EP0389855B1 - Retarding cloth, fixed to the bottom of a projectile containing submunitions - Google Patents

Description

The invention relates to a brake cloth to be attached to a projectile according to the preamble of claim 1.

Such a brake cloth is known from DE 36 08 107 C1 for braking the ground released by a spin-stabilized carrier casing for pushing out submunitions to the rear. As soon as a sufficient annular gap opens between the base and the casing, the brake cloth is turned radially due to the effects of centrifugal force and thus influences the trajectory of the base due to the increased flow resistance and the increased moment of inertia. To promote the clamping process, centrifugal masses can act on the brake cloth. But even without these additional centrifugal forces, such high mechanical forces act on the brake pad due to the high speed that it can be damaged, especially since only a retaining ring is provided for attachment to the projectile, around which the brake pad is wrapped around with its inner edge, so that extremely high voltage loads occur in a small-area connection area.

The braking device known from US-A-4,565,341 for influencing the descent path of a projectile (there a submunition released from the casing after lifting off the ground) does not consist of a simple brake cloth that radially expands due to the effects of centrifugal force, but two cloths are assembled to form an asymmetrical, flat balloon structure. This also turns out due to centrifugal force, the space between these two cloths inflating via air inlet openings as a result of the inflow in order to result in a relatively stable quasi-conical braking and stabilizing element in the form of a ballut behind the rear of the projectile. This ballut is attached to the projectile by means of two washers, which clamp the center of the lower wall of the ballut between them using tension screws. A connecting shaft is used for the structural connection of the ballut to the projectile tail. The main disadvantage is the larger storage space required for a ballut compared to a simple brake pad. At high speeds of rotation, it must also be expected that such centrifugal forces act on the ballut that the available inflow does not inflate it sufficiently, but assumes a flat structure and therefore does not provide the aerodynamic stabilization and braking effect specified for the system sequence. It is also to be feared that the structure of the ballut material will be damaged under the influence of large centrifugal forces, while on the other hand a material that is too stable does not ensure the elasticity required for a rapid, reproducible inflation process of the ballut interior.

The invention is therefore based on the object of developing a generic type of brake pad in such a way that it meets the mechanical stresses of high centrifugal forces and nevertheless exhibits good opening behavior.

This object is achieved in that the generic brake pad is designed according to the features of the main claim.

Equipping the brake cloth with a central plate element results in the largest possible fastening surface and thus an optimal distribution and absorption of the effects of centrifugal force, especially if, according to a preferred type of fastening, the plate element is adhesively bonded to the brake cloth. Because of the large connection area, a single fastening plate is basically sufficient, but by enclosing the cloth between two such plate elements, the mechanical strength can be increased even further. In addition, approximately radially extending reinforcement bands are provided on at least one side of the brake cloth, which are covered towards the center by the plate element and are therefore included in the connection between the plate element and the central area of the brake cloth. This results in a particularly favorable transfer of force when reinforcement bands fastened on both sides of the brake cloth are in turn enclosed, for example glued, together with the central surface area of the brake cloth between two plate elements.

The brake cloth is clamped between the two plate elements, so that a good mechanical connection between the brake cloth and the two plate elements results after the multicomponent adhesive has hardened.

The plate elements are preferably provided with through holes, one through hole of one plate element being aligned with a corresponding through hole of the second plate element, and one fastening element is inserted through each of the through holes aligned with one another. Such a design of the brake cloth has the advantage that the plate elements which clamp the brake cloth between themselves can be screwed to one another or to the bottom of the carrier projectile by means of the fastening elements. The fasteners are e.g. around screws with which the brake cloth is preferably attached to the front of the floor facing the carrier projectile.

