EP0578522A1 - Closure member for a launcher tube - Google Patents

Abstract

A closure member, intended to be mounted on one end of a storage and launcher tube for a munition in order to protect its inside from external attacks, comprises a cover (5) intended to extend over the entire cross-section of the end of the tube and to be secured in a fluid-tight manner all around the edge of this tube end and to be released at least partially from this end at the time of launching, characterised in that this cover is fixed to the inside of a protective cap (6, 16) made of flexible material comprising a retaining tab (11, 21) fixed externally to the tube close to this end, by means of which the cover is retrieved by the protective cap at the time of launching. <IMAGE>

Description

The invention relates to sealing or sealing the ends of a launching tube, in mobile practice, for missiles, rockets or similar munitions.

As is known, there are tubes or boxes used both for storing ammunition and for launching it. In order to avoid, before launching, any penetration into the tube of undesirable products likely to disturb the launching phase, with sometimes dramatic consequences, it is known to provide the launching tube, after having incorporated the ammunition, with covers closing the front and rear ends. In this way, including after possible manipulations in a hostile environment, the operator only has to check the integrity of the covers to make sure when firing his weapon clean.

These hoods or shutter elements can be of several types, depending on whether their clearance from the end of the tube which they close off is done independently before firing (sometimes called doors) or at the very start of shoot.

The first case most often corresponds to heavy weapons in practice configured as a battery. Thus for example the document FR-2.620.808, which relates to missile containers notably on board warships, and the document FR-2.555.725, concerning “containerized” missile systems on vehicles, on land or on vessel, provide hinged covers or doors.

The second case corresponds in practice to light weapons, for example carried and handled by his servant. The release of the front end of the launch tube is then done by ejection or fragmentation of the closure element. In fact, several cases arise depending on whether the ejection or fragmentation results from the action of a pyrotechnic element or an explosive cord triggered at the time of the firing (see for example documents FR-2,555,725, US-4,301. 708, or US Pat. No. 3,962,951), of the gas pressure generated by the ignition (see in particular documents DE-1,016,603, EP-0.022,756 or FR-2,230,955) or of the thrust exerted by the very nose of the munition being launched (see in particular documents EP-0.434.938, FR-1.436.333, FR-2.038.112, GB-1.206.945 or US-4.498.368). When there is fragmentation, a retention of all or part of the fragments may be provided at the periphery of the end of the tube considered (see for example the aforementioned documents FR-1.436.333 or US-4.498.368, or even the document cited above EP-2,620,808 which provides for substantial re-sealing of the rear end of battery-mounted missile launchers).

These various known solutions, with release of the ends at the very moment of firing, have the disadvantage of inevitably revealing debris which are ejected in an uncontrolled manner, especially when the requirements as to the level of protection which the obturation element considered. In addition, these solutions are generally complex.

The object of the invention is to overcome the aforementioned drawbacks by means of a closure element for at least one of the ends, in particular the front, of a storage and launching tube for ammunition, preferably portable, which can, despite simple construction, ensuring in storage phase, in combination with the tube itself, a high and lasting level of protection over time climatic, mechanical, electromagnetic, nuclear, biological and / or chemical aggressions, while guaranteeing reliably, even after a long storage period (which can typically reach, or even exceed, 10 years), the complete release of said end under the effect of the pressure front appearing at the time of the firing, and this without uncontrolled ejection of debris or putting the servant of said tube at risk.

To this end, the invention provides a closure element intended to be mounted on one end of a tube for storing and launching ammunition in order to protect the interior thereof from external aggressions, comprising a cover intended to extend over the entire section of the tube end and to be tightly secured all along the edge of this tube end and to be released at least in part with respect to this end at the time of launching, characterized in that this cover is fixed inside a protective cover made of flexible material comprising a retaining tab fixed externally to the tube near this end, whereby the cover is recovered at the time of launching by the protective cover .

In this way, when the cover is detached at least in part from the end of the tube, it is, in its entirety, retained in the tube in particular thanks to the tab of the protective cap. There is therefore no uncontrolled ejection of debris. The cover is in practice made of rigid material so as to provide the desired level of protection, in particular mechanical, while the protective cover can provide sound and visual protection of this cover (that is to say can be used to absorb any incidental sound or light wave whose referral would betray the presence of the weapon). It will be appreciated that the invention goes against previous practice aimed at preserving a symmetry for fixing the cover relative to the axis of the tube.

