Electrical heater de-icer

• US 5,475,204 A
• Filed: 05/17/1993
• Issued: 12/12/1995
• Est. Priority Date: 06/01/1990
• Status: Expired due to Fees

• Current Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Wilson, Tommy M., Leffel, Kevin, Giamati, Michael J.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): SWITZER, MICHAEL
• Application Number:
  US08/063,367
• Time in Patent Office: 939 Days
• Field of Search: 219/548, 219/549, 219/550, 219/528, 219/529, 338/210, 338/212, 338/283, 338/293, 338/314, 191/62, 244/134 R, 244/134 A, 244/134 D
• US Class Current: 219/548
• CPC Class Codes: B64D 15/12 by electric heating electric heating elements in general H05B
• CPC Class Codes: B64D 15/14 controlled cyclically along length of surface

Abstract

A de-icer for a structural member of an aircraft is provided. The de-icer includes first and second heaters having first and second electrically conductive strips, respectively. The first and second conductive strips are configured to form first and second marginal portions, respectively. The first and second heaters are positioned relative to each other such that the marginal portions are overlapped.

Claims

1. An electrothermal de-icer for inhibiting accumulation of ice on an aircraft structural member, comprising:

an electrically conductive first element configured in a serpentine-like pattern and disposed over a first area of the structural member in which accumulation of ice is inhibited during flight by electrothermally heating the first element;

an electrically conductive second element configured in a serpentine-like pattern and disposed over a second area of the structural member in which accumulation of ice is inhibited during flight by electrothermally heating the second element, said second area being adjacent said first area; and

,

wherein the first element and the second element partially overlap along marginal portions of each element such that the marginal portion of the first element extends into the second area and the marginal portion of the second element extends into the first area, and said heating of said first and second elements is independently controlled.

2. The de-icer of claim 1, wherein the first and second elements are attached to an outer surface of the structural member.

3. The de-icer of claim 1, wherein the first and second elements are attached to the structural member by means of a flexible backing made of a material including fiberglass.

4. The de-icer of claim 3, wherein the backing has a thickness within the range of about 0.002 inch to 0.010 inch.

5. The de-icer of claim 1, further comprising an insulating layer for promoting distribution of heat throughout the de-icer, the insulating layer being disposed over the structural member beneath the first and second elements.

6. The de-icer of claim 1, wherein the first element and the second element are in the form of ribbons having a first end and a second end, the first end and the second end each including an enlarged area that defines an electrical contact.

7. The de-icer of claim 6, wherein each of the electrical contacts is covered by the first element or the second element.

10. The de-icer of claim 1, wherein the first element comprises a metal ribbon etched on a flexible backing.

11. The de-icer of claim 2, further comprising a weather-resistant layer covering the first and second elements.

12. The de-icer of claim 11, wherein the weather resistant layer includes a stainless steel erosion shield, and wherein the first and second elements are disposed intermediate the stainless steel erosion shield and the outer surface of the structural member.

13. The de-icer of claim 3, wherein the first element and the second element are made from a copper-aluminum alloy.

14. The de-icer of claim 13, wherein the copper-aluminum alloy is etched on the flexible backing.

15. The de-icer of claim 5, wherein the insulating layer comprises a resinous matrix in which hollow glass spheres are impregnated.

16. The de-icer of claim 15, wherein the resinous matrix has a thickness of about 0.04 inch.

17. The de-icer of claim 1, wherein the first element comprises a first strip including a multitude of elongate first members, each of the first members being spaced from adjacent first members by a first inter-segmental gap, and a multitude of first turn portions interconnecting the first members to form a serpentine ribbon with a plurality of the first turn portions lying in the marginal portion of the first element where they are overlapped with the second element, each first turn portion having a pair of first outside corners spaced from a pair of first inside corners;

and,

wherein electrothermal heating of the first turn portions proximate the first outside corners is less than electrothermal heating proximate the first inside corners due to current flux being non-uniform in the first turn portions.