It has proven to be expedient if, for the mechanical reinforcement of the brake cloth on the brake cloth, reinforcement bands are provided which extend from the central surface section of the brake cloth towards its outer circumference, the central surface section facing length sections of the reinforcement bands being covered by the two plates. The reinforcement bands can run in the radial direction or preferably inclined against the radial direction in a tangential direction or in a direction approximated to the tangential direction away from the central surface section, whereby the tensioning process of the brake cloth is further improved after the floor has been separated from the carrier projectile. In that the Longitudinal sections of the reinforcement bands facing the central surface section are fixed between the two plate elements, a large part of the mechanical loads on the stretched brake cloth is taken over by the reinforcement bands. The brake cloth is thus mechanically relieved, so that loads leading to premature breakage of the brake cloth are avoided.

The reinforcement bands are preferably provided on both opposing base surfaces of the brake cloth. This results in very even force relationships in the tensioned brake blanket and a uniform tensioning behavior of the brake blanket.

The reinforcing bands can extend in pairs in a V-shape from the central surface section of the brake cloth to the peripheral edge, one leg of the / each V-shape being provided on one and the second leg of the / each V-shape being provided on the opposite second base area. This results in an at least approximately tangential orientation of the reinforcement bands, through which the effective centrifugal forces are transmitted in an improved manner.

In order to avoid weak points in the reinforcement bands, it has proven to be expedient if the through holes of the plate elements which are aligned with one another are provided for pushing through the fastening elements between the two spaced-apart end sections of the two legs of each V-shape facing the central surface section. With such a design of the brake cloth, the reinforcement bands do not have any holes aligned with the through holes of the plate elements, so that weak points in the reinforcement bands are avoided.

In such a brake cloth, the V-shapes of the reinforcement bands are preferably provided in an evenly distributed manner starting from the central surface section of the brake cloth in the circumferential direction of the brake cloth. This results not only in a very uniform unfolding and tensioning of the brake cloth over the bottom of the floor separated from the carrier projectile, but also in an even distribution of forces between the stretched brake cloth and the carrier projectile floor.

The brake cloth preferably has an equilateral polygonal peripheral contour. The circumferential contour of the brake cloth can thus be triangular on the same side or preferably pentagonal on the same side or pentagonal on the same side or the like. be trained. Such a design of the brake cloth results in the further advantage that a single reinforcement band alternately on one surface of the brake cloth from one corner to a second corner, on the opposite second side from the second corner to a third corner, from the third corner again on the first Side of the brake cloth to a fourth corner, etc., until the reinforcement tape returns to the first corner. The more corners such a brake cloth has, the smaller the incircle enclosed by the reinforcement band, along which the through holes of the plate elements are arranged in an evenly distributed manner, without the through holes penetrating the reinforcement band to form weak points.

Fig. 1

eine Draufsicht auf ein aufgespanntes gleichseitig fünfeckiges Bremstuch mit V-förmig verlaufenden Verstärkungsbändern und mit einem um den Umfangsrand des Bremstuches umlaufenden zusätzlichen Verstärkungsband,

Fig. 2

eine Ansicht eines Plattenelementes von vorne,

Fig. 3

einen Schnitt entlang der Schnittlinie III-III in Fig.2,

Fig. 4

einen Schnitt durch ein abschnittweise gezeichnetes Bremstuch, das zwischen zwei Plattenelementen befestigt ist,

Fig. 5

eine schematische Ansicht eines aufgespannten gleichseitig fünfeckigen Bremstuches, bei dem sich der Verlauf des Verstärkungsbandes von dem in Fig. 1 gezeichneten Verstärkungsbandverlauf unterscheidet,

Fig. 6

eine der Fig. 5 entsprechende schematiche Darstellung einer Ausbildung des Bremstuches, das jedoch gleichseitig siebeneckig mit einem Verstärkungsbnd gestaltet ist,

Fig. 7

eine Ausbildung des abschnittweise gezeichneten Bremstuches, bei dem die Anordnung der Verstärkungsbänder von der in Fig. 1 gezeichneten Anordnung verschieden ist, und

Fig. 8

eine der Fig. 4 entsprechende Schnittdarstellung durch ein abschnittweise gezeichnetes Bremstuch, das mit einem einzigen Plattenelement verbunden ist.