• l'opercule comporte une paroi de fond et une jupe destinée à longer extérieurement l'extrémité de tube et à lui être fixée,
• l'opercule comporte, entre cette paroi de fond et cette jupe, une zone annulaire de moindre résistance,
• cette zone annulaire de moindre résistance est une zone de raccordement à angle droit réalisée par emboutissage entre la jupe et la paroi de fond,
• l'opercule est fixé à la coiffe protectrice par sa seule paroi de fond,
• l'opercule est fixé à la coiffe par de la colle,
• cette colle est thermofusible,
• la patte de fixation se raccorde à une bande annulaire destinée à entourer l'extrémité de tube,
• la coiffe longe circonférentiellement cette bande,
• la coiffe et la bande annulaire sont, en plus de la patte de fixation, reliées par des zones frangibles (faciles à rompre),
• le matériau souple de la coiffe protectrice est thermorétractable,
• le matériau souple est du polyéthylène,
• l'opercule est en un matériau électriquement conducteur,
• ce matériau électriquement conducteur est à base de cuivre.

According to preferred teachings of the invention possibly combined:

• the cover comprises a bottom wall and a skirt intended to extend externally along the end of the tube and to be fixed to it,
• the cover comprises, between this bottom wall and this skirt, an annular zone of least resistance,
• this annular zone of least resistance is a right-angle connection zone produced by stamping between the skirt and the bottom wall,
• the cover is fixed to the protective cap by its single bottom wall,
• the cover is fixed to the cap by glue,
• this glue is hot melt,
• the fixing lug is connected to an annular band intended to surround the end of the tube,
• the cap circumferentially runs along this strip,
• the cap and the annular band are, in addition to the fixing lug, connected by frangible zones (easy to break),
• the flexible material of the protective cap is heat-shrinkable,
• the flexible material is polyethylene,
• the cover is made of an electrically conductive material,
• this electrically conductive material is based on copper.

The invention also relates to a launch tube provided at one, preferably at each, end of such a closure element. When the tube has an electrically conductive metal wall, the cover is also preferably electrically conductive, the connection between this wall (possibly stripped near the end) and the cover being advantageously made by an electrically conductive adhesive. At the front end, the closure element is preferably connected to the tube by an annular band to which the tab of the cap is connected while, at the rear end, the tab of the cap may be sufficient on its own. to secure the tube.

• la figure 1 est une vue éclatée en coupe axiale de l'extrémité avant d'un tube de lancement et de son élément d'obturation,
• la figure 2 est une vue en élévation à plus grande echelle de la coiffe protectrice de la figure 1, après rotation de 90° autour de l'axe du tube,
• la figure 3 est une vue en coupe axiale de la coiffe de l'élément d'obturation de l'extrémité arrière du tube de la figure 1,
• la figure 4 est une vue en élévation, après rotation de 90° autour de l'axe du tube, de la coiffe de la figure 3, et
• la figure 5 est une vue en coupe axiale, avec arrachement partiel, de l'extrémité de tube et de l'élément d'obturation de la figure 1 et d'un outillage pour la fixation de cet élément sur cette extrémité de tube.

Objects, characteristics and advantages of the invention appear from the following description, given by way of nonlimiting example, with reference to the appended drawings in which:

• FIG. 1 is an exploded view in axial section of the front end of a launching tube and of its closure element,
• FIG. 2 is a view in elevation on a larger scale of the protective cap of FIG. 1, after rotation of 90 ° around the axis of the tube,
• FIG. 3 is a view in axial section of the cap of the closure element of the rear end of the tube of FIG. 1,
• FIG. 4 is an elevation view, after rotation of 90 ° around the axis of the tube, of the cap of FIG. 3, and
• Figure 5 is an axial sectional view, partially broken away, of the tube end and of the closure element of Figure 1 and of a tool for fixing this element on this tube end.

FIG. 1 shows an end 1A, preferably the front end, of a launch tube designated as a whole by the reference 1 and which is used for storing ammunition such as a missile, rocket or the like and then for launching it. This tube in itself, with its ammunition (not shown), is of any suitable known type and will not be described in detail.

