EP0207822B1 - Safety device for an explosive projectile to be launched from a barrel - Google Patents

Safety device for an explosive projectile to be launched from a barrel Download PDF

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Publication number
EP0207822B1
EP0207822B1 EP86401088A EP86401088A EP0207822B1 EP 0207822 B1 EP0207822 B1 EP 0207822B1 EP 86401088 A EP86401088 A EP 86401088A EP 86401088 A EP86401088 A EP 86401088A EP 0207822 B1 EP0207822 B1 EP 0207822B1
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EP
European Patent Office
Prior art keywords
latching
safety device
spring
latching means
flap
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EP86401088A
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German (de)
French (fr)
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EP0207822A1 (en
Inventor
Alain Bonnet
Georges Lemonnier
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CESSIONE;GIAT INDUSTRIES
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Direction General pour lArmement DGA
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
    • F42C15/00—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges
    • F42C15/38—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges wherein arming is effected by chemical action

Definitions

  • the technical sector of the present invention is that of safety devices for explosive devices of the mine, missile or rocket type.
  • an explosive device must have two safety systems that can be operated independently of one another.
  • a safety screen or shutter is generally used, interrupting the pyrotechnic chain of the device and capable of fulfilling all the safety requirements.
  • the operation of the machine must be such that the safety devices should not be erased until after a certain time after launch, which requires detection of the ejection order.
  • the patent FR-A 2 509 037 describes a safety device equipping a projectile launched from a cannon and actuated under the effect of acceleration to ensure the alignment of the pyrotechnic chain.
  • This safety device is applied to the striker of the projectile. It notably includes a shape memory clamping ring which shrinks by heating to release the striker. However, this heating is caused by the friction of the air on the projectile, which makes its operation random.
  • the object of the present invention is to provide a safety device usable in explosive devices of the mine, missile or rocket type launched using a tube mounted for example on a helicopter.
  • the invention therefore relates to a safety device for an explosive device of the rocket or missile mine type, launched from a tube comprising in particular a safety flap held by a first locking means, the erasure of which is prohibited by a blocking means such a device forming part of the state of the art, characterized in that it comprises a second means for locking the flap, indexed on the tube and an intermediate locking means for the movement of the second locking means cooperating with the blocking means on the one hand, and a shape memory spring whose heating is controlled before firing to lock the flap by the blocking means and whose subsequent change in mechanical characteristics controls the erasure of the blocking means and the release of the flap.
  • the locking means consist of pins whose translations are controlled by helical springs.
  • the second locking means is substantially perpendicular to the first locking means and the intermediate locking means is parallel to said first means.
  • the shape memory spring controls the movement of the first locking means by increasing its elastic modulus.
  • the locking means also ensures the locking of the intermediate locking means, and its erasure is controlled by the shape memory spring thus authorizing the translation of the intermediate locking means and the release of the second locking means.
  • the first locking means releases the screen by the action of a helical spring acting against the thrust exerted by the shape memory spring and erasing the locking means in a groove formed in the intermediate locking means.
  • the shape memory spring controls the movement of the intermediate locking means by reducing its modulus of elasticity.
  • the intermediate lock comprises a body subjected to the action of the shape memory spring at its free end and provided at the other end with a blocking finger cooperating with the second lock on the one hand, and an axis (34) sliding inside the body using a spring bearing on an input integral with the axis and on an internal shoulder of the body on the other hand.
  • the body has a notch on its external surface cooperating with the blocking means to ensure its erasure and the release of the first locking means.
  • the screen and the first and second locking means cooperate by means of balls.
  • a result of the present invention lies in its small footprint allowing miniaturization.
  • the device according to the invention replaces the ejection order detector and the arming delay.
  • the spring by its elongation and its retraction with delay, plays a double role.
  • the invention therefore makes use of the shape memory effect by activation that certain alloys have, the most common of which is a nickel-titanium (50/50), copper-zinc-aluminum / copper-aluminum alloy. minium-nickel or gold-silver-platinum.
  • a shape memory alloy is an alloy which, having undergone a deformation, regains its initial shape as soon as its temperature increases under the effect of the passage of an electric current. This effect is different from that of a bimetallic strip because it only occurs at a particular temperature which is chosen during its definition and does not regain its previous form unless it is subjected to a new mechanical deformation. This effect results from a reversible martensic transformation, that is to say a modification of the crystal structure.
  • the alloy To have a shape memory, the alloy must undergo a reversible austenite-martensite transformation of its crystal structure. This transformation, which occurs without diffusion, consists in the passage of the so-called austenitic structure in the high temperature phase into a different crystalline structure called martensic by cooling the alloy. Many alloys have a martensic transformation, but shape memory alloys have an extremely symmetrical martensic structure. These have a typical centered cubic structure in the austenitic phase and a highly twinned structure in the martensic phase. This twin structure allows the alloy to absorb significant shape changes and return to the initial shape when returning to the austenitic structure.
