US2900906A - Self-destruction device - Google Patents

Description

Aug. 25, 1959 c. R. OLSEN SELF-DESTRUCTION DEVICE Fild June so. 1955 INVENTOR. CHARLES R. OLSEN ATTORNEYS Patented Aug. 25, 1959 SELF-DESTRUCTION DEVICE Charles R. Olsen, China Lake, Calif., assignor to the United States of America as represented by the Secretary of the Navy Application June 30, 1955, Serial No. 519,291

11 Claims. (Cl. 102-49) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein 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.

This invention relates to means for causing self-destruction of rockets or other projectiles and more specifically to new and improved combined percussion and self-destruction fuze means to insure the self-destruction of warheads of projectiles after they have traveled a predetermined time without having first been exploded by contact with a target.

Self-destruction is considered as an essential functional characteristic of many types of projectiles. Particularly in air-to-air or ground-to-air firing of projectiles it is important that self-destruction be incorporated in such missiles so that if the target is missed, other objects beyond the target and on the ground below will not be endangered. This is, of course, most particularly true of missiles having percussion or impact fuzes, since after arming, such missiles would not explode until some object were struck. In attacks on enemy aircraft over friendly territory, the absence of selfdestruction means could cause great damage to friendly personnel and property.

In view of the obvious necessity for such devices, there have been numerous types of combined percussion and self-destruction fuzes developed in the past. In general, the self-destruction function has been combined with the percussion fuze function by the utilization of dual clockwork systems or by the inclusion of self-destructive fuzes sensitive to decrease of angular velocity or rotation to which the shell is subjected while following its trajectory.

The angular velocity sensitive types respond to relatively high rates of rotation, utilizing centrifugal force developed on firing and the continuing decrease thereof during flight to control operation of self-destruction fuze means. Such types were particularly developed for anti-aircraft projectiles intended to be fired from guns and subject to comparatively high rates of rotation or spin in flight and are thus not reliably operative in applications involving slower spin rates, as in certain types of rockets.

Dual clockwork systems are subject to the disadvantages of complexity in structure with consequent relatively high cost and of being sensitive to setback forces due to firing and to injury in rough handling.

It has been common in all such previous self-destructor arrangements to incorporate the self-destruction secondary fuze directly Within the primary fuze structure, resulting in either greater difiiculty of design (since the allowable space in nose fuzes is limited) or in enlargement of the nose fuze. Moreover, such incorporation necessitates the development of an entirely new fuze combination not usable except in the self-destruction usage.

I have discovered that it is possible to initiate a shock wave at one end of a Warhead which can travel through the body of the war head and be utilized to cause firing in an armed fuze at the other end of the warhead, if said fuze is of the shock sensitive type, as for example a fuze utilizing a piezoelectric element in the firing mechanism. By virtue of this discovery, it is possible to utilize known fuze structures without redesign and increased complication of structure and cost of manufacture and to evolve systems of self-destruction not dependent upon high rates of spin or on fragile dual clockwork systems. Thus, according to my invention, incorporation of a shock-wave initiating means designated a self-destructor package, in the base of a warhead and the provision of a suitable time delay therefor can be effective to initiate a shock wave to cause self-destruction after arming of the fuze and the lapse of a given period without impact to cause firing of the fuze in the normal manner.

It is, therefore, an object of this invention to provide new and improved self-destruction means for projectiles.

It is a further object of this invention to provide improved self-destruction means for projectiles having warheads provided with impact fuzes, said self-destruction means not requiring direct incorporation into said fuzes so that existing fuze models of certain types can be used without alteration.

It is a still further object of my invention to provide improved self-destruction means not dependent upon rate of spin or changes thereof for performance of the selfdestruction function.

Another object of my invention is to provide new and improved self-destruction means which are operated by the initiation of a shock-wave in one portion of a warhead to cause firing of an impact fuze mounted in another portion of the warhead if such fuze is not detonated by contact of the projectile with an object.

Still another object of my invention is to provide new and improved self-destruction devices for warheads which are characterized by being simpler and less costly in construction, and by being more reliable and of greater scope of application than prior known self-destruction devices.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

Fig. 1 is an elevational view of a projectile in the form of a rocket illustrating the positioning thereon of a warhead incorporating my invention;

Fig. 2 is a sectional view of an impact fuze which may be used as an element of my improved self-destruction combination, and which is mounted in the nose of the warhead of the projectile as shown in Fig. 1;

Fig. 3 is a fragmentary elevational view, partially in section showing my novel self-destruction package assembled at the rear end of a warhead at the point of juncture of the warhead with a rocket motor tube, representing that portion of the rocket between the arrows 33 of Fig. 1.

