Edge design for impact resistant windshield
First Claim
1. An impact resistant window comprising:
- a plurality of transparent synthetic plastic sheets bonded together by at least one flexible interlayer, the innermost sheet being formed of polycarbonate;
a metal bearing strip adhesively bonded on the inner face of the innermost polycarbonate sheet along at least part of an edge of the window, the inboard edge of the bearing strip curling gradually away from the inner face of the innermost sheet presenting a convex side of the bearing strip towards the innermost sheet;
a flexible adhesive between the bearing strip and the innermost sheet including a generally wedge-shaped portion between the convex side of the inboard edge of the bearing strip and the adjacent face of the innermost sheet; and
means for connecting the edge of the window and bearing strip to a frame or the like.
5 Assignments
0 Petitions
Accused Products
Abstract
This aircraft windshield resistant to penetration by impact with birds has a plurality of transparent plastic sheets bonded together with flexible interlayers. The innermost sheet of the laminate is formed of a polycarbonate. A metal bearing strip is adhesively bonded to the inside face of the innermost sheet along at least one edge with the inboard edge of the bearing strip curling gradually away from the inner face of the innermost plastic sheet and with a wedge-shaped body of flexible adhesive therebetween. A row of countersunk attachment holes along the edge of the windshield extends through the transparent sheets and the bearing strip and each contains a bushing for receiving a flat head bolt for connecting the windshield to an airframe structure. The inner end of each bushing has an enlarged shoulder having a length not less than the thickness of the bearing strip for bearing on the airframe structure. In case of bird impact the windshield can flex and the bearing strip inhibits edge breakage and tearing of the windshield adjacent the attachment holes. It also assures an adequate bend radius in the plastic to prevent breakage. Broaching of the bolt heads through plastic absorbs impact energy and protects the bolts from tensile and bending failure. A shallow V-shaped edge sealant configuration is also provided.
42 Citations
29 Claims
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1. An impact resistant window comprising:
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a plurality of transparent synthetic plastic sheets bonded together by at least one flexible interlayer, the innermost sheet being formed of polycarbonate; a metal bearing strip adhesively bonded on the inner face of the innermost polycarbonate sheet along at least part of an edge of the window, the inboard edge of the bearing strip curling gradually away from the inner face of the innermost sheet presenting a convex side of the bearing strip towards the innermost sheet; a flexible adhesive between the bearing strip and the innermost sheet including a generally wedge-shaped portion between the convex side of the inboard edge of the bearing strip and the adjacent face of the innermost sheet; and means for connecting the edge of the window and bearing strip to a frame or the like. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An impact resistant window comprising:
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a transparent laminate including a plurality of transparent synthetic plastic sheets bonded together by at least one flexible interlayer, the innermost sheet being formed of polycarbonate; a metal bearing strip adhesively bonded to the inner face of the innermost sheet along at least part of an outboard edge of the window; and a row of attachment holes extending through the transparent laminate and metal bearing strip along such an edge; and
whereinthe effective strength and ductility of the bearing strip between such row of holes and the edge of the window in the plane of the window is approximately the same as the effective strength and ductility of the innermost polycarbonate sheet between such row of holes and the edge of the window in the plane of the window. - View Dependent Claims (11, 12, 13)
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14. An impact resistant window comprising:
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a transparent laminate including a plurality of transparent synthetic plastic sheets bonded together by at least one flexible interlayer, the innermost sheet being formed of polycarbonate; an edge strip along the outside of an edge of the window; a row of attachment holes along the edge of the window extending through at least a portion of the transparent sheets and the edge strip; and a countersink at the outermost end of each such hole for receiving the head of a bolt extending through such attachment hole, such a countersink being in the edge strip and having a diameter sufficient for receiving the head of a bolt which can apply a load in a direction normal to the plane of the window, the resistance to broaching of the edge strip adjacent the countersink being less than the strength of a bolt extending through such an attachment hole. - View Dependent Claims (15, 16, 17)
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18. An impact resistant aircraft windshield comprising:
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a plurality of transparent synthetic plastic sheets bonded together by at least one flexible interlayer, the innermost sheet being formed of polycarbonate; a metal bearing strip adhesively bonded on the inner face of the innermost polycarbonate sheet along at least part of an edge of the window; a row of attachment holes along the edge of the window extending through at least a portion of such transparent sheets and the bearing strip; a bushing in each attachment hole and including an enlarged shoulder portion on the inner end in the portion of such attachment hole extending through the metal bearing strip; a conical countersink at the outermost end of such attachment hole including a conical countersunk portion on the outermost end of the bushing in such hole; a flat head bolt extending through such bushing and through an aircraft frame member, the head of the bolt engaging the countersunk portion on the outer end of the bushing, the inner enlarged shoulder portion of the bushing bearing against the aircraft frame member; and a spherical washer and spherical nut on such bolt on the opposite side of the aircraft frame member from the bolt head for securing the windshield to the aircraft frame member. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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25. An impact resistant aircraft windshield comprising:
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a plurality of transparent synthetic plastic sheets bonded together by at least one flexible interlayer, the innermost sheet being formed of polycarbonate; a metal bearing strip adhesively bonded on the inner face of the innermost polycarbonate sheet along at least part of an edge of the window; a row of attachment holes along the edge of the window extending through at least a portion of such transparent sheets and the bearing strip; a metal bushing in each attachment hole; the effective strength and ductility of the bearing strip between the row of attachment holes and the edge of the windshield in the plane of the windshield being approximately the same as the effective strength and ductility of the plastic sheets between the row of attachment holes and the edge of the windshield in the plane of the windshield; a bolt extending through such bushing and through an aircraft frame member, the head of the bolt engaging the outer end of the bushing, the inner end of the bushing bearing against the aircraft frame member; and a nut on such bolt on the opposite side of the aircraft frame member from the bolt head for securing the windshield to the aircraft frame member. - View Dependent Claims (26)
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27. An impact resistant aircraft windshield comprising:
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a plurality of transparent synthetic plastic sheets bonded together by at least one flexible interlayer, the innermost sheet being formed of polycarbonate; a metal bearing strip adhesively bonded on the inner face of the innermost polycarbonate sheet along at least part of an edge of the window; a reinforced plastic edge strip adhesively bonded to an outer face of one of the sheets along such edge; a row of attachment holes along the edge of the window extending through at least a portion of such transparent sheets, the edge strip, and the bearing strip; a bushing in each attachment hole; a bolt extending through such bushing and through an aircraft frame member, the head of the bolt engaging the outer end of the bushing, the inner end of the bushing bearing against the aircraft frame member; and a spherical washer and spherical nut on such bolt on the opposite side of the aircraft frame member from the bolt head for securing the windshield to the aircraft frame member; and
whereinthe resistance to pulling such a bolt head through the edge strip is greater than the resistance to pulling the bolt head through the polycarbonate sheets, and less than the tensile strength of such bolt. - View Dependent Claims (28, 29)
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Specification