  • the force due to shape memory is determined by starting from the force which a spring can exert according to Hocke's law before the characteristics of the austenitic Ni-Ti alloy.
  • the corresponding stroke is determined by considering the modulus of this martensic alloy and the force obtained from the austenitic form.
  • a helical spring with shape memory having the following characteristics:
  • the flap is part of a pyrotechnic chain shown in fig. 2, of a completely classic type.
  • the shutter 2 is held stationary by two latches 4 and 5 integrated in the respective housings 6 and 7 formed in the body of the projectile.
  • the lock comprises a body 4a whose external diameter corresponds to the internal diameter of the housing 6, extended by frustoconical bearing surfaces on which one bears a ball 8 constituting the locking means.
  • the body 4a is extended on the flap side 2 by a rod 4b engaging in a hole 9 in the flap, the external diameter of this end being less than that of the body.
  • a helical spring 10 is disposed around the end 4b between the body 4a and a shoulder 11 of the housing 6.
  • the other end 4c of the body is subjected to the action of a spring 12 with shape memory bearing on a plate 13.
  • the latch 5 is engaged at one end in a hole 14 in the flap and bears at the other end on the launching tube 3.
  • the latch 5 comprises, in the vicinity of the flap 2, a radial hole or a groove 15, the cooperation of which with the intermediate locking means will be explained below, the other end being supported on the tube 3.
  • the lock 5 is provided with a shoulder 16.
  • a helical spring 17 is disposed between the shoulder 16 and a stop 18 of the housing 7 and ensures, after ejection of the machine, the release of the flap 2 by the lock 5
  • the latch 5 is arranged perpendicular to the latch 4.
  • the intermediate locking means represented by the latch 19, is arranged parallel to the latch 4 in a housing 20a, in which it slides and comes to bear on a stop 20b.
  • This lock 19 comprises a body 19a and a cylindrical finger 19b; the body 19a consists of a frustoconical part bearing on the ball 8 and a cylindrical part whose external diameter corresponds to the internal diameter of the housing 20a.
  • This cylindrical part is provided with a circular groove 21 intended to cooperate with the ball 8.
  • a spring 22 is arranged around the finger 19b and bears on the body 19a and on a shoulder 23 of the housing 20.
  • the finger 19b engages in the radial hole 15 of the latch 5 so as to prohibit its possible translation.
  • Fig. 2 shows a section A-A according to FIG. 1 where we see the flap 2, the hole 9, the latches 5 and 10 and the pyrotechnic elements adjacent to the flap. These elements are for example constituted upstream of the shutter 2, the primer 24 initiated electrically for example and downstream by the priming relay 25.
  • the alignment of the pyrotechnic chain is achieved by translation or rotation of the flap 2 in which a relay 26 is inserted. Thus, the relay 26 is aligned with the primer 24 and the relay 25 which ensures the transmission of the detonation.
  • FIGS. 3, 4 and 5 The operation of the device is illustrated in FIGS. 3, 4 and 5.
  • the spring 12 Prior to the launch of the machine 1, the spring 12 is supplied with a voltage U (fig. 3) which has the effect of raising its temperature above the threshold causing its change in characteristics.
  • U a voltage which has the effect of raising its temperature above the threshold causing its change in characteristics.
  • the extension of this spring causes the translation of the lock 4 and the compression of the spring 10.
  • the ball 8 can then disappear under the action of the intermediate lock 19 actuated by the spring 22.
  • the lock 5 is then released but remains stationary as long as device 1 remains in tube 3.
  • the spring 17 causes the translation of the latch 5 and releases the screen 2.
  • the stroke of the latch 19 is calculated so that the ball 8 can be erased in the 'notch 21 of the latch 19.
  • the tension U then disappears and the spring 12 loses after a certain cooling time its mechanical characteristics.
  • the spring 12 no longer opposes the opposite action of the spring 10 (fig. 5) and the translation of the latch 4 causes the ball 8 to be completely erased in the notch 21.
  • the final unlocking of the screen 2 is thus achieved and the translation or rotation thereof can occur, under the effect of a spring not shown, to align the pyrotechnic chain.
  • the flap then comprises a first imprint 27 in which is placed a ball 28 held in place by the latch 4, the release of which is prohibited by the ball 8, cooperating with the conical bearing surface 29 of this latch and a second imprint 30 in which is placed a ball 31 held in place by the latch 5 bearing on the launching tube.
  • the latch 19 consists of a body 32 having a blind longitudinal bore 33 inside which slides an axis 34 provided with a stop 35.
  • the body 32 is terminated by a claw 36 for hooking the spring 12, and comprises an internal shoulder 37.
  • a helical spring 38 is placed around the axis 34 between the stop 35 and the shoulder 37.
  • the body also has an external groove 21 intended to cooperate with the ball 8.
  • the spring 12 with shape memory is connected to an electric power source 39 delivering the current necessary for its heating.
  • the operation is as follows. Prior to launching the explosive device 1, the spring 12 is supplied with a voltage U, which has the effect of raising its temperature above the threshold causing its change in characteristics. The spring 12 is compressed and causes the translation of the body 32 compressing the spring 38. The latch 5 is then released. After launching the machine, the lock is no longer held by the tube 3 and the spring 17 acts by releasing the ball 31.
  • the supply of the spring 12 is cut off, which causes its previous mechanical characteristics to disappear.
  • the spring 38 can then come into action which causes the translation of the body 32 until the groove 21 arrives at the level of the ball 8.
  • the ball 8 is then driven into the groove 21 by the conical bearing 29 of the latch 4 under the effect of the spring 11.
  • the ball 28 is then released and the flap 2 can be actuated in a conventional manner either by translation or by rotation to align the pyrotechnic chain as described in relation to FIG. 2.

