Flight crash survivable storage unit with aquarium container for flight recorder memory

• US 5,756,934 A
• Filed: 10/11/1994
• Issued: 05/26/1998
• Est. Priority Date: 10/11/1994
• Status: Expired due to Term

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Loral Fairchild Corp. (Newell Brands Inc.)
• Inventors: Purdom, Gregory W.
• Primary Examiner(s): Kincaid, Kristine L.
• Assistant Examiner(s): SODERQUIST, KRISTINA D
• Application Number:
  US08/320,265
• Time in Patent Office: 1,323 Days
• Field of Search: 174/52.1, 174/52.2, 206/501, 206/502, 206/408, 200/4.02, 200/453, 200/468, 29/248
• US Class Current: 174/544
• CPC Class Codes: H05K 5/021 specially adapted for data recorders, e.g. for flight recorders
• CPC Class Codes: H05K 5/0213 Venting apertures; Constructional details thereof

Abstract

An enclosure for protecting a heat sensitive item from high temperatures and shock which includes: (a) an outer housing including an inner cavity for containing at least one heat sensitive item; (b) an aquarium located within the inner cavity including at least one protective compartment within which the at least one heat sensitive item is located; (c) a thermal mass, located within the inner cavity and covering at least a portion of the exterior surface of the aquarium; and (d) a venting mechanism for venting any moisture, that penetrates the aquarium and enters the at least one protective compartment included therein, to the ambient air outside the outer housing. The invention finds particular utility in the Flight Recorder field where heat sensitive components, such as solid state memories, may be subject to fire and shock often resulting from an aircraft crash. The invention also features a corrosion protection capability which is effective when the item being protected is in close proximity to a source of moisture. Further aspects of the invention are directed to processes for fabricating enclosures of then type contemplated by the invention (a Flight Crash Survival Storage Unit (FCSSU) in the Flight Recorder context), and to an aquarium per se for use in a FCSSU of the type contemplated by the invention.

Claims

1. A corrosion resistant apparatus for thermally protecting at least one heat sensitive item from high temperatures, shock and moisture utilizing a thermal mass containing a liquid, comprising:

(a) an outer housing including an inner cavity for containing at least one heat sensitive item;

(b) an aquarium located within said inner cavity including at least one protective compartment within which said at least one heat sensitive item is located;

(c) a thermal mass containing a liquid, located within said inner cavity and covering at least a portion of the exterior surface of said aquarium, wherein energy absorption from vaporization of said liquid is utilized to protect said at least one heat sensitive item;

(d) means for venting any moisture, that penetrates said aquarium and enters said at least one protective compartment included therein, to the ambient air outside said outer housing wherein said means for venting directly connects said at least one protective compartment to the ambient air; and

(e) means for venting steam from said inner cavity to the ambient air outside said outer housing.

2. Apparatus as set forth in claim 1 wherein said means for venting steam is sized to allow steam to escape from said inner cavity while maintaining pressure and temperature within said inner cavity within a predefined range.

3. Apparatus as set forth in claim 2 further comprising means for sealing said means for venting steam until said thermal mass is heated to a predetermined temperature.

4. Apparatus as set forth in claim 3 wherein said means for sealing further comprises at least one thermal vent plug which is released at said predetermined temperature.

5. Apparatus as set forth in claim 4 wherein said at least one thermal vent plug comprises wax, paraffin, bismuth alloy or electrical solder.

6. Apparatus as set forth in claim 1 further comprising a a cover for said outer housing which when combined with said outer housing forms an enclosure for said inner cavity.

7. Apparatus as set forth in claim 6 further comprising a cable coupled to said at least one heat sensitive item, wherein said cable exits said at least one protective compartment and extends to and through the enclosure formed by the combination of said cover and said outer housing.

8. Apparatus as set forth in claim 7 wherein said cable is isolated from the exterior surface of said aquarium by said thermal mass.

9. Apparatus as set forth in claim 8 wherein said means for venting any moisture further comprises at least one vent tube which exits said at least one protective compartment and extends to and through the enclosure formed by the combination of said cover and said outer housing.

10. Apparatus as set forth in claim 1 wherein said at least one heat sensitive item is coated with a material which protects said item from moisture.

11. Apparatus as set forth in claim 1 wherein said at least one heat sensitive item includes a solid state memory device.

