EP0633449B1 - Safety and arming device for an explosive object - Google Patents

Description

The technical field of the invention is that of devices of security and armament for explosive devices of mine type, missiles or rockets, intended to be ejected from a tube of launch.

The security and arming system of an explosive device of this type usually has a primer door which is immobilized by at least two independently actuable locks one of the other. They must also not be erased until after some time after launch, which then requires detect the order or time of ejection.

US-A-3451306 describes a security device in which a striker is kept immobilized by a lock, pushed by a spring, and which comes to bear on a surface internal launch tube. No element is interposed between the rod and the launch tube.

Patent FR-A-2582799 which forms the preamble to the independent claim 1, proposes a safety device and weapon for explosive device of mine type ejected by a tube launch. It has two locks, one of which comes resting on the launch tube. Manufacturing tolerances of the launch tube, of the explosive device and of these elements components are such that the length of this latch must vary by several millimeters in order to correctly ensure its function.

This dispersion of tolerances leads to the need set off each explosive device according to its tube launch. For this, it is necessary to make a lock length adapted to the measurements made on each incoming piece in the measurement chain.

To overcome the problem of making locks on measure, it is possible to realize a family of locks progressive length, but this solution nevertheless requires always taking measurements and a stock of locks available.

The integration of explosive devices into their tube launch is therefore always very heavy and no automation is really only possible.

It is the aim of the present invention to propose a security and arming device which is fitted with a lock standard independent of manufacturing tolerances different parts of the explosive device and the launch tube.

It's another goal to ensure constant pressure on the lock of the security and arming device.

The subject of the invention is therefore a safety device and weaponry, for an explosive device of the mine type, rocket or missile launched from a launch tube, comprising a primer door component immobilized by at least one lock intended to be held by an internal surface of the launch tube, characterized in that it comprises a blade intended to come between the internal surface of the launch tube and the lock by exerting on the latter a substantially constant effort intended to ensure the holding the lock by the tube in the locked position of the shutter, the blade being deformed beyond its limit elastic without exceeding its breaking strength limit when the craft is in place in the launch tube.

Advantageously, the blade has at least three folds, a first fold being pressed against the latch, the two other folds being in abutment against the internal surface of the launch tube, when it is in place in the launch tube.

According to another embodiment, the blade comprises at minus five folds, a first fold being in abutment against the latch, two other folds pressing against the surface internal of the launch tube and the last two being in support against the body of the explosive device, when it is in place in the launch tube.

Preferably, the blade is integral with one of the faces of the explosive device.

According to an alternative embodiment, in the case of a Explosive device of the mine type provided with tabs stabilization, the blade is integral with one of the tabs of stabilization.

• la figure 1 représente, schématiquement en coupe, un dispositif de sécurité et d'armement en position sécurité/stockage, selon un premier mode de réalisation de l'invention.
• la figure 2 représente, schématiquement en coupe partielle, une mine équipée du dispositif de sécurité et d'armement de la figure 1.
• les figures 3a et 3b représentent une lame du dispositif de sécurité et d'armement selon l'invention, la figure 3a étant un développé de la lame, suivant la direction A de la figure 3b.
• la figure 4 représente une vue partielle, suivant la direction F de la figure 2.
• la figure 5 représente en demi-coupe une mine placée dans son tube de lancement.
• la figure 6 représente en coupe partielle une mine équipée d'un dispositif de sécurité et d'armement selon un deuxième mode de réalisation de l'invention.
• la figure 7 représente une vue partielle, suivant la direction G de la figure 6.
• la figure 8 représente, schématiquement en coupe le dispositif de sécurité et d'armement de la figure 1 selon un troisième mode de réalisation de l'invention.