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  • General Engineering & Computer Science (AREA)
  • Toys (AREA)

Description

Le secteur technique de la présente invention est celui des dispositifs de sécurité pour les engins explosifs de type mine, missile ou roquette.The technical sector of the present invention is that of safety devices for explosive devices of the mine, missile or rocket type.

On sait qu'un engin explosif doit être muni de deux systèmes de sécurité actionnables indépendamment l'un de l'autre. On utilise généralement un écran ou volet de sécurité interrompant la chaîne pyrotechnique de l'engin et apte à remplir toutes les exigences de sécurité. Le fonctionnement de l'engin doit être tel que les dispositifs de sécurité ne doivent s'effacer qu'après un certain temps après le lancement, ce qui impose la détection de l'ordre d'éjection.We know that an explosive device must have two safety systems that can be operated independently of one another. A safety screen or shutter is generally used, interrupting the pyrotechnic chain of the device and capable of fulfilling all the safety requirements. The operation of the machine must be such that the safety devices should not be erased until after a certain time after launch, which requires detection of the ejection order.

Les systèmes actuels de détection sont soit électromécaniques soit pyrotechniques lorsque le signal d'éjection est électrique.Current detection systems are either electromechanical or pyrotechnic when the ejection signal is electric.

L'inconvénient des systèmes électromécaniques réside dans les faibles efforts conduisant à leur activation et surtout dans leur encombrement relativement important, ce qui est incompatible avec des engins explosifs de faible volume.The drawback of electromechanical systems lies in the low forces leading to their activation and especially in their relatively large size, which is incompatible with explosive devices of small volume.

Quant aux systèmes pyrotechniques, on sait, compte tenu de la faible énergie qu'il faut leur donner pour les faire fonctionner, qu'il n'est pas possible d'obtenir une sécurité satisfaisante. De plus, des effets secondaires dus aux gaz produits ou à l'onde de choc ne peuvent être maîtrisés complètement.As for pyrotechnic systems, it is known, given the low energy that must be given to them to operate them, that it is not possible to obtain satisfactory safety. In addition, side effects from the gases produced or the shock wave cannot be fully controlled.

Les dispositifs précédents sont souvent accompagnés par des systèmes horlogers ou par des systèmes faisant appel à l'écoulement d'un fluide ou de billes, jouant le rôle de retardateur. L'inconvénient des systèmes horlogers réside principalement dans leur encombrement très important et dans leur grande sensibilité aux poussières. Quant aux systèmes par écoulement, les liquides posent le problème de la viscosité en fonction de la température et l'air celui de l'humidité qui conduit à la formation de givre obstruant les orifices. Enfin, avec les billes, on a un frottement solide favorisant la dispersion.The foregoing devices are often accompanied by watch systems or by systems calling upon the flow of a fluid or balls, playing the role of retarder. The drawback of watchmaking systems lies mainly in their very large dimensions and in their great sensitivity to dust. As for flow systems, liquids pose the problem of viscosity as a function of temperature and air that of humidity which leads to the formation of frost obstructing the orifices. Finally, with the balls, there is a solid friction favoring the dispersion.

Le brevet FR-A 2 509 037 décrit un dispositif de sécurité équipant un projectile lancé à partir d'un canon et actionné sous l'effet de l'accélération pour assurer l'alignement de la chaîne pyrotechnique. Ce dispositif de sécurité est appliqué au percuteur du projectile. Il comprend notamment une bague de serrage à mémoire de forme qui se rétracte par échauffement pour libérer le percuteur. Toutefois, cet échauffement est provoqué par le frottement de l'air sur le projectile, ce qui rend aléatoire son fonctionnement.The patent FR-A 2 509 037 describes a safety device equipping a projectile launched from a cannon and actuated under the effect of acceleration to ensure the alignment of the pyrotechnic chain. This safety device is applied to the striker of the projectile. It notably includes a shape memory clamping ring which shrinks by heating to release the striker. However, this heating is caused by the friction of the air on the projectile, which makes its operation random.

Le but de la présente invention est de fournir un dispositif de sécurité utilisable dans les engins explosifs du type mine, missile ou roquette lancé à l'aide d'un tube monté par exemple sur un hélicoptère.The object of the present invention is to provide a safety device usable in explosive devices of the mine, missile or rocket type launched using a tube mounted for example on a helicopter.

L'invention a donc pour objet un dispositif de sécurité pour un engin explosif du type mine roquette ou missile, lancé à partir d'un tube comprenant notamment un volet de sécurité maintenu par un premier moyen de verrouillage dont l'effacement est interdit par un moyen de blocage un tel dispositif faisant partie de l'état de la techique, caractérisé en ce qu'il comporte un second moyen de verrouillage du volet, indexé sur le tube et un moyen de verrouillage intermédiaire du déplacement du second moyen de verrouillage coopérant avec le moyen de blocage d'une part, et un ressort à mémoire de forme dont l'échauffement est commandé avant le tir pour verrouiller le volet par le moyen de blocage et dont le changement ultérieur de caractéristiques mécaniques commande l'effacement du moyen de blocage et la libération du volet.The invention therefore relates to a safety device for an explosive device of the rocket or missile mine type, launched from a tube comprising in particular a safety flap held by a first locking means, the erasure of which is prohibited by a blocking means such a device forming part of the state of the art, characterized in that it comprises a second means for locking the flap, indexed on the tube and an intermediate locking means for the movement of the second locking means cooperating with the blocking means on the one hand, and a shape memory spring whose heating is controlled before firing to lock the flap by the blocking means and whose subsequent change in mechanical characteristics controls the erasure of the blocking means and the release of the flap.