18. The de-icer of claim 17, wherein the first members are less than about 0.06 inch wide, the first inter-segmental gaps are less than about 0.05 inch wide, a portion of each first member bounded by two of the turn portions has a length that is at least five times greater than a width of that member, each first turn portion has a pair of rounded inside corners and a pair of sharp outside corners and the included angle of each outside corner is approximately 90°

.

19. The de-icer of claim 18, further comprising an insulating layer for promoting distribution of heat throughout the de-icer, the insulating layer being disposed over the structural member beneath the first and second elements.

20. The de-icer of claim 19, wherein the insulating layer comprises a resinous matrix in which hollow glass spheres are impregnated.

21. The de-icer of claim 20, wherein the resinous matrix has a thickness of about 0.04 inch.

22. The de-icer of claim 17, wherein the second element comprises a second strip including a multitude of elongate second members, each of the second members being spaced from adjacent second members by a second inter-segmental gap, and a multitude of second turn portions interconnecting the second members to form a serpentine ribbon with a plurality of the second turn portions lying in the marginal portion of the second element where they are overlapped with the first element, each second turn portion having a pair of second outside corners spaced from a pair of second inside corners;

and,

wherein electrothermal heating in the second turn portions proximate the second outside corners is less than electrothermal heating proximate the second inside corners due to current flux being non-uniform in the second turn portions.

23. The de-icer of claim 22, wherein the first and second members are less than about 0.06 inch wide, the first and second inter-segmental gaps are less than about 0.05 inch wide, a portion of each first and second member bounded by two of the turn portions has a length that is at least five times greater than a width of that member, each first and second turn portion has a pair of rounded inside corners and a pair of sharp outside corners and the included angle of each outside corner is approximately 90°

.

24. The de-icer of claim 23, further comprising an insulating layer for promoting distribution of heat throughout the de-icer, the insulating layer being disposed over the structural member beneath the first and second elements.

25. The de-icer of claim 24, wherein the insulating layer comprises a resinous matrix in which hollow glass spheres are impregnated.

26. The de-icer of claim 25, wherein the resinous matrix has a thickness of about 0.04 inch

27. The de-icer of claim 22, wherein the first turn portions are offset relative to the second turn portions such that a first turn portion overlaps a second inter-segmental gap between two second turn portions with the first outside corners superposed over the second outside corners.

28. The de-icer of claim 1, wherein the first element comprises a multitude of elongate first members disposed generally perpendicular to a first common axis, each of the first members being spaced from adjacent first members by a first inter-segmental gap, and a multitude of first turn portions interconnecting the first members to form a serpentine ribbon;

and,

wherein the second element comprises a multitude of elongate second members disposed generally perpendicular to a second common axis, each of the second members being spaced from adjacent second members by a second inter-segmental gap, and a multitude of second turn portions interconnecting the second members to form a serpentine ribbon.

29. The de-icer of claim 28, further comprising an insulating layer for promoting distribution of heat throughout the de-icer disposed over the structural member beneath the first and second elements.

30. The de-icer of claim 29, wherein the insulating layer comprises a resinous matrix in which hollow glass spheres are impregnated.

31. The de-icer of claim 30, wherein the resinous matrix has a thickness of about 0.04 inch.

32. The de-icer of claim 28, wherein the first and second common axes are parallel to each other, and a first member and a second member overlap along the marginal portions of each element.

33. The de-icer of claim 28, wherein the first and second common axes are parallel to each other, and a plurality of first turn portions and a plurality of second turn portions overlap along the marginal portions of each element.

34. The de-icer of claim 28, wherein the first and second common axes are perpendicular to each other, and a second member and a plurality of first turn portions overlap along the marginal portions of each element.

8. The de-icer of claim 38, wherein the structural member has a spanwise axis, and wherein the first element is aligned parallel to the spanwise axis and second element is aligned parallel to the chordwise axis.

9. The de-icer of claim 38, wherein the structural member has a spanwise axis, and the first and second elements are aligned parallel to the spanwise axis.