GB2153309A

GB2153309A - A parachute for munition

Info

Publication number: GB2153309A
Application number: GB08501096A
Authority: GB
Inventors: Erich Bock; Willi Schonborn; Manfred Kastenhuber
Original assignee: Diehl GmbH and Co
Current assignee: Diehl Verwaltungs Stiftung
Priority date: 1984-01-24
Filing date: 1985-01-16
Publication date: 1985-08-21
Also published as: IT1183288B; IT8519186A0; FR2558437A1; IT8519186A1; GB8501096D0; DE3402239C2; GB2153309B; FR2558437B1; DE3402239A1; NL8403653A

Abstract

A parachute-loadable scatter munition (1), which is ejected from a container on the aircraft, is after the ejection from the container exposed to a very severe incident air flow (3). In order to help the parachute (2) unfold reliably, swinging movements of the scatter munition (1) are rapidly damped and parachute lines (20-27) neither twist, tangle nor knot; the parachute lines (20-27) are inserted in M- and/or V-shaped configuration in a material sleeve (11) having pockets (12-14) which is arranged on the scatter munition. <IMAGE>

Description

SPECIFICATION A parachute and a device for storing and paying out lines of the parachute This invention relates to a device for storing and paying out lines of a parachute and to a parachute, more particularly but not exclusively for a payload such as a munition.

It is proposed in U.S. Patent Specification No. 4,333,400, for the recovery of a munition fuze by means of parachute, to arrange the parachute, together with the lines fastened to the fuze, inside a projectile. The fuze is ejected from the projectile at a suitable point in time with the parachute by means of a pyrotechnical charge.

It has also been proposed to provide a shock-absorption arrangement on the payload of a parachute, in which the shroud lines of the parachute are wound in the form of a coil on the load, which coil is unwound as the parachute opens. On the drawing-off (unwinding) the shroud lines from the load, the shock wave or jolt occurring on opening the parachute is reduced. By reason of the distance or spread between the parachute and the load becoming larger, the swinging movement of the load is converted into a slower movement.

This arrangement is suitable for scatter munition which does not have to be precisely aligned in the flight direction.

On ejection of scatter munition from a container of a missile flying at a speed of about Mach-l, as a result of the incident air flow such severe forces may act on the munition and on the lines that parts of the munition are loosened by the shock-like stress which may occur.

The scatter munition is ejected laterally in low-level flight from about 50 m above the ground. In order to avoid self-exposure to danger from the missile, reliable unfolding of the parachute of the submunition has to be within about 0.35 seconds.

On the other hand, the lines may become entangled or become knotted during the phase of unwinding or unwravelling the lines from the coiled-line arrangement.

Also, a severe swinging movement of the scatter munition may not be avoidable, so that the effective part of the munition becomes only partially efficient.

An object of the present invention is to provide a device which, even in the case of extremely unfavourable incident air flow, helps the orderly extraction of the lines and, upon the extraction of the lines, may align the load relatively early in the flight direction, in which respect a severe swinging of the load is alleviated. Also, the initial shock on opening of the parachute, which acts on the load, is to be damped adequately.

According to the present invention there is provided a device for storing and paying out folded lines of a parachute, said lines, in use, connecting a load to the parachute and the load being securely connected (on the parachute side) to peripheral, approximately axially-parallel pockets of the device for the reception of one or more of said lines, at least two line portions of one of said lines being arranged approximately in V-form side-by-side (meander-shaped) in one of the pockets.

Further according to the present invention there is provided a parachute including the device according to the immediately preceding paragraph.

The parachute, consisting of parachute canopy and lines, is arranged on the load in an annular space between the load and a tube which can be blasted off (ejected). Upon the blasting off of the tube, this tube draws the parachute canopy off from the load; then also a predetermined breaking line arranged therebetween tears. After pulling off the canopy, the lines maintain their position in the sleeve pockets up until their extraction from the pockets. Thus, the lines are prevented from twisting, tangling or knotting in the incident flow and thus from impairing the reliable opening of the parachute. By way of the parachute canopy, the lines are drawn, upon friction of the line portions mutually and against the pockets, in an orderly controlled manner from their pockets.The pockets also at least help to align the load relatively early, i.e. during drawing out the lines, with a uniformly increasing restoring moment in the flight direction. Thus, upon transverse oncoming or incident flow on the load, the angle of swing or the angle of incidence between the line direction and the longitudinal axis of the load, during the parachute-opening jolt (which with a load of about 1 5 kg and a speed of about 290 ms-' ' amounts to about 50 kN or to a deceleration force of about 100 g) is so reduced that damage to the load does not occur. Without the pockets, upon such transverse incident flow the load is only aligned when the parachute is fully extended, in which respect the opening jolt acts fully on the load which is not yet aligned in the flight direction.The pockets, acted upon by transverse incident flow, exert an increased friction on the lines while the lines are drawn out of the pockets, so that the line-extraction resistance and the restoring moment is increased in a controlled manner. This assists the alignment of the load in the flight direction.