Les moyens de verrouillage sont constitués par des axes dont les translations sont commandées par des ressorts hélicoïdaux.The locking means consist of pins whose translations are controlled by helical springs.

Le second moyen de verrouillage est sensiblement perpendiculaire au premier moyen de verrouillage et le moyen de verrouillage intermédiaire est parallèle audit premier moyen.The second locking means is substantially perpendicular to the first locking means and the intermediate locking means is parallel to said first means.

Le ressort à mémoire de forme commande le déplacement du premier moyen de verrouillage par augmentation de son module d'élasticité.The shape memory spring controls the movement of the first locking means by increasing its elastic modulus.

Le moyen de blocage assure de plus le blocage du moyen de verrouillage intermédiaire, et son effacement est commandé par le ressort à mémoire de forme autorisant ainsi la translation du moyen de verrouillage intermédiaire et la libération du second moyen de verrouillage.The locking means also ensures the locking of the intermediate locking means, and its erasure is controlled by the shape memory spring thus authorizing the translation of the intermediate locking means and the release of the second locking means.

Le premier moyen de verrouillage libère l'écran par action d'un ressort hélicoïdal agissant contre la poussée exercée par le ressort à mémoire de forme et effaçant le moyen de blocage dans une rainure pratiquée dans le moyen de verrouillage intermédiaire.The first locking means releases the screen by the action of a helical spring acting against the thrust exerted by the shape memory spring and erasing the locking means in a groove formed in the intermediate locking means.

Le ressort à mémoire de forme commande le déplacement du moyen de verrouillage intermédiaire par diminution de son module d'élasticité.The shape memory spring controls the movement of the intermediate locking means by reducing its modulus of elasticity.

Le verrou intermédiaire comprend un corps soumis à l'action du ressort à mémoire de forme à son extrémité libre et muni à l'autre extrémité d'un doigt de blocage coopérant avec le second verrou d'une part, et un axe (34) coulissant à l'intérieur du corps à l'aide d'un ressort prenant appui sur une entrée solidaire de l'axe et sur un épaulement interne du corps d'autre part.The intermediate lock comprises a body subjected to the action of the shape memory spring at its free end and provided at the other end with a blocking finger cooperating with the second lock on the one hand, and an axis (34) sliding inside the body using a spring bearing on an input integral with the axis and on an internal shoulder of the body on the other hand.

Le corps comporte une encoche à sa surface externe coopérant avec le moyen de blocage pour assurer son effacement et la libération du premier moyen de verrouillage.The body has a notch on its external surface cooperating with the blocking means to ensure its erasure and the release of the first locking means.

L'écran et les premier et second moyens de verouillage coopérent par l'intermédiaire de billes.The screen and the first and second locking means cooperate by means of balls.

Un résultat de la présente invention réside dans son faible encombrement permettant une miniaturisation.A result of the present invention lies in its small footprint allowing miniaturization.

Un autre résultat réside dans le fait que le système demande une énergie suffisamment importante pour conserver un niveau de sécurité suffisant et procure des efforts compatibles avec le reste de la sécurité.Another result resides in the fact that the system requires sufficient energy to maintain a sufficient level of security and provides efforts compatible with the rest of the security.

Un autre résultat réside dans le fait que le dispositif selon l'invention remplace le détecteur d'ordre d'éjection et le retard d'armement. En effet, le ressort, par son allongement et sa rétraction avec retard, joue un double rôle.Another result lies in the fact that the device according to the invention replaces the ejection order detector and the arming delay. Indeed, the spring, by its elongation and its retraction with delay, plays a double role.

