Electronic water-activated parachute release and life vest inflator

Claim 2

A water-sensitive energizing electrical circuit for detonating electrical explosive devices upon immersion in water comprising, in combination, a source of electrical current, a first means of generating an electrical current pulse at an output, a switching means for minimizing current leakage from said current source prior to immersion of said circuit in water and for switching said first means to generate a current pulse responsive to immersion in water, said switching means being connected between said current source and said first means, and a temperature compensation means for minimizing temperature dependence of said first means and said switching means respectively, said temperature compensation means being connected between said current source and each of said means respectively.

Claim 3

The circuit of claim 1 further defined in that said electrical current source comprises a battery having a positive terminal, a negative terminal and an intermediate positive voltage tap.

Claim 4

The circuit of claim 2 further defined in that first means for generating an electrical current pulse comprises a capacitor connected between the positive and negative terminals of the battery in parallel with the electrical explosive device, sensing means for sensing electrical potential across said capacitor, said sensing means being connected to said temperature compensating means, a first controlled switching means having a conducting and a non-conducting state connected in series in a circuit loop defined by said capacitor and said electrical explosive device and having a gate connected to said sensing means whereby said first controlled switching means changes from a non-conducting to a conducting state responsive to a signal from said sensing means allowing electrical charge buildup across said capacitor to discharge through said electrical explosive device.

Claim 5

The circuit of claim 3 further defined in that said first controlled switching means comprises a silicon-controlled switch having a gate connection; a first resistance connected serially between the gate connection and the sensing means and a second resistance connected serially between said gate connection and the negative terminal of the battery, said silicon-controlled switch having a non-conducting state when a negative potential is impressed on said gate connection and having a conducting state when a positive potential is impressed upon said gate.

Claim 6

The circuit of claim 4 further defined in that said sensing means comprises a PNP transistor having an emitter connected to said intermediate positive voltage tap of the battery, a base connected between said capacitor and said negative terminal of said battery and a collector connected to said first resistance; said PNP transistor having a ''''turn on'''' potential difference between the base and emitter at which electrical conduction occurs through the emitter and collector; said temperature-compensating means being connected serially with a resistance between said base of said transistor and said positive terminal of said battery for compensating a decreasing ''''turn on'''' potential difference between said base and said emitter of said transistor as temperature increases, whereby, upon said capacitor becoming fully charged, the potential difference between the base and emitter of the transistor reaches the ''''turn on'''' potential difference and allows conduction of a positive potential from said positive voltage tap through the emitter and collector of the transistor to be impressed upon said gate of said silicon-controlled switch.

Claim 7

The circuit of claim 2 further defined in that said switching means for minimizing current leakage from said current source prior to immersion of said circuit in water and for switching said first means to generate a current pulse comprises, in combination, a first water-sensing electrode electrically connected to the positive terminal of said battery, a second water-sensing electrode electrically connected to the negative terminal of said battery, means for sensing electrical conduction between said first and second electrodes, a second controlled switching means for allowing current flow to said first means, said second controlled switching means being serially connected between the negative terminal of said battery and said first means and having a gate connection, said second controlled switching means having a non-conducting state when a negative potential is impressed upon said gate connection and a conducting state when a positive potential is impressed upon said gate connection, said gate connection being connected to said means for sensing current conduction between said first and second electrodes, whereby said means for sensing conduction between said electrodes impresses a positive potential on said gate of said second controlled switch causing it to become conducting, allowing current flow into first means.

Claim 8

The circuit of claim 6 further defined in that said second controlled switching means comprises a silicon-controlled switch connected serially between said first means and said negative terminal of said battery having a gate connection; a fourth resistance connected serially between said gate connection and said means for sensing current flow between said electrodes and a fifth resistance connected serially between fourth resistance and said negative terminal of said battery.

Claim 9

The circuit of claim 7 further defined in that said means for sensing current conduction between said electrodes comprises, in combination, a second PNP transistor having a base connected between said first electrode and said positive terminal of said battery, an emitter connected to said positive voltage tap of said battery and a collector connected to said fourth resistance; said second transistor having a ''''turn on'''' potential difference between said base and emitter at which electrical current conduction occurs through said emitter and collector; said temperature-compensation means being connected serially between the base of said second transistor and the positive voltage terminal of said battery for compensating a decreasing ''''turn on'''' potential difference between the base and emitter of said second transistor as temperature increases, whereby current conduction between said first and second electrodes causes a ''''turn on'''' potential difference between said base and emitter of said second transistor allowing a positive potential from said voltage tap to be impressed through the emitter and collector of said second transistor on said gate of said second silicon-controlled switch to thereby allow current conduction to said first means.

Claim 10

The circuit of claim 8 further defined in that said temperature-compensating means comprises a silicon diode and in that said PNP transistor is a silicon PNP transistor.