Referring now to Fig. 1, there is illustrated one application in which this invention may be embodied; namely, a gas propelled rocket comprising the conventional arrangement of a motor tube M, to the forward end of which the war head W is suitably attached, said Warhead containing explosives and constituting the pay load of the rocket. A fuze F is attached to the forward end of the warhead and is provided with instrumentalities for arming the warhead and exploding it upon contact with an object. The ignition means for such rockets usually comprises an electrical conductor suitably connected to- 3 r the rocket igniting means and insulated from the body of the rocket. In the exemplary embodiment here illustrated, such ignition means comprises a band I suitably secured in an external channel of a collar or coupling member positioned between the motor section M and the warhead W "and serving to. hold said motor section and warhead in assembled relation to one another. The rocket is, of course, provided with a stabilizing tail-fin assembly T.

The fuze F is shown in detail in Fig. 2. As previously mentioned, my self-destructor package may be used with any shock sensitive fuze. Accordingly, the details of the fuze are not the subject matter of this invention and are not to be construed as limiting, since they are specifically disclosed and described only to allow fullerunderstanding of the invention. Fuze F, as shown, comprises the usual internally chambered metallicbody member 10,

screw-threaded at its rear end, as at '12 for attachment to a warhead. In a forward compartment or chamber 14 of body member 10, are housed a piston or hammer member 28 bearing upon a piezoelectric crystal 26 which is supported upon the flat back surface of a brush-holder and brush assembly 22. An insulating bushing 20 extends through a restricted bore connecting the chamber 1 4 to an adjoining rotor chamber 16 and insulates the piezoelectric crystal and the brush-holder from the metal walls of body 10, the wires constituting brush 24- extending into rotor chamber 16 for electrical contact with instrumentalities therein, as shown. A cap member 30 encloses the forward protruding end of piston member 28 and islightly soldered to body member =10, as at 32 to hold piston member 22 against relative movement in handling. Responsive to the application of a substantial impact upon the cap member the solder may be broken to permit the piston to be driven against the piezoelectric crystal 26, to generate voltage in the crystal.

Rotor chamber 16 includes means, not shown, for rotatably supporting an arming rotor 34. The arming means of the fuze may be of any type, but the means. herein disclosed for purposes of illustration is of' the type which is so weighted that it is compelled to rotate by acceleration of the rocket. The specific nature'of such a rotor is not a part of this invention, one form thereof being described in the application of Winifred F. Sapp, Serial Number 342,039, filed March 12, 1953.

Arming rotor 34 is provided with a plurality of radial pockets for retaining the elements of a fuze delay train;

comprising an electric primer element 36 and delay and detonating. means 38, as illustrated. The position of rotor 34 shown in Fig. 2 is, of course, the unarmed position. Rotation of the rotor in response to acceleration upon firing of the missile results in movement of the radial pockets to a position in, which the electrical contact point of primer 36 may be touched by the wires of brush 24. Booster chamber 18 which is in communica-; tion with chamber '16, as shown, is internally threaded.

electric primer element is in contact with brush 24. If'

the projectile, after such arming, contacts a target the impact drives piston 28 .rearwardly (after shearing solder 32 holding piston cap 30 fixed to body to generate a voltage in piezoelectric crystal 26 which causesran electric current to be transmitted toelectric primer "36 to.

cause: ignition thereof with resulting ignition of; the delay and detonator train 38, igniter 46 booster charge 44. Ignition of charge 44bursts cup 42 and'setsoflt' the m n. ha g 48 in he rhea In Fig. 3, there is shown the general assembly of one known type of rocket at the point of connection of the motor tube M to the warhead W. A generally annular collar member 50 is fixedly attached telescopically within motor tube M and is screw-threaded internally, as at 52 for assembly with the closed rear end of the warhead W. Collar member 50 has a radially outwardly extending portion 54 extending to the outer periphery of the rocket and separating the warhead W from the motor tube M. The outwardly extending portion 54 is provided with an annular groove in which are positioned insulating material 56 and -a conductor or contact band 58, the later being insulated from metallic rocket body surfaces by the former. An insulated lead wire 60, electrically connected to contact band '58, extends to the interior of the collar member 50 for electrical connection to rocket ignition initiating means and -selfdestruction means to be subsequently described.

