US3893396A

US3893396A - Parachute-borne flare device

Info

Publication number: US3893396A
Application number: US391760A
Authority: US
Inventors: Bjorn Herman Olof Simmons
Original assignee: Bofors AB
Current assignee: Saab Bofors AB
Priority date: 1969-12-03
Filing date: 1973-08-27
Publication date: 1975-07-08
Anticipated expiration: 1992-07-08
Also published as: GB1315723A; DE2059626C3; NL7017521A; DE2059626B2; DE2059626A1; FR2072799A5

Abstract

There is shown a parachute-borne flare device which is airlifted by a suitable carrier such as a projectile, rocket, etc., and which is automatically ejected from its carrier at a selected point of the trajectory and readied operational for illuminating a specific target such as a ground area. The flare device includes guide vanes which divide the flare emanating at the downwardly facing end of the flare composition body after ignition thereof into several spaced apart partial flares. These partial flares present an approximately linear pattern toward the ground area to be illuminated and are also substantially freed of darkening due to soot and smoke by air flows through the gaps between the partial flares.

Description

United States Patent Simmons July 8, 1975 [54] PARACHUTE-BORNE FLARE DEVICE 3,670,657 6/1972 Evans l02/87 ,7 O, 67 3 I973 M h dt IO 34. [75] Inventor: Bjiirn Herman Olof Simmons, 3 2 I I am ar 2/ 3 Karlskoga swade P ry E mi e Robert F Stahl rima xa n r Assigneel Akiiebolagel BOfOfS, Sweden Attorney, Agent, or Firm-Hane, Baxley & Spiecens [22] Filed: Aug. 27, 1973 21 Appl. No.: 391,760 [57] ABSTRACT There is shown a parachute-borne flare device which [30] Forelgn Apphcmwn pnonty Data is air-lifted by a suitable carrier such as a projectile, 3, I969 Swede" -l6623/69 rocket, etc., and which is automatically ejected from Related U S A "cam," Data its carrier at a selected point of the trajectory and pp readied operational for illuminating a specific. target [63] fgy 'T' of such as a ground area. The flare device includes guide a an oned vanes which divide the flare emanating at the downwardly facing end of the flare composition body after {2 S agg ignition thereof into several spaced apart partial flares. These partial flares present an approximately near [58] Field 9 pattern toward the ground area to be illuminated and are also substantially freed of darkening due to soot and smoke by air flows through the gaps between the [56] References Cited partial flares UNITED STATES PATENTS 1,327,372 1/1920 Bessiere 102 27 Clam, 14 Drawing F'gum 3,036,451 5/1962 Miller l02/37.8 3,l27,838 4/l964 Moratti et al..1....... 244/317 3,l40,583 7/l964 Hopper 244/322 X SHEET FIGSB FIG. 5A

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1 s ck PARACHUTE-BORNE FLARE DEVICE This invention is a continuation-impart application of my copending application Ser. No. 93,995, filed Dec. 1, I970, now abandoned.

The invention relates to an illuminating device, and more particularly, to a parachute-borne flare device for illuminating a selected target such as a ground area when and while the flare device floats toward the ground suspended from its parachute.

BACKGROUND Parachute-borne flare devices of the general kind above referred to are generally air-lifted by a suitable carrier such as a projectile fired from a gun barrel such as a rifled gun barrel; they may also be air-lifted by a rocket or other suitable carrier such as a bomb or dropped from an airplane. When the projectile, etc., used for air-lifting the flare device reaches a predetermined point of its trajectory, the flare assembly is ejected as a unit from the projectile by a self-activating explosive charge. Other self-activating charges or also hot gases generated upon expulsion of the flare device cause readying of the expelled flare device unit, that is, the parachute of the device is released for unfolding; the flare composition body is ignited at its end facing the area to be illuminated and components initially used for holding together the flare device and protecting the same but now constituting debris are removed out of the path of the now parachute-supported flare device.

The afore-referred to operations for air-lifting and readying the parachute-borne flare device are presumed to be conventional; they are well known to experts in the art and there are numerous U.S. patents and patent applications and also foreign patents and patent applications which describe means suitable for the purpose. The present invention starts at the point at which the flare is readied for operation, that is, the flare composition is suspended from its parachute and ignited at its downwardly facing end.

