Mechanical stabilizer

Abstract

1. In a munition having a body and a rear base, said rear base having a fr and an outer flange defining a recess, The improvement comprising, in combination therewith, a rear stabilizer for controlling the trajectory of said munition, said rear stabilizer comprising a helical coil spring having convolutions of gradually increasing widths, said spring being attached at its innermost convolution directly to the center region of said floor of said recess, and a collapsible frustoconical covering for said spring extending from the innermost to the outermost convolution of said spring, Said spring and covering being normally confined in compressed and collapsed condition in said recess and having the portion of the covering which surrounds the outermost convolution of said spring in engagement with the flange of said recess, and said covering forming in the released position of said spring an empty hollow elongated inverted frustoconical stabilizing surface at the rear of said munition; Whereby when said munition is launched, said spring will extend itself outwardly upon centrifugal forces generated by in-flight movements of said munition.

Description

This invention relates to an apparatus for use in an air-to-ground missile delivery system. More particular, this invention relates to an apparatus for selectively controlling the orientation of a gravitating airborne missile.

One of the conventional methods of delivering a disbursed pattern of missiles to a specified target is from a gravitating airborne carrier which is usually launched by means of artillery or from a fast moving aircraft. As the carrier reaches a predetermined point in its trajectory, a mass of missiles are deployed in somewhat of a dispersed pattern in the air. However, as the missiles gravitate towards the ground, some will oscillate, tumble or will become otherwise disoriented in their flight. This becomes a problem in the case of a missile activated by an impact functioning fuze. These missiles must be properly oriented or the detonators thereof will not be activated upon impact with the ground.

In the past, the orientation means for such missiles consisted in metal vanes, extended lengths of ribbon or merely the specially designed outer configuration of the missile itself. These devices function to orient the missile upon ejection from the carrier. However, in the case of mechanically operated vanes, there is a varied time differential between the ejection of the missile and the instant that the device reaches the fully operative state. As is apparent, this factor not only affects the trajectory of the missile but also varies the ultimate location of the impact area. Also, the point of deployment of the missiles must be of sufficient height to insure successful operation of these devices prior to impact. It is also found that these devices are complicated and, in many instances, defective or become defective in operation due to damage sustained in the collision of the missiles immediately after deployment. These devices are also comparatively heavy, difficult to manufacture and expensive. As a result, the destruct capabilities of the pay-load are adversely affected due to the restricted weight-carrying capacity of the conventional carriers.

As for the extended ribbon type devices, they are somewhat simple to manufacture and light in weight. However, they have a tendency to tangle or otherwise become disarranged in shape and knotted during operation. They are also unreliable in heavy winds or under other adverse weather conditions such as rain or snow. Also, in the case of a missile with a specially designed configuration having aerodynamic attributes, the device is usually difficult to manufacture and quite expensive which limits its use in wide spread field operations where exceedingly large quantities of missiles are utilized in every day activities.

The subject invention fulfills the needs of the art, as described above, by being effective at low elevations, inexpensive, light in weight, simpler in construction and use, and totally reliable under adverse conditions.

It is an object of this invention to provide an apparatus of improved construction for use in an air-to-ground missile delivery system.

Another object is to provide an improved apparatus for use in controlling the orientation, stabilization, deceleration, and trajectory of a gravitating airborne missile.

A further object is to provide an apparatus for use in selective orientation of an airborne missile.

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

FIG. 1 is a side view, partially in section, of the device of this invention adapted in distended form to an impact activated missile.

FIG. 2 is a side view, partially in section, of another embodiment of the device.

FIG. 3 is a cross-sectional view showing the device in the compressed form in the accommodating space of the missile.

Similar numerals refer to similar parts throughout the several views.

Referring to FIGS. 1 and 2, the device is in the form of a surface covered, helical shaped distensible orientation means 11 such as a spring and the like which is adapted to be attached, in a conventional manner, to the rear base of a missile 12 at a point opposed in direction to the desired site of impact with the ground. As shown, the circumvolution of the peripheral circuit of the helically shaped device along the longitudinal axis may be gradually increasing in value with respect to its diameter, as in FIG. 1, or it may be substantially constant in value as in FIG. 2. In either case, the outer circumscribing area of the device may be covered with lightweight cloth or nylon 13 and, in each case, the device is adapted to take the form of a helicoid 14 in the compacted or compressed state without, in any way, disrupting its inherent ability to become distended or expanded in shape.