Annular collar member 50 is provided internally with a chamber at its rearward end for housing the usual propellent grain igniter assembly 62 which comprises a main igniting powder charge, as shown and a squib 63, electrically connected to a post 64 and to a suitable ground. The igniter assembly 62 is retained in positionby a cap member 65 bearing against the inner wall of collar 50 and against the rearward edge of the warhead W and having a central opening therein through which post 64 extends for attachment to electrical lead wire 60. Collar member 50 is also provided with means to externally support a sealing ring and with an internal groove to support a wire 66 which supports a rod of ballistic modifier material in proper proximity and position to the propellent grain G of the rocket, as shown,

, what forwardly of the rear end of the warhead body to mer element 69 as shown. The side walls of the compartment are provided with inwardly projecting means,

as for example, projections 77 to cooperate with crimp 71' and spring 75 to hold container 69 in position. (310 sure member 71 has a central thin-Walled depressed por tion in which is housed an electrically operable delay squib 72 of old and well known variety which is capable of interposing a substantially predictable given delay period between the time of excitation. and the performance of an igniting function. Squib 72 is retained in position in the said depressed portion by a membrane 73 secured to the closure member 71 by a pair of rivets 74, 74'. Rivet '7-4 is insulated from closure member 71, and senves also to support a leaf spring electric contact 75 in position'to maintain electrical contact with post 64. Each rivet serves as a connecting post and has connected thereto one of a pair of electrical lead wires 76 connected to delay squib 72 and extending through seal 73, to complete a circuit from post 64 and successively through, leaf spring 75, the insulated rivet 74 to which the leaf spring is connected, the squib wire connected to the other rivet 74', and thence to electrical ground. Thus, upon the existence of a current producing voltage in propellent grain initiating circuit 58, 60, 64, 63,;curear l als fl thmus l ments. 75 and; 7 4 andfthe initiating (primer) portion of delay squib 72 so that, after a substantially predetermined delay, squib 72 will explode, rupture the wall of the depressed portion of the lid or closure 71, and ignite the propellent material 70. The burning of said material 70, causes rapid formation of gases to cause the hammer element to sever its connection with the closure 71, force its way past the projections 77 and strike a hammer blow against wall 67 of the warhead. This initiates a shock wave in the explosive material in the warhead which is effective to cause shock responsive means in the nose fuze (a piezo electric crystal in the illustrated example) to generate a voltage which, if the fuze F is armed, is effective to excite the electrical primer in the fuze to explode the warhead as previously described.

While the foregoing detailed description is considered adequate to describe the operation of my invention, there is here included a further short rsum of the operation of the novel combination disclosed. In the firing of the rocket, the application of an electrical potential to band 58, causes current to flow through lead 60 to post 64 and thence to squib 63 to set off igniter 62 which causes ignition of propellent grain G to form propulsive gases causing the rocket to accelerate. Simultaneously, current flows from post 64 through leaf spring conductor 75, and electrical connection (rivet) 74 and through delay squib 72 to ground to initiate burning of said squib 72 and to start the predetermined period leading to the eventual burning of propellent grain 7 0.

Acceleration of the rocket results in rotation of rotor 34 to a position in which the fuze train, comprising primer 36 and detonator 38, is aligned with and contacted by brush 24. The missile is now armed, and if it strikes a target, piston 28 is driven rearwardly against piezoelectric crystal 26 producing a voltage which causes successive ignition of electric primer 36, detonator 38, igniter 46 and booster 44 to cause ignition of the main explosive charge 48 of warhead W.

If no target is struck after a predetermined period of time (5 sec., for example), which delay is determined by the nature of delay squib 72, the warhead is exploded by my self-destructor means as follows, it being remembered that at this stage the fuze is armed as described in the preceding paragraph. This main explosion is brought about by the explosion of squib 72 after the predetermined period with resultant burning through the wall of the depressed portion of closure 71 in which squib 72 is housed to ignite the gas generating material 70. The burning of this material generates gases which cause the hammer element 69 to strike a hammer blow against the wall 67 of warhead W starting a shock wave which travels through the wall of the warhead to the piezoelectric crystal 26 causing compression thereof. The voltage generated causes activation of electric primer 36 in the armed fuze and explosion of the explosive material in the warhead exactly as previously described in the case of impact firing.

From the foregoing, it should be apparent that I have created new and useful improvements in self-destruction devices for warheads, such improvements being predicated on an entirely new theory of operation, viz., the use of pyrotechnic delay means to ignite explosive means to initiate a shock wave at a point remote from a primary impact or percussion fuze arrangement to cause explosion of the warhead if the primary fuze is not fired by impact. The attendant advantages of self-destruction without overcomplication of nose-fuze constructions and without dependency upon projectile spin or dual clockwork arrangements should be obvious.

The nose-fuze destructor package combination described herein is not intended to be limited to the specific nosefuze or specific destructor package disclosed in the illustrative embodiment described in this specification. Any shock sensitive fuze arrangement could be substituted for the particular one disclosed. Similarly, the destructor package portion of the combination may comprise any means for first interposing a predetermined delay and then initiating a shock wave at a point in the missile remote from the fuze means. I consider my invention in its broadest sense, to be in the combination of the instrumentalities rather than in the details thereof, since many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that the scope of the invention is to be limited only by the scope of the claims in the light of such teachings and not by the particular illustrative example disclosed.

