US 3903804 A
Description (OCR text may contain errors)
'ilnited States Patent Luttrell et al.
Sept. 9, 1975 ROCKET-PROPELLED CLUSTER WEAPON Primary Exam'inerVerlin R. Pendegrass Attorney, Agent, or FirmR. S. Sciascia; J. A. Cooke 57 ABSTRACT A warhead for an aerial missile containing a plurality of submissiles. The warhead is provided with an inertia responsive mass which in response to acceleration forces overcomes the forward urging of spring to maintain a pair of normally outwardly urged detents seated in the annular groove on a centrally disposed axial shaft thereby to maintain the slideable warhead nose forwardly urged to seal the warhead against admission of ram air pressure into the warhead cavity. Upon deceleration, the spring urges the inertia mass forwardly enabling the detents to unseat and the warhead nose to slide rearwardly thereby permitting admission of ram air pressure into the warhead cavity which affects rupture of the warhead fairing and release of the submissiles along an intercept path to the target.
12 Claims, 1 Drawing Figure PATENTEDSEP :915
John L. Luhrell William E. Preston William 8. Richardson INVENTORS.
MN Wm ATTORNEYS.
ROCKET-PROPELLED CLUSTER WEAPON 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.
The present invention relates to warheads and more particularly to a warhead for a rocket or missile containing a cluster of submissiles which are released from the warhead at the time of burnout of the rocket propellant for impact with the target.
It has long been the practice to employ multiparticle warheads for projectiles or rockets, the particles being formed by fragmentation of the warhead casing upon the detonation of an explosive charge within the warhead. Although such warheads work satisfactorily under most conditions, the full potential of the warhead is not utilized because the size of the particles produced by the fragmentation of the warhead is unpredictable and is at best difficult to control by scoring of the warhead casing. In the conventional warheads, the fragments from the warhead casing produced upon detonation of the explosive charge are usually projected in all directions in a random manner, thus producing the situation that the particular particles which hit the target may strike the target at a tangential angle and therefore do not inflict their full damage upon the target.
The general purpose of this invention is to provide a warhead for a rocket which embraces all of the advantages of similarly employed warheads and possesses none of the aforedescribed disadvantages. To attain this objective, the warhead of the present invention contains a cluster of submissiles having flight stabilizing fins thereon and being positioned within a warhead fairing which is caused to open upon the burnout of the rocket propellant whereby the rocket and fairing decelerate and permit the submissiles to continue their travel toward the target at hypervelocity speeds. Upon release from the fairing, the flight stabilized submissiles travel in an intercept path with the target along slightly diverging paths to produce a shotgun-like pattern to as sure impact with the target by one or more of the submissiles at an angle substantially normal to the target, thus enabling the submissile to inflict its maximum destructive capability.
It is an object of this invention to provide a simple and reliable yet highly effective weapon for projecting a plurality of inert projectiles at a target.
Another object of the invention is to provide a warhead for launching a cluster of projectiles along an intercept path with a target at hypervelocity speeds.
Another object of the invention is to provide a rocket warhead for releasing a cluster of projectiles in such a manner that each of the projectiles takes an intercept path with a target.
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:
The FIGURE shows a longitudinal view of the weapon with the warhead of the weapon shown in section.
Referring now to the drawing, there is shown a warhead adapted to be attached to the forward portion of a rocket 11 by any suitable means, the details of the rocket not being significant for the purposes of this invention since the warhead may be delivered by any one of a plurality of conventional rockets. The body of the warhead is defined by a substantially frusto-conical fairing 12 having an axial bore 13 extending therethrough to receive the nose element for triggering the cluster release system. The fairing is further provided with a counterbore 14 to define a chamber for receiving a cluster of inert submissiles 15. Each of the submissiles is formed from an inert high density material and is provided with an elongated configuration having a low aerodynamic drag and being provided with fins 16 on the tail portion thereof to stabilize the flight of the submissile during its travel toward the target upon release from the warhead. The submissiles are packed in annular cluster around an annular submissile support block 17 which is secured to a axial shaft 18 mounted upon a support base 19. The support base 19 is secured to the forward portion of a rocket motor casing 11 by any suitable means and has formed therein slots 21 to receive the tail fins 16 of the submissiles to hold the submissiles in their stacked array.