Upon transverse incident flow, because of the sudden change in the drawing-out direction of the lines at the pocket outlet there results a higher extraction resistance at the outlet of the pocket.

The outlet opening of each pocket may lie outside the centre of gravity of the load, so that a restoring moment is generated during the extraction or drawing out of the lines from the pocket.

The pockets may consist of a material which meets requirements, which pockets may be producible in a cost-favourable manner by cutters, bonding, or by welding. These pockets are easy to apply to the load and can be connected securely to the load by any inconvenient method. The pockets require little space.

Through the position of the lines in the pockets of the packing sleeve, a further fixing of the lines by thread or adhesive bands is dispensed with. The lines can be easily fixed in the pockets with only slight expenditure of effort. Through the uniform packing density at the periphery of the packing space of the packing sleeve, the entire packing procedure of the parachute is facilitated.

The friction upon the extraction (drawing out) of the lines from the pockets acts in a shock-absorbing manner, since the turbulences of the air at the parachute generate jolts which are adequately damped during the extraction of the still folded lines.

The essence of the invention consists in that already at the start of the extraction of the lines from the pockets at the load the restoring moment by virtue of the deceleration effect of the parachute canopy beginning with the unfurling and of the afore-described friction conditions of the lines acts and continues until the lines are drawn completely out of the pockets.

Further according to the present invention there is provided a parachute, for example for a munition in which in a closed state, shroud lines attached to a canopy of the parachute are arranged in a folded state within pockets, the arrangement being such that upon opening of the parachute in an incident air flow the shroud lines are drawn out of the pockets and the pockets provide a frictional resistance to the shroud lines being drawn therefrom so that said lines are drawn from the pockets in a controlled manner.

Still further according to the present inventio there is provided a parachute for a payload, for example a munition in which in a closed state, shroud lines attached to a canopy of the parachute are arranged in a folded state within pockets of a packing sleeve surrounding the payload, the arrangement being such that upon launch of the payload, by way of the canopy the shroud lines are drawn out of the pockets, against a frictional resistance provided thereby, in a controlled manner thereby restraining the shroud lines from becoming entangled and damping the induced swinging movement of the payload to assist in alignment of the payload in the flight direction.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a scatter munition ejected from a container of a missile, after the parachute canopy has been pulled off the munition; Figure 2 shows the arrangement in accordance with Fig. 1 with the parachute fully opened; Figure 3 shows a section taken on line Ill-Ill of Fig. 2; Figures 4 to 6 show various possible modifications or arrangements of lines in the pockets of a packing sleeve of the parachute.

In accordance with Fig. 1, a scatter munition 1 with a parachute 2 is arranged in the incident air flow as indicated by the arrows 3.

The parachute canopy 2 is connected by way of a line arrangement 6 in accordance with Figs. 2, 3 and 6 to the scatter munition 1.

A cylindrical portion 10 of the scatter munition 1 carries a packing sleeve 11 with pockets 1 2 to 14 made from woven material stitched along seams on the periphery.

In accordance with Figs. 2 and 3, in each case two of the shroud lines 20 to 27 are provided with a line reinforcement 28 to 31 having hinging eyeiets 32. These hinging eyelets 32 are mounted on pins 33 of the scatter munition. At the parachute canopy the lines 20 to 27 are provided with reinforcements 35. Length 51 of the sleeve 11 corresponds with the required line stowage length.

In accordance with Fig. 4, a line pair 26, 27 of line arrangement 4 is folded in an Mshaped (W-shaped in the orientation shown) configuration in a pocket 1 2. For ease of illustration the pocket 1 2 is shown cut open, so that pocket portions 1 2a and 1 2b project laterally from pocket seams 11 a.

The free line portions 26a, 27a and the line reinforcement 30 are towards the parachute canopy. Arranged within the packing sleeve 11 are the line portions 26b, 26e and respectively 27b, 27e.

In accordance with Fig. 5, in a pocket 1 2 of the packing sleeve 11, line arrangement 5 has only two line portions 40b and 40e of a line 40 arranged side-by-side in an approximately V-shaped configuration; otherwise, the arrangement with respect to the line portions 40a, corresponds to the arrangement described with regard to Fig. 4.

In accordance with Fig. 6, the principle of the line arrangement in accordance with Fig.

4 is combined together with the principle of the line arrangement in accordance with Fig.

5 and represents the line arrangement 6.

Again for ease of illustration, the cut pocket portions of the pockets are omitted. In the pocket 12, the lines 26, 27 are arranged in M-shaped configuration in accordance with Fig. 4 and in the pockets 13, 14 the lines 26, 27 are arranged approximately in V-shaped configuration.

Regarding the mode of operation: In accordance with Fig. 1, the scatter munition 1, the line arrangements 4 to 6 and the parachute canopy 2 are exposed to the incident flow in accordance with the arrows 3.

