Percussion pyrotechnic device for a pyrotechnic gas generator and associated coupling device for coupling between an airbag and a pyrotechnic gas generator

Abstract

The invention relates to a percussion pyrotechnic device (3) for a pyrotechnic gas generator (4), comprising a body (30) internally housing a pyrotechnic charge and a perforator, said body being extended by a proximal end piece (34) delimiting an interior channel able to be placed in communication with a gas cartridge (2), wherein said proximal end piece has an exterior circumferential section (37), flanked by two seals (38), at least one radial exhaust hole (40) being provided in said exterior circumferential section between the two seals, the at least one radial exhaust hole opening into said interior channel. The invention finds an application in an inflatable protection system, particularly a personal inflatable protection system having an airbag to be inflated in the event of a fall.

Description

[0001] DESCRIPTION

[0002] TITLE: Pyrotechnic percussion device, for a pyrotechnic gas generator, and associated coupling device for coupling between an airbag and a pyrotechnic gas generator

[0003] [Technical field]

[0004] The invention relates to a pyrotechnic percussion device for a pyrotechnic gas generator, as well as to a coupling device for coupling between an airbag and a pyrotechnic gas generator.

[0005] The invention finds an application for an inflatable protection system, and in particular a personal inflatable protection system which provides an inflatable cushion to be inflated in the event of a fall, for the purpose of cushioning and therefore protecting the wearer by minimizing the risk of injury at the time of impact with the ground.

[0006] This invention is particularly of interest for the protection of elderly people whose constitution and bones become fragile with age and whose sense of balance may diminish, particularly with walking difficulties and certain illnesses such as Parkinson's.

[0007] A favorite, but not limited, application is the protection of the hips and pelvis, to prevent fracture of the upper part of the femur, or femoral neck.

[0008] [State of the art]

[0009] In a known manner, a pyrotechnic gas generator comprises a gas cartridge containing a pressurized gas and having a mouth closed by a closure element, and a pyrotechnic percussion device comprising a pyrotechnic charge which can be activated by an electrical signal, via a connection cable, during a predetermined condition (for example in the event of a fall detected by a suitable detector). This pyrotechnic percussion device comprises a perforator which is moved to pierce the closure element under the effect of the combustion gases generated by the pyrotechnic charge.

[0010] It is thus necessary to seal the pyrotechnic gas generator to the airbag so that the pressurized gas contained in the gas cartridge escapes into the airbag when the pyrotechnic charge is activated. Document FR3055858 describes an example of an inflatable protection system which comprises a tubular “T” shaped body having two opposite axial orifices, with a proximal axial orifice in which the mouth of the gas cartridge is mounted, and a distal axial orifice in which the pyrotechnic percussion device is mounted, and a radial orifice which communicates with the airbag.

[0011] However, such a system is impractical to use, especially when the gas cartridge and the pyrotechnic percussion device have to be replaced after a trigger, because one has to be removed first and then the other; and furthermore, the tubular "T" body is not very suitable, in terms of size, for being worn by a person, for example on a belt placed around the waist.

[0012] Document US2022 / 0095709 proposes the integration of a pyrotechnic gas generator into a belt for the deployment of an airbag intended to protect the wearer's hips and pelvis. However, the solution proposed in this document is not very suitable for easy replacement after deployment.

[0013] [Summary of the invention]

[0014] The invention proposes to address this replacement problem by proposing a pyrotechnic percussion device and an associated coupling device which allow the pyrotechnic gas generator to be easily changed after activation and inflation of the airbag.

[0015] Another aim of the invention is to reduce the size of the inflatable protection system, and in particular of the coupling device and the pyrotechnic gas generator.

[0016] To this end, the invention proposes a pyrotechnic percussion device, for a pyrotechnic gas generator, comprising a body internally housing a pyrotechnic charge and a perforator, said body being extended by a proximal end piece delimiting an internal channel capable of being placed in communication with a gas cartridge, in which said proximal end piece has an external circumferential section, framed by two seals, at least one radial exhaust hole being provided in said external circumferential section between the two seals, the at least one radial exhaust hole opening into said internal channel.

