US3610151A

US3610151A - Nonelectric squib assembly

Info

Publication number: US3610151A
Application number: US823351A
Authority: US
Inventors: Rudolph E Nett
Original assignee: United States Department of the Army
Current assignee: United States Department of the Army
Priority date: 1969-05-09
Filing date: 1969-05-09
Publication date: 1971-10-05
Anticipated expiration: 1988-10-05

Abstract

A nonelectric squib assembly consisting of a squib body and a firing mechanism housing. The squib body includes a metallic seal separating a firing mechanism in the housing from a percussion primer in the squib body. The primary feature of the metallic seal is that it prevents missile motor pressure from producing a path for gases to flow back through the entire assembly. The metallic seal is dented by the firing mechanism to activate the primer thereby permitting primer gases to ignite a charge of boron-potassium nitrate carried in the squib body, which in turn is used to initiate the motor ignitor.

Description

United States Patent [7 2] Inventor Rudolph E. Nett Los Angeles, Calif. [21] Appl. No. 823,351 [22] Filed May 9, 1969 [45] Patented Oct. 5, 1971 [73] Assignee The United States of America as represented by the Secretary of the Army [54] NONELECTRIC SQUIB ASSEMBLY 1 Claim, 1 Drawing Fig. I [52] US. Cl 102/29 [51] Int. Cl. F42c 15/06 [50] Field of Search 102/27, 29, 45,497, 70, 86.5, DIG. 1

[56] References Cited UNITED STATES PATENTS 3,114,290 12/1963 Harvey et al 102/DlG. 1

3,129,663 4/1964 Schnepfe,.lr. 102/27 3,274,937 9/1966 Kyle l02/28X Primary Examiner-Verlin R. Pendegrass Attorneys-William G. Gapcynski, Lawrence A. Neureither,

Leonard Flank and Charles R. Carter ABSTRACT: A nonelectric squib assembly consisting of a squib body and a firing mechanism housing. The squib body includes a metallic seal separating a firing mechanism in the housing from a percussion primer in the squib body. The primary feature of the metallic seal is that it prevents missile motor pressure from producing a path for gases to flow back through the entire assembly. The metallic seal is dented by the firing mechanism to activate the primer thereby permitting primer gases to ignite a charge of boron-potassium nitrate carried in the squib body, which in turn is used to initiate the motor ignitor.

PATENTEU Gm 519?: 3,610,151

Rudolph E. Nefl INVENTOR NONELECTRIC SQUIB ASSEMBLY BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The present invention provides a solution to this problem by providing a nonelectric squib which offers less hazard to operating personnel and property than the electric squib yet performs all the functions required of an electric squib. This perfon'nance is accomplished by a metallic seal that prevents missile motor pressure from producing a path for gases of flow back through the entire assembly. The seal also allows the use of a small charge to drive a firing pin to dent the seal and thereby initiate the squib. Final arming is performed external to the missile and late in the countdown thus reducing exposure of personnel to hazard.

This invention may be better understood from the following detailed description taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE shown in the drawing is a sectional perspective view of the nonelectric squib.

PREFERRED EMBODIMENT OF THE INVENTION Reference numeral 1 indicates generally the nonelectric squib assembly. A firing mechanism housing 2 is shown in axial alignment with and attached at one end of a squib body and houses a small booster charge (not shown). The firing mechanism is secured to the squib body to complete final anning of the missile. A shear pin 3 holds a piston-type firing pin 4 until the booster charge forces pin 4 thus shearing pin 3 and allowing pin 4 to slidably move forward. The firing pin has an operating contact point 4: The squib body includes a first chamber 6 housing a percussion primer 7. A seal 8 is in a thin disc made of metal, such as copper,'and is attached in a position so that one side thereof is adjacent contact point 4 and the opposite side of the seal closes off one end of chamber 6.

This seal does not rupture when dented by contact point 4 and thus provides a hermetic seal for the squib body. The seal also prevents missile motor pressure from producing a path for gases to flow back through the entire assembly. An inner disc 9 is made of aluminum foil and located at the opposite end of chamber 6 separating this chamber from one end of a second chamber 10. The primer in chamber 6, when activated, will emit gases that will rupture disc 9 and thereby enter chamber 10 which contains an igniter charge such as boron-potassium nitrate (B-KNO identified by reference numeral II. A composite disc 12 at the opposite end of chamber 10 is a combination made up of a mica disc 13 and a mild steel disc I4. After the igniter charge is ignited, composite disc 12 ruptures to allow the output of the igniter charge to initiate the motor ignitor.

In operation a detonation wave is transmitted to the booster charge in the firing mechanism housing, the charge ignites and drives the firing pin forward shearing the shear pin. The contact point of the firing pin dents the metallic seal to activate the percussion primer. Alter the primer has been activated the primer gases rupture the inner disc and the gases are emitted into the chamber containing the igniter charge such as boronpotassium nitrate which in turn is ignited. The output of the igniter charge ruptures the composite disc and is then used to initiate the motor igniter.

I claim:

1. A nonelectric squib assembly for igniting a missile motor and for preventing gas flowback through the assembly comprising: a squib body having a firing mechanism housing at one end thereof, a first chamber and a second chamber; a filing pin mounted for slidable movement within said squib body, said firing pin having a contact point on one end thereof; a shear pin connected between said squib body and said firing pin to restrain movement of said firing pin until squib operation is started; a metallic seal disposed between said contact point and one end of said first chamber for hennetically sealing the firing pin from gases flowing back when the missile motor is ignited; a percussion primer disposed in said first chamber adjacent said metallic seal; a rupturable inner disc of aluminum foil separating said first chamber from said second chamber and sensitive to gaseous pressures from said primer; a missile motor igniter charge disposed in said second chamber; and a composite disc consisting of mica and mild steel discs at the opposite end of said second chamber for separation of said squib ignition from the missile motor, whereby missile motor pressure is prevented from producing a path for motor gases to flow back through the entire squib assembly.

Claims

1. A nonelectric squib assembly for igniting a missile motor and for preventing gas flowback through the assembly comprising: a squib body having a firing mechanism housing at one end thereof, a first chamber and a second chamber; a firing pin mounted for slidable movement within said squib body, said firing pin having a contact point on one end thereof; a shear pin connected between said squib body and said firing pin to restrain movement of said firing pin until squib operation is started; a metallic seal disposed between said contact point and one end of said first chamber for hermetically sealing the firing pin from gases flowing back when the missile motor is ignited; a percussion primer disposed in said first chamber adjacent said metallic seal; a rupturable inner disc of aluminum foil separating said first chamber from said second chamber and sensitive to gaseous pressures from said primer; a missile motor igniter charge disposed in said second chamber; and a composite disc consisting of mica and mild steel discs at the opposite end of said second chamber for separation of said squib ignition from the missile motor, whereby missile motor pressure is prevented from producing a path for motor gases to flow back through the entire squib assembly.