A problem common to all flare devices ofthe general kind above referred to is to generate a light output which illuminates a selected target area as large as possible, is substantially uniform and lasts a reasonable long period of time. This problem entails that it is desirable to obtain a maximal light output from a given mass of flare composition material, as obviously this mass is limited by the capability of accommodating it in a projectile, etc., which in turn is controlled by the caliber of the barrel from which it is fired.

There are known and widely used flare devices which burn with a single flare. Such devices have various disadvantages such as flickering of the single flare due to the unavoidable flow of wind relative to the flare. Moreover, smoke tends to form on the frontal side of the flare and soot particles also tend to blur the brightness of the produced light. Accordingly, the adequately illuminated target area is bound to be comparatively small; further, and even more important is that the intensity of the illumination is far from uniform, which makes difficult observation of the target area.

There are also known flare devices which divide the flare composition body into several lengthwise sections which are initially held together but are freed for radially spreading upon release of the flare device from its carrier such as a projectile. Each one of the sections is ignited so that a pattern of several flares is formed; such multiple section flare devices produce a broader illumination pattern than a single flare device. Moreover, the total light output is better stabilized than with a single flare device, thereby correspondingly increasing the illumination of the target area. However, they are rather complex and hence expensive.

The illumination of the target area as obtained from the flare device tends to become unstable due to the formation of smoke and flickering of the flare. Under favorable circumstances, an improvement may be ob tained by a normally occurring essentially conical swinging of the body and its parachute. Due to such swinging the flare body is slanted so that its length axis in relation to a vertical line defines an angle which is usually between lO and 40. A relative wind towards the flare as caused by the fall of the flare body toward the target area may thereby cause a deflection of the flare so that the same has a light-giving frontal area. The relative wind may also sweep along this frontal area and thus blow away smoke and soot particles which are unavoidably produced during the burning of the flare body. The illumination of the target area may thus become better than before. However, the swinging of the body and parachute also causes the illumination of the target area to vary continuously as the lightproducing frontal area due to the swinging continuously shifted its spatial position and to a certain extent its shape. Hence, there are rapidly varying shady areas in the target area which makes the observations of objects within the target area difficult. These inconveniences cannot be eliminated by increasing the light intensity as the moving shadows then will become deeper.

In addition to these irregularities and instabilities parachute-borne flare devices as already known have the disadvantage that it is not possible to increase the intensity of light in the target area in a technicallyeconomic way by increasing the diameter of the flare composition body. Practical tests have shown that the specific intensity of light (candela/cm burning area) is probably most favorable when the composition body diameters are 60-70 mm. With larger diameters the specific intensity of light becomes lower. in other words, an increase of the composition body diameter does not produce an equivalent increase in the intensity of light. As an example of the unfavorable specific intensity of light obtained by increasing diameter it may be mentioned that an increase of the diameter of the composition body by results in an increase of the burning area by l%, but an increase of the light intensity by only Hence, even if the total light intensity is increased due to the larger diameter of the composition body, the specific intensity of light of the illuminating body only becomes 65% as compared with the composition body having the smaller diameter.

This phenomenon is probably due to the fact that the light-giving frontal area of the flare cannot be increased very much by increasing the diameter and that the soot particles generated in the flare are preventing the light output from other parts of the flare to reach the target area.

THE INVENTION It is a broad object of the invention to provide a novel and improved parachute-borne flare device which produces a substantially uniform illumination of a selected target area and generates a maximal light intensity for a given flare composition mass.

A more specific object of the invention is to provide a novel and improved parachute-borne flare device in which a single flare emanating from a flare composition body is divided into several spaced apart partial flares and deflected so that an approximately planar or linear frontal light pattern is directed toward the target area thereby producing a maximal illuminated area.

Still another more specific object of the invention is to provide a novel and improved parachute-borne flare device in which the relative positions of partial flares are such that the flares are separated by gaps permitting passage of air flows whereby smoke and soot particles are removed at least to a very substantial degree from the frontal pattern of the partial flares.

SUMMARY OF THE INVENTION This invention solves this problem. The improved light output of a flare device according to the invention is obtained by an extremely careful combination of a number of parameters which occur at the composition body when it is burning. The most important parameters are the angles of the partial flares, the relative wind towards the partial flares, the shape of the partial flares and therefore to a certain extent the number of partial flares and finally the gas velocity of the partial flares which depends on the burning velocity of the composition body and on the contracting of the partial flares.