[0017] Such a solution is particularly advantageous because it will make it possible to reduce the size of the pyrotechnic percussion device, and therefore of the pyrotechnic gas generator as a whole, by providing a radial exhaust, between the two joints, through the radial exhaust hole(s) provided in a proximal end piece adapted to be connected to the gas cartridge. This solution thus makes it possible to reduce the length of the pyrotechnic gas generator, and to facilitate the replacement of this pyrotechnic gas generator.

[0018] According to one feature, the outer circumferential section has a peripheral groove in which the at least one radial escape hole is provided.

[0019] Such a peripheral groove allows the radial exhaust hole(s) to be set back, and thus smaller seals to be used to improve radial compactness.

[0020] In a particular embodiment, both seals are O-rings.

[0021] According to one possibility, the proximal tip has internally a coupling portion shaped for coupling to a mouthpiece of the gas cartridge.

[0022] This coupling portion promotes the watertight mounting of the proximal tip on the mouth of the gas cartridge; this coupling portion can for example be shaped for a screw coupling on the mouth, or alternatively a bayonet coupling or any other form of coupling.

[0023] Alternatively, the body is extended by a distal tip, opposite the proximal tip, this distal tip having a reversible locking element to allow reversible locking of the pyrotechnic percussion device on a complementary locking orifice of a coupling device for an airbag.

[0024] Thus, the pyrotechnic percussion device can be easily locked onto the coupling device which forms an interface element (or intermediate element) between this pyrotechnic percussion device and the inflatable cushion; thus the assembly of the pyrotechnic percussion device is made easier and more reliable, because it will be sufficient to ensure this locking, concomitantly with the tight communication necessary for the release of the pressurized gas towards the inflatable cushion.

[0025] According to one variant, the reversible locking element is a rotation locking element comprising an oblong stop element adjacent to a peripheral groove, such as for example a quarter-turn rotation locking element.

[0026] Such a rotational lock consists of locking by a simple rotation which will bring complementary elements into abutment, such as for example by a rotation of 90 degrees (quarter turn) or any other suitable angle. According to other variants, the reversible locking element is chosen from a bayonet locking element, a screw locking element, a snap-in locking element.

[0027] The invention also relates to a pyrotechnic gas generator comprising a gas cartridge and a pyrotechnic percussion device according to the invention as described above, this gas cartridge containing a pressurized gas and having a mouthpiece provided internally with a closure element, and in which this mouthpiece is mounted in the proximal end piece of the pyrotechnic percussion device to be in communication with its internal channel, and the perforator is adapted to pierce the closure element upon activation of the pyrotechnic charge to put the pressurized gas in communication with the internal channel for an escape through the at least one radial escape hole.

[0028] The invention also relates to a coupling device for coupling between an airbag and a pyrotechnic percussion device according to the invention as described above, this coupling device comprising:

[0029] - a connecting interface having an interface opening shaped for a sealed connection with an inflation valve of the airbag,

[0030] - a mounting sleeve secured to the connecting interface, extending along a main axis and capable of internally receiving the outer circumferential section of the proximal tip of the pyrotechnic percussion device; in which the mounting sleeve comprises a cylindrical wall crossed by at least one outlet orifice in communication with the interface opening.

[0031] In other words, this coupling device forms an interface element between the pyrotechnic percussion device (and therefore the pyrotechnic gas generator) and the airbag, and furthermore this coupling device is complementary in its design to that of the pyrotechnic percussion device, because once these two devices are coupled, the radial exhaust hole(s) provided in the proximal end piece will be in sealed communication with the mounting sleeve and especially with the outlet orifice(s), so that the pressurized gas can escape from the gas cartridge towards the airbag.

[0032] According to another possibility, this coupling device comprises a plate secured to the connecting interface and spaced from the mounting sleeve along the main axis, said plate being provided with a complementary locking orifice centered on the main axis and capable of cooperating with a reversible locking element of the pyrotechnic percussion device to allow reversible locking of the pyrotechnic percussion device on said plate.

[0033] Such a plate, with its additional locking hole, is particularly advantageous for locking the pyrotechnic percussion device on the coupling device, and therefore blocking in translation in both directions of translation along the main axis (or longitudinal axis), thus making maintenance and sealing more reliable and easier.

[0034] In a particular embodiment, a slot is provided in the tray to open into the complementary locking hole in order to allow passage of at least one connection cable exiting the pyrotechnic percussion device.

[0035] Such a slot is thus very practical for passing at least one connection cable and thus facilitating assembly, without having to dismantle or partially disconnect this at least one connection cable.

