Bomblet Fuze System

Abstract

A bomblet fuze arming device for use inside a bomblet which is dispensed m a container by a remote means; the device utilizes gas or air pressure to compress an enclosed cavity of air which in turn unlocks a stab-detonator holder and during release from the bomb dispenser performs the arming function by use of a reaction turbine, which locks at the end of the arming function.

Description

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The purpose of the bomblet fuze of this invention is to provide a means of arming a fuze inside a bomblet dispensed by a remote means. The only known method of arming this type fuze is by providing angular velocity to the bomblet and arm by centrifugal force principle. This prior method is unsatisfactory because the bomblet could be armed by spinning by other methods easily. The present invention requires an airtight dispenser containing bomblets of explosive with this fuze system. This bomblet fuze system provides a means of aligning the explosive train inside a dispenser by air pressure without wires, lanyards, tubes or other attachments. The container is pressurized and in turn pressurizes an enclosed cavity of air in the bomblet. This unlocks the stab detonator holder and during dispensing the fuze from the container a simple reduction turbine rotates the detonator holder to the armed position. At completion of the arming cycle the detonator holder locks when zero differential pressure is attained across the reduction turbine. Each bomblet fuze will, upon impact, detonate the bomblet explosive. The prior art pressure activated devices are complicated and expensive and none function the same as the present invention.

Many of the attendant advantages of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a cross-sectional view of a bomblet illustrating an embodiment of the arming device of the present invention.

FIG. 2A is a view of the bomblet taken along line 2--2 of FIG. 1.

FIG. 2B is a partial cross-sectional view showing the stab-detonator in line with the booster change.

FIG. 3 shows a plurality of bomblets in a container-dispenser suspended from an aircraft.

FIGS. 4, 5, 6 and 7 illustrate the arming device during four phases from safe position to fully armed position.

DESCRIPTION OF INVENTION

Referring to the drawings, like numerals refer to like parts in each of the figures.

The bomblet 10 consists of a spherical pragmentation casing 11, for example, containing the main explosive 12. The casing 11 can be scored, etc., in any suitable manner for desired fragmentation upon detonation of explosive 12. Within the bomblet, surrounded by explosive 12, is the arming and firing mechanism 14. This mechanism consists of a rotatable cylinder 16 supported on pivots 17 and 18 in the walls 19 of arming and firing mechanism 14, as shown in FIGS. 1 and 2.

Rotatable cylinder 16 has a stab-detonator 21 as well as an elastomer or bellows chamber 23 mounted therein. Bellows 23 has a simple check-valve-type nozzle 25 thereon which allows only an outward fluid flow from the bellows when the pressure outside is less than that inside the bellows. A lock tab 27 is carried on the end of bellows 23.

Tab 27 initially fits into a cavity 28 in wall 19 retaining the device in a safe position. When bellows 23 is compressed and cylinder 16 rotated by 90.degree. to arm position, tab 27 can lock into cavity 29 as shown in FIG. 7, when the bellows is allowed to expand.

A booster explosive 30 in a wall 19, as shown in FIGS. 2A and 2B, is operable to be detonated by stab-detonator 21 when in the arm position shown in FIGS. 2B and 7. At least one air passage 32 is provided through wall 19, explosive 12 and casing 11 to the exterior of the bomblet 10.

An airtight dispenser-container 34 is loaded with safe-positioned bomblets 10, as shown in FIG. 3, and carried by an aircraft 35 which can supply, for example, 100 p.s.i. for bomblet fuze arming. Container 34 is capable of dispensing the bomblets. Also, container-dispenser 34 may be a warhead canister which is a portion of a missile system.

The operation of the bomblet fuze system described herein can best be described by the four positions, or phases, as illustrated by FIGS. 4, 5, 6 and 7.

In the Phase I position of FIG. 3 the fuze is safe and locked such as during handling, captivation in dispenser 34 and prior to pressurizing the dispenser. In this condition bellows 23 is in a balanced condition, with the pressure inside and outside being the same. Tab 27 locks in cavity 28 keeping stab-detonator 21 out of line with booster 30.

