Glass sheets and methods of shaping glass sheets

• US 9,028,296 B2
• Filed: 08/30/2012
• Issued: 05/12/2015
• Est. Priority Date: 08/30/2012
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Venkatachalam, Siva, Wang, Liming
• Primary Examiner(s): MORGAN, EILEEN P
• Application Number:
  US13/599,090
• Publication Number:
  US 20140065376A1
• Time in Patent Office: 985 Days
• Field of Search: 451/44, 451/57, 451/58, 451/65, 451/70
• US Class Current: 451/44
• CPC Class Codes: B24B 1/00 Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
• CPC Class Codes: B24B 27/0076 grinding machines comprising two or more grinding tools
• CPC Class Codes: B24B 47/225 for bevelling optical work, e.g. lenses
• CPC Class Codes: B24B 7/24 for grinding or polishing glass
• CPC Class Codes: B24B 7/242 for plate glass
• CPC Class Codes: B24B 7/26 for simultaneously grinding or polishing opposite faces of continuously travelling sheets or bands
• CPC Class Codes: B24B 9/10 of plate glass
• CPC Class Codes: B24B 9/107 for glass plates while they are turning
• CPC Class Codes: Y10T 428/24777 Edge feature

Abstract

Methods of shaping a glass sheet each include a step of removing a first portion of the glass sheet to form a first beveled surface. The methods further include the step of removing a second portion of the glass sheet to form a second beveled surface. The methods still further include the step of removing a third portion of the glass sheet comprising a remainder of an end surface of an edge portion of the glass sheet. In further examples, glass sheets are also provided with a first bevel surface intersecting a first glass-sheet surface and an apex surface, and a second bevel surface intersecting a second glass-sheet surface and the apex surface. The glass sheet exhibits a probability of failure of less than 5% at an edge stress of 135 MPa.

Claims

1. A method of shaping a glass sheet comprising a first glass-sheet surface, a second glass-sheet surface opposing the first glass-sheet surface, a thickness defined between the first glass-sheet surface and the second glass-sheet surface, and an edge portion comprising an end surface comprising a median crack surface, wherein the first glass-sheet surface and the end surface intersect along a first edge of the edge portion, the second glass-sheet surface and the end surface intersect along a second edge of the edge portion, and the median crack surface extends from either the first or second edge of the edge portion along the end surface, the method comprising the steps of:

(I) removing a first portion of the glass sheet comprising the first edge with at least one rotating cup wheel, thereby forming a first bevel surface between the first glass-sheet surface and the end surface;

(II) removing a second portion of the glass sheet comprising the second edge with the at least one rotating cup wheel, thereby forming a second bevel surface between the second glass-sheet surface and the end surface; and

then

(III) removing a third portion of the glass sheet comprising a remainder of the end surface with a rotating grooved wheel to form an apex surface between the first and second bevel surfaces,

wherein step (I) and/or step (II) removes the median crack surface, and

wherein steps (I), (II) and (III) provide the glass sheet with a shaped edge that exhibits a probability of failure of less than 5% at an edge stress of 135 MPa.

2. The method of claim 1, wherein steps (I) and (II) are conducted simultaneously.

3. The method of claim 1, wherein the at least one rotating cup wheel of step (I) comprises a first rotating cup wheel and the at least one rotating cup wheel of step (II) comprises a second rotating cup wheel.

4. The method of claim 1, wherein the at least one rotating cup wheel is selected from the group consisting of a metal bond diamond wheel and a resin bond diamond wheel.

5. The method of claim 4, wherein the bonded diamond wheel includes a mesh size ranging from 400 to 1000.

6. The method of claim 1, wherein the grooved wheel is a metal bond wheel with a diamond mesh size ranging from 600 to 1000.

7. The method of claim 1, wherein the grooved wheel comprises a groove configured to accommodate a profile of the glass sheet defined by the first bevel surface, the apex surface, and the second bevel surface.

8. The method of claim 1, wherein, after step (III), further comprising the step (IV) of contacting the glass sheet with a rotating polish wheel to polish at least one of the first bevel surface, the apex surface, and the second bevel surface.

9. The method of claim 1, wherein, after step (III), further comprising the step (IV) of providing a rounded intersection between at least one of the first glass-sheet surface and the first bevel surface, the first bevel surface and the apex surface, the apex surface and the second bevel surface, and the second bevel surface and the second glass-sheet surface.

10. The method of claim 1, wherein, after step (III), further comprising the step (IV) of contacting the glass sheet with a rotating polish wheel including a wheel body selected from the group consisting of a rubber bond wheel, a resin bond wheel, and a polymer bond wheel and a cutting material selected from the group consisting of one or more of a diamond grit, a silicon carbide grit, an alumina grit and a ccria grit.

11. The method of claim 1, wherein the median crack surface extends less than or equal to 15% of the thickness of the glass sheet.

12. A method of shaping a glass sheet comprising a first glass-sheet surface, a second glass-sheet surface opposing the first glass-sheet surface, a thickness defined between the first glass-sheet surface and the second glass-sheet surface, and an edge portion comprising an end surface comprising a median crack surface, wherein the first glass-sheet surface and the end surface intersect along a first edge of the edge portion, the second glass-sheet surface and the end surface intersect along a second edge of the edge portion, and the median crack surface extends from either the first or second edge of the edge portion along the end surface, the method comprising the steps of:

(I) removing a first portion of the glass sheet comprising the first edge, thereby forming a first bevel surface between the first glass-sheet surface and the end surface;

(II) removing a second portion of the glass sheet comprising the second edge, thereby forming a second bevel surface between the second glass-sheet surface and the end surface; and

then

(III) removing a third portion of the glass sheet comprising a remainder of the end surface, thereby forming an apex surface between the first and second bevel surfaces,

wherein step (I) and/or step (II) removes the median crack surface, and

wherein steps (I), (II) and (III) provide the glass sheet with a shaped edge that exhibits a probability of failure of less than 5% at an edge stress of 135 MPa.

13. The method of claim 12, wherein steps (I) and (II) are conducted simultaneously.

14. The method of claim 12, wherein step (I) and/or step (II) includes chamfering with at least one rotating cup wheel.

15. The method of claim 12, wherein step (III) includes removing the third portion with a rotating grooved wheel.