Drawing out of the lines 20-27 has already begun. The parachute 2 with the line arrangements 4 to 6 is disposed by virtue of the ejection direction and the existing incident air flow at an angle 50 with regard to the scatter munition 1. The parachute 2 draws the lines 20 to 27, via the line arrangements 4 to 6, out of the pockets 1 2 to 14 of the packing sleeve 11. On the incident flow side of the packing sleeve 11, the pockets in the flow are compressed by the relatively high incident flow velocity of about 280 me~ ', so that the line portions present there are exposed to a considerably increased frictional resistance. Already, in this way while lines 20 to 27 are drawn from the packing sleeve 11 a considerable restoring moment is generated at the load.A considerable contribution to the restoring moment is also supplied by the increased frictional resistance of the lines 20 to 27 at the opening edges 11 b of the pockets 1 2 to 15; important in this respect is the angling of the said lines (i.e. the sudden change in direction of the lines at the pocket outlets) caused by the angle 50.

In the described embodiment, the hinging points for load and parachute are adjacent to one end of the sleeve. The arrangement of these hinging points may be readily varied.

Thus, these hinging points could be, for example, towards each or either end of the pockets.

The pockets may be open at one end or at both ends.

The pockets could be made from an inherently stable material, such as metal or plastics material or from a flexible material such as knitted fabric, nets or foils made of plastics material or metal. It is desired that the pocket inner wall brings about a high coefficient of friction with the lines.

Besides the described ways of insertion of the lines, these can also be inserted in an Sshaped configuration. Bearing in mind the pre-requisite for an orderly extraction of the lines, besides the one-layer arrangement of the lines in the pockets also a two- or multilayer arrangement is possible.

The term "payload" as used throughout this specification is used in its broadest sense and is intended to mean a useful load and not necessarily an explosive charge.

Claims

1. A device for storing and paying out folded lines of a parachute, said lines, in use, connecting a load to the parachute and the load being securely connected (on the parachute side) to peripheral, approximately axially-parallel pockets of the device for the reception of one or more of said lines, at least two line portions of one of said lines being arranged approximately in V-form side-by-side (meander-shaped) in one of the pockets.

2. A device as claimed in Claim 1 in which the pockets are provided in a hollowcylindrical packing sleeve.

3. A device as claimed in Claim 1 or Claim 2 in which the lines of a line pair are received in approximately M-shaped configuration in the pockets.

4. A device as claimed in Claim 3 in which fastening points are provided adjacent to the apex of the bridge piece of the M-shape and adjacent to the free ends thereof the Mshape.

5. A device as claimed in Claim 1 or Claim 2 in which the lines of a line pair lie in a first one of said pockets associated with fastening of the lines of the load in M-shape configuration and also lie symmetrically thereto on each side of said first pocket, in two neighbouring (lateral) pockets approximately in V-shape configuration.

6. A device as claimed in Claim 5 in which three fastening points are provided: at the apex end of the bridge piece of the Mshape and the free ends of the V-shapes.

7. A device as claimed in any one of the preceding claims in which the apex of a line or apices of the lines lie inside or only just outside the pocket or pockets respectively.

8. A parachute including a device as claimed in any one of the preceding claims.

9. The combination of at least one parachute as claimed in Claim 8 and a payload stored within a container onboard a missile or flying body.

10. A parachute substantially as herein described and illustrated with reference to Figs. 1 to 4 of the accompanying drawings, or substantialy as modified in accordance with Fig. 5 or Fig. 6 of the accompanying drawings.

11. A parachute, for example for a munition, in which in a closed state, shroud lines attached to a canopy of the parachute are arranged in a folded state within pockets, the arrangement being such that upon opening of the parachute in an incident air flow the shroud lines are drawn out of the pockets and the pockets provide a frictional resistance to the shroud lines being drawn therefrom so that said lines are drawn from the pockets in a controlled manner.

1 2. A parachute for a payload, for example a munition, in which in a closed state, shroud lines attached to a canopy of the parachute are arranged in a folded state within pockets of a packing sleeve surrounding the payload, the arrangement being such that upon launch of the layload, by way of the canopy the shroud lines are drawn out of the pockets, against a frictional resistance provided thereby, in a controlled manner thereby restraining the shroud lines from becoming entangled and damping the induced swinging movement of the payload to assist in alignment of the payload in the flight direction.

1 3. A parachute as claimed in Claim 12 in which the pockets are arranged substantially in an axially parallel fashion angularly spaced about the sleeve axis.

14. A parachute as claimed in Claim 1 2 in which, in use, the canopy and lines are arranged in a space between the payload and an ejection tube which pulls the parachute canopy off the payload on launch of the payload from a flying body or projectile.

1 5. A parachute as claimed in any one of Claims 11 to 14 in which the pockets are arranged in a plurality of layers.

16. A parachute as claimed in any one of Claims 11 to 1 5 in which the pockets are of metal or plastics.

1 7. A parachute as claimed in any one of Claims 11 to 1 6 in which the pockets open at one or both ends.

1 8. The combination of a parachute as claimed in any one of Claims 11 to 1 7 and a payload in which an outlet opening of each pocket is remote from the centre of gravity of the payload.