Heatable transparency

• US 9,491,806 B2
• Filed: 09/30/2011
• Issued: 11/08/2016
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: McCarthy, William Casey
• Primary Examiner(s): Angwin, David
• Assistant Examiner(s): Singh, Amit K
• Application Number:
  US13/249,861
• Publication Number:
  US 20130082043A1
• Time in Patent Office: 1,866 Days
• Field of Search: 219/203, 219/522, 219/541
• US Class Current: 1/1
• CPC Class Codes: H05B 2203/005 using multiple resistive elements or resistive zones isolated from each other
• 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

An aircraft transparency has a heatable member to remove fog, ice and snow from the outer surface of the transparency. The heatable member includes a pair of spaced parallel bus bars with the ends of the bus bars offset from one another, and a coating including a plurality of spaced segments of an electrically conductive coating electrically connecting the bus bars. The ratio of the major diagonal to the minor diagonal is in the range of greater than 1 to 1.25 to more uniformly heat the coating and the outer surface of the transparency.

Claims

1. In an improved laminated aircraft window having a first surface defined as an outer major surface and an opposite second surface defined as an inner major surface, a first side opposite to and spaced from a second side, a third side opposite to and spaced from a fourth side, with the first side joined to the third side at a first corner, the third side joined to the second side at a second corner, the fourth side joined to the second side at a third corner, and the fourth side joined to the first side at a fourth corner to provide the laminated aircraft window with a four sided configuration,

a heatable member between the inner and outer major surfaces of the laminated aircraft window, wherein when the heatable member is energized to heat the outer major surface of the laminated aircraft window ice, snow and/or fog on the outer major surface of the window is melted, wherein the heatable member is securely mounted on a supporting surface, the supporting surface between the inner major surface and the outer major surface of the laminated aircraft window,

the heatable member comprising a first continuous bus bar spaced from a second continuous bus bar, and a continuous electrically conductive coating between and in electrical contact with the bus bars, the first end of the first bus bar adjacent to and spaced a first distance from the first side of the laminated aircraft window and the second end of the first bus bar adjacent to and spaced a second distance from the second side, the first end of the second bus bar adjacent to and spaced a third distance from the first side of the window, and the second end of the second bus bar adjacent to and spaced a fourth distance from the second side of the window, wherein each of the first and second bus bars define a continuous path from adjacent the first side to adjacent the second side of the laminated aircraft window, wherein the first distance is greater than the third distance and the fourth distance is greater than the second distance to the first and the second ends of the first and second bus bars;

wherein the continuous electric coating between the bus bars and the offset between ends of the bus bars provides for the non uniform heating of the outer major surface of the laminated aircraft window, the improvement comprises;

the outer surface of the laminated aircraft window is a first surface of a glass sheet, the glass sheet having an opposite second surface, wherein the opposite second surface of the glass sheet is the supporting surface for the bus bars and the electrically conductive coating and

the electrically conductive coating of the improved laminated aircraft window comprising a plurality of electrically conductive segments, each of the segments comprising a first segment side and an opposite second segment side, wherein the first segment side of each of the segments is in electrical contact with the first bus bar, the second segment side of each of the segments is in electrical contact with the second bus bar, and portions of each of the segments between the first bus bar and the second bus bar in spaced relationship to one another to prevent electrical contact between adjacent ones of the segments between the bus bars, wherein each of the segments has a major diagonal and a minor diagonal, and, wherein the major diagonal has a length different from the length of the minor diagonal such that a ratio of the length of the major diagonal to the length of the minor diagonal is in the range of greater than 1 to 1.25,

wherein the first side of each of the segments is connected to the first bus bar, and the second side of each of the segments is connected to the second bus bar, wherein the ratio of the length of the major diagonal to the length of the minor diagonal in the range of greater than 1 to 1.25 sets the first and the second corners of each of the segments off set from their respective ones of the third corner and fourth corner of each of the segments to provide a plurality of segments of electrically conductive coatings wherein the segments of the coating are similar to one another such that energizing the heating member of the improved laminated aircraft window uniformly heats the outer surface of the laminated aircraft window to melt snow, ice and/or fog from the outer surface of the window.

