US3881419A

US3881419A - Pyrotechnic initiator

Info

Publication number: US3881419A
Application number: US412509A
Authority: US
Inventors: Gayle A Bea
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1973-11-02
Filing date: 1973-11-02
Publication date: 1975-05-06
Anticipated expiration: 1992-05-06

Abstract

A pyrotechnic initiator with an inherent out-of-line safe/arm feature. The initiator is comprised of a solenoid striker, a diaphragm located between a source of gas vapor and the striker, a secondary explosive, and an igniter. The solenoid punctures the diaphragm allowing the contents from the source of gas vapor to pass into an explosive chamber where a voltage from the igniter ignites the gas. The explosion caused thereby initiates the secondary explosive which produces the desired explosive output.

Description

mted States Patent 1 1 3,331,419 1131 May 6, 1975 [5 PYROTECHNIC INITIATOR 3,630,151 12/1971 Rakowsky 102/70 R [75] Inventor: Gayle A. Bea, Mountain View, Calif. I

Primary Examiner-Benyamm A. Borchelt [73] Assigneez The United States of America as Assistant Jordan represented by the Secretary of the Attorney, Agent, or Firm-R. S. Sciascia; Charles D. B.

Navy, Washington, DC. Curry [22] Filed: Nov. 2, 11973 [57] ABSTRACT 7 Claims, 2 Drawing Figures [52] US. Cl 102/70 R [51] Int. Cl. 1F41Zc 15/28 [58] Field of Search 102/702 R, 70.2 A, 70 R;

[56] References Cited UNITED STATES PATENTS 1,318,954 10/1919 Barlow........... 102/70 R 2,129,875 9/1938 Rost 89/7 3,602,142 8/1971 Bigeon 102/702 R 39 I I 23 I PYROTECHNIC INITIATOR BACKGROUND OF THE INVENTION 1. Field of the Invention The subject matter of the present invention relates generally to Pyrotechnic Initiator and more particuiarly to a pyrotechnic initiator with an inherent out-of-line safe/arm feature.

2. Description of the Prior Art Pyrotechnic initiators used squibs and detonators with mechanical out of line devices that provided positive interruption of the pyrotechnic chain using a clock like mechanism.

SUMMARY OF THE INVENTION Briefly, the present invention is a pyrotechnic initia tor with an inherent out-of-line safe/arm feature. The initiator is comprised of a solenoid striker, a diaphragm located between a source of gas vapor and the striker, a secondary explosive, and an igniter. The solenoid punctures the diaphragm allowing the contents from the source of gas vapor to pass into an explosive chamher where a voltage from the igniter ignites the gas. The explosion caused thereby initiates the secondary explosive which produces the desired explosive output.

STATEMENT OF THE OBJECTS OF THE INVENTION A primary object of the present invention is to provide a pyrotechnic initiator with an inherent out-of-line safe/arm feature.

Another object of the present invention is to provide an initiator which requires two separate and unrelated initiation events to occur in sequence.

Another object of the present invention is to provide a pyrotechnic initiator which is extremely safe and reliable in its operation.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an isometric representation of the pyrotech' nic initiator; and

FIG. 2 is a cross-sectional view of the initiator of FIG. 1, parts being broken away for purposes of clarity.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. l and 2, pyrotechnic initiator 111 is generally comprised of the casing I3, secondary charge I5, explosive chamber 19, initiator 23, gas car tridge 25, diaphragm 27 and striker 29.

The casing 13 contains

bored cavities

3T, 33 and 35. Cavity 31 provides space for secondary explosive mate rial I7. Cavity 31 is larger to provide space for initiator 23. Cavity 35 provides a passage for striker mechanism 29 and also forms a chamber for the flowing gas emitted from cartridge 25 when blade 29a pierces dia phragm 27. Casing 13 includes a cavity 33 that interconnects explosive gas chamber 19 and cavity 35. Explosive chamber 19 connects onto chamber 39 forming end vent 21 which opens into the atmosphere or equivalent environments. Casing 13 also includes aperture 41 to accept diaphragm 27 and cartridge 25 respectively.

