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Constant output high-precision microcapillary pyrotechnic initiator

Imported: 24 Feb '17 | Published: 06 Jan '04

Sami Daoud

USPTO - Utility Patents

Abstract

A high-precision pyrotechnic initiator is well adapted for rapid, precise ignition of solid and liquid energetics. A rigid housing, for example formed of stainless steel, contains a pyrotechnic. When ignited, the reaction, or explosion, of the pyrotechnic is confined to the housing. The release of energy creates a hot particulate in which the formation of solid byproducts is mitigated or eliminated. The flame is directed through an outlet. In one embodiment, a microcapillary tube may be placed in communication with the outlet, the tube including a primary front vent and secondary side vents, which serve to increase system efficiency and reliability. A dual bridge wire may be provided for improving system reliability. The resulting assembly thereby performs the combined functions of both an igniter and a flash tube and a complete ignition train is provided in a manner that overcomes the limitations of the conventional configurations.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the invention will be apparent from the more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.

FIG. 1 is a cross-sectional view of a microcapillary initiator configured in accordance with the present invention in a dormant state, prior to activation.

FIG. 2 is a cross-sectional view of the microcapillary initiator of FIG. 1 during activation, in accordance with the present invention.

FIG. 3A is a cross-sectional closeup view of the region of the O-ring of the microcapillary initiator of FIG.

1. FIG. 3B is a closeup view of the position of the O-ring prior to activation, while FIG. 3C is a closeup view of the position of the O-ring following activation.

FIG. 4A is a perspective view of the header body illustrating a cross-patterned bridge wire configuration including first and second redundant bridge wires, for improved reliability, in accordance with the present invention.

FIG. 4B is a perspective view of the header body illustrating a parallel bridge wire configuration including first and second redundant bridge wires, for improved reliability, in accordance with the present invention.

Claims

1. A pyrotechnic initiator comprising:

2. The pyrotechnic initiator of claim 1 wherein the O-ring deforms upon activation of the pyrotechnic charge to seal a gap between the outer surface of the vent tube and the outlet.

3. The pyrotechnic initiator of claim 1 wherein the O-ring is of a first width that is less than a second width of the groove.

4. The pyrotechnic initiator of claim 1 wherein the O-ring comprises first, second and third sub-O-rings positioned adjacent each other in the groove.

5. The pyrotechnic initiator of claim 1 wherein the first and third sub-O-rings are positioned on opposite sides of the second O-ring and wherein the first and third sub-O-rings comprise Bakelite and wherein the second O-ring comprises neoprene.

6. The pyrotechnic initiator of claim 4 further comprising a bridge wire for conducting current to initiate activation of the pyrotechnic charge.

7. The pyrotechnic initiator of claim 6 wherein the bridge wire comprises first and second redundant bridge wires.

8. The pyrotechnic initiator of claim 7 wherein the first and second redundant bridge wires are configured in a cross pattern for distribution of the current through the pyrotechnic charge.

9. The pyrotechnic initiator of claim 6 further comprising first and second contact pins passing through the housing and electrically coupled to corresponding first and second portions of the bridge wire for delivering current to the bridge wire.

10. The pyrotechnic initiator of claim 9 further comprising a pin seal along at least a portion of the bodies of the first and second pins for sealing the interface between the first and second pins and the housing.

11. The pyrotechnic initiator of claim 1 further comprising a first moisture barrier at the entrance aperture of the primary vent.

12. The pyrotechnic initiator of claim 11 wherein the first moisture barrier comprises a fluoropolymeric seal.

13. The pyrotechnic initiator of claim 1 further comprising a retention sleeve in the chamber between the pyrotechnic charge and the vent tube, the retention sleeve mating with a head portion of the vent tube for securing the vent tube in the outlet.

14. The pyrotechnic initiator of claim 13 wherein the retention sleeve comprises nylon.

15. The pyrotechnic initiator of claim 1 wherein the pyrotechnic charge comprises a material selected from the group of materials consisting of: cis-bis-(5-nitrotetrazolato)tetraminecobalt(III)perchlorate (BNCP), zirconium potassium perchlorate (ZPP), titanium-hydride-potassium-perchlorate (THPP), and lead azide (PbN

6).

16. The pyrotechnic initiator of claim 1 wherein the housing comprises stainless steel of sufficient thickness so as to contain the energy released by the pyrotechnic charge when activated.

17. The pyrotechnic initiator of claim 1 wherein the housing comprises a plurality of body portions that are welded together to form the housing.