The dividing of the single flare emanating from the composition body when burning in a number of partial flares is obtained by suitably shaped and disposed guide vanes.

The relative wind problem is resolved by the fall speed of the body and its parachute. This fall speed is determined principally by the parachute. The relative wind imparts to the partial flares a deflection so that each partial flare will have a light-giving frontal area which points toward the target area.

The shapes of the partial flares must be so designed so that gaps are formed between each two adjacent partial flares. Each partial flare should also have a relatively large discharging area which substantially corresponds to the percentage share of the total burning area of the illuminating body, that is, when the number of partial flares is five, each partial flare will display an area that is near 20% of the total burning area of the body. If the partial flare is contracted, the contraction reflects the area of the body. The need for gaps also entails that a small number of partial flares appears to be more advantageous than a large number of partial flares as there is a risk that the partial flares will flow together when a large number of partial flares is provided. Four or five partial flares have been found to be the most advantageous number. The available burning area is, of course, also important with respect to the number of partial flares. With a larger burning area of, for example 60 mm and more, a higher number of partial flares may be practical.

The gas velocity that is developed at the flare composition body in conjunction with the relative wind also afiects the deflection of the partial flares. The higher gas velocity and the higher relative wind, the smaller the partial flares may be.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, several embodiments of the invention are shown by way of example and not by way of limitation.

IN THE DRAWINGS FIG. 1 is an elevational diagrammatic view of a parachute-borne flare device in its operational position;

FIG. 2 is an elevational side view of a modification of a flare device according to the invention in its operational position;

FIG. 3 is a bottom view of FIG. 4;

FIG. 4 is an elevational perspective view of a further modification of the flare device according to the invention, partly in section;

FIG. 4A is a fragmentary perspective view of the flare device according to FIG. 6 showing the pattern formed by the partial flares;

FIG. 4B is a diagrammatic top view of the guide vanes assembly as used in the flare device of FIG. 6',

FIG. 4C is a diagrammatic side view of the guide vanes as used in FIG. 6;

FIG. 5 is an elevational perspective fragmentary view of a further modification of a flare device according to the invention;

FIG. 5A is a bottom view of the flare device according to FIG. 7;

FIG. SE is a sectional side view of FIG. 7A;

FIG. 6 is an elevational perspective fragmentary detail view, partly in section, of a flare device according to the invention, the guide vanes of the device being shown in their folded or inactive position;

FIG. 6A is a view similar to FIG. 8 but showing the guide vanes in their unfolded or active position;

FIG. 7 is a graph showing the illumination effect of a flare device according to the invention in comparison with that of a conventional flare device of the parachute-borne type; and

FIG. 8 is a graph showing the light distribution as obtained on a selected target area with a flare device according to the invention in comparison with that obtained with a conventional flare device of the parachute-borne type.

DETAILED DESCRIPTION OF THE DRAWINGS As heretofore pointed out, parachute-borne flare devices of the general kind herein referred to are usually air-lifted by a carrier such as a projectile fired from a gun barrel such as a rifled barrel. After ejection of the flare device as a unit from the projectile at a preselected point of the trajectory thereof, steps are initiated generally by the use of self-detonating charges to effect unfolding of the parachute of the device, and finally, ignition of the flare composition body at the end thereof facing the ground.

The present invention is not concerned with the airlifting of the flare device, but it presumes the lifting of the device and the readying thereof for operation to be conventional. In other words, the invention starts with the condition in which the device is shown in figures such as FIG. 1.

Referring now to the figures more in detail, and first to FIG. I, the flare device as shown in the figure, comprises a combustible flare composition body made of a conventional material. Many such compositions are known to the experts in the art and the composition itself does not constitute part of the invention. The composition is encased by a canister 13 of elongate preferably cylindrical configuration. The canister serves not only to hold the material of the body together, but also to assure that the body burns at its downwardly end face only. For this purpose, the canister is closed at the operational upper end but leaves open and thus uncovered the operational downward facing area of the composition. According to FIG. 1, the flare composition in its canister is supported by a parachute only the guy wires 2 of which are shown in FIG. I.

