Composite backed prestressed mirror for solar facet

• US 7,309,398 B2
• Filed: 08/27/2003
• Issued: 12/18/2007
• Est. Priority Date: 06/27/2000
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Blackmon, James B, Dean, David L
• Primary Examiner(s): WARD, JESSICA LEE
• Application Number:
  US10/649,023
• Publication Number:
  US 20040040641A1
• Time in Patent Office: 1,574 Days
• Field of Search: 527/851
• US Class Current: 156/99
• CPC Class Codes: C03B 23/0357 by suction without blowing, e.g. with vacuum or by venturi effect
• CPC Class Codes: F24S 23/82 characterised by the material or the construction of the reflector
• CPC Class Codes: G02B 26/0825 the reflecting element being a flexible sheet or membrane, e.g. for varying the focus flexible mirrors for cosmetic use A45D42/24
• CPC Class Codes: G02B 7/183 specially adapted for very large mirrors, e.g. for astronomy, or solar concentrators
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y10T 156/1002 with permanent bending or reshaping or surface deformation of self sustaining lamina

Abstract

A glass structure, such as a mirror facet, having a glass member, a composite structure and a support structure. The composite structure includes a rigid interlayer which is bonded to the glass member and exerts a compressive force thereon to place the glass member in compression. The support structure is used to mount the glass structure and prevents the glass member from collapsing due to the compressive force exerted by the rigid interlayer. The glass structure is particularly well adapted for use in forming heliostats, parabolic dishes, trough concentrators, or other like elements for use in solar power systems, and does not suffer from the limitations or prior forms of such devices.

Claims

1. A method for forming a glass structure comprising:

providing a glass member with a front surface and a rear surface;

forming a rigid interlayer on the rear surface of the glass member by applying a first resin to the rear surface of the glass member and curing the first resin such that the rigid interlayer applies a compressive force to the rear surface of the glass member;

securing a reinforcing structure directly to the rigid interlayer opposite the rear surface of the class member, the reinforcing structure formed by applying a second resin in a liquid state to a reinforcing member; and

securing a support member to the reinforcing structure to support the glass structure and to facilitate mounting the glass structure.

2. The method of claim 1, wherein curing the first resin is performed at a predetermined temperature that is greater than or equal to a maximum temperature at which the glass structure will be used.

3. The method of claim 1, wherein the glass member is a mirror.

4. The method of claim 1, wherein after providing the glass member, the method includes forming the glass member to a predetermined shape.

5. The method of claim 4, wherein the glass member is formed on a vacuum tool.

6. The method of claim 1, wherein securing the reinforcing structure to the rigid interlayer comprises:

applying the reinforcing structure to the rigid interlayer; and

curing the first resin to bond the reinforcing structure to the rigid interlayer.

7. The method of claim 6, wherein securing the reinforcing structure to the rigid interlayer and securing the support member to the reinforcing structure are performed substantially simultaneously when the first resin is cured.

8. The method of claim 6, wherein curing the first resin is performed at a predetermined temperature that is greater than or equal to a maximum temperature at which the glass structure will be used.

9. A method for forming a mirror assembly comprising:

providing a mirror having a front surface that is associated with light reflection and a rear surface;

applying a first resin to the rear surface of the mirror to;

curing the first resin to form a rigid interlayer, the first resin shrinking as it cures to apply a compressive force to the rear surface;

securing a reinforcing structure directly on the rigid interlayer, the reinforcing structure formed by applying a second resin in a liquid state to a reinforcing member; and

curing the second resin to secure the reinforcing structure to the rear surface of the mirror, the reinforcing structure supporting the mirror and facilitating mounting of the mirror.

10. The method of claim 9, wherein the first resin is selected from at least one of unsaturated polyesters, bismaleimides, epoxy vinyl esters and epoxies.

11. The method of claim 9, wherein the reinforcing structure includes a support structure.

12. The method of claim 9, wherein the mirror includes a glass panel having a thickness of about 0.001 inch to about 0.4 inch.

13. The method of claim 9, wherein the compressive force has a magnitude that is sufficient to drive the whole of the mirror into a state of compression.

14. The method of claim 13, wherein the mirror is preformed such that the front surface of the mirror conforms to a non-flat shape.

15. The method of claim 14, wherein the non-flat shape is selected from at least one of:

shapes formed at least in part by a spherical radius and parabolic shapes.

16. A method for forming a mirror assembly comprising:

providing a glass member having a glass panel with a thickness that is less than about 0.4 inch thick and a reflective material that is associated with a surface of the glass panel to effect light reflection, the glass member having a front surface and a rear surface;

forming the glass member such that the light reflecting surface conforms to a predetermined shape;

applying a first resin in a liquid state to a surface of the glass member opposite the light reflecting surface;

curing the first resin to form a rigid interlayer, the first resin shrinking as it cures and applying a compressive force to the surface of the glass member opposite the light reflecting surface, the compressive force having a magnitude such that the entire cross-sectional thickness of the glass member is maintained in a state of compression;

applying a second resin in a liquid state to a reinforcing member to form a reinforcing structure;

securing the reinforcing structure directly to the rigid interlayer;

coupling at least one support structure to the reinforcing structure;

curing the second resin such that the rigid interlayer, the reinforcing member and the support structure cooperate to support the glass member and facilitate mounting of the mirror assembly.