The invention will be better understood on reading the description of particular embodiments, made with reference to the appended drawings in which:

• FIG. 1 shows, diagrammatically in section, a security and arming device in the security / storage position, according to a first embodiment of the invention.
• FIG. 2 represents, schematically in partial section, a mine equipped with the safety and arming device of FIG. 1.
• Figures 3a and 3b show a blade of the security and arming device according to the invention, Figure 3a being a developed blade, in the direction A of Figure 3b.
• FIG. 4 represents a partial view, in the direction F of FIG. 2.
• Figure 5 shows in half-section a mine placed in its launch tube.
• Figure 6 shows in partial section a mine equipped with a safety and arming device according to a second embodiment of the invention.
• FIG. 7 represents a partial view, in the direction G of FIG. 6.
• Figure 8 shows, schematically in section the security and arming device of Figure 1 according to a third embodiment of the invention.

FIG. 1 represents a section of an explosive device 1, at its security and arming device 2, placed inside a launch tube 3. A door flap primer 4 ensures, in a conventional manner, the interruption of a pyrotechnic chain not shown here. Component 4 is held stationary by two locks 5 and 6 that can be actuated independently of each other.

The latch 5 is slidably mounted in a housing 9 made in the body of explosive device 1. It comprises a body 10, of external diameter corresponding to the internal diameter of the housing 9, extended by a span cylindrical 11 of smaller diameter whose end has a groove 12 whose function will be explained more far.

The other end 13 of the latch 5, of smaller diameter to the housing 9 penetrates inside a counterbore 14 of the shutter 4.

A helical spring 15, resting on the one hand against the body 10 and on the other hand against an integral cover 16 of the body of the explosive device 1, brings the lock 5 into abutment against the bottom 17 of the counterbore 14.

The latch 5 also has a narrowing 18 against which bears a ball 19 and which extends by a first frustoconical bearing 20 followed by a portion cylindrical guide 21 to the diameter of the housing 9 and a second frustoconical bearing 22.

The lock 6 is engaged by its end 23 in a counterbore 24 of the shutter 4. It comprises in the vicinity of the shutter 4, a groove 25 inside which is housed the end 26 of an intermediate locking means 27. This the latter has a finger 28 which slides in a housing 29 and which is arranged substantially parallel to the lock 5.

The finger 28 comprises a body 30 against which comes supports the ball 19 and a cylindrical guide surface 31, of external diameter corresponding substantially to the diameter internal of the housing 29.

The body 30 is connected to the cylindrical surface 31 by a narrowing 32 and a frustoconical bearing 33 intended for cooperate with the ball 19. The finger 28 comprises, in the extension of the body 30, a shoulder 34 and a part cylindrical 35.

A helical spring 36 is guided by the part cylindrical 35 and bears against the shoulder 34 and the cover 16. He pushes the finger 28 into abutment at the bottom of groove 25.

Latch 6, slidably mounted in a bore 37 of the body of the explosive device 1, has a shoulder 38. A coil spring 39 is disposed between the shoulder 38 and a stop 40 of a housing 41 coaxial with the bore 37. The end 42 of the latch 6 is held by the surface internal launch tube 3 via a blade 43 which will be described later.

• pendant la trajectoire de l'obus, la force centrifuge, engendrée par la rotation de l'obus, provoque dans un premier temps l'effacement du doigt 28 jusqu'en butée contre le couvercle 16 et dans un deuxième temps l'effacement du verrou 5, qui pousse la bille 19 contre le rétrécissement 32 du doigt 28. Le verrou 5 se retrouve piégé en position effacée par une épingle élastique 62 qui pénètre dans la gorge 12.
• lors du dépotage de la mine hors de l'obus cargo, la lame 43 qui est soumise à la force centrifuge se déforme de manière plastique, libérant ainsi le verrou 6 qui s'éjecte sous la pression du ressort hélicoïdal 39. Le volet 4 se retrouve ainsi totalement déverrouillé et libre de toute translation et/ou rotation. La lame pourrait également être dimensionnée de façon à se briser sous l'effet de la force centrifuge.