As has been previously pointed out, a principal object of the invention is to illuminate a selected ground area with sufficient and reasonably uniform light intensity; obviously, it is also desirable to make the area thus illuminated as large as possible. For this purpose, a flare dividing means 12 is provided. This dividing means is secured to the open end of canister 13 by suitable fastening means 14 such as spokes 14a joined by a central boss 14b.

The flare divider comprises several guide vanes 12a of a generally truncated pyramidical configuration and disposed symmetrically with respect to the center axis of the flare composition body. The configuration and disposition of the guide vanes will be described more in detail in connection with the subsequent figures. It suffices to state in connection with FIG. 1 that the guide vanes divide and deflect the flare emanating from the exposed area of the flare composition upon ignition thereof into four circumferentially spaced apart partial flares.

The possibility of folding down the guide vanes until the flare device is ejected from a projectile in which it is air-lifted is often of great practical importance as the length of the projectile and thus also the space available for accommodating the flare assembly is controlled by the caliber of the barrel used for air-lifting the flare device.

As it is now apparent, the partial flares due to the deflection action of the guide vanes will be separated by gaps, thereby permitting passage of air between the partial flares. The partial flares due to the configuration of the vanes and the slow downward drifting of the flare device tend to assume the generally planar configuration indicated in FIG. 1. As may be noted from this figure, the partial flares have a substantially linear extension within a plane approximately normal to the center axis 4 of the device. As a result, the illumination angle as it is indicated by lines 6 and 7, is a very wide one and thus the illuminated target area is a correspondingly large one. Moreover, due to the passage of air between the individual flares, smoke and soot particles will be forced upwardly, as it is indicated at 30, thus avoiding at least to a substantial extent blurring of the illumination of the ground area.

Referring to FIGS. 2 and 3, these figures illustrate the stabilization of the relative locations of the partial flare as it is achieved by the structure according to the invention. There is shown a canister 23 including the combustile flare composition and mounting a dividing device 24 which divides the flare as it emanates from the previously described exposed bottom area of the composition into four partial flares 25, only two of which are shown in FIG. 2 for the sake of clarity of illustration, while FIG. 3 shows all four partial flares. The flares are deflected by the guide vanes 24a to define acute angles B relative to the center axis 27 of the composition body when and while they are close to the root of the partial flares namely, the burning surface of the composition body a and are then further deflected to define a substantially right-angle relative to said center axis as it is shown in FIG. 2. The specific configuration of the guide vanes are shown more in detail in subsequent figures and described in detail in connection therewith.

FIG. 3 clearly shows gas channels in which the gas velocity is presumed to be of a value suitable for the most efficient burning action, as has been previously indicated. The gas velocity is indicated by dashed arrows 26. Moreover, the shapes of the partial flares near the roots thereof are defined in FIG. 5 by an angle 71 which is an angle in the projection of the actual partial flare in a plane transverse of the lengthwise axis 27. An angle 'y2 indicates the gaps between the partial flares. There is further symbolically indicated a wind flow 28 which is due to the gradual floating of the parachute and the flare body suspended therefrom toward the ground. The gas flows and the air flows cause a deflection of the partial flares which results in the frontal flare areas 250. These are the areas which produce the desired illumination of the selected ground area. As a result, the frontal areas which are the most crucial ones as to the output of light are thus cleared of smoke and soot particles. Tests have shown that the total output in light intensity is very high and also substantially stable. Suitable values of the actual parameters in the combination of gas velocity as obtained by the distribution of the deflecting guide vanes are given in the subsequent tabulation. In this tabulation one of the parameters is chosen to be a constant and therefore is not listed in the tabulation, namely, the gas velocity. Suitable values for the gas velocity are between 5 to 50 m/sec in the listed examples. The body diameter of the composition has some effect in the examples as to the selected number of partial flares and it is for that reason that the parameters for the number of partial flares have been included in the tabulation.

It is apparent that combinations in accordance with the invention can be obtained by other values of the parameter than are shown in the tabulation; generally, the relatively small angle of the partial flares produces the most advantageous combinations because the other parameters can then be kept at more normal values. Thus, the angles between 5 to 50 are convenient, and particularly angles between 10 to 25 are desirable.