L'invention fait donc application de l'effet de mémoire de forme par activation que possèdent certains alliages dont le plus courant est un alliage nickel-titane (50/50), cuivre-zinc-aluminium/cuivre-aluminium-nickel ou or-argent-platine. Un alliage à mémoire de forme est un alliage qui, ayant subi une déformation, retrouve sa forme initiale dès que sa température augmente sous l'effet du passage d'un courant électrique. Cet effet est différent de celui d'un bilame car il ne se produit qu'à une température particulière qui est chosie lors de sa définition et ne retrouve pas sa forme antérieure à moins de subir une nouvelle déformation mécanique. Cet effet résulte d'une transformation martensique réversible c'est à dire une modification de la structure cristalline. Pour posséder une mémoire de forme, l'alliage doit subir une transformation austénite-martensite réversible de sa structure cristalline. Cette transformation, qui se produit sans diffusion, consiste dans le passage de la structure dite austénitique dans la phase haute température en structure cristalline différente dite martensique par refroidissement de l'alliage. Beaucoup d'alliages présentent une transformation martensique mais les alliages à mémoire de forme possèdent une structure martensique extrêmement symétrique. Ceux-ci possèdent une structure cubique centrée typique en phase austénitique et une structure hautement maclée en phase martensique. Cette structure maclée permet à l'alliage d'absorber des changements de forme significatifs et de retrouver la forme initiale lors du retour à la structure austénitique. Tout ceci est bien connu de l'homme de l'art et on peut utiliser dans l'invention un ressort à mémoire de forme vendu dans le commerce ou adapter ses caractéristiques en fonction des utilisations techniques ou suivant le type d'engin explosif. En règle générale, on détermine la force due à la mémoire de forme en partant de la force que peut exercer un ressort suivant la loi de Hocke avant les caractéristiques de l'alliage Ni-Ti austénitique. La course correspondante est déterminée en considérant le module de cet alliage martensique et la force obtenue à partir de la forme austénitique.The invention therefore makes use of the shape memory effect by activation that certain alloys have, the most common of which is a nickel-titanium (50/50), copper-zinc-aluminum / copper-aluminum alloy. minium-nickel or gold-silver-platinum. A shape memory alloy is an alloy which, having undergone a deformation, regains its initial shape as soon as its temperature increases under the effect of the passage of an electric current. This effect is different from that of a bimetallic strip because it only occurs at a particular temperature which is chosen during its definition and does not regain its previous form unless it is subjected to a new mechanical deformation. This effect results from a reversible martensic transformation, that is to say a modification of the crystal structure. To have a shape memory, the alloy must undergo a reversible austenite-martensite transformation of its crystal structure. This transformation, which occurs without diffusion, consists in the passage of the so-called austenitic structure in the high temperature phase into a different crystalline structure called martensic by cooling the alloy. Many alloys have a martensic transformation, but shape memory alloys have an extremely symmetrical martensic structure. These have a typical centered cubic structure in the austenitic phase and a highly twinned structure in the martensic phase. This twin structure allows the alloy to absorb significant shape changes and return to the initial shape when returning to the austenitic structure. All this is well known to those skilled in the art and it is possible to use in the invention a shape memory spring commercially available or to adapt its characteristics according to technical uses or according to the type of explosive device. As a general rule, the force due to shape memory is determined by starting from the force which a spring can exert according to Hocke's law before the characteristics of the austenitic Ni-Ti alloy. The corresponding stroke is determined by considering the modulus of this martensic alloy and the force obtained from the austenitic form.

A titre d'illustration, on peut utiliser dans l'invention un ressort hélicoïdal à mémoire de forme ayant les caractéristiques suivantes :

Figure imgb0001
By way of illustration, it is possible to use in the invention a helical spring with shape memory having the following characteristics:
Figure imgb0001

On va illustrer l'invention par la description de deux modes détaillés de réalisation en relation avec un dessin sur lequel :

  • - la figure 1 illustre un exemple de réalisation selon une coupe transversale du dispositif de sécurité.
  • - la figure 2 est une coupe selon A-A de la fig.1.
  • - les figures 3, 4 et 5 illustrent le fonctionnement du dispositif
  • - la figure 6 représente un autre exemple de réalisation selon une coupe transversale du dispositif de sécurité.
The invention will be illustrated by the description of two detailed embodiments in relation to a drawing in which:
  • - Figure 1 illustrates an exemplary embodiment in a cross section of the safety device.
  • - Figure 2 is a section along AA of fig.1.
  • - Figures 3, 4 and 5 illustrate the operation of the device
  • - Figure 6 shows another embodiment according to a cross section of the safety device.

On a représenté sur la fig.1 une coupe d'un projectile 1 au niveau d'un volet de sécurité 2, à l'intérieur d'un tube de lancement 3. Bien entendu, le volet fait partie d'une chaîne pyrotechnique représentée à la fig.2, de type tout à fait classique. Le volet 2 est maintenu immobile par deux verrous 4 et 5 intégrés dans les logements respectifs 6 et 7 pratiqués dans le corps du projectile. Le verrou comprend un corps 4a dont le diamètre externe correspond au diamètre interne du logement 6, prolongé par des portées tronconiques sur une desquelles prend appui une bille 8 constituant le moyen de blocage. Le corps 4a est prolongé du côté de volet 2 par une tige 4b s'engageant dans un percement 9 du volet, le diamètre externe de cette extrémité étant inférieur à celui du corps. Un ressort hélicoïdal 10 est disposé autour de l'extrémité 4b entre le corps 4a et un épaulement 11 du logement 6. L'autre extrémité 4c du corps est soumise à l'action d'un ressort 12 à mémoire de forme prenant appui sur une plaque 13.There is shown in fig.1 a section of a projectile 1 at a safety flap 2, inside a launch tube 3. Of course, the flap is part of a pyrotechnic chain shown in fig. 2, of a completely classic type. The shutter 2 is held stationary by two latches 4 and 5 integrated in the respective housings 6 and 7 formed in the body of the projectile. The lock comprises a body 4a whose external diameter corresponds to the internal diameter of the housing 6, extended by frustoconical bearing surfaces on which one bears a ball 8 constituting the locking means. The body 4a is extended on the flap side 2 by a rod 4b engaging in a hole 9 in the flap, the external diameter of this end being less than that of the body. A helical spring 10 is disposed around the end 4b between the body 4a and a shoulder 11 of the housing 6. The other end 4c of the body is subjected to the action of a spring 12 with shape memory bearing on a plate 13.

