Electroexplosive primer ignition assembly

Claim 2

An electrical ignition assembly for firing an adjacent mass of propellant, said assembly, when loaded, exhibiting a no-fire characteristic of at least 60 seconds duration when subjected to a current of approximately 0.75 ampere, and said assembly further exhibiting an all-fire characteristic occurring within at most 10 milliseconds when subjected to a current of at least 2.5 amperes, said ignition assembly comprising: a. an electrode; b. electrically insulating heat sink means having a thermal conductivity in the range of about

Claim 3

The ignition assembly of claim 1, further comprising a charge of a densely packed homogenous mixture of granulated primer material disposed adjacent to said bridge wire, said primer material consisting essentially of about 18 percent to about 30 percent powdered zirconium, about 14 percent to about 26 percent antimony sulfide, and about 50 percent to about 70 percent barium nitrate.

Claim 4

The ignition assembly of claim 2, wherein said heat sink means is formed from a material selected from the group consisting of thermosetting epoxy resin, thermosetting mineral-filled epoxy resin, and alumina.

Claim 5

The ignition assembly of claim 2, wherein said bridge wire is Nichrome.

Claim 6

The ignition assembly of claim 2, wherein said granulated charge of primer material is of a particle size which will pass through a 325-mesh screen.

Claim 7

The ignition assembly of claim 2, wherein said primer material contains about 24 percent powdered zirconium, about 20 percent antimony sulfide, and about 56 percent barium nitrate.

Claim 8

An electrical ignition assembly for firing an ejection type cartridge, said assembly exhibiting a no-fire characteristic of at leasT 60 seconds duration when subjected to a current of approximately 0.75 ampere, and said assembly further exhibiting an all-fire characteristic occurring within at most 10 milliseconds when subjected to a current of at least 2.5 amperes, said ignition assembly comprising: a. an electrode for connection to a source of electric current; b. electrically grounded means defining a sidewall of a primer chamber; c. an electrically insulating heat sink body interposed between said electrode and said grounded means, said heat sink body defining a bottom wall of said primer chamber and said heat sink body being formed from a material selected from the group consisting of thermosetting epoxy resin, thermosetting mineral-filled epoxy resin, and alumina; and d. a bridge wire interconnecting said electrode and said grounded means, said bridge wire extending across the bottom wall of said primer chamber in face-to-face contact with said heat sink body, said bridge wire having a temperature coefficient of resistivity of approximately .0004 ohm-cm at 20* C. and a unit resistance in the range of about 1.2 ohms to about 2.0 ohms.

Claim 9

An electrical ignition assembly for firing an ejection type cartridge, said assembly exhibiting a no-fire characteristic of at leasT 60 seconds duration when subjected to a current of approximately 0.75 ampere, and said assembly further exhibiting an all-fire characteristic occurring within at most 10 milliseconds when subjected to a current of at least 2.5 amperes, said ignition assembly comprising: a. an electrode for connection to a source of electric current; b. electrically grounded means defining a sidewall of a primer chamber; c. an electrically insulating heat sink body interposed between said electrode and said grounded means, said heat sink body defining a bottom wall of said primer chamber and said heat sink body being formed from a material selected from the group consisting of thermosetting epoxy resin, thermosetting mineral-filled epoxy resin, and alumina; and d. a bridge wire interconnecting said electrode and said grounded means, said bridge wire extending across the bottom wall of said primer chamber in face-to-face contact with said heat sink body, said bridge wire having a temperature coefficient of resistivity of approximately .0004 ohm-cm at 20* C. and a unit resistance in the range of about 1.2 ohms to about 2.0 ohms.

Claim 10

The ignition assembly of claim 7, further comprising a granulated homogeneous mixture of primer material densely packed into said primer chamber to contact said bridge wire, said primer material consisting essentially of from about 18 percent to about 30 percent powdered zirconium, from about 14 percent to about 26 percent antimony sulfide, and from about 50 percent to about 70 percent barium nitrate.

