Pneumatic Separation Device

At present, all anti-armor missile systems carry the propulsion units (boost and flight motors) internally, i.e., inside the missile fuselage. When these motors have "burned out", i.e. provided all of their propulsive energy to the missile for acceleration downrange, they become parasitic weight and make no other contribution to the flight of the missile. Externally mounted propulsion units (boosters) which can be jettisoned after the transfer of their energy to the missile allow the remaining missile components to be packaged in a smaller, separate volume, thereby reducing the frontal area of the missile. Upon release of the boosters in a kinetic energy missile application, the drag on the missile that had been caused by the externally mounted boosters is eliminated. This enables the low-drag centerbody of the missile to maintain a high velocity for a much longer period of time than it would otherwise and thereby increase drastically its effectiveness.

The Pneumatic Separation Device allows the motors to be attached externally to the missile's fuselage from which, having accelerated the missile to a maximum attainable velocity, they can be detached and discarded, thus minimizing the drag on the missile and increasing its effective range. The detachment occurs when the inflated bellows completely ejects the motor thrust transfer strut, which is permanently attached to the booster, from the centerbody cavity where the strut had been inserted.

External attachment of the motors also removes the restriction on the motor size, since the motors no longer have to fit inside the missile fuselage, enabling the utilization of larger, faster and more efficient motors.

FIG. 1 shows an overview of the missile assembled with the boosters.

FIG. 2 is a diagram of a preferred embodiment of the Pneumatic Separation Device.

FIG. 3 shows retraction of the piston and an early stage of bellows inflation.

FIG. 4 illustrates a complete ejection of the motor thrust transfer strut from the cavity and closing of the hole in the missile body wall.

FIG. 5 shows the rotation ring assembly in relation to the missile and the boosters.

Referring now to the Figures wherein like numbers bespeak of like parts, FIG. 1 shows a side view of missile 101 and boosters 103 which are attached to the missile and give it power in takeoff and acceleration in flight.

FIG. 2 shows a cut-away diagram of a preferred embodiment of the Pneumatic Separation Device. All of the components of the device are affixed to missile 101 except motor thrust transfer strut 223 which is fixedly attached at one end to booster 103 and is detachably inserted at the other end into cavity 221 at a side of missile 101.

Chamber 201 holds therein high-pressure gas. Exit from the chamber is provided by spout 203 which is initially closed by valve 205. Valve 205 is coupled to pyrotechnic device 207, such as a squib, which is connected via conventional coupling means 209 to an onboard computer, not shown. At a predetermined time which coincides with the missile's maximum velocity, a firing voltage is delivered from the time circuit in the guidance and control portion of the computer via coupling means 209 to pyrotechnic device 207. The pyrotechnic device, in response to the voltage, ignites and opens the sealed valve 205, thereby releasing the high-pressure gas from chamber 201. Escaping through the open valve, the gas travels through gas transfer line 211 which is suitably coupled between the valve and reservoir 213 and enters reservoir 213.

Prior to the flight of the missile, motor thrust transfer strut 223 is inserted into cavity 221 to be detachably mounted on top of uninflated bellows 219, and is held in place by retractable piston 217 which is inserted into slot 225 at a side of the strut. Piston 217, in turn, is kept in slot 225 by spring 215 and is sealed by O-ring 227. Reservoir 213 is juxtaposed to piston 217 so that while the piston remains in slot 225, there is no continuous flow path through the reservoir to bellows 219. In essence, piston 217, while it remains in slot 225, divides reservoir 213 into two non-communicating compartments 213A and 213B. However, as gas, that flows through transfer line 211, enters compartment 213A, pressure mounts in the compartment and force is exerted at area 228 tending to dislodge piston 217 from slot 225. As the piston is thusly dislodged, orifice 229, located at a subcaliber section of the piston connects reservoir compartments 213A and 213B to create a continuous flow path to bellows 219. As piston 217 retracts from slot 225 and allows bellows 219 to inflate with the gas, it also frees motor thrust transfer strut 223 which is now no longer constrained in the plane orthogonal to the missile centerline, as shown in FIG. 3. In other words, strut 223 is now free to move in and out. The thrust of booster 103 against the walls of cavity 221 keeps the booster from moving in the orthogonal direction until bellows 219 is fully inflated with the gas. As bellows 219 is filled with gas, it produces a force sufficient to overcome the thrust-induced friction of the strut in the cavity, and moves the strut outwardly causing an angle of attack of the forward end of the booster to the airstream direction, as depicted in FIG. 4. Upon complete removal of strut 223 from cavity 221, a plate 231 covers hole 401 in the missile body wall. Plate 231 may be attached to the missile by any suitable means, such as a hinge mechanism.

A related separation device is disclosed in a co-pending application titled "Manifold Separation Device" Ser. No. 07/896,631, by David A. Gibson and Charles S. Cornelius. This application was filed simultaneously with applicants' application and is assigned to the U.S. Government as represented by the Department of the Army.

Although a particular embodiment and form of this invention has been illustrated, it is apparent that various modifications and embodiments of the invention may be made by those skilled in the art without departing from the scope and spirit of the foregoing disclosure.

One such modification is a rotating ring assembly 501 which is located at the aft of the boosters, as shown in FIG. 5, to help facilitate the separation of boosters 103 from missile 101 by rotating the boosters around the ring assembly after complete ejection of the struts from the cavities. The rotation ring assembly allows the rear of the boosters to pivot so that the nozzles of the boosters do not strike the missile as the missile flies through the ring.

Another modification is shaving corner 403 of strut 223 to give it a slanted shape so that as the strut is ejected from cavity 221 at an angle, the possibility of collision between corner 403 and missile 101 is reduced.

The above-described Pneumatic Separation Device may further be adapted for use in separating any initially joined bodies while moving in any medium.

Accordingly, the scope of the invention should be limited only by the claims appended hereto.