FIG. 7 shows the specific light intensity of the burning area relative to the diameter of the burning area. Curve [9 indicates the light intensity I/cm for a flare device with a single, that is, undivided flare that is, of a prior art flare. As shown, the specific light intensity decreases sharply with increasing diameter of the flare body. Curve 20 shows the light intensity I for a prior art undivided flare which is obtained with an arrangement of partial flares according to the invention. Curves 19a and 200 show the corresponding values for partial or divided flares according to the invention. As will be noted, the decline of the light intensity is much smaller for curve 20a than it is for curve 20.

The graph of FIG. 8 shows the variation in time of the light intensity at a given point on the target area. Curve 2] refers to flare devices having a single, that is, undivided flare, while curve 22 represents the light intensity at a given point of the target area which is obtained with a flare device having partial flares according to the invention. As is readily apparent, curve 21 represents a much more uniform light intensity than does curve 22.

FIG. 4 shows a flare device with three guide vanes 31 which are symetrically, that is, circumferentially spaced about the center axis of a generally cylindrical canister 32 containing the flare composition body. Vanes 31 are preferably integral with a base plate 33 which in turn is secured to canister 32 at the open end thereof by suitable fastening means such as a flange 32a.

It has been found that a fairly small number of partial flares such as three to five is preferable to a large number due to the importance of maintaining sufficiently wide gaps or spaces between the partial flares.

It has also been found advantageous to cover the composition body 34 with an inner covering 35 as can be seen in FIG. 4 through the cutout in the wall of canister 32. This covering serves to limit the burning of the composition body when ignited to its exposed bottom surface that is, the surface which faces the ground when the flare body is in its operational position. For igniting the exposed area of the combination body, suitable and conventional ignition means are used. Such ignition means are diagrammatically indicated as comprising a plate 36 having a plurality of openings 37 and communicating with a gap 38 left between covering plate 36 and the thus exposed annular area of the composition body. A spacing ring 39 may be placed between the base plate 33 and covering plate 36. The ignition means further comprise a cap 40 including a priming charge and a delay means, if desired. They may be ignited by a suitable self-activating charge when the device is expelled from the projectile or rocket and which it is air-lifted, as previously described. The charge when activated ignites the flare at least over a large part of its exposed area via gap 38. As the details of the ignition means are not essential for the purpose of the invention they are hence not described in detail. In fact, in some instances they can be entirely omitted, in which case ignition is effected by hot gases generated by the ejecting means used for ejecting the flare device as a unit from the projectile. In any event, ignition of the composition body is presumed to be effected by conventional means.

FIG. 4A discloses the distribution of the partial flares as it is obtained by using guide vanes 31, as shown more in detail in FIG. 4B. FIG. 4A also shows the frontal areas as are forced upon by the configuration of guide vanes 31. As can best be seen in FIG. 4, these guide vanes have a concavely curved surface with respect to the center axis of the flare composition body and are generally shovel-shaped. They are preferably integral with base plate 33, but may also be secured thereto by suitable fastening means.

FIG. 4C shows guide vanes of more tapered configuration than is shown in FIG. 43. They should also be visualized as having a convexly curved surface relative to the center axis of the composition body.

The guide vanes 31 are shown in detail in FIG. 48. They are tapered toward their free ends and they are so curved and slanted relative to base plate 33 that they divide the initial single flare into partial flares and then deflect these partial flares into positions in which they define an angle relative to the center axis of the composition body (The angle [3 of FIG. 2), an angle representing the width of the partial flares near the roots thereof (The angle -yl of FIG. 3) and a separation angle (The angle 72 of FIG. 3) to permit airflows between the partial flares. Such air flows prevent accumulation of soot particles and smoke, thus assuring that the useful light output of the partial flares is at a maximum.

FIG. 4A clearly indicates the frontal areas 310 of the partial flares, that is, the areas which generate the il- Iumination of the selected ground area.

FIG. 5 shows an exemplification of a flare device according to the invention in which a flare divider 42 divides the initial single flare 43 emitted by the exposed area of the composition body upon ignition thereof into four partial flares 430. Only three of these partial flares are shown in FIG. 5 for reasons of clarification of illustration. The flare divider is secured to canister 32 by flange 320 on the container and includes guide vanes 44 best shown in FIGS. 5A and 5B. The vanes are mounted on a ring 45 which has a right-angle crosssection as it is best seen in FIG. 5B. The vanes are socured to this ring by spokes 46 which are joined at their inner free end by a boss member 47. This boss member also serves to mount ignition means (not shown), which as previously described are self-activated at a preselected point of time during the unfolding of the flare device after ejection thereof from the projectile or other carrier used for air-lifting the flare devices.

