Bending of glass sheets comprising localized cooling

Patent metadata

Field	Value
Publication number	US-11964896-B2
Application number	US-201816624570-A
Country	US
Kind code	B2
Filing date	Jun 26, 2018
Priority date	Jun 29, 2017
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

A device and a process for manufacturing a bent individual glass sheet including a peripheral compression belt, wherein the process includes the heating thereof to its bending temperature in a furnace, the individual bending thereof, and the general cooling thereof. One zone of the sheet at least partially inside the peripheral compression belt, referred to as locally cooled zone, undergoes, after the heating of the sheet, a local cooling faster than the general cooling, when the sheet is at a temperature of at least 530° C. The cutting of the sheet on the locally cooled zone creates edges having edge compressive stresses.

First claim

The invention claimed is:

1. A device for bending an individual glass sheet comprising:
a furnace comprising heating elements for heating the individual glass sheet to its bending temperature, said individual glass sheet being an unbent individual glass sheet;
a bending tool for bending the unbent individual glass sheet heated to its bending temperature in said furnace, the bending tool including an upper bending form and a movable lower bending counterform, the movable lower bending counterform configured to press the unbent individual glass sheet heated to its bending temperature in said furnace against the upper bending form to form a bent individual glass sheet, the upper bending form and movable lower bending counterform being dimensioned so that, at the bending tool, a peripheral area of the unbend individual glass sheet is pressed against a main surface of the upper bending form to transform said unbent individual glass sheet into said bent individual glass sheet;
a conveyor configured to move the unbent individual glass sheet through the furnace and to the bending tool so that the unbent individual glass sheet is positioned by said conveyor at a pickup location at said bending tool that is between the upper bending form and the movable lower bending counterform, wherein said movable lower bending counterform is movable between a position below said pickup location to a position above said pick up location to pick up said unbent individual glass sheet and move said unbent individual glass sheet towards the upper bending form;
a movable cooling frame that is movable between the upper bending form and the movable lower bending counterform to receive the bent individual glass sheet from the upper bending form,
an air blowing unit arranged in a cooling zone that is downstream of the bending tool and that is adapted to administer a general cooling of the entire individual bent glass sheet so as to semi-temper or temper the individual bent glass sheet, and
a local cooling system for local cooling of only a portion of the unbent or bent individual glass sheet after the unbent or bent individual glass sheet is heated by the heating elements to a bending temperature to introduce a temperature differential between said portion of the unbent or bent individual glass sheet that is locally cooled and a remaining portion of the unbent or bent individual glass sheet when said unbent or bent individual glass sheet is above a temperature at which the glass of the unbent or bent glass sheet sets, the local cooling system being arranged downstream of the heating elements and movable at a position that is upstream of the cooling zone such that the local cooling of only said portion of the unbent or bent individual glass sheet is carried out by the local cooling system prior to (i) conveying the individual glass bent glass sheet into the cooling zone and (ii) administering by the air blowing the general cooling of the individual bent glass sheet to semi-temper or temmper the individual bent glass sheet,
wherein
(a) the local cooling system includes a first cooling tool that is movable with the movable lower bending counterform such that the first cooling tool and the movable lower bending counterform arre movable vertically from the position below said pickup location towards the upper bending form during which the movable lower bending counterform picks up the unbent individual glass sheet at said pickup location and vertically transports the unbent individual glass sheet above the pickup location towards the upper bending form to bend the unbent individual glass sheet and form the bent individual glass sheet, the first cooling tool forming a first local cooling zone covering an area of between 0.5 cm 2 and 70 cm 2 on a first main face of the unbent or bent individual glass sheet, or
(b) the local cooling system includes a second cooling tool that is incorporated in the upper bending form, the second cooling tool forming a second local cooling zone covering an area of between 0.5 cm 2 and 70 cm 2 on a second main face of the individual glass sheet that is opposite the first main face, or
(c) the local cooling system includes said first and second cooling tools, or

wherein the local cooling system includes said first and second cooling tools, or wherein the local cooling system includes a third cooling tool that is movable with the movable cooling frame between the upper bending form and the movable lower bending counterform, the third cooling tool forming a third local cooling zone covering an area of between 0.5 cm 2 and 70 cm 2 on the first main face of the individual glass sheet,
wherein the local cooling system is constructed and arrange to locally cool said portion of the unbent or bent individual glass sheet in a zone that extends outside a peripheral zone of the glass sheet that includes a peripheral compression belt.

2. The device as claimed in claim 1 , wherein the local cooling system for a local cooling is placed in order to intervene over a zone of the glass sheet while the glass sheet is on or under the bending tool.

3. The device as claimed in claim 1 , wherein the local cooling system includes said first cooling tool and the first cooling tool is attached to said movable lower bending counterform.

4. The device as claimed in claim 1 , wherein the local cooling system includes only said second cooling tool.

5. The device as claimed in claim 1 , wherein the local cooling system includes said third cooling tool, the third cooling tool being attached to said cooling frame.

6. The device as claimed in claim 1 , wherein the first, second and third cooling tools act by convection and/or conduction and/or radiation.

7. The device as claimed in claim 6 , wherein at least one of the first, second and third cooling tool comprises an air blowing nozzle.

8. The device as claimed in claim 1 , wherein the conveyor for moving the unbent individual glass sheet comprises a roller bed.

9. The device as claimed in claim 1 , wherein the bending tool is located downstream of the heating elements so that the unbent individual glass sheet is bent at the bending station after being exposed to the heating elements.

10. A line for manufacturing a bent glazing comprising an individual glass sheet, said line comprising the device from claim 1 and a cutting tool for cutting the bent individual glass sheet.

11. the device as claimed in claim 1 , wherein the local cooling system includes only said first and second cooling tools.

12. The device as claimed in claim 1 , wherein the local cooling system is configured to carry out said local cooling by conduction and/or radiation.

Assignees

• Saint Gobain

Inventors

• Burgaud David
• Hennion Alexandre
• Gobin Jérôme

Classifications

• C03B23/0235 Primary

  involving applying local or additional heating, cooling or insulating means · CPC title

• C03B23/0307

  Press-bending involving applying local or additional heating, cooling or insulating means · CPC title

• C03B27/0404

  Nozzles, blow heads, blowing units or their arrangements, specially adapted for flat or bent glass sheets · CPC title

• C03B27/0413

  Stresses, e.g. patterns, values or formulae for flat or bent glass sheets · CPC title

• C03B27/044

  for flat or bent glass sheets being in a horizontal position · CPC title