Sound absorbing aircraft transparency and method of making same

• US 5,965,853 A
• Filed: 11/07/1997
• Issued: 10/12/1999
• Est. Priority Date: 03/31/1997
• Status: Expired due to Term

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Hornsey, William W.
• Primary Examiner(s): Dang, Khanh
• Application Number:
  US08/966,329
• Time in Patent Office: 704 Days
• Field of Search: 181/284, 181/286, 181/289, 181/290, 181/291, 181/292, 181/294, 181/207, 181/208, 428/34, 428/215, 428/415, 428/425.6, 428/425.9, 428/430
• US Class Current: 181/289
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: B32B 17/10137 Chemical strengthening
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/1077 containing polyurethane
• CPC Class Codes: B32B 2307/102 Insulating
• CPC Class Codes: B64C 1/1492 Structure and mounting of the transparent elements in the window or windscreen
• CPC Class Codes: E06B 3/6707 specially adapted for increased acoustical insulation doors, windows for insulation against noise E06B5/20
• CPC Class Codes: H05B 2203/013 Heaters using resistive films or coatings
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

The present invention relates to a vibration dampening/sound absorbing aircraft transparency which includes an outboard pane assembly, a vibration dampening/sound absorbing pane assembly and a spacer frame assembly for retaining the outboard pane assembly and the vibration dampening/sound absorbing pane assembly in spaced-apart generally parallel facing relationship to provide a space therebetween. The vibration dampening/sound absorbing pane assembly is a multilayer laminate which includes a substrate, an adhesive interlayer provided over a surface of the substrate and a sound dampening material layer provided over the adhesive interlayer and adhered by the adhesive interlayer to the substrate. In an alternative embodiment, the aircraft transparency of the present invention includes in addition to the foregoing, a transparent electroconductive coating interposed between the adhesive interlayer and the substrate and facilities in contact with the electroconductive coating to pass a current through the electroconductive coating to heat the coating sufficiently to remove or to prevent the accumulation of fog, ice, frost and the like on the aircraft transparency.

Claims

1. A vibration dampening sound absorbing aircraft transparency comprising:

an outboard pane assembly;

a vibration dampening/sound absorbing pane assembly wherein said vibration dampening/sound absorbing pane assembly is a laminate comprising a substrate, an adhesive interlayer deposited over the substrate and a sound dampening material layer deposited over said adhesive interlayer and adhered to the substrate by the adhesive interlayer;

a spacer frame assembly for retaining said outboard pane and said vibration dampening/sound absorbing pane assembly in spaced-apart generally parallel facing relationship and providing an airspace between said outboard pane and said vibration dampening/sound absorbing pane assembly.

2. The aircraft transparency of claim 1 wherein the sound dampening material layer is a laminate comprising a polyvinyl butyral layer and a polymer disposed over and in contact with said polyvinyl butyral layer.

3. The aircraft transparency of claim 2 wherein said polymer is a polyester.

4. The aircraft transparency of claim 2 wherein said sound dampening material layer further comprises a layer of an abrasion resistant coating disposed over and in contact with said polyester polymer layer.

5. The aircraft transparency of claim 1 wherein said adhesive interlayer is selected from the group consisting of polyvinyl butyral and urethane.

6. The aircraft transparency of claim 5 wherein said polyvinyl butyral adhesive interlayer is about 0.02 to 0.03 inch (0.051 to 0.08 cm) thick.

7. The aircraft transparency of claim 1 wherein said substrate is a glass substrate and is about 0.06 to 0.12 inch (0.15 cm to 0.30 cm) thick.

8. The aircraft transparency of claim 7 wherein said glass is a chemically tempered glass sold by PPG Industries, Inc., under the mark Herculite®

II.

9. The aircraft transparency of claim 8 wherein said Herculite®

chemically tempered glass substrate is about 0.078 inch (0.20 cm) thick.

10. The aircraft transparency of claim 1 further comprising a transparent electroconductive coating interposed between said adhesive interlayer and said substrate and a means for applying electrical current to said electroconductive coating to heat said electroconductive coating.

11. The aircraft transparency of claim 10 wherein means for applying electrical current to said electroconductive coating comprises a pair of bus bars bonded to said substrate in spaced-apart parallel relationship along the longitudinal edges of said substrate.

12. The aircraft transparency of claim 10 wherein said transparent electroconductive coating is selected from the group consisting of tin oxide and indium tin oxide.

13. The aircraft transparency of claim 10 wherein said transparent electroconductive coating is about 200 to 1300 Angstroms thick.

14. The aircraft transparency of claim 1 wherein said outboard pane is a laminated pane comprising an inboard acrylic layer, an outboard acrylic layer and an interlayer interposed between and adhering together said inboard acrylic pane and said outboard acrylic pane.

15. The aircraft transparency of claim 14 wherein said inboard acrylic layer is stretched acrylic and is about 0.2 to 0.4 inch (0.51 cm to 1.02 cm) thick, said outboard acrylic layer is stretched acrylic and is about 0.2 to 0.4 inch (0.51 to 1.02 cm) thick and said interlayer is polyvinyl butyral and is about 0.025 to 0.05 inch (0.06 to 0.13 cm) thick.

16. The aircraft transparency of claim 1 wherein said vibration dampening/sound absorbing pane is retained by said spacer frame assembly with said sound dampening material layer disposed toward said airspace.

17. The aircraft transparency of claim 1 wherein said vibration dampening/sound absorbing pane is retained by said spacer frame assembly with said substrate disposed toward said airspace.

18. In a vibration dampening sound absorbing aircraft transparency of the type having an outboard pane assembly, vibration dampening/sound absorbing pane assembly and a spacer frame assembly mounting the outboard pane assembly and vibration dampening/sound absorbing pane assembly to space the outboard pane assembly from the vibration dampening/sound absorbing pane assembly from one another, the improvement comprising:

the vibration dampening/sound absorbing pane assembly including an electroconductive coating, a plurality of layers laminated together with at least one of the layers having sound dampening properties and at least one of the sound absorbing layers includes a polyvinyl butyral layer and a means for applying electrical current to the electroconductive coating to heat the coating.

19. A heatable vibration dampening/sound absorbing pane comprising:

a substrate having a major surface;

an electroconductive coating on a major surface of the substrate;

spaced bus bar in electrical contact with the coating;

an adhesive interlayer disposed over the coating; and

a sound dampening laminate adhered to said adhesive interlayer.