As can best be seen in FIG. 5A, the guide vanes in FIGS. 5, 5A and 5B are concavely curved with respect to the center axis of canister 32 of the composition body therein while the guide vanes 31 in FIGS. 4, 4A, 4B and 4C are convexly curved to this axis; otherwise, the configuration of vanes 44 is also so that the vanes initially deflect the partial flares radially outwardly and also so that gaps are maintained between the partial flares for permitting air-flows between the partial flares as hereinbefore described.

FIGS. 6 and 6A show a further exemplification of the flare device. The flare device according to FIGS. 6 and 6A is similar in principle to those previously described, and accordingly the same reference numerals are used to identify corresponding components.

Mounting of the guide vanes 48 is effected in the flare device of FIGS. 6 and 6A by means of a boss member 51. This boss member is held by spokes 50 which in turn are secured to a ring member 49. This ring member has a right-angle cross-section and is in turn secured to ring 39 at the open end of canister 32 as previously described. More specifically, the vanes are attached to the boss member by springloaded hinges 52 and have a concave surface relative to the center axis of canister 32 similar to the vanes of FIG. 5. The deflection and separation actions of the vanes are as previously described.

As is clearly shown in FIGS. 6 and 6A, the spokes are tapered at their ends 500 joined to ring member 49 so that the transverse width of the spokes at the tapered end thereof substantially matches the cross-wise width of ring member 40.

The vanes are shown in FIG. 6 in the position in which they are folded back upon the exposed surface of the composition body. The portion of the vanes protruding above the rim of ring member 49 facilitates such folding back of the vanes, and also protects the same when they are in the folded position. The folded position of the vanes is the one in which they are until the flare device is readied for operation, as previously described when the flare device has reached the stage in which the vanes are free to be moved by the bias action of the hinges into the operational position of FIG. 6A. This figure does not show the partial flares, but it is evident from the previous description that the partial flares are deflected to occupy the positions shown for instance in FIG. 5.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention, it will be understood by those skilled in the art, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed is:

l. A parachute-borne flare device, said device comprising:

an elongate body of a combustile flare composition;

a covering means covering the side wall and one end of said body to limit burning of the body to the area thereof exposed at the other end of the covering means, said one end of the covering being arranged for attachment to a parachute and the exposed area being the bottom area in the operational position of the device;

flare dividing means supported by the covering means at said exposed area of the body of the flare composition for dividing a single flare generated upon ignition of the body at said exposed area into partial flares, said dividing means including guide vanes downwardly extending in relation to said bottom area and circumferentially spaced about the center axis of said body, said vanes being canted radially outwardly and curved to deflect partial flares radially outwardly to define a first angle B of to 50 to said center axis and also to define a second angle 'y2 deflecting said partial flares into angular positions relative to each other and defining a gap between each two partial flares to allow passage of air therebetween and further defining an approximately linear pattern approximately normal to said center axis.

2. The flare device according to claim 1 wherein said flare dividing means comprise at least three spaced apart guide vanes to divide the flare into at least three partial flares.

3. The flare device according to claim 1 wherein said flare dividing means comprise mounting means securing the same to the covering means at the open end thereof, said mounting means including a ring member secured to the covering means at the open end thereof and spokes extending radially inwardly from said ring member, each of said spokes mounting one of said guide vanes.

4. The flare device according to claim 3 wherein a central boss member joins said spokes at the inner ends thereof, said spokes and said boss member being disposed substantially in a common plane and constituting a base member including an opening for each partial flare at the open end of the covering means.

5. The flare device according to claim 1 wherein said dividing means include a boss member, and an ignition means for igniting the composition body at the uncovered area thereof is supported by said boss member.

6. The flare device according to claim 1 wherein said flare dividing means comprise a base member including an opening for each of said partial flares, said base member being secured to the covering means at the open end thereof and overlying said exposed area of the composition body, and wherein each of said guide vanes is substantially shovelshaped having a wall portion concavely curved relative to said center axis. said vanes being tapered toward their free ends.

7. The flare device according to claim 6 wherein each of said guide vanes overlies approximately one-half of the base member opening for the respective partial flare.