2. The aircraft window according to claim 1, wherein the first bus bar and the second bus bar have different lengths and are non-parallel to one another,

wherein the first, second, third and fourth sides of each segment defines a perimeter of its respective segment, the plurality of segments comprises a first segment and an adjacent segment defined as a second segment, and the fourth side of the first segment is in facing relationship to and spaced from the third side of the second segment, wherein the first side of the first and the second segments overlays the first bus bar and the second side of the first and the second segments overlays the second bus bar, and

a straight imaginary line normal to the longitudinal axis of the first bus bar defines a path that extends from a corner between the first side end the third side of the first segment toward the second bus bar, the path crossing over the perimeter of the first segment prior to contacting the second bus bar.

3. The aircraft window according to claim 2 wherein the fourth side of the first segment and the third side of the second segment overlaying the first bus bar are spaced from one another and the fourth side of the first segment and the third side of the second segment overlaying the second bus bar are spaced from one another.

4. The aircraft window according to claim 2 wherein the fourth side of the first segment and the third side of the second segment overlaying the first bus bar are in contact with one another and the fourth side of the first segment and the fourth side of the second segment overlaying the second bus bar are in contact with one another.

5. The aircraft window according to claim 1, wherein the first bus bar and the second bus bar have different lengths and are non-parallel to one another,

the first and the second bus bars each has a longitudinal axis extending from their first end to their second end,

wherein the first, second, third and fourth sides of each segment defines a perimeter of its respective segment, the plurality of segments comprises a first segment and an adjacent segment defined as a second segment, and the fourth side of the first segment is in facing relationship to and spaced from the third side of the second segment,

wherein the first side of the first and the second segments overlays the first bus bar and the second side of the first and the second segments overlays the second bus bar, and a straight imaginary line normal to the longitudinal axis of the first bus bar defines a path that extends from a corner between the first side and the third side of the first segment toward the second bus bar and crosses over the perimeter of the first segment at the second side defined as a crossing point,

wherein a distance from a corner between the second side and the third side and the crossing point at the second side is in the range of 75-100% of the length of the second side as measured between the third side and the fourth side of the first segment at the second bus bar.

6. The aircraft window according to claim 1, wherein the first bus bar and the second bus bar have the same length, are parallel to one another, and each has a longitudinal axis extending from their first end to their second end, wherein the first, second, third and fourth sides of each segment defines a perimeter of its respective segment, the plurality of segments comprises a first segment and an adjacent segment defined as a second segment, and the fourth side of the first segment is in facing relationship to and spaced from the third side of the second segment, wherein the first side of the first and the second segments overlays the first bus bar and the second side of the first and the second segments overlays the second bus bar,

and a straight imaginary line normal to the longitudinal axis of the first bus bar defines a path that extends from a corner between the first side and the third side of the first segment toward the second bus bar, the path crossing over the perimeter of the first segment prior to contacting the second bus bar.

7. The aircraft window according to claim 1, wherein the first bus bar and the second bus bar have the same length and are parallel to one another, the first and the second bus bars each has a longitudinal axis extending from their first end to their second end,

wherein the first, second, third and fourth sides of each segment defines a perimeter of its respective segment, the plurality of segments comprises a first segment and an adjacent segment defined as a second segment, and the fourth side of the first segment is in facing relationship to and spaced from the third side of the second segment,

wherein the first side of the first and the second segments overlays the first bus bar and the second side of the first and the second segments overlays the second bus bar, and a straight imaginary line normal to the longitudinal axis of the first bus bar defines a path that extends from a corner between the first side and the third side of the first segment toward the second bus bar and crosses over the perimeter of the first segment at the second side defined as a crossing point, wherein a distance from a corner between the second side and the third side and the crossing point at the second side is in the range of 75-100% of the length of the second side of the first segment as measured between the third side and the fourth side at the second bus bar.

8. The aircraft window according to claim 1 wherein the heatable member is a component of a transparency for a land vehicle;

of a canopy, cabin window and windshield for an air and space vehicle, of a window for above or below water vessel, and of a window for a viewing side or door for containers.

9. The aircraft window according to claim 1 wherein the ratio is in the range of greater than 1 to equal to or less than 1.02.