It will just be indicated here that this tube, preferably portable, is formed at its front end of an electrically conductive cylindrical strip 2 of axis XX, surrounded by an external wall 3. By way of example, the strip is in copper and the outer wall is a winding of carbon fibers.

The outer wall advantageously stops at a short distance from the edge or free edge of the strip so as to leave it naked over this short distance.

The copper strip takes part in particular in the mechanical resistance of the tube and in its electromagnetic shielding.

On this end 1A of the tube is mounted a closure element designated as a whole by the reference 4, and formed by a cover 5 and a protective cap 6 made of flexible material.

The cover 5, intended for sealingly sealing the section of the end 1A, has a bottom wall 7, in practice flat, extending over this entire section and is tightly secured all along the edge of this end thanks to a skirt 8, here cylindrical, intended to extend outwardly from the end of the tube, preferably over all or part of the distance d over which the metal strip 2 is left bare. This cover is advantageously obtained by stamping.

This cover is preferably electrically conductive (here copper), like the strip, so as to allow an electromagnetic continuity tube-seal.

The connection of the cover to the tube is preferably ensured by this skirt, by crimping, bonding or welding. In the example considered, this connection is ensured by advantageously conductive adhesive so as to reinforce the aforementioned electromagnetic continuity. The existence of this skirt allows very good mechanical fixing and good sealing.

This cover 5 is fixed inside the protective cap 6, preferably by its single bottom wall, which makes it possible to prevent the fixing material, for example glue (advantageously hot-melt), from overflowing onto the tube itself.

This cap 6 also includes a bottom wall 9 connected at its periphery to a cylindrical skirt 10 running along the skirt 8 of the cover, preferably over a distance at least equal to the axial dimension of the skirt 8 of the cover so to mark it well and extend around the tube itself. The fact that there is no glue between the skirts 10 and 8 prevents that there can be an untimely bonding of the skirt 10 on the tube itself.

This skirt 10 is extended axially opposite the bottom wall 9 by a fixing lug 11 fixed externally to the tube at a distance from this end.

Preferably, more precisely, this tab extends circumferentially so as to form an annular band 12 intended to surround the tube beyond the stripped zone.

Preferably, this annular strip circumferentially runs along the skirt 10 so as to be separated from it only by a slot 13 extending over an angular sector less than 360 ° so as to leave the tab 11 on an angular amplitude (by example between 20 ° and 50 °, preferably 40 °) sufficient to allow the tab 11 to resist tearing during ejection of the cover.

This slot does not need to be complete, that is to say it can extend over only part of the thickness of the assembly 10 + 12, or be dotted as long as it determines an unclosed line of less resistance (for example of lesser thickness).

The protective cap 6 is here fixed to the tube by gluing along the annular strip, for example by the same hot-melt adhesive as that used to fix the bottom walls of the cover and the cap.

FIG. 2 represents this cap 6 with pre-gluing layers 14 and 15.

This cap is preferably made of a heat-shrinkable material, polyethylene for example.

Figures 3 and 4 show another cap 16 for receiving a cover (not shown) of the same type as that, 5, of Figure 1. The closure element thus formed, in particular usable for the rear end of the tube 1, does not differ from that of FIG. 1 only by the fact that the bottom wall 19 and the skirt 20 of the cap are connected to the tube by a single tab 21, of constant circumferential dimension as is clear from FIG. 4. Pre-gluing zones are designated in FIG. 3 by references 24 and 25.

In this case, the tab is advantageously non-retractable.

• a. on met en place l'opercule 5 après avoir mis la colle électriquement conductrice entre la partie à nu du feuillard et la jupe 8 de l'opercule,
• b. on met en place sur l'opercule et le tube la coiffe 6, préencollée et prédécoupée,
• c. on met en place sur et autour de la coiffe 6 un outillage de collage et de rétraction schématisé en 30 à la figure 5, comportant une paroi de fond 31 et, solidaire de cette paroi en alliage d'aluminium série 2000 (par exemple 2024, c'est-à-dire un alliage Al-Cu) une jupe 32 longées extérieurement par des résistances chauffantes 33 et 34 noyées dans une résine polymérisée sur la paroi et la jupe,
• d. on alimente électriquement les résistances chauffantes 33 et 34, ce qui assure :
  • * la polymérisation de la colle conductrice,
  • * la rétraction de la coiffe 6 sur l'opercule et le tube ainsi que la fusion de la colle thermofusible.