12. Apparatus as set forth in claim 1 wherein said at least one protective compartment includes padding for further protecting s aid at least one heat sensitive item from shock.

13. Apparatus as set forth in claim 6 wherein said means for venting any moisture further comprises a ribbon cable electrically coupled to said at least one heat sensitive item, wherein said ribbon cable exits said at least one protective compartment and extends to and through the enclosure formed by the combination of said cover and said outer housing, and further wherein said ribbon cable has at least one vent tube integrally formed therein for venting moisture.

14. Apparatus as set forth in claim 13 wherein said ribbon cable is isolated from the exterior surface of said aquarium by said thermal mass.

15. Apparatus as set forth in claim 1 wherein said thermal mass is further operative to perform as a thermal insulator.

16. Apparatus as set forth in claim 15 wherein said thermal mass is a mixture of silicon and water.

17. Apparatus as set forth in claim 1 wherein said outer housing is metallic.

18. Apparatus as set forth in claim 1 wherein said outer housing consists essentially of titanium.

19. Apparatus as set forth in claim 1 wherein said outer housing consists essentially of stainless steel.

20. Apparatus as set forth in claim 1 wherein said thermal mass includes a phase change material (PCM).

21. Apparatus as set forth in claim 20 wherein said PCM is water.

22. Apparatus as set forth in claim 21 wherein said water is contained in a dry material which inhibits the water from freezing or expanding.

23. Apparatus as set forth in claim 22 wherein said dry material comprises sponge, silica, polyacrylamide, calcium silicate or pottery clay.

24. Apparatus as set forth in claim 20 wherein said thermal mass is a dry powder formed by combining water and silica.

25. Apparatus as set forth in claim 1 wherein said thermal mass acts as a shock absorber.

26. Apparatus as set forth in claim 25 wherein said thermal mass is a gel formed by combining water and polyacrylamide.

27. A flight recorder apparatus including means for thermally protecting a solid state memory device from high temperatures, shock and moisture utilizing a thermal mass containing a liquid, comprising:

(a) at least one heat sensitive item;

(b) a corrosion resistant Flight Crash Survivable Storage Unit (FCSSU) that contains and protects said at least one memory device from shock, moisture and fire utilizing a thermal mass containing a liquid, wherein said FCSSU comprises;

(b1) an outer housing including an inner cavity for containing at least one heat sensitive item;

(b2) an aquarium located within said inner cavity including at least one protective compartment within which said at least one heat sensitive item is located;

(b3) a thermal mass containing a liquid, located within said inner cavity and covering at least a portion of the exterior surface of said aquarium, wherein energy absorption from vaporization of said liquid is utilized to protect said at least one heat sensitive item;

(b4) means for venting any moisture, that penetrates said aquarium and enters said at least one protective compartment included therein, to the ambient air outside said outer housing wherein said means for venting directly connects said at least one protective compartment to the ambient air; and

(b5) means for venting steam from said inner cavity to the ambient air outside said outer housing.

28. Apparatus as set forth in claim 27 wherein said means for venting steam is sized to allow steam to escape from said inner cavity while maintaining the pressure and temperature within said inner cavity within a predefined range.

29. Apparatus as set forth in claim 28 further comprising a means for sealing said means for venting steam until said thermal mass is heated to a predetermined temperature.

30. Apparatus as set forth in claim 29 wherein said means for sealing further comprises at least one thermal vent plug which is released at said predetermined temperature.

31. Apparatus as set forth in claim 30 wherein said at least one thermal vent plug comprises wax, paraffin, bismuth alloy or electrical solder.

32. Apparatus as set forth in claim 27 further comprising a a cover for said outer housing which when combined with said outer housing forms an enclosure for said inner cavity.

33. Apparatus as set forth in claim 32 further comprising a cable coupled to said at least one heat sensitive item, wherein said cable exits said at least one protective compartment and extends to and through the enclosure formed by the combination of said cover and said outer housing.

34. Apparatus as set forth in claim 33 wherein said cable is isolated from the exterior surface of said aquarium by said thermal mass.

35. Apparatus as set forth in claim 34 wherein said means for venting any moisture further comprises at least one vent tube which exits said at least one protective compartment and extends to and through the enclosure formed by the combination of said cover and said outer housing.

36. Apparatus as set forth in claim 27 wherein said at least one heat sensitive item is coated with a material which protects said item from moisture.

37. Apparatus as set forth in claim 27 wherein said at least one heat sensitive item includes a solid state memory device.

