Propeller deicer

• US 4,386,749 A
• Filed: 06/12/1978
• Issued: 06/07/1983
• Est. Priority Date: 03/04/1977
• Status: Expired due to Term

• Current Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Sweet, David B., Hoffman, Wayne E.
• Primary Examiner(s): Frankfort, Charles E.
• Application Number:
  US05/914,636
• Time in Patent Office: 1,821 Days
• Field of Search: 244/134 R, 244/134 D, 219/201, 219/202, 219/528, 219/537, 219/549, 219/552, 219/553
• US Class Current: 244/134.00D
• CPC Class Codes: B64D 15/12 by electric heating electric heating elements in general H05B

Abstract

A deicer for use on the propeller of an aircraft wherein the heating elements or elements of the deicer which are embedded in an electrically non-conductive material adhered to a propeller blade provide a gradient type of heat distribution pattern having the greatest heat concentration at the area of the propeller closer to the shank end and a lower heat concentration at the area of the propeller further away from the shank end.

Claims

1. An electrically heated propeller deicer pad for a propeller blade with a shank end and an outboard end, said deicer pad comprising a generally flexible sheet of electrically non-conductive material for mounting upon the leading edge of the propeller blade with one end of said deicer pad defining a deicer shank end at the shank end of the propeller blade and the other end of said deicer pad extending on said blade in a direction away from said shank end toward the outboard end of said propeller blade defining a deicer outboard end, said deicer pad having a pair of laterally spaced side edges interconnecting said one end with said deicer outboard end, an electrically conductive heating element being the sole means for deicing located within said deicer flexible sheet material, said heating element extending as a continuous electrically conductive heating element across said leading edge and laterally toward said side edges of said deicer pad back and forth for the full length of said deicer pad, electrical power input means connected to said heating element at said shank end, and said heating element having a gradient power density extending from said one end to said other end of said deicer pad with the greatest power density being at said shank end.

2. An electrically heated propeller deicer as set forth in claim 1 wherein said heating element comprises a continuous ribbon element that zig-zags back and forth laterally across said flexible sheet from one of said side edges to the other one of said side edges;

and said continuous conductor element increases in cross-sectional area in the direction of said outboard end to provide a tapered power density from said one end to said other end of said deicer pad.

3. An electrically heated propeller deicer as set forth in claim 2 wherein said continuous ribbon conductor element has electrical insulation means between said zig-zag path to maintain the conductive flow of current in said zig-zag path on said ribbon conductor element.

4. An electrically heated propeller deicer for use on a propeller blade having a shank end and an outboard end;

said deicer consisting of a flexible sheet of electrically non-conductive material with an inboard end, an outboard end and laterally spaced side edges interconnecting said inboard end and said outboard end;

said deicer mounted upon the leading edge of the propeller blade with the inboard end of said deicer at the shank end of the propeller blade and the outboard end of said deicer extending on said blade in a direction away from said shank end toward the outboard end of said propeller blade, a plurality of heating elements embedded within said flexible sheet;

said heating elements being the sole deicing means within said deicer;

said elements located along the length of said deicer and extending outwardly adjacent to said side edges;

electrical power input means connected to said heating elements;

each of said heating elements interconnected to form a continuous flow path from said inboard end to said outboard end of said deicer and from said outboard end of said deicer to said inboared end; and

said heating elements in combination having a stepped gradient power density that extends from said inboard end to said outboard end with the greatest power density at said inboard end.

5. An electrically heated propeller deicer as set forth in claim 4 wherein each of said heating elements comprises a group of heating ribbons, the ribbons in each group having the same power density, each group of ribbons in aligned order providing a decreasing power density in the direction of said outboard end to provide said stepped gradient power density.

6. An electrically heated propeller deicer as set forth in claim 5 wherein said group of ribbons form a continuous conductor that extends from said inboard end to said outboard end and back to said inboard end.

7. An electrically heated propeller deicer for a propeller blade with a shank end and an outboard end, said deicer generally consisting of a flexible sheet of electrically non-conductive material for mounting upon the leading edge of the propeller blade, said deicer having an inboard end and an outboard end, said deicer mounted on said blade with the inboard end of said deicer at the shank end of the propeller blade and the outboard end of said deicer extending on said blade in a direction away from said shank end toward the outboard end of said propeller blade, a pair of electrically conductive heating elements located within said flexible sheet and extending from said inboard end to said outboard end of said deicer, said electrically conductive heating elements extending transversely across said flexible sheet from adjacent one side edge to adjacent the other side edge, one of said pair of elements located adjacent to said inbord end and the other of said pair of elements located toward the outboard end of said deicer, electrical power input means connected to each of said heating elements, said heating elements providing a gradient power density extending from said inboard end to said outboard end with the greatest power density at said inboard end.