Further details, features and advantages result from the following description of exemplary embodiments of the inventive method shown in the drawing Brake pad. It shows:

Fig. 1

2 shows a plan view of a stretched equilateral pentagonal brake cloth with reinforcing bands running in a V-shape and with an additional reinforcing band running around the peripheral edge of the brake cloth,

Fig. 2

a view of a plate element from the front,

Fig. 3

2 shows a section along the section line III-III in FIG. 2,

Fig. 4

4 shows a section through a brake cloth drawn in sections, which is fastened between two plate elements,

Fig. 5

1 shows a schematic view of a stretched equilateral pentagonal brake cloth, in which the course of the reinforcement band differs from the reinforcement band course shown in FIG. 1,

Fig. 6

5 shows a schematic representation of an embodiment of the brake cloth, which, however, is equilateral with a reinforcement band,

Fig. 7

a design of the brake pad drawn in sections, in which the arrangement of the reinforcing bands is different from the arrangement shown in Fig. 1, and

Fig. 8

one of FIG. 4 corresponding sectional view through a brake pad drawn in sections, the is connected to a single plate element.

1 shows a brake cloth 10 in the open state. The brake pad 10 is clamped between two plate elements 12 with its central surface section 14. The plate elements 12 are formed with through holes 16 which are provided on a circle which is concentric with the center 18 and are evenly spaced from one another. The two plate elements 12 are arranged on the two opposing main surfaces of the brake cloth 10 in such a way that the through holes 16 are aligned with one another.

The brake pad 10 has an equilateral pentagonal outer circumference 20, and accordingly each plate element 12 is provided with five through holes 16. Between the central surface section 14 covered by the plate elements 12 and the corners 22 of the brake cloth 10 there are reinforcing tapes 24, which are clamped with their end sections 26 facing the central surface section 14 between the two plate elements 12 and which end in front of the through holes 16. As can be clearly seen from this figure, the reinforcement bands 24 run along the two sides of the brake cloth 10 in a V-shape, with one leg 28 of each V-shaped reinforcement band 24 on one side of the brake cloth 10 and the respective second leg 30 on the Opposite second side of the brake pad 10 runs between the central surface section 14 and the corresponding corner 22 of the brake pad. In this way, there is a uniform orientation of the reinforcement bands 24 or their legs 28 and 30 and an approximately tangential orientation of the legs 28 and 30 of the reinforcement bands 24, so that a uniform Clamping of the brake pad 10 and an even distribution of forces is ensured.

An additional reinforcing band 34 is attached to the peripheral edge portion 32 adjacent to the outer periphery 20 of the brake cloth 10. This additional reinforcement band 34 is preferably attached to both opposite sides of the brake pad 10. The reinforcement bands 24, 34 can be fastened, for example, by a zigzag seam.

Mass elements 36 may be present in the area of the corners 22. These mass elements 36 can be sewn into the reinforcement bands.

The advantage of such a brake cloth is that there is an excellent transmission of the torque from the bottom 38 of a carrier projectile to the brake cloth 10 via the two plate elements 12 which clamp the brake cloth 10 between them. After the reinforcing bands 24, with their end sections 26 facing the central surface section 14, are also clamped between the two plate elements 12 and are oriented in an at least approximately tangential direction away from the plate elements 12, the reinforcing bands 24 transmit the torque to the brake pad 10 and thus one secure clamping of the brake pad 10 further supported.

FIGS. 2 and 3 show a view from the front or a sectional view of one of the two plate elements 12 which is formed with through holes 16 which are arranged coaxially and equidistantly from one another to the center 18. The plate elements 12 are preferably made of a fiber-reinforced plastic, which is, for example glass fiber reinforced plastic. The / each plate member 12 is formed with a central hole 40.