What is claimed is:

1. In a missile including a casing carrying an explosive charge, a fuze, a mechanism for arming said fuze, and means operative after arming of the fuze by said mechanism to initiate detonation of the charge upon the application of a shock force to said means as by impact of the missile with a target, the improvements comprising a device carried by the missile adapted to produce in the said casing a shock wave of suflicient intensity to travel through said casing to cause operation of the first mentioned means whereby to cause detonation of the explosive charge, and delay means for effecting operation of said device a predetermined period of time after firing of the missile whereby to effect self-destruction of the missile should impact of the latter with a target not occur within the predetermined period of time.

2. A warhead for projectiles comprising a casing adapted to be filled with an explosive charge, shock sensitive fuze means mounted in the nose of said casing and including means for arming said fuze means upon firing of said projectile, means to detonate said charge upon the application of a shock force to said fuze means as by impact of the projectile with an object, and self-destruction means mounted in another portion of said casing, said self-destruction means comprising means to produce in the casing a shock wave adapted to travel therethrough to operate said fuze means after arming to cause detonation of said explosive charge if no object is struck in a predetermined time.

3. A warhead according to claim 2, wherein said fuze means comprises a housing, an acceleration operated arming means mounted for movement in said housing, an electrically responsive detonating means carried by said arming means, a piezoelectric crystal mounted in said housing and provided with electrical conducting means operable to contact said detonating means when said arming means is in an armed position, and a piston in the forward end of said housing mounted for longitudinal movement in response to impact of the Warhead with an object and operable to strike said crystal to generate a voltage to cause operation of said electrically responsive detonating means if said arming means has moved to the armed position, said piezoelectric crystal being also operable to generate such a voltage due to the shock Wave produced upon operation of said self-destruction means if no such impact with an object occurs.

4. A warhead according to claim 2, wherein said selfdestruction means comprises a container, a gas generating charge in said container, a delay squib mounted on said container and adapted, after a predetermined delay, to explode and ignite said gas generating charge to cause said container to break apart, a portion thereof striking said casing a hammer blow to produce said shock wave.

5. A warhead according to claim 4 further including a means for projecting said projectile, igniting means for said delay squib, and means interconnecting said last two mentioned means whereby operation of said projecting means causes simultaneous igniting of said delay squib to initiate the said predetermined delay period.

6. A gas propelled rocket comprising a motor section including propulsive gas generating means, a warhead attached to the forward end of said motor section to be propelled therewith, said warhead comprising a casing adapted to be filled with an explosive charge, shock sensi tive; fu-Ze means mounted on the forward portion of said casing, said fuze means including means to arm the film means upon firing of said rocket and to detonate said charge upon the application of a shock force to said fuze means as by impact of the missile with an object and self-destruction means mounted in another portion of said Warhead casing, said self-destruction means comprising means to produce in the casing a shock wave adapted to travel through the casing to operate said fuze means to cause detonation of said explosive charge if no object is struck in a predetermined time.

7. A Warhead according to claim 6, wherein said selfdestruction means comprises a container, a gas generating charge in said container, a delay squib mounted on said container and adapted, after a predetermined delay, to

explode and ignite said gas generating charge to cause.

said container to break apart, a portion thereof striking said casing a hammer blow to produce Said shock wave.

8. A rocket according to claim 7 having electrically operated means to initiate said propulsive gas generating means to. fire said rocket, means to ignite said delay squib, and means interconnecting said two last mentioned means whereby firing. of the rocket is effective to simultaneously ignite said delay squib to initiate the said predetermined delay period.

9. A Warhead for projectiles comprising a hollow cas ment to a projectile, means for attachment offuze means at the. forward end of said casing, an internal lateral wall at the rearward portion of. said casing defining the rear.

. o 8 wall of a compartment for holding an explosive charge, the side walls of said casing extending rearwardly of said lateral, wall to define a chamber, a shock sensitive accel'era-tion armed fuzemeans attached to said forward end of said casing, means for arming said fuze means, shock sensitive fuze initiating means and sel'f destruction means mounted in said chamber, said self-destruction means including means to initiate a shock Wave in said lateral wall a predetermined period after firing of said projectile, whereby said shock Wave may travel through said casing to operate said shock sensitive fuze'means to explode an explosive charge in said compartment.

10. A Warhead according to claim 9, wherein said selfdestructing means comprises a container, a gas generating charge in said container, a delay squib mounted on said container and adapted, after a predetermined delay, to explode and ignite said gas generating charge to cause said container to break apart, a portion thereof striking said casing a hammer blow to produce said shock wave.

11-. A warhead according to claim 10 further including means for projecting said projectile, igniting means for said delay squib, and means interconnecting said two last mentioned means whereby the operation of said pro jecting means. causes simultaneous igniting of said delay squib to initiate the said predetermined delay period.

References Cited in the file of'tliis patent UNITED STATES PATENTS Zo-rnig Sept. 28, 1937 2,531,121 Nov. 21,1950

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