18. A pyrotechnic initiator comprising:

19. The pyrotechnic initiator of claim 18 further comprising a bridge wire for conducting current to initiate activation of the pyrotechnic charge.

20. The pyrotechnic initiator of claim 19 wherein the bridge wire comprises first and second redundant bridge wires.

21. The pyrotechnic initiator of claim 20 wherein the first and second redundant bridge wires are configured in a cross pattern for distribution of the current through the pyrotechnic charge.

22. The pyrotechnic initiator of claim 20 wherein the first and second redundant bridge wires are configured in parallel for distribution of the current through the pyrotechnic charge.

23. The pyrotechnic initiator of claim 18 wherein the O-ring is of a first width that is less than a second width of the groove.

24. The pyrotechnic initiator of claim 18 wherein the O-ring comprises first, second and third sub-O-rings positioned adjacent each other in the groove.

25. The pyrotechnic initiator of claim 18 wherein the first and third sub-O-rings are positioned on opposite sides of the second O-ring and wherein the first and third sub-O-rings comprise Bakelite and wherein the second O-ring comprises neoprene.

26. The pyrotechnic initiator of claim 18 further comprising a first moisture barrier at the entrance aperture of the primary vent.

27. The pyrotechnic initiator of claim 26 wherein the first moisture barrier comprises a fluoropolymeric seal.

28. The pyrotechnic initiator of claim 18 further comprising a retention sleeve in the chamber between the pyrotechnic charge and the vent tube, the retention sleeve mating with a head portion of the vent tube for securing the vent tube in the outlet.

29. The pyrotechnic initiator of claim 28 wherein the retention sleeve comprises nylon.

30. The pyrotechnic initiator of claim 18 wherein the housing comprises stainless steel of sufficient thickness so as to contain the energy released by the pyrotechnic charge when activated.

31. The pyrotechnic initiator of claim 18 wherein the housing comprises a plurality of body portions that are welded together to form the housing.

32. A pyrotechnic initiator comprising:

33. The pyrotechnic initiator of claim 32 wherein at least one of the plurality of adjacent O-rings deforms upon activation of the pyrotechnic charge to seal a gap between the outer surface of the vent tube and the outlet.

34. The pyrotechnic initiator of claim 32 wherein the plarality of adjacent O-rings is of a combined first width that is less than a second width of the groove.

35. The pyrotechnic initiator of claim 32 wherein the plurality of adjacent O-rings comprises first, second and third sub-O-rings.

36. The pyrotechnic initiator of claim 35 wherein the first and third sub-O-rings are positioned on opposite sides of the second O-ring and wherein the first and third sub-O-rings comprise Bakelite and wherein the second O-ring comprises neoprene.

37. The pyrotechnic initiator of claim 32 further comprising a bridge wire for conducting current to initiate activation of the pyrotechnic charge.

38. The pyrotechnic initiator of claim 37 wherein the bridge wire comprises first and second redundant bridge wires.

39. The pyrotechnic initiator of claim 38 wherein the first and second redundant bridge wires are configured in a cross pattern for distribution of the current through the pyrotechnic charge.

40. The pyrotechnic initiator of claim 38 wherein the first and second redundant bridge wires are configured in parallel for distribution of the current through the pyrotechnic charge.

41. The pyrotechnic initiator of claim 37 further comprising first and second contact pins passing through the housing and electrically coupled to corresponding first and second portions of the bridge wire for delivering current to the bridge wire.

42. The pyrotechnic initiator of claim 41 further comprising a pin seal along at least a portion of the bodies of the first and second pins for sealing the interface between the first and second pins and the housing.

43. The pyrotechnic initiator of claim 32 further comprising a first moisture barrier at the entrance aperture of the primary vent.

44. The pyrotechnic initiator of claim 43 wherein the first moisture barrier comprises a fluoropolymeric seal.

45. The pyrotechnic initiator of claim 32 further comprising a retention sleeve in the chamber between the pyrotechnic charge and the vent tube, the retention sleeve mating with a head portion of the vent tube for securing the vent tube in the outlet.

46. The pyrotechnic initiator of claim 45 wherein the retention sleeve comprises nylon.

47. The pyrotechnic initiator of claim 32 wherein the pyrotechnic charge comprises a material selected from the group of materials consisting of:

48. The pyrotechnic initiator of claim 32 wherein the housing comprises stainless steel of sufficient thickness so as to contain the energy released by the pyrotechnic charge when activated.

49. The pyrotechnic initiator of claim 32 wherein the housing comprises a plurality of body portions that are welded together to form the housing.