Electro-expulsive separation system

• US 4,690,353 A
• Filed: 05/31/1985
• Issued: 09/01/1987
• Est. Priority Date: 05/31/1985
• Status: Expired due to Term

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Lee, Robert D., Haslim, Leonard A.
• Primary Examiner(s): Duggan, Donovan F.
• Application Number:
  US06/739,792
• Time in Patent Office: 823 Days
• Field of Search: 310/15, 310/308-310, 318/114, 318/119, 318/116, 244/134 R-134 D
• US Class Current: 244/134.00D
• CPC Class Codes: B64D 15/163 using electro-impulsive devices

Abstract

An electro-expulsive system 20 has one or more overlapped conductors OC1-OCN each comprising a flexible ribbon conductor 32 which is folded back on itself. The conductors are embedded in an elastomeric material 33. Large current pulses are fed to the conductors OC1-OCN from power storage units 1-N. As a result of the antiparallel currents I and I'"'"', the opposed segments of a conductor 32 are forcefully separated and the elastomeric material is distended. Void 34 in the elastomer aids the separation of the conductor segments. The distention is almost instantaneous when a current pulse reaches the conductor and the distention tends to remove any solid body on the surface of the elastomeric material.

Claims

1. Apparatus comprising first and second opposed, flexible, ribbon-shaped, electrically conductive members, a resilient insulating member being of generally sheet-like configuration having first and second opposed surfaces, said first and second conductive members being embedded in spaced apart relationship and electrically isolated from each other in said resilient insulating member with said first and second conductive members being adjacent said first and second surfaces of said insulating member, respectively, said electrically conductive members being electrically interconnected so that any electrical current flowing in said first conductive member also flows in said second conductive member in a direction opposite to the flow in said first conductive member, said resilient insulating member having at least one void positioned between said first and second conductive members so as to facilitate separation between said first and second conductive members when electric current is routed through said conductive members and said conductive members repel each other, said void having a height less than the distance between said conductive members so that a portion of said insulating member is between said opposed conductive members.

2. Apparatus as in claim 1 wherein said void is generally of a slot-like configuration and is at least coextensive with said opposed surfaces.

3. Apparatus as in claim 1 wherein said void is entirely surrounded by said resilient insulating material and a vacuum is created in said void when the void is distended by the repelled conductive members.

4. The apparatus of claim 1 wherein at least one wall of said void is lined with a release film.

5. Apparatus as set forth in claim 1 wherein said conductive members have a serpentine configuration.

6. The apparatus of claim 1 in which there are a plurality of pairs of opposed electrically conductive members and a plurality of voids.

7. The apparatus of claim 5 wherein the electrically conductive members of one pair have a linear configuration and the electrically conductive members of another pair have a serpentine configuration.

8. The apparatus of claim 1 wherein the resilient insulating member comprises an erosion resistant elastomer.

9. The apparatus of claim 1 wherein the resilient insulating member has an outer layer of erosion resistant elastomer.

10. The apparatus of claim 1 in which there are a plurality of pairs of opposed electrically conductive members and the members sandwich said void.

11. The apparatus of claim 1 wherein said electrically conductive members are formed from tantalum.

12. The apparatus of claim 1 wherein an electromagnetic shield is embedded in said resilient insulating member in proximity to at least one conductive member.

13. In combination, the apparatus of claim 1 and an airfoil, said first surface of said resilient insulating member being attached to the outer surface of said airfoil.

14. The combination of claim 13 wherein said airfoil is a wing leading edge and said resilient insulating member is flexed to conform to said outer surface of said airfoil.

15. The combination of claim 13 in which said airfoil is a helicopter rotor blade.

16. The combination of claim 13 in which said airfoil is an engine intake duct.

17. Apparatus as set forth in claim 1 further comprising circuit means coupled to said conductive members for generating large current pulses, the current flow direction in said first conductive member being opposite to the current flow direction in said second conductive member, the opposing currents and the resulting interacting magnetic fields producing an electrorepulsive force between said first and second conductive members to move said conductive members apart and to distend said resilient insulating member.

18. The apparatus of claim 17 including a plurality of pairs of opposed conductive members and wherein said circuit means successively generates a large current pulse to each pair of conductive members.

19. The apparatus of claim 17 wherein said circuit means includes at least one electrical energy storage capacitor and means for alternately charging and discharging said capacitor.

20. The apparatus of claim 19 in which said charging and discharging means comprises a power source, a first switch for connecting said capacitor to said power source, a second switch for connecting said capacitor to said conductive members, and a timing circuit for opening said second switch when said first switch is closed, and opening said first switch when said second switch is closed.

21. A circuit for a system for separating a solid body from a surface, which comprises first and second ribbon-shaped, flexible conductive members in overlying, closely spaced relationship, a sheet-like resilient member adapted to be interposed between said surface and said solid body, said conductive members being imbedded in said resilient member and said resilient member having a void positioned between said conductive members to facilitate separation of said conductive members, said conductive members being electrically insulated from each other along their length and connected so that a current flowing in a given direction in said first conductive member flows in an opposite direction in said second conductive member and causes said conductive members to separate, at least one storage capacitor connected to a power source through a first switch, said storage capacitor being connected in a low resistance path to said first and second conductive members through a second switch, and a timing circuit connected to open said second switch when said first switch is closed to charge said storage capacitor, and to open said first switch when said second switch is closed to discharge said storage capacitor into said first and second conductive members.

22. The circuit of claim 21 in which said at least one storage capacitor comprises a plurality of parallel connected capacitors.

23. The circuit of claim 21 comprising a plurality of pairs of said first and second ribbon-shaped, flexible conductive members, at least one storage capacitor and first and second switches being provided for each conductive member pair, and said timing circuit being configured to close said second switches to discharge said storage capacitors into said conductive member pairs successively.

24. The circuit of claim 21 additionally comprising means for discharging said at least one storage capacitor in absence of power to said circuit.

25. The circuit of claim 21 in which said first and second conductive members are formed from a conductor which is folded back on itself so as to have two closely-spaced substantially overlapped segments or legs comprising said first and second conductive members.

26. The solid body separating system of claim 25 in which said first and second conductive members are serpentine in configuration.

27. The solid body separating system of claim 26 in which said first and second conductive members are formed from tantalum.