[0036] In a particular embodiment, the complementary locking orifice is delimited internally by an oblong circumference in order to be able to cooperate in locking with the reversible locking element which is a rotation locking element comprising an oblong stop element adjacent to a peripheral groove.

[0037] Alternatively, the complementary locking orifice is shaped to be able to cooperate in locking with the reversible locking element chosen from a bayonet locking element, a screw locking element, a snap-in locking element.

[0038] Advantageously, the plate is connected to the mounting sleeve by a chute which extends the mounting sleeve to the plate; which is advantageous for guiding the pyrotechnic percussion device towards the complementary locking hole.

[0039] According to one possibility, the at least one outlet orifice extends radially relative to the main axis; in other words, it extends in a direction orthogonal to the main axis.

[0040] According to another possibility, the connecting interface comprises a base having an upper face from which the mounting sleeve projects, and a lower face opposite the upper face and in which the interface opening is provided in communication with the at least one outlet orifice of the mounting sleeve. The invention also relates to an inflatable protection system comprising a coupling device according to the invention, and an inflatable cushion, in which the connecting interface of the coupling device is secured to an inflation valve of the inflatable cushion so that this inflation valve is in sealed connection with the interface opening and with the at least one outlet orifice.

[0041] According to one feature, the inflatable protection system further comprises a pyrotechnic percussion device according to the invention, in which the outer circumferential section of the proximal end piece of the pyrotechnic percussion device is mounted in a sealed manner in the mounting sleeve of the coupling device, so that the at least one radial exhaust hole is in communication with the at least one outlet orifice and therefore with the inflation valve of the airbag.

[0042] According to another characteristic, the inflatable protection system, the distal tip of the pyrotechnic percussion device is held and locked on the plate of the coupling device for translational locking along the main axis, by cooperation between the reversible locking element of said distal tip and the complementary locking orifice of said plate.

[0043] According to another characteristic, the pyrotechnic percussion device comprises at least one connection cable which comes out of its distal tip and which is engaged through the slot provided in the plate.

[0044] According to another characteristic, the inflatable protection system further comprises a gas cartridge containing a pressurized gas and having a mouthpiece provided internally with a sealing element, where this mouthpiece is mounted in the proximal end piece of the pyrotechnic percussion device to be in communication with its internal channel, and the perforator is adapted to pierce the sealing element upon activation of the pyrotechnic charge to put the pressurized gas in communication with the internal channel for an escape through the at least one radial escape hole in order to inflate the inflatable cushion.

[0045] The invention finally relates to a personal safety device comprising an individual accessory capable of being worn on a wearer, this individual accessory supporting at least one inflatable protection system according to the invention.

[0046] In an advantageous application, this individual accessory is a belt adapted to be worn around the waist of the wearer, for protection of the pelvis or hips of the wearer during inflation of the airbag of the at least one inflatable protection system. [Brief description of the figures]

[0047] Other characteristics and advantages of the present invention will appear on reading the detailed description below, of a non-limiting example of implementation, made with reference to the appended figures in which:

[0048] [Fig 1] is a schematic view of a coupling device according to the invention, mounted on an airbag, seen from the outside of the airbag;

[0049] [Fig 2] is a schematic view is a schematic view of the coupling device of Figure 1, mounted on the airbag, seen from the inside of the airbag;

[0050] [Fig 3] is a schematic view of a pyrotechnic gas generator according to the invention, comprising a gas cartridge coupled to a pyrotechnic percussion device according to the invention, with the coupling device of Figure 1 during a connection phase;

[0051] [Fig 4] is a schematic view of the pyrotechnic gas generator of Figure 3 connected and locked to the coupling device;

[0052] [Fig 5] is a schematic view of the pyrotechnic gas generator alone;

[0053] [Fig 6] is an exploded schematic view in axial section of the pyrotechnic gas generator;

[0054] [Fig 7] is a schematic view in assembly and in axial section of the pyrotechnic gas generator;

[0055] [Fig 8] is a schematic view of the pyrotechnic percussion device (without the gas cartridge) before its connection to the coupling device;

[0056] [Fig 9] is another schematic view of the pyrotechnic percussion device before its connection to the coupling device;

[0057] [Fig 10] is another schematic view, this time from below, of the pyrotechnic percussion device before its connection to the coupling device;

[0058] [Fig 11] is a schematic view of the pyrotechnic percussion device during its connection to the coupling device;

[0059] [Fig 12] is another schematic view of the pyrotechnic percussion device during its connection to the coupling device;

[0060] [Fig 13] is a schematic view of the pyrotechnic percussion device at the end of its connection and locking on the coupling device;

[0061] [Fig 14] is a schematic view of a personal safety device comprising a belt incorporating two inflation systems according to the invention; [Fig 15] is a schematic view of the personal safety device of Figure 14, without the pyrotechnic gas generators on the two inflation systems.

