US3398916A - Device for correcting the trajectory of projectiles and the so-equipped projectiles - Google Patents

Description

A 27, 1968 F. E. A. VAN VYVE 3,398,916

DEVICE FOR CORRECTING THE TRAJECTORY OF PROJECTILES AND THE SO-EQUIPPED PROJECTILES Filed June 19, 1967 FRFDERIC EDWARD ANWINE VAN V) VF INVENTOR. W .L 6g,

A 'MRNEYS United States Patent 3,398,916 DEVICE FOR CORRECTING THE TRAJECTORY 0F PROJECTILES AND THE SO-EQUIPPED PROJECTILES Frederic Edouard Antoine Van Vyve, Viveguis, Belgium, assignor to Fabrique Nationale dArmes de Guerre Societe Anouyme, Herstal-lez-Liege, Belgium Filed June 19, 1967, Ser. No. 646,899 Claims priority, appligation Belgium, July 4, 1966,

2 Claims. cl. 244-311 ABSTRACT OF THE DISCLOSURE A trajectory correcting device including an auxiliary projectile for a projectile rotating about its longitudinal axis along the trajectory thereof and comprising a remotely controllable detecting device.

Background of the invention This invention relates to projectiles of the type comprising a remotely controllable detecting device, said projectile being rotated along its trajectory by its own characteristics or those of its launching means.

The detecting device may be of any suitable type remotely controllable either by electromagnetic waves or by waves emitted from a source of coherent luminous waves (laser) or by infrared waves, e.g. those emitted by a motor exhaust and the like.

These waves may be emitted or reflected by the target or the shooter and generally they may reach the detecting device in any suitable manner.

The object of the present invention is to cause the suitable intervening of a substantial lateral thrust capable of modifying almost instantaneously the trajectory of the projectile to bring it on the target.

One of the major difiiculties encountered heretofore results from the importance of the amplitude of the angular correction being brought to the trajectory of the projectile to ensure a favorable probability of reaching the target within a very large variety of shooting conditions.

It has already been proposed to provide the projectiles with a'lateral thrust device expelling at due time and in the intended direction a mass of gases the ejection of which causes a rapid modification of the projectile slant, thereby resulting in a modification of the trajectory.

However, this solution is precarious 'due to, on one hand, the small value of the gas mass expelled with respect to the projectile mass and consequently the relatively small value of the resulting force system and, on the other hand, the way of applying said force. In fact, it is observed that this lateral is applied in such manner that it results only in a torque causing the projectile to slant by rotating about its center of gravity, the resulting slant modifying progressively the trajectory owing to the aerodynamic characteristics of the projectile. Accordingly, the modification of the trajectory requires a relatively long time and the angular value of this modification may not be obtained with a suflicient accuracy.

In addition, in such known devices, the pivoting speed of the projectile about its center of gravity owing to the ejection of the gas mass must be brought back to Zero by another force, thereby giving rise to an additional inaccuracy of the angular correction of the projectile trajectory and a substantial complication of the construction and the operation thereof.

It is an object of the present invention to provide a trajectory correcting device, more particularly for projectiles of the above mentioned type, with which the 3,398,916 Patented Aug. 27, 1968 drawbacks of the known devices are systematically avoided.

Another object of the invention is to make such device from a minimum number of constituting elements readily assembled, thereby allowing to reach relatively low cost prices with respect to the performances of the projectile.

Still another object of the invention relates to a particular construction of such device offering a great resistance to lateral stresses when correcting the trajectory.

Summary of the invention The correcting device according to the invention is characterized in that it comprises a make-up charge and an auxiliary projectile arranged in such manner that the resultant of the reaction forces created by the ejection of said auxiliary projectile is lateral, passes through or at close vicinity to the center of gravity of the projectile and is such that it may induce almost instantaneously a correction of the trajectory to bring the projectile on the target.

Thus, the new trajectory of the main projectile is determined by the resultant of two orthogonal linear movements the first of which is caused by the propelling force of the main projectile, while the second movement results from the propelling force of the auxiliary projectile passing through or at close vicinity to the center of gravity of the said main projectile.

It is apparent that said auxiliary projectile will be injeoted substantially at the time of the detection and said time itself will correspond to such an angular position of the projectile that the speed vector of the auxiliary projectile is situated within or approximately within a plane including both the target and the longitudinal axis of the main projectile.

It will be observed that the speed vector of the auxiliary projectile may be also situated within a plane slightly diiferent from that just described above to take account of surrounding factors such as, for instance, the time necessary for ejecting the auxiliary projectile, the shifting of the target and the like.

It is important that the speed of the projectile remains constant along its trajectory. For this purpose, the projectile provided with the device according to the invention will be correlatively conditioned by any suitable means providing for such constant speed. In a preferred embodiment of the invention, the projectile will be provided with a flight motor to define accurately the angular amplitude of the trajectory correction resulting from the combination of said speed with the transverse speed imparted by the lateral thrust.

The flight motor will be such that the thrust with which it actuates the projectile, is approximately equal to the resistance to the advance of the projectile relatively to its initial speed.

Without limitation, an example of trajectory correcting device for a projectile and a so equipped projectile will be described hereafter in their essential elements with reference to the enclosed drawings wherein:

FIGURE 1 shows very diagrammatically a longitudinal section of a projectile and the correcting device according to the invention;

FIGURE 2 shows a section taken on the line IIII of FIGURE 1;

FIGURE 3 shows diagrammatically the correcting process resulting from the device and the projectile according to the invention.