Le verrou 5 est engagé à une extrémité dans un percement 14 du volet et prend appui à l'autre extrémité sur le tube 3 de lancement. Le verrou 5 comporte au voisinage du volet 2 un percement radial ou une gorge 15, dont la coopération avec le moyen de verrouillage intermédiaire sera expliqué ci-après, l'autre extrémité étant en appui sur le tube 3. A l'intérieur du logement 7, le verrou 5 est muni d'un épaulement 16. Un ressort hélicoïdal 17 est disposé entre l'épaulement 16 et une butée 18 du logement 7 et assure, après éjection de l'engin, la libération du volet 2 par le verrou 5. Sur la figure, on voit que le verrou 5 est disposé perpendiculairement au verrou 4.The latch 5 is engaged at one end in a hole 14 in the flap and bears at the other end on the launching tube 3. The latch 5 comprises, in the vicinity of the flap 2, a radial hole or a groove 15, the cooperation of which with the intermediate locking means will be explained below, the other end being supported on the tube 3. Inside the housing 7, the lock 5 is provided with a shoulder 16. A helical spring 17 is disposed between the shoulder 16 and a stop 18 of the housing 7 and ensures, after ejection of the machine, the release of the flap 2 by the lock 5 In the figure, it can be seen that the latch 5 is arranged perpendicular to the latch 4.

Le moyen de verrouillage intermédiaire, représenté par le verrou 19, est disposé parallèlement au verrou 4 dans un logement 20a, dans lequel il coulisse et vient s'appuyer sur une butée 20b. Ce verrou 19 comprend un corps 19a et un doigt cylindrique 19b ; le corps 19a est constitué d'une partie tronconique en appui sur la bille 8 et d'une partie cylindrique dont le diamètre externe correspond au diamètre interne du logement 20a. Cette partie cylindrique est munie d'une rainure circulaire 21 destinée à coopérer avec la bille 8. Un ressort 22 est disposé autour du doigt 19b et prend appui sur le corps 19a et sur un épaulement 23 du logement 20. Le doigt 19b s'engage dans le percement radial 15 du verrou 5 de façon à interdire sa translation éventuelle.The intermediate locking means, represented by the latch 19, is arranged parallel to the latch 4 in a housing 20a, in which it slides and comes to bear on a stop 20b. This lock 19 comprises a body 19a and a cylindrical finger 19b; the body 19a consists of a frustoconical part bearing on the ball 8 and a cylindrical part whose external diameter corresponds to the internal diameter of the housing 20a. This cylindrical part is provided with a circular groove 21 intended to cooperate with the ball 8. A spring 22 is arranged around the finger 19b and bears on the body 19a and on a shoulder 23 of the housing 20. The finger 19b engages in the radial hole 15 of the latch 5 so as to prohibit its possible translation.

La fig. 2 montre une coupe A-A selon la fig. 1 où on voit le volet 2, le percement 9, les verrous 5 et 10 et les éléments pyrotechniques adjacents au volet. Ces éléments sont par exemple constitués en amont du volet 2, de l'amorce 24 initiée électriquement par exemple et en aval par le relais 25 d'amorçage. L'alignement de la chaîne pyrotechniqe est réalisé par translation ou rotation du volet 2 dans lequel est inséré un relais 26. Ainsi, le relais 26 est aligné avec l'amorce 24 et le relais 25 ce qui assure la transmission de la détonation.Fig. 2 shows a section A-A according to FIG. 1 where we see the flap 2, the hole 9, the latches 5 and 10 and the pyrotechnic elements adjacent to the flap. These elements are for example constituted upstream of the shutter 2, the primer 24 initiated electrically for example and downstream by the priming relay 25. The alignment of the pyrotechnic chain is achieved by translation or rotation of the flap 2 in which a relay 26 is inserted. Thus, the relay 26 is aligned with the primer 24 and the relay 25 which ensures the transmission of the detonation.

Le fonctionnement du dispositif est illustré sur les fig. 3, 4 et 5. Préalablement au lancement de l'engin 1, le ressort 12 est alimenté sous une tension U (fig. 3) ce qui a pour effet d'élever sa température au-dessus du seuil provoquant son changement de caractéristiques. L'allongement de ce ressort provoque la translation du verrou 4 et la compression du ressort 10. La bille 8 peut alors s'effacer sous l'action du verrou intermédiaire 19 actionné par le ressort 22. Le verrou 5 est alors libéré mais reste immobile tant que l'engin 1 reste dans le tube 3.The operation of the device is illustrated in FIGS. 3, 4 and 5. Prior to the launch of the machine 1, the spring 12 is supplied with a voltage U (fig. 3) which has the effect of raising its temperature above the threshold causing its change in characteristics. The extension of this spring causes the translation of the lock 4 and the compression of the spring 10. The ball 8 can then disappear under the action of the intermediate lock 19 actuated by the spring 22. The lock 5 is then released but remains stationary as long as device 1 remains in tube 3.