For the assembly (see FIG. 5) of the closure element 4 on the end 1A, the following operations can be followed, after having optionally exposed the strip 2 in the immediate vicinity of the edge thereof:

• at. the cover 5 is put in place after having put the electrically conductive adhesive between the exposed part of the strip and the skirt 8 of the cover,
• b. the cap 6, pre-glued and precut, is placed on the cover and the tube,
• vs. a bonding and retraction tool shown diagrammatically at 30 in FIG. 5 is placed on and around the cap 6, comprising a bottom wall 31 and, integral with this wall of aluminum alloy series 2000 (for example 2024, that is to say an Al-Cu alloy) a skirt 32 externally skirted by heating resistors 33 and 34 embedded in a polymerized resin on the wall and the skirt,
• d. the heating resistors 33 and 34 are electrically supplied, which ensures:
  • * polymerization of the conductive adhesive,
  • * the shrinkage of the cap 6 on the cover and the tube as well as the melting of the hot-melt adhesive.

A pressure constraint can be applied radially to the tube-seal junction, for example thanks to the retraction of the cap, which avoids having to maneuver the bonding tool.

Operation d can be performed in a time relatively short (30 seconds for example).

As a variant, by varying the coefficient of expansion of the polyethylene, the succession of steps is modified as follows: before mounting the cap on the cover, it is heated in an oven for for example 10 min at 100 ° C; after placement on the cover and on the tube, the polyethylene is allowed to retract in the open air, with prepolymerization of the conductive adhesive.

There is no longer any need for tools.

A final treatment is then carried out, completing the polymerization of the conductive adhesive.

For example, the cap is made of polyethylene supplied by RAYCHEM in Denmark, or by HELLERMAN in England; the tooling is obtained after from WATLOW France (in Pontoise) which imports it from Germany (Company WAHOW, RFA) while the conductive adhesive, for example, based on silver particles is obtained from RAYCHEM under the reference SS 1184 or from CHOMERICS under the reference CHO-BOND 584-29; the hot-melt adhesive is obtained from RAYCHEM under the reference S 1112 or from HELLERMANN under the reference WM 250.

The cover has for example a thickness of 0.1 mm and a final diameter of 168 mm and a skirt height of 6 mm. The cap of FIG. 2 has a thickness of 1.5 mm, a shrinkage temperature less than or equal to 150 ° and a skirt height of 20 mm, that is to say greater than the above-mentioned height of the skirt. the cover; the annular band has a height of 30 mm.

In fact, it can be seen in FIG. 5 that the slot 13 is located below the free edge of the skirt of the cover, preferably opposite the layer 3 protecting the strip 2.

The mass of the front and rear elements of the tube is typically at most 100 g.

Such a sealing element resisted in particular dry heat (+ 71 ° C), cold (-46 ° C), corrosion in particular by caustic soda (2% aqueous solution), by boric acid (1.7% aqueous solution) or by concentrated freon.

At the latest when it is put into service, the (conventional) tube is fitted with its accessories allowing the shooting (trigger, viewfinder, etc.).

During the firing sequence of the missile, the missile stack and the gyroscopes are activated, the launching device of the gyroscopes creates an overpressure in the launching tube.

The front and rear covers resist this overpressure.

The ignition of the launching propellants generates a pressure wave, part of which is reflected by the rear cover, allowing the front cover to be broken, which is recovered by its protective cap, the latter remaining linked to the launching tube.

At the start of the ignition phase of the thrusters, the rear cover resists a rise in pressure before being broken and recovered by its protective cap, the assembly remaining inside the safety cone.

The rupture of the cover at the bottom wall is here guaranteed by the fact that the cover is obtained by stamping: the connection between the bottom wall and the skirt is an area of least resistance, typically fragile, typically represented by a radius of 0.1 mm. As a variant, an annular line of least resistance, intended to be broken during launching, can be obtained by any suitable known means (dashed lines, notch, etc.) which does not harm the desired level of protection.

During the rupture of the cover, typically at the bottom wall, the cap swings around the tab which forms a hinge. The retention of the cover by the tab is improved by the fact that, not being linked to the cover, the skirt of the cover can participate by its deformation, in the absorption of the ejection energy.