As shown in FIG. 3, the nylon covered helically shaped orientation device may be secured, in the helicoid form 13 in the accommodating space of the impact activated missile 12 during manufacture of the missile or at any time prior to storage in the carrier, by directly attaching the innermost convolution of spring 11 to the center region of the recess 14 defined by the floor and a surrounding outer flange of the rear base, so that the portion of the covering which surrounds the outermost convolution of spring 11 engages said flange. Due to the volumetric characteristics of the described device, in the helicoid form, comparatively less space is required to store the missile in the carrier than is required with the conventionally available orientation devices. As a result, the missiles adapted with the present device may be placed in nestable alignment in a conventional carrier due to the construction of the device. In this way, the destruct capabilities or payload of a conventional carrier, having restricted capacity in weight and volumetric size, may be substantially increased due to the fact that the light-weight device of this invention may be incorporated in the structure or accommodating space of the missile itself.

In operation, the carrier of the missiles will be launched from artillery or from a high speed aircraft. At a predetermined point in the trajectory of the gravitating airborne missile, the plurality of missiles will be deployed in somewhat of a dispersed pattern in the air. As soon as the pressure upon the helicoid, incident to nesting, is released, the helicoid shaped device will immediately expand to its full distended length. As a result, the nylon covered peripheral area of the distended helically shaped device will produce an empty hollow inverted frustoconical surface which, when exposed to the airstreams, will tend to orient the gravitating missile in the desired, upright, stabilizing position accompanied by a drag, which will decelerate the missile and positively control the trajectory of the missile. It has been found that if a missile is adapted with the device of this invention, in the manner described and shown, such gravitating airborne missile will orient itself in all cases in an upright position in the air so that the site of impact will be substantially in the detonating area of the impact activated pin of the fuze.

It has also been found that at lower levels of elevation in the order of 50 feet, a missile adapted with the present device will stabilize in substantially less time thereby orienting the missile in the desired manner prior to impact. Due to the inherent nature of a helical shaped device such as a compression spring, it will expand to its full length in less than about 1 second and will maintain the center of gravity of the missile in the upright state to achieve aerodynamic stability. However, the spring should be made of light-weight material so that the orientation of the missile does not vary from the desired attitude in space. We have found that, in typical device for use with the most common impact oriented missiles, the weight of the device should be between 0.10 to about 0.5 ounce and the length of the expanded device should be between 0.5 to 1 foot long. The compressive strength of such device is preferable between 0.5 and 2 pounds per square inch and the thickness of the body should be between 0.03 and 0.125 inch depending on the material the spring consists of.

The advantages accompanying the use of the device of this invention include the fact that it is inexpensive to manufacture due to its construction. A missile adapted with the present device may be nestably aligned in the carrier increasing the destruct capabilities of the entire system. As a grenade or missile is deployed from a carrier, there are several components of force acting on the missile itself. These include centrifugal force, gravity and a forward component of force due to the velocity of the item. It has been found that, notwithstanding these forces, the present device will orient the missile in the most favorable position for impact. It also provides accuracy of delivery to a specified target area by inducing a constant drag on the missile throughout the trajectory thereof.

Obviously, many modifications and variations of the present invention are possible in the light of the above teaching. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

We claim:

1. In a munition having a body and a rear base, said rear base having a floor and an outer flange defining a recess,

the improvement comprising, in combination therewith, a rear stabilizer for controlling the trajectory of said munition, said rear stabilizer comprising a helical coil spring having convolutions of gradually increasing widths, said spring being attached at its innermost convolution directly to the center region of said floor of said recess, and a collapsible frustoconical covering for said spring extending from the innermost to the outermost convolution of said spring,

said spring and covering being normally confined in compressed and collapsed condition in said recess and having the portion of the covering which surrounds the outermost convolution of said spring in engagement with the flange of said recess, and said covering forming in the released position of said spring an empty hollow elongated inverted frustoconical stabilizing surface at the rear of said munition;

whereby when said munition is launched, said spring will extend itself outwardly upon centrifugal forces generated by in-flight movements of said munition.

2. The invention of claim 1, wherein said covering is fabric.

3. The invention of claim 1, wherein said covering is nylon.