Method for making an electrically heatable windshield

Abstract

This specification teaches a method for making an electrically heatable windshield of laminated construction. In the method, a pair of glass templets are cut (10) and they include a long glass templet and a short glass templet. The templets are separated (20) from one another. An opaque ceramic paint is applied (30) to an edge portion of a coatable surface of a selected glass templet and is dried (40) thereon. Bus bars are also applied (50) to and dried (60) on the coatable surface of the long glass templet. The glass templets are united (70) and subjected to a bending operation (80) to form a shaped windshield pair. The long glass templet and short glass templet are separated (90). A transparent electrically conductive coating is applied (100) between the bus bars located on the selected glass templet. The templets are reunited (110) with an interposed laminating interlayer material and thereafter laminated (120) together to achieve a shaped laminated windshield which is heatable by the flow of electrical energy therethrough.

We claim: 
     
       1. A method for making an electrically heatable windshield of laminated construction, which comprises the steps of: cutting a pair of glass templates, said templates including a long glass template and a short glass templet;   separating said long and said short glass templet from one another;   applying an opaque ceramic paint to an edge portion of a coatable surface of a selected one of said glass templets which will face a laminating interlayer when the windshield is in an installed position in a vehicle;   drying said ceramic paint to bond said ceramic paint to said coatable surface of said selected glass templet;   applying electrical conductive bus bars to said coatable surface of said selected glass templet;   drying said bus bars to bond said bus bars to said coatable surface of said selected glass templet;   uniting said long glass templet and said short glass templet;   bending said long glass templet and said short glass templet to form a shaped windshield pair;   separating said long templet and said short templet forming said shaped windshield pair;   applying a transparent electrically conductive coating between said bus bars located on said coatable surface of said selected glass templet;   uniting said long glass templet and said short glass templet with an interposed laminating interlayer therebetween; and   laminating said long glass templet and said short glass templet with said interposed laminating interlayer thereby to achieve a shaped laminated windshield which is heatable by the flow of electrical energy therethrough.   
     
     
       2. A method for making an electrically heatable windshield of laminated construction, which comprises the steps of: cutting a pair of glass templates, said templates including a long glass template and a short glass templet;   separating said long and said short glass templet from one another;   applying an opaque ceramic paint to an edge portion of a coatable surface of said long glass templet which will face the interior of a vehicle when the windshield is in an installed position in that vehicle;   drying said ceramic paint to bond said ceramic paint to said coatable surface of said long glass templet;   applying electrically conductive bus bars to said coatable surface of said long glass templet;   drying said bus bars to bond said bus bars to said coatable surface of said long glass templet;   uniting said long glass templet and said short glass templet;   bending said long glass templet and said short glass templet to form a shaped windshield pair;   separating said long templet and said short templet forming said shaped windshield pair;   applying a transparent electrically conductive coating between said bus bars located on said coatable surface of said long glass templet;   uniting said long glass templet and said short glass templet with an interposed laminating interlayer therebetween; and   laminating said long glass templet and said short glass templet with said interposed laminating interlayer thereby to achieve a shaped laminated windshield which is heatable by the flow of electrical energy therethrough.   
     
     
       3. A method for making an electrically heatable windshield of laminated construction, which comprises the steps of: cutting a pair of glass templates, said templates including a long glass templet and a short glass templet;   separating said long and said short glass templet from one another;   applying an opaque ceramic paint to an edge portion of a coatable surface of said short glass templet which will face a laminating interlayer when the windshield is in an installed position in a vehicle;   drying said ceramic paint to bond said ceramic paint to said coatable surface of said short glass templet;   applying electrically conductive bus bars to said coatable surface of said short glass templet;   drying said bus bars to bond said bars to said coatable surface of said short glass templet;   uniting said long glass templet and said short glass templet;   bending said long glass templet and said short glass templet to form a shaped windshield pair;   separating said long templet and said short templet forming said shaped windshield pair;   applying a transparent electrically conductive coating between said bus bars located on said coatable surface of said short glass templet;   uniting said long glass templet and said short glass templet with an interposed laminating interlayer therebetween; and   laminating said long glass templet and said short glass templet with said interposed laminating interlayer thereby to achieve a shaped laminated windshield which is heatable by the flow of electrical energy therethrough. .Iadd.   
     
     
       4.  A method for making an electrically heatable vehicle windshield of laminated construction, said method comprising the steps of: applying an opaque ceramic paint to an edge portion of a coatable surface of a selected one of a pair of glass windshield templets;   then drying said paint sufficiently to bond it to said coatable surface;   then applying electrically conductive bus bars to said coatable surface;   then drying said bus bars sufficiently to bond them to said coatable surface;   then uniting said selected templet and the other templet of said pair of glass windshield templets and bending them to form a shaped windshield pair, the drying steps being sufficient to avoid sticking of said templets by said paint during said bending step;   then separating said templets of said shaped windshield pair;   then applying a transparent, electrically conductive coating on said coatable surface between said bus bars;   then uniting said selected templet and the other templet of said shaped windshield pair with a laminating interlayer interposed between them, said coatable surface facing said interlayer; and   then laminating said selected templet, other templet and interlayer to produce a shaped laminated windshield which is heatable by the flow of electrical energy therethrough. .Iaddend. .Iadd.   
     
     
       5.  The method of claim 4 wherein said drying step comprises prefiring said ceramic paint. .Iaddend. .Iadd.6. The method of claim 5 wherein said prefiring is carried out at a temperature of about 1150° F. for a time period of about 2-4 minutes. .Iaddend. .Iadd.7. A method for making an electrically heatable vehicle windshield of laminated construction, said method comprising the steps of: applying an opaque ceramic paint to an edge portion of a coatable surface of a first glass windshield templet;   then prefiring said ceramic paint;   then applying electrically conductive bus bars to said coatable surface at least partially overlying said ceramic paint;   then prefiring said bus bars;   then uniting said first templet with a second templet, said coatable surface facing said second templet, and bending them together to form a shaped windshield pair;   then separating said templets and applying a transparent, electrically conductive coating on said coatable surface between said bus bars;   then uniting said templets with a laminating interlayer interposed between them, said coatable surface facing said interlayer; and   then laminating said templets and interlayer together. .Iaddend.