[0062] [Detailed description of one or more embodiments of the invention]

[0063] With reference to the Figures, an inflatable protection system according to an exemplary embodiment of the invention mainly comprises four elements:

[0064] - an inflatable cushion 1 (partially visible in Figures 1 and 2) having an inflation valve 10 for introducing pressurized gas in order to inflate said inflatable cushion 1;

[0065] - a gas cartridge 2 containing a pressurized gas and having a mouth 20 provided internally with a sealing element 21, in order to seal the evacuation of the pressurized gas;

[0066] - a pyrotechnic percussion device 3 coupled to the gas cartridge 2 to together form a pyrotechnic gas generator 4; and

[0067] - a coupling device 5 for coupling between the airbag 1 and the pyrotechnic percussion device 3.

[0068] The pyrotechnic percussion device 3 comprises a cylindrical body 30 internally housing a pyrotechnic charge 31 and a perforator 32 (illustrated schematically in Figures 6 and 7), this pyrotechnic charge 31 being connected to at least one connection cable 33 exiting the pyrotechnic percussion device 3 for connection with an activation unit (not illustrated) adapted to activate the pyrotechnic charge 31 by an electrical signal, via the at least one connection cable 33, so that the perforator 32 can be moved to pierce the closure element 21 of the gas cartridge 2 under the effect of the combustion gases generated by the pyrotechnic charge 31. This at least one connection cable 33 ends with a connection member 330 (illustrated in Figure 4) of the plug or connector type, male or female.

[0069] This body 30 extends along a longitudinal axis X and is extended longitudinally by a proximal end piece 34 delimiting an internal channel 35 and which internally has a coupling portion 36 (in communication with the internal channel 35) shaped for coupling to the mouth 20 of the gas cartridge 2. If the mouth 20 of the gas cartridge 2 is in the form of a threaded mouth (in other words with an external thread 22 shown diagrammatically in Figure 6), then the coupling portion 36 has a thread suitable for coupling by screwing onto this threaded mouth. Thus, this internal channel 35 is able to be placed in communication with the gas cartridge 2, in other words the mouth 20 of the gas cartridge 2 is able to be mounted in the proximal end piece 34 to be in communication with its internal channel 35.

[0070] This proximal end piece 34 has an external circumferential section 37, of cylindrical shape, framed by two seals 38 (which are here O-rings) and in which is formed a peripheral groove 39 in which is provided at least one radial escape hole 40; this at least one radial escape hole 40 being thus provided between the two seals 38 to open into the internal channel 35.

[0071] Thus, when the proximal tip 34 is coupled to the mouth 20 of the gas cartridge 2, the perforator 32 is located opposite the closure element 21 in order to be able to pierce the latter so that the pressurized gas is evacuated into the internal channel 35 and escapes radially through the at least one radial exhaust hole 40, between the two seals 38. In the example illustrated, the at least one radial exhaust hole 40 comprises several radial exhaust holes 40 distributed over the circumference of the peripheral groove 39.

[0072] This body 30 is extended longitudinally by a distal tip 41, opposite the proximal tip 34, this distal tip 41 having a reversible locking element 42 to allow reversible locking of the pyrotechnic percussion device 3 on a complementary locking orifice 50 of the coupling device 5 described in more detail later. The at least one connection cable 33 opens or exits from this distal tip 41.

[0073] The coupling device 5 comprises a connecting interface 51 having an interface opening 52 (visible in Figures 2 and 10) shaped for a sealed connection with the inflation valve 10 of the airbag 1. This connecting interface 51 comprises a plate-shaped base 53 intended to be housed in a secure and sealed manner in an opening of the inflation valve 10, for example between two walls or sheets of the airbag 1 (in Figure 2 a single wall or sheet is illustrated).