The angular position of this tab is chosen so that, after rupture, the cover and the cap do not interfere with the sighting means or the guide means associated with the tube.

The front closure element has a breaking strength typically between 1 bar and 1.5 bar while that of the rear element is typically between 1.5 bar and 3.5 bar.

It goes without saying that the above description has been offered only by way of nonlimiting example and that numerous variants can be proposed by those skilled in the art without departing from the scope of the invention.

Claims (26)

Sealing element intended to be mounted on one end of a tube for storing and launching ammunition to protect the interior thereof from external aggressions, comprising a cover (5) intended to extend over the entire section of the tube end and to be tightly secured all along the edge of this tube end and to be released at least in part from this end at the time of launching, characterized in that this cover is fixed inside a protective cap (6, 16) of flexible material comprising a retaining tab (11, 21) fixed externally to the tube near this end, whereby the cover is recovered at the time of launching by the protective cap. Sealing element according to claim 1, characterized in that the cover (5) comprises a bottom wall (7) and a skirt (8) intended to externally skirt the end (1A) of the tube and to be fixed to it . Sealing element according to claim 2, characterized in that the cover comprises, between this bottom wall and this skirt, an annular zone of least resistance. Sealing element according to claim 3, characterized in that this annular zone of least resistance is a right-angle connection zone produced by stamping between the skirt and the bottom wall. Sealing element according to any one of claims 2 to 4, characterized in that the cover (5) is fixed to the protective cap (6, 16) by its single bottom wall (7). Sealing element according to any one of claims 1 to 5, characterized in that the cover is fixed to the cap by glue. Sealing element according to claim 6, characterized in that this adhesive is hot-melt. Sealing element according to any one of claims 1 to 7, characterized in that the fixing lug (11) is connected to an annular strip (12) intended to surround the end of the tube. Sealing element according to claim 8, characterized in that the cap circumferentially runs along this strip. Sealing element according to claim 9, characterized in that the cap and the annular band are, in addition to the fixing lug, connected by frangible zones. Sealing element according to any one of claims 1 to 10, characterized in that the flexible material of the protective cap is heat-shrinkable. Sealing element according to claim 11, characterized in that the flexible material is polyethylene. Sealing element according to any one of claims 1 to 12, characterized in that the cover is made of an electrically conductive material. Sealing element according to claim 13, characterized in that this electrically conductive material is based on copper. Tube (1) for storing and launching ammunition provided in at least one (1A) of its two front and rear ends with a closure element (4) comprising a cover (5) extending over the entire section of this end and tightly secured along the edge of this end, characterized in that this cover is fixed inside a protective cap (6, 16) made of flexible material comprising a tab (11, 21 ) attached externally to the tube near this end. Storage and launching tube according to claim 15, characterized in that the cover (5) has a bottom wall (7) and a skirt (8) which externally runs along the end of the tube and is fixed thereto. Storage and launching tube according to claim 16, characterized in that the cover is fixed to the protective cap by its single bottom wall. Storage and launching tube according to any one of Claims 15 to 17, characterized in that this end comprises an electrically conductive wall, the cover is made of electrically conductive material and is fixed to this wall by an electrically conductive adhesive. Storage and launching tube according to claim 18, characterized in that the cover is copper-based. Storage and launching tube according to any one of Claims 15 to 19, characterized in that the cover is fixed to the protective cap by hot-melt adhesive. Storage and launching tube according to any one of Claims 15 to 20, characterized in that this end being the front end of the tube, the fixing lug is connected to an annular band surrounding this end. Storage and launching tube according to claim 21, characterized in that the cover circumferentially runs along this strip. Storage and launching tube according to claim 22, characterized in that the cap and the annular band are, in addition to the fixing lug, connected by frangible zones. Storage and launching tube according to any one of Claims 15 to 23, characterized in that the flexible material of the protective cap is heat-shrinkable. Storage and launching tube according to any one of Claims 15 to 24, characterized in that the flexible material is polyethylene. Storage and launching tube according to any one of Claims 15 to 25, characterized in that it has at its other end a second closure element comprising a lid tightly secured along the edge of this other end , and fixed inside a second protective cap made of flexible material comprising a tab fixed externally to the tube near this end.

Images