cooling section in a particular direction.
- 19. A system as set forth in claim 12 including a quenching section adapted to rapidly quench the glass sheet to form a tempered-glass sheet
- 20. A system as set forth in claim 19 wherein said quenching section includes a series of selectively operable rollers that rotate in a desired direction to introduce the glass sheet into said quenching section and move the glass sheet through said quenching section in a particular direction.
- 21. A system as set forth in claim 12 wherein said cooling section includes at least one cooling system positioned over and/or below the pre-heated glass sheet to apply compressed air as the glass sheet progresses through said heating section.
- 22. A system for heating, forming, and tempering a glass sheet comprising:
a pre-heating section having at least one heat source positioned over and/or below the glass sheet and adapted to raise a temperature of the glass sheet to a temperature substantially at or above a softening temperature of the glass sheet; a heating/cooling section having at least one radio-frequency energy source positioned over and/or below the glass sheet and adapted to raise a temperature of the pre-heated glass sheet to a temperature substantially at or above a forming temperature of the pre-heated glass sheet and to maintain a desired temperature differential between a center and an outer surface of the glass sheet with the center having a higher temperature than a temperature of the outer surface, the heating and cooling combining to form a tempered-glass sheet.
- 23. A system as set forth in claim 22 wherein said at least one radio-frequency energy source includes at least one hollow electrode to apply the radio-frequency energy to the glass sheet and connected to a source of compressed air to apply the compressed air through said at least one hollow electrode as the glass sheet.
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The present application claims benefit of U.S. Provisional Patent Application No. 60/323,223 filed Sep. 19, 2001 and entitled “System for Simultaneously Heating and Cooling Glass to Produce Tempered Glass.”
Provisional Applications (1)
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Number |
Date |
Country |
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60323223 |
Sep 2001 |
US |