8. The flare device according to claim 6 wherein said flare dividing means comprise mounting means securing the same to the covering means at the open end thereof, said mounting means including a ring member secured to the covering means at the open end thereof and spokes extending radially inwardly from said ring member. each of said spokes mounting one of said guide vanes, and wherein the circumferential distance between the corners of the guide vanes at the edges thereof attached to the base member is larger than the outer radius of said ring member, the crosswise width of the spokes at the points of attachment thereof to said ring member being about equal to the cross-sectional width of the ring member.

9. The flare device according to claim 1 wherein said flare dividing means comprise mounting means securing the same to the covering means at the open end thereof, said mounting means including a ring member secured to the covering means at the open end thereof and spokes extending radially inwardly from said ring, each of said spokes mounting one of said guide vanes, said ring member having a right-angle crosssection, and wherein the cross-sectional width of said spokes is disposed in planes normal to the plane of the ring member.

10. The flare device according to claim 9 wherein each guide vane comprises a flare deflecting wall portion concavely curved relative to the center axis of said composition body, and each vane is inwardly tapered toward its end attached to the respective spoke.

11. The flare device according to claim 7 wherein each of said guide vanes is outwardly slanted relative to said boss member so as to cover only part of the opening for the respective partial flare.

12. The flare device according to claim 1 wherein said flare dividing means comprises mounting means including springloaded hinge means hinging said guide vanes to the mounting means, said hinge means biasing the vanes from an initial inactive position substantially parallel to said exposed area of the composition body toward an elevated active position.

13. The flare device according to claim 12 wherein said mounting means further comprise a centrally positioned boss member, said spring-loaded hinges being supported by said boss member and in turn supporting said guide vanes.

14. The flare device according to claim 1 wherein vanes are symmetrically disposed about the center axis of said body. each of said vanes having a curved configuration and a flat base edge, said base edge being secured to said cover plate and the vanes facing each other with their convexly curved side.

16. The flare device according to claim 15 wherein said vanes are substantially shovel-shapedv

Claims

1. A parachute-borne flare device, said device comprising: an elongate body of a combustile flare composition; a covering means covering the side wall and one end of said body to limit burning of the body to the area thereof exposed at the other end of the covering means, said one end of the covering being arranged for attachment to a parachute and the exposed area being the bottom area in the operational position of the device; flare dividing means supported by the covering means at said exposed area of the body of the flare composition for dividing a single flare generated upon ignition of the body at said exposed area into partial flares, said dividing means including guide vanes downwardly extending in relation to said bottom area and circumferentially spaced about the center axis of said body, said vanes being canted radially outwardly and curved to deflect partial flares radially outwardly to define a first angle Beta of 5* to 50* to said center axis and also to define a second angle gamma 2 deflecting said partial flares into angular positions relative to each other and defining a gap between each two partial flares to allow passage of air therebetween and further defining an approximately linear pattern approximately normal to said center axis.

6. The flare device according to claim 1 wherein said flare dividing means comprise a base member including an opening for each of said partial flares, said base member being secured to the covering means at the open end thereof and overlying said exposed area of the composition body, and wherein each of said guide vanes is substantially shovelshaped having a wall portion concavely curved relative to said center axis, said vanes being tapered toward their free ends.

8. The flare device according to claim 6 wherein said flare dividing means comprise mounting means securing the same to the covering means at the open end thereof, said mounting means including a ring member secured to the covering means at the open end thereof and spokes extending radially inwardly from said ring member, each of said spokes mounting one of said guide vanes, and wherein the circumferential distance between the corners of the guide vanes at the edges thereof attached to the base member is larger than the outer radius of said ring member, the crosswise width of the spokes at the points of attachment thereof to said ring member being about equal to the cross-sectional width of the ring member.

14. The flare device according to claim 1 wherein said flare dividing means comprise mounting means including a ring member fixedly secured to the open end of the covering means and a flange member securing the guide vanes to the ring member.

15. The flaRe device according to claim 1 wherein a perforated cover plate covers said other end of the elongate composition body, and wherein said guide vanes are symmetrically disposed about the center axis of said body, each of said vanes having a curved configuration and a flat base edge, said base edge being secured to said cover plate and the vanes facing each other with their convexly curved side.

16. The flare device according to claim 15 wherein said vanes are substantially shovel-shaped.