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1. US6131412 - Adjusting temperature of glass sheets in tempering furnace

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]
What is claimed is:
1. A method of adjusting the temperature of a glass sheet in a tempering furnace, said method comprising:
advancing the glass sheet on a roller conveyor through the tempering furnace,
heating the glass sheet on the roller conveyor from above and below,
oscillating the glass sheet in a reciprocating manner on the rollers as the glass sheet is advanced through the tempering furnace,
measuring the temperature of the glass sheet in the tempering furnace, and
controlling a dwell time of the glass sheet in the tempering furnace based on the temperature measured of the same glass sheet while in said tempering furnace, wherein during oscillation, the glass sheet is at rest when the sheet undergoes change of direction, the temperature of the sheet being measured when the sheet is at rest.
2. A method as claimed in claim 1, wherein the dwell time is controlled by adjusting a speed of oscillation.
3. A method as claimed in claim 1, wherein the dwell time is controlled by adjusting a length of oscillation.
4. A method as claimed in claim 1, comprising providing a desired heating curve for the glass sheet, and controlling a time of oscillation of the glass sheet in response to measured temperature so that the temperature of the glass sheet substantially corresponds to said heating curve.
5. A method as claimed in claim 1, wherein the temperature of the glass sheet is measured at a plurality of points in the tempering furnace.
6. A method as claimed in claim 5, wherein said points at which the temperature of the sheet is measured are parallel to one another.
7. A method as claimed in claim 1, comprising measuring the temperature of the sheet with a pyrometer.
8. A method as claimed in claim 1, comprising determining locations of the glass sheet before the glass sheet is introduced into the tempering furnace to insure that the glass sheet will be at measuring points in the furnace for temperature measurement of the glass sheet.
9. Equipment for adjusting the temperature of glass sheets in a tempering furnace, said equipment comprising:
a plurality of rollers in said tempering furnace for supporting and advancing the glass sheets through the tempering furnace in horizontal attitude,
means for heating the glass sheets from above and below as the glass sheets pass through the tempering furnace,
means for reciprocating the rollers to oscillate the glass sheets as the glass sheets pass through the tempering furnace,
means for measuring the temperature of the glass sheets in the tempering furnace, and
means for adjusting a dwell time of each of the glass sheets in the tempering furnace based on the measurement of the temperature of said each of the glass sheets while in said tempering furnace, wherein the glass sheets are at rest when the sheets change direction during oscillation thereof, said temperature of the glass sheets being measured by said temperature measuring means when the glass sheets are at rest.
10. Equipment as claimed in claim 9, wherein the means for adjusting the oscillation time comprises means for adjusting oscillation time of the means for reciprocating the rollers.
11. Equipment as claimed in claim 9, wherein a plurality of said means for measuring the temperature of said glass sheets are provided in said tempering furnace.
12. Equipment as claimed in claim 11, wherein the plurality of temperature measuring means are parallel to one another.
13. Equipment as claimed in claim 9, wherein the temperature measuring means comprises a pyrometer.
14. Equipment as claimed in claim 9, comprising detector means for determining the position of the glass sheets prior to entry of the glass sheets into the tempering furnace.