Fig. 4 shows a brake pad 10 shown in sections, which is clamped between two plate elements 12. The brake pad 10 has a central hole 42 which is aligned with the central holes 40 of the two plate elements 12. The attachment between the two plate elements 12 and the brake cloth 10 is carried out by an adhesive connection between the two sides 44 and 46 of the brake cloth 10 and the base surfaces of the plate elements 12 facing these sides are aligned, and through which (not shown) fastening elements are inserted, which are, for example. fastening screws with which the brake cloth 10 is fastened to the (not shown) bottom of a carrier projectile containing submunitions.

In FIGS. 5 and 6, two embodiments of the brake cloth 10 are shown schematically in the open state, which differ from the exemplary embodiment of the brake cloth 10 shown in FIG. 1 in particular in that there are not a plurality of V-shaped reinforcing bands 24 on the brake cloth 10 , but in each case only a single reinforcement band 24 which, starting from a corner 22 in FIG. 5 on one side of the brake pad 10 to the next but one corner 22, from this next but one corner 22 on the opposite second side to the penultimate corner 22, from there on the first side of the brake pad to the second corner 22 and from the second corner on the opposite second side of the brake pad 10 to the fourth corner 22 and from the fourth corner 22 on the first Side of the brake pad 10 runs back to the first corner 22. The legs 28 and 30 running alternately on one or on the other side of the brake cloth 10 delimit a pentagonal central surface section 14 in FIG. 5, in which the through holes 16 from the legs 28 and 30 of FIG Reinforcement tape 24 are provided spaced so that the through holes 16 do not overlap with the reinforcement tape 24. The through holes 16 are preferably provided in the corner sections of the central surface section 14 defined by the legs 28 and 30, respectively. The reference number 20 here also denotes the outer circumference of the brake cloth 10.

The brake cloth 10 shown schematically in FIG. 6 differs from the brake cloth 10 shown in FIG. 5 in particular in that it has an equilateral heptagonal outer circumference 20, the self-reinforcing band 24 starting from a corner 22 with a Leg 28 runs on one side of the brake pad 10 to the next but one fourth corner 22, from this fourth corner 22 with a second leg 30 along the second side of the brake pad 10 back to the seventh corner 22, from the seventh corner 22 with a leg 28 on the first side of the brake pad 10 to the third corner 22, from there with a second leg 30 on the opposite second side of the brake pad 10 to the sixth corner 22, from the sixth corner 22 with one leg 28 on the first side of the brake pad 10 to the second corner 22 , from there with a second leg 30 on the second side of the brake cloth 10 to the fifth corner 22 of the brake door ches 10 and from there with a leg 28 to the first corner 22 back. Through the legs 28 and 30 of the reinforcing band 24 is an equilateral heptagonal Central surface section 14 is defined, within which seven through holes 16 of the plate elements 12 arranged on the two opposite sides of the brake pad 10 are provided on a circle which is concentric with the center 18 and are evenly spaced from one another. The through holes 16 do not intersect with the legs 28 and 30 of the reinforcing tape 24, so that there is good mechanical strength. The through holes 16 are also provided in this embodiment of the brake pad 10 preferably in the vicinity of the corners of the central surface section 14.

Fig. 7 shows on a larger scale a portion of an embodiment of the brake pad 10 in the open state, which is provided with V-shaped reinforcing bands 24. This embodiment of the brake cloth 10 differs from the design of the brake cloth 10 shown in FIG. 1 in particular in that the end sections 26 of the reinforcing bands 24 facing the central surface section 14 have a different orientation with respect to the center 18, ie the distance between the two legs 28 and 30 of each V-shaped reinforcement band 24, which converge to the outer circumference 20, not shown in this figure, is smaller than the distance between the legs 28 and 30 of each V-shaped reinforcement band 24 of the brake pad 10 shown in FIG. 1 the opposite sides of the brake pad 10 attached plate elements 12, one of which is only indicated in sections here, are oriented with their through holes 16 relative to the V-shaped reinforcing bands 24 such that the aligned through holes 16 of the two plate elements 12 each have only two legs V-shaped verse Strengthening tapes 24 penetrate while four further legs of the V-shaped reinforcing tapes 24th are provided laterally next to the corresponding through holes 16. For the rest, the design of the brake cloth 10 shown in FIG. 7 is similar to the embodiment of the brake cloth 10 shown in FIG. 1, so that there is no need to describe all further details of the brake cloth in detail in connection with FIG. 7. The reference number 48 in FIG. 7 indicates an abrasion protection element which is provided to reduce the mechanical contact of the reinforcing bands 24 with the bottom of the carrier projectile containing submunitions.