Description of the preferred embodiment 3 into two chambers 6-7 by a cross-piece 8 the longitudinal axis A-A of which is at right angles or substantially at right angles to the longitudinal axis BB of the projectile.

In that case, the chamber 6 houses the charge, generally a hollow charge represented at 9. Chamber 7 houses a suitable device providing for the flight speed of the projectile. In the selected embodiment, this device comprises a flight motor represented in 10. The cross-piece 8 has a blind hole 11 the longitudinal axis of which merges with the said axis A-A.

Said blind hole houses at least a priming element or device 12, a charge 13, an auxiliary projectile, namely a plug 14 and a lid 15.

The highly resistant body is preferably reinforced by any suitable means in the plane of the lateral thrust.

In this respect and, in a particular embodiment, the tubular element will have an increasing thickness from its ends or at a distance from its ends 1617 and in the direction of the cross-piece 8. Similarly, the bottom of the said blind hole 11 will be conditioned or shaped to present a great resistance. W

The head 3 will comprise a detecting device 18 which will be selected in accordance with the used detecting way, i.e. the nature of the waves of the emitter.

Heretofore, there are known a number of such detecting devices likely to be remotely controlled, even at an important distance, by magnetic, heat and light waves and the like.

The head 3 will be generally provided with a conventional protecting cap 19 having a spherical, ogival or similar shape. According to conditions, a transparent or opaque material will be selected but, in any case, said material will be permeable to the waves having to reach or operate the detecting device represented in 18.

Generally, use will be advantageously made of plastic materials which are well known at the present and which are also used for similar purposes.

The fins 4 will be also shaped and conditioned in any suitable manner.

The detecting device or the projectile provided therewith will operate substantially as follows: the projectile 1 is brought as accurately as possible to bear on a point adjacent to the target. At a point of the trajectory of the projectile 1, the detecting device 18 is remotely energized by a known means, e.g. by directing directly a train or a beam of waves thereto or by reflecting said waves, e.g. from the target or in any other manner. At that time, as diagrammatically represented in FIGURE 3, the projectile 1 is subjected simultaneously to the flight speed before the lateral thrust represented by the vector V1 and at a complementary speed indicated by vector W2 and resulting from the relative speed of the auxiliary projectile 14 indicated by vector W1. Accordingly, the projectile 1 is then subjected to a resulting speed indicated by vector V2 which must be tangential to a trajectory represented in t passing through the target 0 or at close vicinity of the latter.

For that purpose, it will be noted that the detecting device 18 will be necessarily energized, i.e. that also the charge 13 for propelling the auxiliary projectile 14 will be fired when the vector W1 representing the speed of the auxiliary projectile lies within or approximately within a plane including both the longitudinal axis BB of the projectile 1 and the target 0.

It Will be apparent that the tolerances are directly depending upon the shooting conditions and that the auxiliary charge 13 could be also fired for any other relative position of said vector W1 so that the projectile impacts against the target or at close vicinity thereof.

It will be noted that, with relatively simple measures, the projectile according to the invention provides a very great shooting accuracy. In fact, the principal parameters having an influence upon the precision may be predetermined with sufficient accuracy, provided of course that the launching arm has been correctly aimed. In fact, the angle at which the detecting device 8 may see the target is known and the value of said angle makes possible to a determination of the angular value of the correction being given to the trajectory of the projectile, the speed of the latter being constant and known. The value of this correction may be reproduced with sufiicient accuracy since the resultant of the reaction forces acting upon the center of gravity G of the projectile at the time of the ejection of the auxiliary projectile is known within sufiicient limits, said center of gravity G being shifted in a very short time. It is also to be noted that the thrust of the flight motor is selected to be equal or practically equal to the resistance to advance of the projectile relatively to its initial speed. Of course, this makes it possible to maintain the angle of lateral correction (angle of lateral thrust) constant for every flight state.

It is apparent that the characteristics of this invention will be worked under essentially varying forms in accordance with the means adapted for the detection under the particular conditions disclosed herein to induce the lateral thrust so that the projectile will be maintained in rotation at a reduced speed about its axis and the like. Generally, the projectile will be provided with a single charge and auxiliary projectile. It is apparent that, in particular cases, two or more charges and make-up projectiles could be applied provided that they meet the operating requirements disclosed herein.

In brief, this invention covers any detection projectile using the foregoing characteristics as well as the projectile parts specially conditioned therefor.

What I claim is:

1. A projectile, comprising an elongated tubular body, a hollow head carried by one end of said body, a detecting device within said head, a central cross piece located within said body between the ends thereof and dividing the interior of the body into a front chamber and a rear chamber, said cross piece having a blind hole the longitudinal axis of which extends at right angles to the longitudinal axis of said body, a charge within said front chamber, a flight motor within said rear chamber for maintaining constant the speed of the projectile, a priming element in said hole, an auxiliary charge in said hole controlled by said detecting device, and an auxiliary projectile in said hole substantially in the center of gravity of the projectile, whereby resultant reaction forces caused by the lateral ejection of said auxiliary projectile pass through said center of gravity.

2. A projectile according to claim 1, wherein the tubular body has an increasing thickness from its ends and in the direction of the central cross-piece.

References Cited UNITED STATES PATENTS 2,029,491 2/1936 Lane 102-5 X 2,258,281 10/1941 Dunajelf 2443.21 X 3,107,617 10/1963 Loeper et al. 102- 61 3,141,411 7/1964 Menke 2443.16

BENJAMIN A. BORCHELT, Primary Examiner. T. H. WEBB, Assistant Examiner.

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