EP1680381B1 - Method of producing a device for the multipath transmission of a pyrotechnic command - Google Patents

Description

TECHNICAL AREA

The present invention relates generally to the dominant of multichannel transmission devices of a pyrotechnic order comprising a lateral transmission pyrotechnic relay, and more particularly to their manufacturing processes.

As an indication, this type of transmission device can be used in any kind of pyrotechnic system, and in particular in any pyrotechnic system of civil or military vehicles, such as an aircraft.

STATE OF THE PRIOR ART

The multichannel transmission devices of a pyrotechnic order comprising a lateral transmission pyrotechnic relay are well known in the prior art, in particular for their high level of reliability in the transmission of the pyrotechnic order. This type of relay generally has an envelope comprising a flat portion intended to be facing a plurality of ends of pyrotechnic input and output lines.

The document FR 2 519 784 describes in particular a multi-channel transmission device for the transmission of a pyrotechnic order, the device comprising an explosive band whose detonation causes the raising of a movable plate to output relays.

This flat portion of the envelope is in fact intended to be projected against the ends of the output pyrotechnic lines during the detonation of the pyrotechnic relay, in order to transmit the pyrotechnic order to these same lines.

Moreover, it is also known that in order to obtain an effective projection of the flat portion of the envelope during the detonation of the pyrotechnic relay, this projection being also called "plate bearing", it is not only necessary to provide that the relay envelope has a flat portion opposite the ends of lines, but this envelope must also respect specific and precise dimensions, and be made using a metallic material such as lead, aluminum or aluminum. one of its alloys.

All these conditions necessary for obtaining good priming of the ends of the pyrotechnic output lines, by plate recovery, imply that pyrotechnic lateral transmission relays are extremely difficult and expensive to manufacture, especially when using dies. for the continuous realization of the envelope of these relays.

STATEMENT OF THE INVENTION

The purpose of the invention is therefore to propose a multi-directional transmission device of a pyrotechnic order comprising a lateral transmission pyrotechnic relay at least partially overcoming the disadvantages mentioned above relating to the embodiments of the prior art.

• la mise en place, dans une rainure prévue sur le dispositif, d'un cordeau détonant de transmission axiale comprenant une enveloppe ; et
• le formage par pressage, du cordeau détonant de transmission axiale dans la rainure, de manière à ce que le cordeau détonant formé constitue le relais pyrotechnique de transmission latérale disposant d'une portion plane destinée à être en regard de la pluralité d'extrémités des lignes pyrotechniques d'entrée et de sortie et, à ce que le relais pyrotechnique de transmission latérale épouse tout ou partie des parois de la rainure.

To do this, the subject of the invention is a method of manufacturing a device for multichannel transmission of a pyrotechnic junk comprising a lateral transmission pyrotechnic relay, the latter having an envelope comprising a flat portion intended to be facing a plurality of ends of pyrotechnic input and output lines, so that the flat portion is projected against the ends of the pyrotechnic output lines during the detonation of the lateral transmission pyrotechnic relay. According to the invention, the manufacturing method comprises the following steps:

• placing, in a groove provided on the device, an axial transmission detonating cord comprising an envelope; and
• the pressing forming of the axial transmission detonating cord in the groove, so that the formed detonating cord constitutes the lateral transmission pyrotechnic relay having a flat portion intended to face the plurality of ends of the lines; pyrotechnic input and output, and that the pyrotechnic lateral transmission relay fits all or part of the walls of the groove.

Advantageously, in the method according to the invention, the particular dimensions of the lateral transmission pyrotechnic relay are obtained no longer during the initial manufacture of the latter, but by forming a detonating cord of axial transmission inside the the groove. This forming step is performed by exerting a simple pressing on the same cord after it has been placed inside the groove provided for this purpose, in the purpose that its envelope deforms in a predetermined manner by marrying all or part of the walls of this groove.

Therefore, with such a method, the pyrotechnic relay can advantageously be manufactured from an axial transmission detonating cord, preferably of circular section and corresponding to a low-cost product "sold on catalog", and by transforming this axial transmission line into a lateral transmission pyrotechnic relay with a groove whose precise dimensions can be obtained very easily, for example by performing a simple machining.

Thus, the manufacturing method according to the invention is considerably less expensive to implement than those proposed in the prior art, aimed at separately manufacturing the pyrotechnic relay for lateral transmission of the plug of the device, and then assembling these same two elements later. to their manufacture.

Preferably and as mentioned above, the detonating cord of axial transmission is of circular section, and has for example a diameter of about 3.5 mm. Advantageously, this type of cord of low cost is widely used, which helps to make the manufacturing process also inexpensive. In addition, it could be provided that the envelope of the detonating cord of axial transmission is lead, aluminum or in one of its alloys, these materials being indeed quite optimized to ensure a good projection of this envelope during the detonation of the relay.

