Overpressure-assisted gravity bending method and device suitable therefor

Patent metadata

Field	Value
Publication number	US-10577271-B2
Application number	US-201615578699-A
Country	US
Kind code	B2
Filing date	Aug 26, 2016
Priority date	Sep 8, 2015
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

The present invention relates to a device and method for bending at least one glass pane. The device includes: a gravity bending mould with a supporting surface, which is suitable for arranging at least one glass pane thereon; an upper shaping tool arranged opposite the supporting surface, the upper shaping tool being suitable for producing an overpressure on a surface of the at least one glass pane arranged on the supporting surface, and the surface of the at least one glass pane faces away from the supporting surface. The shaping tool has a cover that forms a hollow space open in the direction of the gravity bending mould and is equipped with a sealing lip arranged on an edge section of the cover for making contact with the surface of the at least one glass pane, and the shaping tool is equipped with means for introducing a gas into the hollow space in order to produce the overpressure.

First claim

The invention claimed is:

1. A device for bending at least one glass pane, comprising: a gravity bending mould with a supporting surface, which is suitable for arranging at least one glass pane thereon; and an upper shaping tool arranged opposite the supporting surface, the upper shaping tool being suitable for producing an overpressure on a first surface of the at least one glass pane arranged on the supporting surface, the first surface facing away from the supporting surface, wherein the upper shaping tool has a cover that forms a hollow space open in a direction of the gravity bending mould and comprises a flexible sealing lip disposed between the cover and the first surface when contacting the first surface, the flexible sealing lip comprising a first portion contacting an edge section of the cover on a side of the edge section facing the hollow space and a second portion, integral with the first portion, distanced and extending apart from the edge section of the cover towards a region interior to the hollow space for making contact with the first surface, the second portion containing a weighting belt, and wherein the upper shaping tool is equipped with means for introducing a gas into the hollow space in order to produce the overpressure.

2. The device according to claim 1 , wherein a contact region between the second portion of the sealing lip and the first surface has a distance of at most 20 cm from a side edge of the glass pane.

3. The device according to claim 1 , wherein the sealing lip is made of a felt or fleece.

4. The device according to claim 3 , wherein the felt or the fleece is metal-containing.

5. The device according to claim 3 , wherein the felt or the fleece is stainless-steel containing.

6. The device according to claim 1 , wherein the weighting belt contains glass fibres and/or metal fibres.

7. The device according to claim 1 , wherein the edge section is directed downward.

8. The device according to claim 7 , wherein the edge section is arranged substantially vertically.

9. The device according to claim 1 , wherein the gravity bending mould has a frame-like, concave supporting surface.

10. The device according to claim 1 , wherein the cover has a material thickness of at most 5 mm.

11. The device according to claim 1 , wherein the weighting belt contains a glass fibre-metal fibre mixture.

12. A method for bending at least one glass pane, comprising:
arranging at least one glass pane on a supporting surface of a gravity bending mould;
heating the at least one glass pane to at least its softening temperature;
producing an overpressure on a first surface of the at least one glass pane facing away from the supporting surface using an upper shaping tool that has a cover that forms a hollow space open in the direction of the gravity bending mould and comprises a flexible sealing lip disposed between the cover and the first surface and contacting the first surface, the flexible sealing lip comprising a first portion contacting an edge section of the cover on a side of the edge section facing the hollow space and a second portion, integral with the first portion, distanced and extending apart from the edge section of the cover towards a region interior to the hollow space for making contact with the first surface, the second portion containing a weighting belt, wherein the overpressure is produced by introducing a gas into the hollow space; and
cooling the glass pane.

13. The method according to claim 12 , wherein, during bending, the sealing lip is arranged completely above the first surface of the at least one glass pane.

14. The method according to claim 12 , wherein the edge section surrounds the at least one glass pane during bending and the sealing lip extends beyond a side edge of the glass pane.

15. The method according to claim 12 , wherein the overpressure is from 5 mbar to 50 mbar.

16. The method according to claim 12 , wherein the overpressure is produced for a period of at most 60 seconds on the first surface of the glass pane.

17. The method according to claim 12 , wherein the glass pane contains soda lime glass and the maximum temperature to which the glass pane is heated is less than 630° C.

18. The method according to claim 17 , wherein the maximum temperature to which the glass pane is heated is less than 620° C.

19. The method according to claim 12 , wherein the overpressure is from 10 mbar to 30 mbar.

20. A method of using an upper shaping tool that has a cover that forms a hollow space open in the direction of the gravity bending mould and comprises a flexible sealing lip arranged on an edge section of the cover, for assisting a gravity bending process, wherein, with the upper shaping tool, an overpressure is produced on the first surface of a glass pane facing away from a gravity bending mould, by disposing the flexible sealing lip between the cover and a first surface of the glass pane, the flexible sealing lip comprising a first portion contacting the edge section of the cover on a side of the edge section facing the hollow space and a second portion, integral with the first portion, distanced and extending apart from the edge section of the cover towards a region interior to the hollow space for making contact with the first surface, the second portion containing a weighting belt, bringing the sealing lip into contact with the first surface and introducing a gas into the hollow space.

Assignees

• Saint Gobain

Inventors

• Le Ny Jean-Marie
• Balduin Michael
• Schall Guenther

Classifications

• C03B23/0252 Primary

  by gravity only, e.g. sagging (C03B23/035 takes precedence) · CPC title

• C03B23/0258

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

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• C03B23/0093

  Tools and machines specially adapted for re-forming shaped glass articles in general, e.g. chucks (C03B23/0086, C03B23/02, C03B23/04, C03B23/18 take precedence) · CPC title

• C03B23/0256

  Gravity bending accelerated by applying mechanical forces, e.g. inertia, weights or local forces · CPC title