The at least approximately tangential course of the reinforcement bands 24 on the two opposite sides of the brake cloth advantageously ensures an improvement in the absorption of the opening load on the brake cloth 10. The brake cloth consists, for example, of a nylon fabric which is designed in such a way that it can absorb the aerodynamic flow forces which occur when the brake cloth is being stretched or when it is open. The reinforcing bands 24 and 34 can be made of Kevlar material, for example.

8 shows a central portion of a brake pad 10 that has a central hole 42. A plate element 12, which is designed, for example, as a steel disk, is glued to a large area on one side 44 of the brake cloth. The plate element 12 has a central hole 40 and is arranged or glued to the brake cloth 10 in such a way that the holes 40 and 42 are aligned with one another. In this figure, the representation of through holes 16, as can be seen, for example, in FIG. 4, has been omitted. That means however, not that in the embodiment shown in FIG. 8, the plate element 12 cannot have such through holes.

Claims (10)

1. A brake cloth (10) which is to be fastened to a projectile and which spreads itself after the separation of the projectile from its carrier for the deceleration and for influencing the trajectory, characterised in that the brake cloth (10) is fastened in the region of its central area (14) to at least one plate component (12), as far as under which portions (26) of reinforcing bands (24) extend, which for the mechanical reinforcement of the brake cloth (10) extend in the direction of the outer periphery (20) thereof.
2. A brake cloth according to claim 1, characterised in that the reinforcing bands (24) are provided on both mutually opposite sides (44,46) of the brake cloth (10).
3. A brake cloth according to claim 1 or 2, characterised in that the reinforcing bands (24) extend in pairs starting from the central area (14) of the brake cloth (10) to the peripheral edge (32) so as to converge in a V-shaped manner, one limb (28) of the/each V-shape being provided on one and the second limb (30) of the/each V-shape being provided on the opposite second side (44,46) of the brake cloth (10).
4. A brake cloth according to claim 3, characterised in that between the two end portions (26), facing the central area (14) and spaced apart from one another, of the two limbs (28, 30) of each V-shape mutually aligned through-holes (16) of the plate elements (12) are provided for the sticking-through of the fastening elements.
5. A brake cloth according to any one of claims 1 to 4, characterised in that the V-shapes of the reinforcing bands (24) starting from the central area (14) of the brake cloth (10) are provided in uniformly distributed manner in the peripheral direction of the brake cloth (10).
6. A brake cloth according to any one of the preceding claims, characterised in that the brake cloth (10) has an equilaterally odd-numberedly polygonal peripheral contour.
7. A brake cloth according to any one of the preceding claims, characterised in that additional reinforcing bands (34) are fastened to the outer periphery (20) of the brake cloth (10).
8. A brake cloth according to any one of claims 1 to 7, characterised in that the reinforcing bands (24, 34) are provided with mass elements (36) in the region of the outer periphery (20) of the brake cloth (10).
9. A brake cloth according to any one of the preceding claims, characterised in that the brake cloth (10) is arranged with a central area (14) between two plate elements (12) forming the fastening mechanism.
10. A brake cloth according to any one of the preceding claims, characterised in that each plate element (12) is provided with through-holes (16), through each of which a fastening element is stuck.

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