Claim 11

The invention specified in claim 1, and an inflating assembly for an inflatable life vest including a cannister containing high pressure gas, having a piercable closure membrane disposed across a necked section of said cannister, and a structure adapted to hermetically receive said necked section of said cannister for conveying gas from said cannister to said inflatable life vest, the structure comprising a piercing mechanism incorporated into said structure adapted to pierce said closure membrane and actuator means for operating said piercing mechanism, responsive to an electrical current pulse from said first means; said first means, said switching means and said actuator means being encapsulated in a unitary package adapted to be mounted on said structure.

Claim 12

The device of claim 10 wherein said piercing mechanism comprises a piercing pin disposed in a passageway defined through said structure, said passageway communicating with the necked section of said cannister received in said structure, said pin having a point proximate said closure membrane across said necked section of said cannister and having a rounded head extending out of said passageway, a rotatable cam pivotably mounted in said structure, adapted to drive the rounded head of said pin into said passageway upon rotation, to thereby pierce said closure membrane, said rotatable cam being adapted for rotation responsive to said actuator means.

Claim 13

The device of claim 11 further defined in that said actuator means comprises, in combination, a retainer sleeve having an open end and a closed end, a plunger disposed in said retainer sleeve adapted to extend out said open end of said sleeve responsive to gas pressure and engage and rotate said rotatable cam, an explosive charge for generating gas pressure upon detonation disposed within said sleeve between said plunger and said closed end of said sleeve, and means for electrically detonating said charge whereby said plunger moves outward from said sleeve responsive to gas pressure generated by said exploding charge to rotate said cam and drive said piercing pin through said closure membrane of said cannister.

Claim 14

The device of claim 12 further defined in that said means for electrically detonating said explosive charge comprises a bridgewire which vaporizes upon conduction of an electrical current pulse therethrough, said bridgewire being imbedded in said said explosive charge, and in that said first means includes a self-contained current source.

Claim 15

The device of claim 13 further defined in that said switching means for switching said first means to generate a current pulse in response to immersion in water further includes a means for minimizing current leakage from said current source prior to immersion of said assembly in water.

Claim 16

The device of claim 14 wherein said piercing mechanism further includes a lever pivotably mounted on said structure for rotating said rotatable cam, whereby said piercing mechanism can be operated manually by said lever.

Claim 17

The device of claim 15 further comprising a temperature-compensating means for minimizing the temperature dependence of said first means and said switching means which means includes a silicon diode and a silicon PNP transistor.

Claim 18

The device of claim 16 further defined in that said life vest includes an enclosure for receiving said inflating assembly, said enclosure having a stretched fabric membrane for allowing passage of water and for preventing passage of particulate debris.

Claim 19

The device of claim 14 here further defined in that said current source comprises a baTtery.

Claim 20

In a parachute strap release mechanism, including a webbing frame, a webbing pin pivotably connected at one end to said frame, a side bar for releasably securing the free end of said webbing pin for holding a strap, and a latching means for securing said side bar to said frame, the combination comprising, a first means for generating an electrical current pulse at an output, switching means for switching said first means to generate a current pulse responsive to immersion in water, actuator means for disengaging said latching means and for forcing said side bar outward to release said webbing pin responsive to an electrical current pulse from said first means, and temperature-compensating means for minimizing the temperature dependence of said first means and said switching means; said first means, said switching means, said actuator means and said temperature-compensating means being encapsulated in a unitary package mounted integrally within said webbing frame.

Claim 21

In a parachute strap release mechanism, including a webbing frame, a webbing pin pivotably connected at one end to said frame, a side bar for releasably securing the free end of said webbing pin for holding a strap, and a latching means for securing said side bar to said frame, the combination comprising, a first means for generating an electrical current pulse at an output, switching means for switching said first means to generate a current pulse responsive to immersion in water, actuator means for disengaging said latching means and for forcing said side bar outward to release said webbing pin responsive to an electrical current pulse from said first means, and temperature-compensating means for minimizing the temperature dependence of said first means and said switching means; said first means, said switching means, said actuator means and said temperature-compensating means being encapsulated in a unitary package mounted integrally within said webbing frame.

Claim 22

The device of claim 19 further defined in that said actuator means comprises, in combination, a chamber having an open end and a closed end, a piston disposed in said chamber adapted to extend out said open end of said chamber responsive to gas pressure, an explosive charge for generating gas pressure upon detonation disposed within said chamber between said piston and said closed end of said chamber, and means for electrically detonating said charge whereby said piston moves outward from said chamber responsive to gas pressure generated by said charge to disengage said latching means and to force said side bar outward to thereby release said webbing pin.

Claim 23

The device described in claim 20 further defined in that said means for electrically detonating said explosive charge comprise a bridgewire which vaporizes upon conduction of an electrical current pulse therethrough, and in that said first means includes a self contained current source.

Claim 24

The device described in claim 21 further defined in that said switching means for switching said first means to generate a current pulse responsive to immersion in water further includes a means for minimizing current leakage from said current source prior to immersion of said release in water.