Preferably, the groove and the lateral transmission pyrotechnic relay are made to each have a substantially rectangular section, this particular geometry being effectively adapted to provide an effect satisfactory plate recovery, and thus a good boot of the ends of the pyrotechnic output lines.

Furthermore, the step of forming by pressing the detonating cord of axial transmission is performed so as to cause the crimping of the latter inside the groove. In this way, it is no longer necessary to proceed to a sticking step of the relay inside the groove, as was the case in the prior art. Thus, in addition to removing the harmful glue in the long run for the pyrotechnic operation of the relay, the automatic obtaining of the crimping of the latter during the forming step directly results in a non-negligible reduction in the time required for the implementation of the method of manufacturing the multichannel transmission device.

Preferably, the groove is made in a plug of the multichannel transmission device, and the method comprises a step of assembling a cover of the multichannel transmission device on the same plug, this step being performed so that a plurality of through holes provided on the cover, are closed at one of their ends by the flat portion of the envelope of the pyrotechnic relay.

Finally, it can be provided that the method further comprises a step of assembling the assembly constituted by the plug with the pyrotechnic relay, and the cover, on a housing of the multichannel transmission device, this step being performed of so that a plurality of through-passages provided on the housing are located respectively in the extension of the through-holes provided on the cover, the through passages of the housing being designed so that each is able to receive a pyrotechnic input line or exit.

Other advantages and features of the invention will become apparent in the detailed non-limiting description below.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 est une vue partiellement éclatée en perspective d'un dispositif de transmission multivoies d'un ordre pyrotechniques comprenant un relais pyrotechnique de transmission latérale, obtenu suite à la mise en oeuvre d'un procédé de fabrication selon un mode de réalisation préféré de la présente invention ; et
• les figures 2a à 2d représentent des vues schématiques de diverses étapes du procédé de fabrication selon le mode de réalisation préféré de la présente invention, conduisant à l'obtention du dispositif de transmission de la figure 1.

This description will be made with reference to the appended drawings among which;

• the figure 1 is a partially exploded view in perspective of a multi-directional transmission device of a pyrotechnic order comprising a lateral transmission pyrotechnic relay, obtained following the implementation of a manufacturing method according to a preferred embodiment of the present invention ; and
• the Figures 2a to 2d represent schematic views of various steps of the manufacturing method according to the preferred embodiment of the present invention, leading to the obtaining of the transmission device of the invention. figure 1 .

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

With reference to the figure 1 , we see a device 1 for multichannel transmission of a pyrotechnic order, this device 1 being obtained following the implementation of a preceded manufacturing in a mode preferred embodiment of the present invention, which will be described in detail later.

The device 1 comprises a casing 2 constituting its main body, this casing 2 being provided with a plurality of through-passages 4, each designed so as to be able to receive a pyrotechnic input or output line 6. In this respect, it is possible to see that the through passages 4 are made to be parallel to each other, and also parallel to a first direction shown schematically by the vertical arrow 7 on the figure 1 . In addition, the pyrotechnic lines 6 are preferably but not exclusively located substantially in the same plane.

In addition, the pyrotechnic lines 6 mounted in the passages 4, for example by screwing, are of the conventional type and preferably capable of being used interchangeably as an input line or output line. By way of illustrative example, the transmission device 1 may be equipped with six identical pyrotechnic lines 6, one or more of which are provided for constituting the input lines of the device 1.

Of course, the number of input lines and the number of output lines can be adapted according to the needs encountered in the specific use of the transmission device 1, it can indeed be used in any kind of pyrotechnic system, is especially in any pyrotechnic system of civil or military vehicles, such as an aircraft.

On the other hand, the housing 2 of the device 1, preferably made of a light alloy, comprises a cylindrical housing 8 inside which is arranged an assembly 10 comprising a plug 12, a lateral transmission pyrotechnic relay 14, and a lid 16 assembled on the plug 12.

The assembly 10 is preferably of cylindrical general shape of circular section, and is arranged substantially parallel to a second direction shown schematically by the horizontal arrow 18 on the figure 1 , this second direction 18 being perpendicular to the first direction 7 above. Therefore, the assembly 10 is substantially perpendicular to the input and output pyrotechnic lines 6, as is clearly visible on the figure 1 . Furthermore, it can also be seen that the passages 4 emerging from the transmission device 1 open on the one hand outside the housing 2, and secondly in the housing 8 perpendicular to these passages 4 and having a complementary shape from that of the set 10.

More specifically, the assembly 10 comprises the plug 12, for example made of steel, and having a groove 20 extending perpendicular to the first direction 7 and parallel to the second direction 18. It is noted that the plug 12 can take the form of a truncated cylinder in a plane parallel to its longitudinal axis, for example so that the portion of cylinder obtained is greater than a half-cylinder.

