LIGHTWEIGHT AIRCRAFT WINDOW WITH LOW DRAG

Abstract

An aircraft window composed of a monolithic interior pane made of polymer material and of a laminated exterior pane made of glass that are separated by an air-filled space, wherein the laminated exterior pane consists of two glass sheets bonded by an adhesive interlayer, and wherein the thickness of the exterior glass sheet is between 0.2 and 2.6 mm, and the thickness of the interior glass sheet is between 0.2 and 2.1 mm.

Claims

1. An aircraft window composed of a monolithic interior pane made of polymer material and of a laminated exterior pane made of glass that are separated by an air-filled space, wherein the laminated exterior pane consists of two glass sheets bonded by an adhesive interlayer, and wherein the thickness of the exterior glass sheet is between 0.2 and 2.6 mm, and the thickness of the interior glass sheet is between 0.2 and 2.1 mm.

2. The aircraft window as claimed in claim 1, wherein the monolithic interior pane is made of polymer material comprising a poly(methyl methacrylate) (PMMA), a polycarbonate (PC), alone or as mixtures or copolymers of several thereof.

3. The aircraft window as claimed in claim 1, wherein the thickness of the exterior glass sheet is between 1.6 and 2.4 mm, and the thickness of the interior glass sheet is between 0.4 and 1.9 mm.

4. The aircraft window as claimed in claim 1, wherein the laminated exterior pane comprises glass sheets made of chemically toughened glass, of soda-lime, aluminosilicate or borosilicate type.

5. The aircraft window as claimed in claim 1, wherein the total thickness of glass of the laminated exterior pane is between 1.5 and 5 mm.

6. The aircraft window as claimed in claim 1, wherein the laminated exterior pane comprises at least one adhesive interlayer chosen from a polyvinyl butyral, optionally having an acoustic damping property, a thermoplastic polyurethane, an ethylene/vinyl acetate copolymer, or an ionomer glass.

7. The aircraft window as claimed in claim 1, wherein on the ground, a main surface of the laminated exterior pane opposite the monolithic interior pane is flat or convex with a lower curvature than that of a surrounding structure of the aircraft, so that in flight, under the effect of pressurization of an interior volume of the aircraft, said main surface of the laminated exterior pane has a curvature substantially identical to that of the surrounding structure of the aircraft.

8. The aircraft window as claimed in claim 1, wherein the air-filled space is at a pressure of an interior volume of the aircraft.

9. The aircraft window as claimed in claim 1, wherein the total thickness of glass of the laminated exterior pane is between 2 and 4.5 mm.

Description

[0019] The appended drawing illustrates the invention:

[0020] FIG. 1 is a partial schematic cross-sectional view of the aircraft window of the invention in the fitting position; the proportions of the dimensions of the constituents are not exact.

[0021] With reference to this drawing, the window comprises a monolithic interior pane 1 made of poly(methyl methacrylate) (PMMA) or polycarbonate (PC) having a thickness of between 2.5 and 12 mm, for example made of 4 mm thick PMMA, and a laminated outer pane 2 made of glass that are separated by an air-filled space 3.

[0022] Several compositions of laminated exterior pane 2 in accordance with the invention are given below, in the order: exterior glass sheet 4/adhesive interlayer 6/interior glass sheet 5: [0023] 2.1 mm/0.76 mm PVB/1.6 mm [0024] 2.1 mm/0.76 mm TPU/1.6 mm [0025] 2.1 mm/0.76 mm ionomer glass/1.6 mm [0026] 2.1 mm/acoustic PVB/1.6 mm [0027] 2.1 mm/acoustic PVB/0.7 mm.

[0028] The glass used is chemically toughened, of soda-lime, aluminosilicate or borosilicate type. [0029] PVB: polyvinyl butyral [0030] TPU: thermoplastic polyurethane [0031] ionomer glass: sold by Kuraray under the registered trademark SentryGlas® XTRA® (SGX®) [0032] acoustic PVB: acoustic tri-layer polyvinyl butyral, sold by Sekisui under the registered trademark S-LEC® Sound Acoustic Film, or else by Kuraray under the registered trademark Trosifol® Acoustic, in various thicknesses.

[0033] The monolithic interior pane 1 and the laminated exterior pane 2 are fitted to the structure of the aircraft (aluminum fitting 7) by means of a silicon seal 8.

[0034] These window structures, in particular those of the laminated exterior pane 2 made of glass cited above, make it possible to lighten the window while avoiding a deformation as an excessively large bulge in flight, which is unfavorable from an aerodynamic point of view.