Après éjection de l'engin explosif 1 (fig. 4), le ressort 17 provoque la translation du verrou 5 et libère l'écran 2. La course du verrou 19 étant calculée de telle façon que la bille 8 puisse s'effacer dans l'encoche 21 du verrou 19. La tension U disparaît alors et le ressort 12 perd après un certain temps de refroidissement ses caractéristiques mécaniques. Le ressort 12 ne s'oppose plus à l'action contraire du ressort 10 (fig. 5) et la translation du verrou 4 provoque l'effacement total de la bille 8 dans l'encoche 21. Le déverrouillage définitif de l'écran 2 est ainsi réalisé et la translation ou de rotation de celui-ci peut intervenir, sous l'effet d'un ressort non représenté, pour aligner la chaîne pyrotechnique.After ejection of the explosive device 1 (fig. 4), the spring 17 causes the translation of the latch 5 and releases the screen 2. The stroke of the latch 19 is calculated so that the ball 8 can be erased in the 'notch 21 of the latch 19. The tension U then disappears and the spring 12 loses after a certain cooling time its mechanical characteristics. The spring 12 no longer opposes the opposite action of the spring 10 (fig. 5) and the translation of the latch 4 causes the ball 8 to be completely erased in the notch 21. The final unlocking of the screen 2 is thus achieved and the translation or rotation thereof can occur, under the effect of a spring not shown, to align the pyrotechnic chain.

Dans le mode de réalisation représenté sur la fig. 6, les éléments identiques sont désignés par les mêmes références. On retrouve les verrous 4, 5 et 19 coulissant dans leurs logements respectifs 6, 7, 20, le volet 2, les ressorts 11, 12 et 17, la bille 8. Dans cette configuration, le ressort 12 n'est plus appliqué au verrou 4 mais au verrou intermédiaire 19.In the embodiment shown in FIG. 6, identical elements are designated by the same references. We find the locks 4, 5 and 19 sliding in their respective housings 6, 7, 20, the shutter 2, the springs 11, 12 and 17, the ball 8. In this configuration, the spring 12 is no longer applied to the lock 4 but with intermediate lock 19.

Le volet comporte alors une première empreinte 27 dans laquelle est placée une bille 28 maintenue en place par le verrou 4 dont le dégagement est interdit par la bille 8, coopérant avec la portée conique 29 de ce verrou et une seconde empreinte 30 dans laquelle est placée une bille 31 maintenue en place par le verrou 5 en appui sur le tube de lancement.The flap then comprises a first imprint 27 in which is placed a ball 28 held in place by the latch 4, the release of which is prohibited by the ball 8, cooperating with the conical bearing surface 29 of this latch and a second imprint 30 in which is placed a ball 31 held in place by the latch 5 bearing on the launching tube.

Le verrou 19 est constitué d'un corps 32 présentant un percement longitudinal borgne 33 à l'intérieur duquel coulisse un axe 34 muni d'une butée 35. Le corps 32 est terminé par une griffe 36 d'accrochage du ressort 12, et comporte un épaulement interne 37. Un ressort hélicoïdal 38 est placé autour de l'axe 34 entre la butée 35 et l'épaulement 37. Le corps comporte également une gorge externe 21 destinée à coopérer avec la bille 8. Le ressort 12 à mémoire de forme est relié à une source d'alimentation électrique 39 délivrant le courant nécessaire à son chauffage.The latch 19 consists of a body 32 having a blind longitudinal bore 33 inside which slides an axis 34 provided with a stop 35. The body 32 is terminated by a claw 36 for hooking the spring 12, and comprises an internal shoulder 37. A helical spring 38 is placed around the axis 34 between the stop 35 and the shoulder 37. The body also has an external groove 21 intended to cooperate with the ball 8. The spring 12 with shape memory is connected to an electric power source 39 delivering the current necessary for its heating.

Le fonctionnement est le suivant. Préalablement au lancement de l'engin explosif 1, le ressort 12 est alimenté sous une tension U, ce qui a pour effet d'élever sa température audessus du seuil provoquant son changement de caractéristiques. Le ressort 12 se comprime et provoque la translation du corps 32 comprimant le ressort 38. Le verrou 5 est alors libéré. Après le lancement de l'engin, le verrou n'est plus maintenu par le tube 3 et le ressort 17 agit en libérant la bille 31.The operation is as follows. Prior to launching the explosive device 1, the spring 12 is supplied with a voltage U, which has the effect of raising its temperature above the threshold causing its change in characteristics. The spring 12 is compressed and causes the translation of the body 32 compressing the spring 38. The latch 5 is then released. After launching the machine, the lock is no longer held by the tube 3 and the spring 17 acts by releasing the ball 31.

Au bout d'un temps prédéterminé, l'alimentation du ressort 12 est coupée ce qui entraîne la disparition de ses caractéristiques mécaniques antérieures. Le ressort 38 peut alors entrer en action ce qui provoque la translation du corps 32 jusqu'à ce que la gorge 21 arrive au niveau de la bille 8.After a predetermined time, the supply of the spring 12 is cut off, which causes its previous mechanical characteristics to disappear. The spring 38 can then come into action which causes the translation of the body 32 until the groove 21 arrives at the level of the ball 8.

