Lightweight heated plastic window element with unique bus bar system
First Claim
1. A lightweight transparent plastic window element comprising a first window component composed of a material selected from the class consisting of acrylic plastics and polycarbonates, an elongated groove having a substantially uniform depth less than the thickness of said first window component extending in one direction along a surface of said first window component, an elongated strip of adherent material of substantially uniform thickness bonded to said elongated groove to form a bus bar bed, a first bus bar element comprising a thin elongated strip of electroconductive, ductile metal of substantially uniform thickness bonded to said elongated strip of adherent material, an array of electroconductive wire embedded in the grooved surface of said substrate and having first end portions extending across said elongated groove in contact with said first bus bar element, and a second bus bar element comprising a metal foil adhesive electrical tape of substantially uniform thickness superimposed over said first end portions of said wire array and bonded to said thin elongated strip of metal to provide a bus bar structure of substantially uniform thickness having a total thickness including the thickness of said bus bar bed approximately equal to the substantially uniform depth of said elongated groove and in electrical contact with said wire array free of spaced solder connections therebetween and a lead wire electrically connected to said bus bar structure.
1 Assignment
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Accused Products
Abstract
A novel solderless connection between a bus bar and an array of electroconductive wires avoids cracks in plastic window elements, particularly the outer component of curved lightweight heated windows, particularly those used in aircraft.
50 Citations
8 Claims
- 1. A lightweight transparent plastic window element comprising a first window component composed of a material selected from the class consisting of acrylic plastics and polycarbonates, an elongated groove having a substantially uniform depth less than the thickness of said first window component extending in one direction along a surface of said first window component, an elongated strip of adherent material of substantially uniform thickness bonded to said elongated groove to form a bus bar bed, a first bus bar element comprising a thin elongated strip of electroconductive, ductile metal of substantially uniform thickness bonded to said elongated strip of adherent material, an array of electroconductive wire embedded in the grooved surface of said substrate and having first end portions extending across said elongated groove in contact with said first bus bar element, and a second bus bar element comprising a metal foil adhesive electrical tape of substantially uniform thickness superimposed over said first end portions of said wire array and bonded to said thin elongated strip of metal to provide a bus bar structure of substantially uniform thickness having a total thickness including the thickness of said bus bar bed approximately equal to the substantially uniform depth of said elongated groove and in electrical contact with said wire array free of spaced solder connections therebetween and a lead wire electrically connected to said bus bar structure.
- 7. A method of making an electroconductive, lightweight transparent window element comprising applying an elongated groove of sustantially uniform depth across a major surface of a first window component composed of a material selected from the class consisting of acrylic plastics and polycarbonates, applying an elongated strip of adherent material of substantially uniform thickness to said elongated groove to form a bus bar bed, applying a first bus bar element comprising a thin elongated strip of electroconductive, ductile metal of substantially uniform thickness to said strip of adherent material, embedding an array of electroconductive wires in said grooved major surface of said substrate so that first end portions of said wire array extend across said elongated groove, mounting a second bus bar element comprising a thin, metal foil adhesive electrical tape whose thickness combined with the thicknesses of said bus bar bed and said first bus bar element is approximately equal to the depth of said groove in superimposed adherent relation to said first bus bar element with said first end portions of said wire array sandwiched between said first bus bar element and said second bus bar element, trimming any excess wire from said array beyond said groove, assembling a second window component composed of a material selected from the class consisting of acrylic plastics and polycarbonates against the grooved surface of said first substrate, and fuse bonding said components under sufficient heat and pressure to form said element.
Specification