The operation of a security and arming device according to the invention and belonging for example to a mine dispersed on the ground from a cargo shell is as follows:

• during the trajectory of the shell, the centrifugal force, generated by the rotation of the shell, causes initially the erasure of the finger 28 until it stops against the cover 16 and in a second time the erasure of the lock 5, which pushes the ball 19 against the narrowing 32 of the finger 28. The latch 5 finds itself trapped in the erased position by an elastic pin 62 which penetrates into the groove 12.
• during the stripping of the mine out of the cargo shell, the blade 43 which is subjected to the centrifugal force deforms in a plastic way, thus releasing the lock 6 which is ejected under the pressure of the helical spring 39. The flap 4 thus finds completely unlocked and free of any translation and / or rotation. The blade could also be dimensioned so as to break under the effect of centrifugal force.

FIG. 2 represents an explosive device 1 which is a dispersible mine for example by means of a cargo shell. This mine 1 is equipped with a positioning device, type of that described in patent FR9214578, which comprises tabs 44 regularly angularly spaced (here 8) and one end of which is made integral of a face 45 of the mine by tie rods 46.

Mine 1 also has two metal washers 47 and 48 positioned on annular notches 49 and 50 fitted respectively on faces 45 and 51. The washers are made integral with the mine by the tie rods 46.

The tongues 44 each have an opening 53 and can be folded into housings 52 fitted in the mine body 1.

The partial section of Figure 2 shows the end 42 of lock 6, belonging to the security system and 2 previously described, end which comes in support against the blade 43. The blade 43 is made integral with mine 1 at its face 51 by one of its ends 55. Due to the presence of lock 6, the passage of a tie rod was impossible here, the joining of the blade 43 and one of the tongues 44 is therefore produced by screws 54.

Figure 3a shows the development of the blade 43 before folding. This has a non-uniform width. The end 55 has a hole 56 intended for the passage of the cap screw 54.

Figure 3b shows the blade 43 after folding, as that she went up on the mine. At its lowest width 1, it has several folds.

The fold 57, which bears against the end 42 of the latch 6, includes a flat surface of dimensions slightly larger than the diameter of the latch 6.

The two folds 58a and 58b are intended to come in contact with the internal surface of the launch tube 3 and are located symmetrically with respect to the fold 57 so to ensure a perfect distribution of the pressure forces.

The provision of folds for the purpose of ensuring exercise a pressing force on the end 42 of the following latch 6 an axial direction thereof. This avoids everything jamming of the bolt when placing the machine explosive in the launch tube.

The last two folds 59a and 59b are intended for press the blade against the body of mine 1 at level of a groove 60 (fig 2) whose usefulness will be specified later.

Figure 4 is a partial view, in the direction F in Figure 2.

The blade 43 has a width 1 less than the width of the opening 53 of the tongue 44 so as not to interfere with the latter when setting up the mine in the cargo shell.

The blade 43, penetrating inside the groove 60 by the folds 59a and 59b is held laterally which avoids its torsional deformation which could be generated during the firing of the cargo shell which is subjected to a very strong angular acceleration.

Figure 6 shows in partial section a half view of mine 1 placed in its launch tube 3 which is, in in the case of a cargo shell, the wall of the latter.

The introduction of mine 1 into the launch tube 3 causes deformation of the blade 43. The pressure force on latch 6, determined by the dimensioning and the material of the blade 43, is such that the elastic limit of the latter is reached without the resistance limit at break is not exceeded: the blade 43 works thus in its plastic phase. This causes constant effort on latch 6 and compensates for any variation important dimensional tolerances.

The dimension and material of the blade 43 will be also determined by taking into account the value of the centrifugal force generated by the rotation of the shell. In effect it must not deform the blade beyond its breaking strength limit.

It is therefore no longer necessary to perform the slightest measurement, which makes it possible to envisage an automation of integration of mines into the cargo shell.

The material of the blade 43 will be chosen from so that it has a relationship between its Resistance to the maximum rupture (Rm) and its elastic resistance (Rp0,2) (practical resistance at 20% defined by French standard NF EN 10002-1) as well as a high elongation A. One could for example use as material constituting the blade 43, steel grade 35 NCD 16 according to standard French NF A 35552.