The warhead is so constructed as to release the cluster of submissiles 15 upon sensing the condition of deceleration caused by burnout of the rocket propellant. The interior of the warhead is provided with an enlarged inner diameter portion 22 to define a cavity to receive ramair pressure after the rocket propellant has been consumed. The warhead fairing is so constructed as to be torn apart by the entrance of ram air pressure into the cavity 22 in such a manner as to provide an uninterrupted path for the submissiles as the fairing and rocket motor further decelerate and the submissiles are permitted to continue on their path toward their target. To permit an easy and effective separation for removal of the fairing assembly, the fairing is constructed of a thin metallic skin and is packed with a lightweight rigid filler material to give it regidity and strength, the metallic skin of the fairing being provided with a plurality of grooves extending from the apex to the base of the frusto-conical fairing to provide weakened portions in the fairing skin. Upon entrance of the ram air pressure into the cavity 22, the ram air pressure acts upon the tapered cavity wall 24 to produce forces on the fairing in a radially outwardly direction, thus causing the fairing to tear along the weakened grooves formed in the fairing skin and consequently be removed from its obstructing position in the path of the submissiles. Entrance of ram air pressure into the cavity 22 is pre vented prior to propellant burnout by means of a cluster release assembly 23 which seals the entrance to the cavity and is withdrawn from its sealing position upon the deceleration of the warhead.
The cluster release assembly 23 has a cylindrical body portion having a diameter substantially equal to the inner diameter of the entrance to the apex of the frusto-conical fairing. The cluster release assembly is provided with a hemispherical end portion 25 which, when the cluster release assembly is in its sealing position, provides the fairing with a continuous smooth aerodynamic surface at the forward end thereof. The cluster release assembly is mounted upon a shaft 26 which is connected to the base 19 by the axial shaft 18. The cluster release assembly is adapted to be moved by ram air pressure acting upon the hemispherical surface 25 from its sealing position shown in the drawing to an open position rearwardly along shaft 26. The release assembly is locked in the position shown by means of a pair of spring fingers 27 having detents 28 integrally formed on the ends thereof, the detents 28 being received within an annular recess 29 formed in the shaft 26. The spring fingers 27 are resiliently baised outwardly out of locking engagement with the annular recess 29 but are held in the locked position by means of a peripheral engagement with a cylindrical inertial weight 31. The inertial Weight is mounted upon the shaft 26 for longitudinal sliding movement thereon and is resiliently baised in a forward direction for contact with a stop plate 32 by means of a helical compression spring 33 positioned within the cylindrical release assembly. The inertial weight is held in the position shown by means of a shear pin 34 positioned within and extending through complimentary apertures formed in the inertial weight and the shaft 26. When the cluster release assembly is in its sealing position shown in the FIGURE, an annular flange 35 mounted upon the release assembly 23 and spaced therefrom is in locking engagement with an inwardly directed reentrant flange 36 formed at the apex of the frusto-conical fairing.
In operation, the rocket l l is aimed at the target and ignited, the setback forces of acceleration act upon the inertial weight 31 to sever the shear pin 34 and permit the inertial weight to fully compress the helical spring 33. During the acceleration of the rocket throughout the burning time of the rocket propellant, the inertial weight holds the helical spring 33 in its fully compressed condition and continues to lock the detents 28 within the annular recess 29 to maintain the cluster release mechanism 23 in its locked sealing position. Upon the consumption of the rocket fuel, the rocket begins to decelerate, thus causing the inertial weight 31 to move forward under the force of deceleration and as assisted by the compression spring 33 so that the inertial weight reaches an abutting contact with the stop plate 32. When the inertial weight is in this position, the locking detents 28 on the spring fingers 27 are permitted to be urged radially outwardly out of engagement with the annular recess 29 in the shaft thereby freeing the cluster. release mechanism 23 for longitudinal movement along the shaft 26. The ram air pressure acting upon the hemispherical end portion 25 of the cluster release assembly forces the cluster release assembly 23 into abutment with annular wall 37 formed on the shaft 26. The cylindrical cluster release mechanism having been moved into contact with wall 37, the locking engagement of annular flanges 35 and 36 is uncoupled and the ram air pressure is permitted to enter the cavity 22. As the ram air pressure acts upon the tapered cavity wall 24, moments of force are developed perpendicular to the axis of the warhead to tear the fairing 12 along its weakened groove portions and remove the fairing from the warhead, thus further decelerating the rocket motor and warhead and permitting the cluster of submissles 15 to continue forwardly along an intercept path toward the target. The aerodynamic pressure acting upon the cluster of submissiles causes the submissiles to be deployed in a shotgun-like pattern while the fins 16 on the tail sections of the submissiles maintain the submissiles in a trajectory substantially identical to that of the trajectory of the warhead prior to burnout of the rocket propellant.