The secondary explosive charge 1'7 may be cyclotrimethylene trinitramine (RDX), pentaerythrital tetranitrate (PETN) or any secondary explosive. The secondary explosive can be eliminated or can be isolated using thru bulkhead transfer techniques well known in the art. The vent or vent hole 21 can be used to vent off the gas in case of leaks or for accidental actuation of the striker. Moreover, vent 211 can be used for pressure regulation. The vent hole 21 may be sealed off or eiiminated altogether to facilitate a hot gas generator operation or to maintain a permanent armed condition.

The initiator 23 can be a glow plug, a hot wire device or its equivalent. Moreover, any AC discharge device well known in the art may be: used to ignite the gas. Both voltage and current into the initiator 23 or any of the devices maintained above can easily be varied to meet any system safety requirements. The gas cartridge 25 is filled with any explosive gas which will fulfill the required function, and sealed by diaphragm 27. The gas cartridge 25 could use a valve rather than the diaphragm 27/striker 29 combination. The gas cartridge 25 can be designed, if desired, to eject either a gas, a vapor or a liquid.

The device It could incorporate a two bottle design or technique. This technique would utilize a mixture of gases or liquids which are each separated in their individual bottles and are combined through a common inlet valve before an explosion. occurs. The striker 29 may be of the solenoid type if desired. Accelerometers may be attached to control the output if desired. A rubber bladder filled with a liquid explosive may also be used. In this case the striker 29 would apply pressure to the bladder causing the liquid to flow into the chamber. This device would function similarly to a fountain pen.

In operation, blade 29a of solenoid striker 29 punctures diaphragm 27 of gas bottie or cartridge 25. This allows the explosive gas 6,, to pass from passage 37 into explosive chamber 19. A voltage is applied to initiator 23 which causes ignition of the explosive gas G The gas explosion initiates the secondary explosive I7 which produces the desired explosive output through the closure. Multiple arm disarm may be achieved by using a larger gas cartridge and valve combination. Any inadvertent leaks can be prevented by using valves, 0- rings or the like. The inherent out-of-line safety feature is attained by removal of the primary explosive (the gas) from the area between the glow plug and the sec ondary explosive. The initiator system allows two separate and unrelated events to occur in sequence to release a gas, activate an initiator in order to initiate an ordnance device. The general structure of initiator 111 or casing I3 may be of any shape or size as desired by one skilled in the art.

What is claimed is:

l. A pyrotechnic initiator comprising in combination:

a. at least one means for storing and containing an explosive gas;

b. at least one means for controlling the flow of the explosive gas;

c. a secondary explosive in contact with the flow of the explosive gas; and

d. a means for igniting said explosive gas and said secondary explosive.

2. The device recited in claim I wherein said means for storing said explosive gas is a gas cartridge.

3 4 3. The device recited in claim 1 wherein said means dary explosive and in operative relationship with said for controlling the flow of the explosive gas is a diaflowing gas and a pyrotechnic initiator in operative phragm located in the flow path of said storing gas contact with said chamber. means and a means for piercing said diaphragm. 6. The device recited in claim 5 wherein said means 4. The device recited in claim 3 wherein said piercing 5 for igniting said gas is a glow plug. means is a striker. 7. The device recited in claim 1 wherein the device 5. The device recited in claim 1 wherein said igniting further includes a means for venting said explosive gas. means comprises a chamber connecting to said secon-

Claims

1. A pyrotechnic initiator comprising in combination: a. at least one means for storing and containing an explosive gas; b. at least one means for controlling the flow of the explosive gas; c. a secondary explosive in contact with the flow of the explosive gas; and d. a means for igniting said explosive gas and said secondary explosive.

2. The device recited in claim 1 wherein said means for storing said explosive gas is a gas cartridge.

3. The device recited in claim 1 wherein said means for controlling the flow of the explosive gas is a diaphragm located in the flow path of said storing gas means and a means for piercing said diaphragm.

4. The device recited in claim 3 wherein said piercing means is a striker.

5. The device recited in claim 1 wherein said igniting means comprises a chamber connecting to said secondary explosive and in operative relationship with said flowing gas and a pyrotechnic initiator in operative contact with said chamber.

6. The device recited in claim 5 wherein said means for igniting said gas is a glow plug.

7. The device recited in claim 1 wherein the device further inclUdes a means for venting said explosive gas.