The pyrotechnic lateral transmission relay 14 is located inside this groove 20, the latter preferably being of substantially rectangular section, in the same way as the relay 14.

In a conventional manner, the pyrotechnic relay 14 comprises an envelope 22, preferably made of lead or aluminum, in which an explosive powder 24 is located.

As mentioned previously, the pyrotechnic relay 14 has a substantially rectangular section whose shape is complementary to that of the section of the groove 20, insofar as the envelope 22 of the relay 14 fully marries the three walls (not referenced) defining the same groove 20.

Of course, in other embodiments of the transmission device 1, the pyrotechnic relay 14 may only partly embrace the walls of the groove 20. Furthermore, it may also be possible to provide a groove 20 having a cross section of the groove 20. a shape other than rectangular, the pyrotechnic relay 14 then again marrying all or part of the walls of this groove 20. In this respect, it is specified that in known manner, the shape of the pyrotechnic relay 14 and that of the groove 20 are chosen so that upon detonation of the relay 14, it can provide a satisfactory plate recovery.

However, it is indicated that a pyrotechnic lateral transmission relay 14 has generally a flat portion 26 substantially perpendicular to the first direction 7, this flat portion 26 being indeed that intended to be projected against the pyrotechnic lines 6 during the transmission of the pyrotechnic order.

So, as we can always see it in reference to the figure 1 , the flat portion 26 of the casing 22 and a plane truncation surface 28 of the plug 12 together form a single flat surface 30 on which the cover 16 can be arranged.

Indeed, when the lid 16 is fixedly assembled on the plug 12, the flat surface 30 is preferably in plane contact with a plane truncation surface 32 of this lid, the latter also taking the form of a truncated cylinder according to a plane parallel to its longitudinal axis.

The cover 16, for example also made of steel, has also a plurality of through holes 34 oriented parallel to the first direction 7, each of these holes 34 being located in the extension of a through passage 4 provided in the housing 2.

Therefore, for each through hole 34, a first end 34a opens at a low end of a passage 4 of the housing, and a second end 34b is closed by the pyrotechnic relay 14, and more particularly by the flat portion 26 of its envelope 22.

Thus, the flat portion 26 is facing one end 36 of each pyrotechnic line input and output 6, each end 36 being actually located inside a through hole 34 extending the opening passage 4 in which is mounted the pyrotechnic line 6 considered.

Therefore, with such an arrangement, when an input pyrotechnic line 6 transmits the pyrotechnic command to the lateral transmission relay 14, the latter detonates causing an extremely reliable plate bearing within each through hole 34 , namely a projection of a portion of the flat portion 26 against the end 36 of the associated pyrotechnic line 6.

Now with reference to Figures 2a to 2d Processes of the manufacturing method according to a preferred embodiment of the present invention will be described, this preferred embodiment being intended to manufacture the transmission device 1 as presented above.

With reference to the figure 2a it can be seen that the plug 12 and its groove 20 are firstly made, for example by machining.

Then, an axial transmission detonating cord 40 is placed inside the groove 20, this detonating cord 40 preferably being of circular section, and having for example a diameter of about 3.5 mm. Thus, at this moment of the implementation of the method, the detonating cord 40 rests by gravity at the bottom of the groove 20, while projecting out of it because of its greater diameter than the depth. groove 20. Moreover, the detonating cord 40 is arranged in this groove 20 so that its longitudinal axis 42 is substantially parallel to the second direction 18 along which extends the same groove 20.

Preferably, the detonating cord 40 used is a standard product whose casing 44 is made indifferently of lead, aluminum or an aluminum alloy.

Once the emplacement of the detonating cord 40 has been carried out, it is then proceeded to a step of forming this cord, by pressing it inside the groove 20. To do this, as can be seen on the figure 2b , the plug 12 is positioned on a support 46, while a press 48 exerts a force on the cord 40 in the first direction 7 towards the bottom of the groove 20, and therefore perpendicular to the longitudinal axis 42 of the cord 40 .

In this way, the detonating cord of axial transmission 40 is deformed under the action of the press 48, and its envelope 44 then gradually marries the three walls of the groove 20. Of course, this pressing forming step is completed when the press 48 comes into plane contact with the flat surface 28 of the plug 12, as shown in FIG. Figure 2c .

At this moment of the implementation of the manufacturing method, the axial transmission cord 40 is such that its envelope 44 embraces the entirety of the walls of the groove 20, and as it presents a flat portion 50 located in the same plane as the plane truncation surface 28 of the plug 12, this flat portion 50 being shown in contact with the press 48 on the Figure 2c . In other words, the axial transmission cord 40 has thus been transformed by forming into the groove 20 to constitute the lateral transmission pyrotechnic relay 14 described above, the flat portion 50 of the cord 40 constituting in fact the portion of FIG. planar envelope 26 for providing the plate projection.