The warhead of this invention is adapted for use with any suitable rocket motor and it has been found that known rocket motors will accelerate the warhead through a velocity of 7,000 to 8,000 feet per second during the propellant burning time of approximately 1 second. By constructing the submissiles of a high density material such as tungsten or depleted uranium and by shaping the submissiles to have a length to diameter ratio of about 5 to l, the submissiles will continue on their intercept paths to the target at an initial velocity of about 8,000 feet per second upon release from the warhead and, due to their low aerodynamic drag, will have very high kinetic energy and momentum upon impact with the target. Upon striking a target, hypervelocity projectiles do not simply perforate the target, but fragment explosively, thus greatly amplifying the destructive effects of the projectiles. The launching rocket motor may be an unguided rocket, thus reducing the expense and eliminating the intricacies of the guidance control system, while the design of the warhead enables the submissiles to intercept the target at angles substantially normal to the target and also maximizes the kinetic energy and momentum of the submissiles to thereby provide a weapon having high destructive capability. When the weapon is used against ground personnel the warhead may be provided with a larger number of submissiles of smaller size than when the weapon is used against material or aerial targets. It is apparent therefore that the present invention provides an inexpensive weapon which is simple in construction and yet very reliable and having a high destructive capability.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
What is claimed is:
1. A missile warhead comprising a frusto-conical warhead fairing having an axial bore extending therethrough,
a base plate adapted to be mounted upon a missle and having the base of the frusto-conical fairing secured thereto, said plate closing one end of said axial bore,
a support shaft mounted upon said base plate and extending into said axial bore,
said fairing having a counterbore formed therein adjacent said base plate,
a plurality of submissiles positioned within said counterbore,
said fairing having an internal cavity formed therein adjacent the open end of said axial bore and being in fluid communication with said axial bore, the diameter of said cavity being greater than the diameter of said bore,
submissile release assembly slideably mounted upon said shaft for movement from a first position wherein said assembly prevents air flow into the cavity to a second position wherein said assembly permits air to fiow into said cavity, and means for locking said release assembly in said first position and for unlocking said release assembly in response to deceleration of the warhead for movement to said second position,
whereby ram air pressure about the warhead may enter the cavity upon deceleration of the warhead occurring at the termination of thrust by a warhead propelling motor to tear away the fairing and release the submissiles for a ballistic trajectory toward a target.
2. The warhead of claim 1 wherein said plurality of submissiles are packed in an annular cluster having an inner diameter greater than the diameter of said axial bore.
3. The warhead of claim 2 wherein said submissiles are constructed of an inert high density material.
4. The warhead of claim 3 wherein said submissiles have a pointed nose portion and an elongated body portion and have fins mounted thereon to stabilize the ballistic flight of the submissiles.
5. The warhead of claim 1 wherein said fairing is constructed of a material which, when subjected to ram air pressure within said cavity, will tear apart and open the fairing for release of the submissiles.
6. The warhead of claim 1 wherein said fairing comprises an annular body having spaced apart walls of thin metallic material,
a mass of lightweight filler material positioned within and filling the space between said walls.
7. The warhead of claim 6 wherein said walls have stress concentrating grooves formed therein and extending from the apex of the fairing to the base of the fairing.
8. The warhead of claim 1 wherein said submissile release assembly comprises a hollow cylindrical housing coaxially mounted upon said shaft for sliding movement thereon,
said cylindrical housing having a hemispherical end portion formed thereon,
whereby when said submissile release assembly is in said first position, the hemispherical end portion provides the fairing with a smooth aerodynamic surface.
9. The warhead of claim 8 further comprising a re-entrant annular flange formed on said fairing adjacent said axial bore at the apex end of said fairing, and
an annular flange formed on the outer peripheral surface of said housing and releasably interlocking said re-entrant flange when said housing is in said first position.
10. The warhead of claim 8 wherein said means for locking said submissile release assembly comprises an annular inertial weight coaxially mounted upon said shaft and being positioned within said cylindrical housing,
a spring for resiliently biasing said weight toward the apex of said fairing,
at least one locking detect mounted upon said housing for locking engagement with a groove formed in said shaft,
a shear pin for releasably holding said weight in a locking position wherein said detents are engaged by said weight and held in locking engagement with the groove in said shaft,
whereby acceleration of the warhead by a propelling motor will sever the shear pin to permit the resilient biasing spring to move the weight toward the apex of the fairing after termination of thrust by the propelling motor, thus permitting the detent to be disengaged from the groove in said shaft to free said housing for movement along the shaft and thereby permit ram air pressure to enter said cavity and remove said fairing and release submissiles.
11. A missile warhead comprising a tapered fairing having an opening at its apex and an internal cavity formed therein a plurality of submissiles positioned within said cavan elongate shaft axially secured within said fairing and having a groove formed therein,
an assembly slideably mounted on said shaft and having an end portion of substantially the same size as said fairing opening and at least one resiliently urged detent,
an inertia mass slideably mounted on said shaft,
resilient means normally urging said mass in a forwardly direction,
said mass moving rearwardly on said shaft in response to acceleration forces to effect seating of said detent in said groove for securing said end portion in sealing engagement with said opening thereby preventing admission of ram air pressure into said cavity, said mass being urged forwardly by said resilient means in response to deceleration forces to effect unseating of said detent and release of said assembly for rearward movement thereby unsecuring said end portion from sealing engagement with said opening and enabling admission of ram air pressure into said cavity for rupturing of said fairing and release of said submissiles.
12. A missile warhead according to claim 11 and including means for maintaining said inertia mass in an initial position on said shaft and for affecting release of said mass for movement in response to a shearing force. l