The various folds are made in the form of rounding and not a sharp angle, which allows a reduction in stress concentrations through better distribution some efforts.

The distribution of forces is also improved by the presence of the two folds 59a and 59b which receive in part of the pressure efforts developed during the introduction of the explosive device into the tube launch.

It will be noted, in FIG. 5, that the fold 59b receives advantageously the end 61 of the tongue 44.

Alternatively, one can very well envisage carrying out the blade 43 secured to a tongue 44, as shown in Figures 6 and 7.

The blade 43 is cut from the tongue 44.

When the mine was unloaded from the cargo shell, the tabs 44 open and deform so permanent by driving the blade 43 which releases the lock 6.

Figure 8 shows the safety device and arming of Figure 1 according to a third mode of realization of the invention.

The blade 43 is made integral with the explosive device 1 by example by means of a connecting screw (not shown) placed at a hole 56 made at the end 55 of the blade 43.

The end 42 of the latch 6 bears against the blade 43 which is constrained during the introduction of the machine explosive inside the launch tube 3.

The pressure force on the latch 6 is determined by the sizing and material of the blade 43. It is such that the elastic limit of the blade is reached without being exceeded the breaking strength limit, the blade thus working in its plastic phase. This causes constant effort on latch 6 and compensates any significant variation in dimensional tolerances.

It is therefore no longer necessary to perform the slightest measured.

The blade 43 has several folds, a fold 57 which abuts against the end 42 of the latch 6 and two folds 58a and 58b which are intended to come into contact with the internal surface of the launch tube 3. The two folds 58a and 58b are located substantially symmetrically by compared to the fold 57 in order to ensure perfect distribution pressure efforts.

The provision of folds for the purpose of ensuring exercise a pressing force on the end 42 of the following latch 6 an axial direction thereof. This avoids everything jamming of the bolt when placing the machine explosive in the launch tube.

The distribution of forces is improved by the shape rounded folds which avoid a concentration of constraints.

The material of the blade 43 will be chosen from so that it has a relationship between its Resistance to the maximum rupture (Rm) and its elastic resistance (Rp0,2) (practical resistance at 20% defined by French standard NF EN 10002-1) as well as a high elongation A. One could for example use as a constituent material of blade 43, steel grade 35 NCD 16 according to the standard French NF A 35552.

Claims (5)

1. A safety and arming device (2) for an explosive device (1) such as a mine, rocket or missile launched from a launcher tube (3), which comprises a primer-carrying shutter (4) immobilized by at least one lock (6) intended to be held in place by an inner surface of the launcher tube, characterized in that it incorporates a blade (43) intended to come between the inner surface of the launcher tube (3) and the lock (6) by exerting a substantially constant load on the latter and intended to ensure that the lock is held in place by the tube in the locked shutter position, the blade being deformed beyond its yield strength without exceeding its breaking point when the explosive device is in place in the launcher tube.
2. A safety and arming device according to Claim 1, characterized in that the blade (43) comprises at least three folds, a first fold (57) pressing against the lock, the two other folds (58a,58b) pressing against an inner surface of the launcher tube, when the latter is in place in the launcher tube.
3. A safety and arming device according to either one of Claims 1 or 2, characterized in that the blade (43) comprises at least five folds, a first fold (57) pressing against the lock, two other folds (58a, 58b) pressing against the inner surface of the launcher tube and the last two (59a, 59b) pressing against the body of the explosive device, when the latter is in place in the launcher tube.
4. A safety and arming device according to any one of Claims 1 to 3, characterized in that the blade (43) is integral with one of the faces of the explosive device.
5. A safety and arming device for an explosive device of the mine type fitted with stabilizing tabs (44) according to any one of Claims 1 to 3, characterized in that the blade (43) is integral with one of the tabs.

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