Prior to launching the bomblets, Phase II shown in FIG. 4, pressure of 100 p.s.i., for example, is applied to the bomblets in dispenser 34. Pressure can be applied from the aircraft or any suitable gas pressure means within the dispenser. The gas pressure via passage 32 in the bomblet causes bellows 23 to be compressed disengaging lock tab 27 from cavity 28. Check valve 25 prevents gas pressure from entering bellows 23. Dispenser-container 34 is then launched from the aircraft and when a safe separation distance from the aircraft the container opens to dispense the bomblets. Where the pressurizing means for compressing bellows 23 is within dispenser 34, the pressurizing can be delayed until the dispenser is a safe separation distance from the launching aircraft.

After tab 27 is unlocked from cavity 28 and at the time the bomblets are dispersed from container 34, the sudden drop in pressure outside the bomblets results in the pressure inside bellows 23 to be higher than outside. At this instant of sudden reversal of differential pressure, compressed gas within bellows 23 exits through reaction nozzle 25 at a greater rate than the bellows expands, causing angular displacement of cylinder 16 toward the armed position, which is now Phase III as shown in FIG. 6. The fuze arms as a result of the pressure drop from 100 p.s.i. to pressure at 15,000 feet altitude, for example, which is 8.3 p.s.i. The space between cylinder 16 and wall 19 gradually widens at 26 from cavity 28 to cavity 29 to allow clearance for locking tab 27 as bellows 23 expands due to decrease in outside pressure.

In Phase IV, FIG. 7, prior to target impact cylinder 16 has rotated 90.degree. into arm position and bellows 23 has expanded extending tab 27 to engage in cavity 29 locking the fuze in the armed position. Static conditions plus the differential pressure between the inside and outside of the bellows provides the necessary condition to arm and lock the fuze ready for impact.

Stab-detonator 21 fires upon target impact detonating booster 30 which in turn detonates main explosive 12.

Claims

What is claimed is:

1. A bomblet fuze safety and arming system comprising:

a. a fragmentation casing,

b. a primary explosive within said casing for fragmenting said casing upon detonation thereof,

c. an arming and firing means within and surrounded by said primary explosive, and consisting of a housing having an explosive booster means in a wall thereof adjacent said primary explosive, and a gas pressure operated locking and rotating means carrying a detonator means rotatably mounted within said housing,

d. a passage extending from the inside of said housing to the exterior of said fragmentation casing through which a gas pressure is applied for actuating said arming and firing means,

e. initially said locking and rotating means being locked in a safe position with said detonator means out-of-line with said explosive booster means,

f. application of gas pressure via said passage being operable to unlock said locking and rotating means,

g. release of said gas pressure which was applied for unlocking said locking and rotating means causing said locking and rotating means to rotate to the armed position with said detonator in line with and adjacent to said explosive booster, said locking and rotating means locking into armed position upon complete removal of said applied gas pressure,

h. said detonator firing upon impact of said bomblet thus initiating said booster and in turn detonating said primary explosive when in armed position.

2. A bomblet fuze as in claim 1 wherein said gas pressure operated locking and rotating means comprises:

a. a compressible gas chamber having a check-valve nozzle thereon which allows gas to flow out only when the pressure inside the chamber is greater than pressure outside and does not allow gas to flow into the chamber,

b. said gas chamber and thus the atmospheric gas therein being operable to be substantially compressed by application of suitable gas pressure via said passage,

c. release of said applied gas pressure causing a differential of gas pressures within and without said chamber whereby gas will flow out through said check-valve nozzle faster than said compressed chamber can expand forming a reaction jet which rotates said locking and rotating to the armed position.

3. A bomblet fuze as in claim 2 wherein said compressible gas chamber is formed of compressible elastomer material.

4. A bomblet fuze as in claim 2 wherein said compressible gas chamber is in the form of a compressible bellows.

5. A bomblet fuze as in claim 2 wherein:

a. said compressible chamber has a locking tab thereon which is operable to lockingly engage into either of two differently positioned cavities in the wall of said housing, one said cavity being at safe position and the other being at armed position,

b. compression of said chamber releasing said tab from the armed position cavity and release of said applied gas pressure allowing said tab to lock into the armed position cavity after said locking and rotating means has been rotated to the armed position.