38. Apparatus as set forth in claim 27 wherein said at least one protective compartment includes padding for further protecting said at least one heat sensitive item from shock.

39. Apparatus as set forth in claim 32 wherein said means for venting any moisture further comprises a ribbon cable electrically coupled to said at least one heat sensitive item, wherein said ribbon cable exits said at least one protective compartment and extends to and through the enclosure formed by the combination of said cover and said outer housing, and further wherein said ribbon cable has at least one vent tube integrally formed therein for venting moisture.

40. Apparatus as set forth in claim 39 wherein said ribbon cable is isolated from the exterior surface of said aquarium by said thermal mass.

41. Apparatus as set forth in claim 27 wherein said thermal mass further is operative to perform as a thermal insulator.

42. Apparatus as set forth in claim 41 wherein said thermal mass is a mixture of silicon and water.

43. Apparatus as set forth in claim 27 wherein said outer housing is metallic and is further comprised of titanium or stainless steel.

44. Apparatus as set forth in claim 27 wherein said thermal mass includes a phase change material (PCM).

45. Apparatus as set forth in claim 44 wherein said PCM is water.

46. Apparatus as set forth in claim 45 wherein said water is contained in a dry material which inhibits the water from freezing or expanding.

47. Apparatus as set forth in claim 46 wherein said dry material comprises sponge, silica, polyacrylamide, calcium silicate or pottery clay.

48. Apparatus as set forth in claim 44 wherein said thermal mass is a dry powder formed by combining water and silica.

49. Apparatus as set forth in claim 29 wherein said thermal mass acts as a shock absorber.

50. Apparatus as set forth in claim 40 wherein said thermal mass is a gel formed by combining water and polyacrylamide.

51. A process for fabricating a Flight Crash Survivable Storage Unit (FCSSU) for a Flight Recorder (FR) comprising the steps of:

(a) fabricating an aquarium that includes at least one heat sensitive item, to be protected from heat, moisture and shock, installed in at least one protective compartment;

(b) installing said aquarium within an outer housing that includes a thermal mass containing a liquid covering at least a portion of the exterior surface of said aquarium;

(c) fabricating means for venting moisture penetrating said aquarium and entering said at least one protective compartment included therein, to directly connect said at least one protective compartment to the ambient air outside said outer housing;

(d) covering said outer housing to form a sealed enclosure for said thermal mass, said aquarium and the at least one heat sensitive item contained therein; and

(e) fabricating a steam vent in said sealed enclosure.

52. A process as set forth in claim 51 further comprising the step of sizing said steam vent to allow steam to escape from within said sealed enclosure while maintaining pressure and temperature therein within a predefined range.

53. A process as set forth in claim 51 wherein said step of fabricating an aquarium further comprising the step of providing an electrical connection to said at least one heat sensitive item via a cable which exits said at least one protective compartment and said aquarium.

54. A process as set forth on claim 53 further comprising the steps of:

(a) utilizing clear acrylic to form aquarium walls;

(b) chemically welding said clear acrylic with a chemical solvent;

(c) sealing a cable exit from said aquarium to prevent moisture transfer; and

(d) separating said cable from said aquarium to minimize heat transfer therebetween.

55. A process as set forth in claim 54 further comprising the step of coating said at least one heat sensitive item with a material that provides moisture protection.

56. A process as set forth in claim 54 further comprising the step of installing shock protection material in said at least one protective compartment.

57. A process as set forth in claim 54 further comprising the step of integrating said means for venting moisture with said cable.

58. Apparatus for protecting a heat sensitive memory device, included in a Flight Recorder (FR), from heat, shock and moisture utilizing a thermal mass containing a liquid, comprising:

(a) a moisture resistant enclosure, for containing the memory device to be protected, covered at least in part by the thermal mass containing a liquid;

(b) an outer housing including an inner cavity for housing said moisture resistant enclosure and said thermal mass containing a liquid;

(c) means for venting moisture from said enclosure wherein said means for venting directly connects said enclosure to the ambient air; and

(d) means for venting steam from said inner cavity to the ambient air outside said outer housing.

59. Apparatus as set forth in claim 58 further comprising a cable, for providing electrical connection to said memory device, which exits said moisture resistant enclosure via a sealed opening in said enclosure.

60. Apparatus as set forth in claim 59 wherein said means for venting moisture is integrated into said cable.