In addition to its simplicity of implementation, this step of forming the detonating cord 40 is advantageous in that it makes it possible simultaneously to ensure the crimping of the pyrotechnic relay 14 obtained inside the groove 20, because of the high forces exerted by the casing 44 on the walls of the groove 20, these forces resulting, of course, from the compression of the detonating cord 40.

It should be noted that in this preferred embodiment of the present invention, the dimensions of the groove 20 and the detonating cord 40 are chosen so that the latter fully embraces the three walls of the groove 20 once the forming step completed, and so that the detonating cord 40 undergoes a predetermined compression ratio during this step. However, it is specified that these dimensions could also be provided so that the envelope 44 marries only a part of these same walls, always with a controlled compression rate of cord 40, without departing from the scope of the invention. .

Then, as is visible on the figure 2d , the lid 16 is rigidly assembled on the plug 12 equipped with the pyrotechnic relay 14. This step can be performed by first contacting the flat surfaces 30 and 32, then by securing the plug 12 and the cover 16, for example using pins. As indicated above, the assembly of the cover 16 on the plug 12 engenders the closure of the second ends 34b of the through holes 34, this closing being effected by means of the flat portion 26 of the envelope 22 of the pyrotechnic relay 14.

Subsequently, the assembly 10 obtained, of cylindrical shape and of substantially circular section, is inserted into the housing 8 of the housing 2 having a shape complementary to that of this assembly 10, so that the first ends 34a of the holes through 34 are located opposite the through passages 4, thus causing them to be in the extension of the through holes 34.

Finally, various conventional operations are then performed in order to obtain the transmission device 1 of the figure 1 , such as the introduction of the pyrotechnic entry and exit lines 6 in their respective passages 4.

Of course, various modifications can be made by those skilled in the art to the method of manufacturing a multi-channel transmission device 1 of a pyrotechnic order which has just been described, solely by way of non-limiting example.

Claims (9)

1. A method of making for a pyrotechnic-type multi-channel transmission device (1), including a lateral transmission pyrotechnic relay (14), the latter equipped with an envelope (22) comprised of a flat portion (26) to face a plurality of input and output pyrotechnic line (6) ends (36) so that the flat portion (26) is projected against the output pyrotechnic line (6) ends during detonation of the lateral transmission pyrotechnic relay (14), characterised in that it includes the following steps:

   - the setting into position, in the designated groove (20) on the device (1), of the axial transmission detonating cord (40), including an envelope (44); and

   - the forming in the said groove (20), by pressing, of the said axial transmission detonating cord (40), so that the formed detonating cord constitutes the pyrotechnic relay for lateral transmission (14), having a flat portion (26) to face the plurality of the input and output pyrotechnic line (6) ends (36) and, so that the lateral transmission pyrotechnic relay (14) adopts all or part of the walls of the groove (20).
2. A method of making according to claim 1, characterised in that the axial transmission detonating cord (40) is of circular section.
3. A method of making according to claim 2, characterised in that that the axial transmission detonating cord (40) has a diameter of approximately 3.5 mm.
4. A method of making according to any one of the preceding claims, characterised in that the envelope (44) of the axial transmission detonating cord (40) is made of material chosen from among the group comprising lead, aluminium and one of its alloys.
5. A method of making according to any one of the preceding claims, characterised in that said groove (20) and said lateral transmission pyrotechnic relay (14) are manufactured in a manner that each one has a substantially rectangular section.
6. A method of making according to any one of the preceding claims, characterised in that the forming step, by pressing said axial transmission detonating cord (40), is carried out in a manner that provokes the crimping of the latter inside said groove (20).
7. A method of making according to any one of the preceding claims, characterised in that said groove (20) is made in a core (12) of the multi-channel transmission device (1).
8. A method of making according to claim 7, characterised in that it includes a step for the assembly of a cover (16) for the multi-channel transmission device (1) over said core (12), this stage being carried out so that a plurality of through holes (34) provided on the cover (16) are sealed at one of their ends (34b) by said flat portion (26) of the envelope (22) of the pyrotechnic relay (14).
9. A method of making according to claim 8, characterised in that it also includes a step for the assembly of the unit (10), comprised of the core (12) equipped with the pyrotechnic relay (14) and the cover (16), on a case (2) for the multi-channel transmission device (1), this step being carried out so that a plurality of emerging passages (4) provided on the case (2) are positioned respectively in the continuity of the through holes (34) provided on the cover (16), the passages emerging (4) from the case (2) being designed so that each one can host an input and output pyrotechnic line (6).

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