La bille 8 est alors chassée dans la gorge 21 par la portée conique 29 du verrou 4 sous l'effet du ressort 11. La bille 28 est alors libérée et le volet 2 peut être actionné de façon classique soit par translation soit par rotation pour aligner la chaîne pyrotechnique comme décrit en relation avec la fig. 2.The ball 8 is then driven into the groove 21 by the conical bearing 29 of the latch 4 under the effect of the spring 11. The ball 28 is then released and the flap 2 can be actuated in a conventional manner either by translation or by rotation to align the pyrotechnic chain as described in relation to FIG. 2.

Claims (10)

1. Safety device for an explosive device (1) of the mine, rocket or missile type, launched from a tube (3) including a safety flap (2) secured by a first latching means (4), the retraction of which is prohibited by a latching means (8), wherein it includes a second latching device (5) latching the flap (2) indexed on the tube (3) and an intermediate latching device (19) controlling the displacement of the second latching device (5), cooperating with the locking means (8), on the one hand, and a memory spring (12), the heating of which is controlled before firing by latching the flap by the locking means, and of which the later change in mechanical properties controls the retraction of the locking means (8) and the release of the flap (2).
2. The safety device of claim 1, wherein the latching means consists of pins whose translations are controlled by helical springs.
3. The safety device of claim 2, wherein the second latching (5) means is roughly perpendicular to the first latching means (4) and in which the intermediate latching means (19) is parallel to the said first means (4).
4. The safety device of claim 3, wherein the memory spring (12) controls the displacement of the first latching device (4) by increasing its Young's modulus.
5. The safety device of claim 4, wherein the locking means (8) also locks the intermediate latching means (19) and its retraction is controlled by the memory spring (12), thereby enabling the translation of the intermediate latching means (19) and release of the second latching means (5).
6. The safety device of claim 5, wherein the first latching means (4) releases the screen (2) by the action of a helical spring (10) acting against the thrust exerted by the memory spring (12) and retracting the locking means (8) in a groove (21) provided in the intermediate latching means.
7. The safety device of claim 3, wherein the memory spring (12) controls the displacement of the intermediate latching means (19) by reducing its Young's modulus.
8. The safety device of claim 7, wherein the inter- mediale latch (19) includes a body (32) subjected to the action of the memory spring (12) and its free end and fitted at the other end with a locking pin cooperating with a second latch (5), on the one hand, and a pin (34) sliding inside the body (32) under the force of a spring (38) bearing against a rim stop (35) integral with the pin and against a shoulder (37) inside the body, on the other hand.
9. The safety device of claim 8, wherein the body (32) includes a groove (21) on its outer surface cooperating with the locking system (8) to provide its retraction and the release of the first latching means (4).
10. The safety device of claim 9, wherein the screen (2) and the first and second latching means (4, 5) cooperate by means of balls (28).
EP86401088A 1985-05-31 1986-05-23 Safety device for an explosive projectile to be launched from a barrel Expired EP0207822B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8508183 1985-05-31
FR8508183A FR2582799B1 (en) 1985-05-31 1985-05-31 SAFETY FOR EXPLOSIVE DEVICES TO BE LAUNCHED FROM A TUBE

Publications (2)

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EP0207822A1 EP0207822A1 (en) 1987-01-07
EP0207822B1 true EP0207822B1 (en) 1989-07-12

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EP86401088A Expired EP0207822B1 (en) 1985-05-31 1986-05-23 Safety device for an explosive projectile to be launched from a barrel

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EP (1) EP0207822B1 (en)
DE (1) DE3664380D1 (en)
FR (1) FR2582799B1 (en)

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Publication number Priority date Publication date Assignee Title
FR2661725B1 (en) * 1990-05-03 1992-09-25 Saint Louis Inst DEVICE FOR SEPARATING TWO SPACES IN THE EVENT OF A TEMPERATURE RISING, METHOD FOR PRODUCING THIS DEVICE AND AMMUNITION COMPRISING SUCH A DEVICE.
FR2707753B1 (en) * 1993-06-28 1995-09-22 Giat Ind Sa Security and arming device for explosive device.

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3352242A (en) * 1963-11-29 1967-11-14 Charles E Mcfann Thermally initiated pyrotechnic delay time fuze

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US2352242A (en) * 1941-02-14 1944-06-27 Apstein Maurice Potential recording marker
US2750888A (en) * 1946-11-13 1956-06-19 Robert O Wynn Long delay bomb tail fuze
US2974484A (en) * 1952-01-23 1961-03-14 Robert A Cooley Ignition system for rocket motors
DE3126289A1 (en) * 1981-07-03 1983-01-20 Diehl GmbH & Co, 8500 Nürnberg SECURITY DEVICE FOR FLOOR LITER
DE3126288A1 (en) * 1981-07-03 1983-05-26 Diehl GmbH & Co, 8500 Nürnberg Safety device for projectile fuzes

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
US3352242A (en) * 1963-11-29 1967-11-14 Charles E Mcfann Thermally initiated pyrotechnic delay time fuze

Also Published As

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DE3664380D1 (en) 1989-08-17
FR2582799A1 (en) 1986-12-05
FR2582799B1 (en) 1987-11-13
EP0207822A1 (en) 1987-01-07

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