Claim 11

The ignition assembly of claim 7, wherein said bridge wire is Nichrome.

Claim 12

The ignition assembly of claim 8, wherein said granulated charge of primer material is of a particular size which will pass through a 325-mesh screen.

Claim 13

The ignition assembly of claim 8, wherein said primer material contains about 24 percent powdered zirconium, about 20 percent antimony sulfide, and about 56 percent barium nitrate.

Claim 14

An electrical ignition assembly for firing an ejection-type cartridge, said assembly, when loaded, exhibiting a no-fire characteristic of at least 60 seconds duration when subjected to a current of approximately 0.75 ampere, and said assembly further exhibiting an all-fire characteristic occurring within at most about 10 milliseconds when subjected to a current of at least about 2.5 amperes, said ignition assembly comprising: a. a housing of electrical conducting material for connection to an electrical ground; b. a lining of electrical insulating material disposed in said housing; c. an electrode disposed in said housing and separated therefrom by said lining, said electrode being for connection to a source of electric current; d. an electrically Calif. element disposed in said housing and electrically connected thereto, said element defining a wall of a primer chamber; e. an electrically insulating heat sink body interposed between said electrode and said element, said heat sink body defining a bottom wall of said primer chamber and said heat sink body being formed from a material selected from the group consisting of thermosetting epoxy resin, mineral filled thermosetting epoxy resin, and alumina; and f. a Nichrome bridge wire interconnecting said electrode and said element, said bridge wire extending across the bottom wall of said primer chamber in contact with said heat sink body, and said bridge wire having a unit resistance in the range of about 1.2 ohms to about 2.0 ohms.

Claim 15

An electrical ignition assembly for firing an ejection-type cartridge, said assembly, when loaded, exhibiting a no-fire characteristic of at least 60 seconds duration when subjected to a current of approximately 0.75 ampere, and said assembly further exhibiting an all-fire characteristic occurring within at most about 10 milliseconds when subjected to a current of at least about 2.5 amperes, said ignition assembly comprising: a. a housing of electrical conducting material for connection to an electrical ground; b. a lining of electrical insulating material disposed in said housing; c. an electrode disposed in said housing and separated therefrom by said lining, said electrode being for connection to a source of electric current; d. an electrically Calif. element disposed in said housing and electrically connected thereto, said element defining a wall of a primer chamber; e. an electrically insulating heat sink body interposed between said electrode and said element, said heat sink body defining a bottom wall of said primer chamber and said heat sink body being formed from a material selected from the group consisting of thermosetting epoxy resin, mineral filled thermosetting epoxy resin, and alumina; and f. a Nichrome bridge wire interconnecting said electrode and said element, said bridge wire extending across the bottom wall of said primer chamber in contact with said heat sink body, and said bridge wire having a unit resistance in the range of about 1.2 ohms to about 2.0 ohms.

Claim 16

An electrical ignition assembly for firing an ejection-type cartridge, said assembly comprising: a. an electrode for connection to a source of electric current; b. an element for connection to an electrical ground, said element defining a sidewall of a primer chamber; c. an electrical insulating heat sink body interposed between said electrodE and said element, said heat sink body defining a bottom wall of said primer chamber; and d. a bridge wire interconnecting said electrode and said element, said bridge wire extending across the bottom wall of said primer chamber in heat exchange contact with said heat sink body.

Claim 17

An electrical ignition assembly for firing an ejection-type cartridge, said assembly comprising: a. an electrode for connection to a source of electric current; b. an element for connection to an electrical ground, said element defining a sidewall of a primer chamber; c. an electrical insulating heat sink body interposed between said electrodE and said element, said heat sink body defining a bottom wall of said primer chamber; and d. a bridge wire interconnecting said electrode and said element, said bridge wire extending across the bottom wall of said primer chamber in heat exchange contact with said heat sink body.