8. An electrically heated propeller deicer as set forth in claim 7 wherein said heating elements are energized for deicing in seriatim order.

9. An electrically heated propeller deicer for a propeller blade with a shank end and an outboard end, said deicer consisting of a generally flat longitudinally extending flexible sheet of electrically nonconductive material for mounting on said blade with the intermediate portion of said deicer located on the leading edge of a propeller blade, said longitudinally extending deicer having an inboard end and an outboard end, said inboard end of said deicer located at said shank end of said propeller blade and said outboard end of said deicer extending on said blade in a direction away from said shank end toward said outboard end of said propeller blade, a plurality of heating ribbons located within said flexible sheet, said ribbons being grouped in seriatim order along the length of said deicer to provide a plurality of heating elements, each of said heating elements decreasing in power density from said inboard end to said outboard end to provide a stepped power density in said deicer that is greatest at said inboard end of said deicer, and electrical power input means connected to said heating elements only along said inboard ends to energize said heating elements.

10. An electrically heated propeller deicer as set forth in claim 9 wherein said heating ribbons form a continuous conductor element that zig-zags back and forth laterally across said flexible sheet to provide a linear power density in a transverse direction across said deicer.

11. An electrical deicing pad for the leading edge of a propeller blade consisting of a flexible sheet of electrically non-conductive material secured to said propeller blade, said propeller blade having a hub and an end, said sheet being a longitudinally extending member with lateral side edges and ends, a plurality of resistance strips in insulated relation to one another connected in series in said pad, said strips extending generally transversely across said sheet and interconnected at the lateral side edges thereof to provide said series connection, one end of said sheet terminating closely adjacent to said hub of said propeller blade and the other end of said elongated sheet being spaced from said hub of said propeller blade and extending toward said end of said propeller blade, and the strips being of lesser resistance to the conductivity of current progressively away from said one end of said elongated sheet to provide a tapered power density to said deicer that has the greatest power density at said one end adjacent said hub.

12. An electrical deicing pad as set forth in claim 11, wherein said strips are grouped so that all of said strips in each group contains the same resistance, all of said groups are connected in series and each group progressively further away from said hub being of lesser power density than the group adjacent thereto to provide said tapered power density.

13. An electrically heated propeller deicer for a propeller, said deicer being a longitudinally extending flexible sheet of electrically non-conductive material for mounting on a propeller blade, said deicer having an inboard end and an outboard end, heating means located within said flexible sheet being the sole deicing means, said heating means having a first set and a second set of U-shaped heating ribbons, each of said U-shaped ribbons having a pair of leg portions and a bridging portion, each bridging portion interconnects the respective one ends of said leg portions to form said U-shaped ribbons, each U-shaped ribbon in said second set being nestled by a U-shaped ribbon in said first set, the other end portion of said leg members of said first set are connected to adjacent other end portions of said leg members of said first set, the other end portion of said leg members of said second set are connected to adjacent other end portions of said leg members of said second set, the other end portion of said second set closest to said outboard end of said deicer being interconnected to the other end portion of said first set closest to outboard end of said deicer to form a continuous electrically conductive heating path that extends in a zig-zag path from said inboard end of said deicer toward said outboard end of said deicer and back to said inboard end of said deicer, electrical power input means connected to said heating ribbons, and said heating ribbons having a tapered power density from said inboard end to said outboard end along said electrically conductive heating path with the greatest power density being at said inboard end of said deicer.

14. An electrically heated propeller deicer pad for a propeller blade with a shank end and a tip end, said deicer pad being a longitudinally extending flexible sheet of electrically non-conductive material for mounting on a propeller blade, said deicer pad having an inboard end and an outbord end, said inboard end of said deicer located at said shank end of said propeller blade and said outboard end of said deicer pad extending on said blade in a direction away from said shank end towards said tip end of said propeller blade, electrically conductive heating means located within said flexible sheet, said heating means being the sole deicing means for said deicer pad, said heating means being a continuous heating ribbon that extends in a zig-zag direction from said inboard end of said deicer towards said outboard end of said deicer pad and back to said inboard end of said deicer pad, electrical power input means connected to said heating ribbon at said inboard end, and said heating ribbon having a gradient electrical resistance from said inboard end to said outboard and back to said inboard end to provide a gradient power density wherein the greatest power density is at said inboard end of said deicer.

15. An electrically heated deicer pad as set forth in claim 14 wherein said continuous electrically conductive heating ribbon increases in cross sectional area progressively from said inboard end to said outboard end.

16. An electrically heated deicer pad as set forth in claim 14 wherein said heating ribbon increases in power density in stepped increments.