[0074] This base 53 has two opposite faces, which are:

[0075] - an upper face 530 facing the outside of the airbag 1; and

[0076] - a lower face 531 facing the inside of the airbag 1 and in which the interface opening 52 is provided.

[0077] The coupling device 5 further comprises two members which are integral with the connecting interface 51 and which project from the upper face 530 of the base 53, namely:

[0078] - a mounting sleeve 54 extending along a main axis (which in situation coincides with the longitudinal axis X of the pyrotechnic percussion device 3) and capable of internally receiving the external circumferential section 37 of the proximal tip 34 of the pyrotechnic percussion device;

[0079] - a plate 55 spaced from the mounting sleeve 54 along the main axis, this plate 55 being provided with the complementary locking orifice 50 centered on the main axis and capable of cooperating with the reversible locking element 42 of the pyrotechnic percussion device 3 to allow reversible locking of the pyrotechnic percussion device 3 on this plate 55.

[0080] The mounting sleeve 54 comprises a cylindrical wall crossed by at least one outlet orifice 56 (visible in Figures 2, 8 and 10) in communication with the interface opening 52, and thus the inflation valve 10 is in sealed connection with the interface opening 52 and with this at least one outlet orifice 56. In the illustrated example, this at least one outlet orifice 56 comprises a single window-shaped outlet orifice 56.

[0081] In other words, this at least one outlet orifice 56 is provided on the underside, on the side of the base 53, in order to put the interior of the mounting sleeve 54 in communication with the interface opening 52, and therefore ultimately put the interior of the mounting sleeve 54 in communication with the inflation valve 10 of the airbag 1.

[0082] The conformation of this coupling device 5, the distance between the mounting sleeve 54 and the plate 55, is such that when coupling the pyrotechnic percussion device 3 (and therefore the pyrotechnic gas generator 4) to the coupling device 5:

[0083] - the distal tip 41 is held and locked on the complementary locking orifice 50, by cooperation between the reversible locking element 42 and the complementary locking orifice 50, thus blocking the pyrotechnic percussion device 3 in translation along the longitudinal axis X in both directions; and

[0084] - the outer circumferential section 37 of the proximal tip 34 is mounted in a sealed manner in the mounting sleeve 54, with the two seals 38 which ensure this sealing by being fitted in a fitted manner inside the mounting sleeve 54, and so that the at least one radial exhaust hole 40 is in communication with the at least one outlet orifice 56 and therefore with the inflation valve 10 of the airbag 1.

[0085] Thus, the peripheral groove 39 is positioned at the level of the at least one outlet orifice 56, so that the radial exhaust of the pressurized gas through the at least one radial exhaust hole 40 extends towards the inflation valve 10 of the airbag 1 to inflate the latter.

[0086] Advantageously, the plate 55 is connected to the mounting sleeve 54 by a chute 57 which extends the mounting sleeve 54 to the plate 55. This chute 57 therefore projects from the upper face 530 of the base 53, and it serves to guide the pyrotechnic percussion device 3 (and therefore the pyrotechnic gas generator 4) during its coupling with the coupling device 5. The chute 57 has a half-cylinder shape having the same diameter as the mounting sleeve 54.

[0087] Furthermore, a slot 58 is provided in the plate 55, for example in a median plane including the main axis, to open into the complementary locking orifice 50. Such a slot 58 thus allows passage of the at least one connection cable 33 coming out of the pyrotechnic percussion device 3, when coupling the pyrotechnic percussion device 3 to the coupling device 5, as illustrated in Figure 3.

[0088] Indeed, if the connection member 330, which is at the end of the at least one connection cable 33, is too large to pass through the complementary locking orifice 50, then this slot 58 will allow the distal tip 41 to be placed through the complementary locking orifice 50 without having to disconnect the connection member 330 from the at least one connection cable 33.

[0089] In the illustrated example, the reversible locking element 42 provided on the distal tip 41 is a quarter-turn rotation locking element, and it comprises an oblong stop element 43 adjacent a peripheral groove 44.

[0090] This oblong stop element 43 is of substantially rectangular shape, and it has two rectilinear longitudinal sides along its length and two arcuate lateral sides along its width; the arcuate lateral sides following a circular contour, and preferably a circular contour of the same diameter as that of the body 30.

[0091] The complementary locking orifice 50 is of a shape complementary to that of the oblong stop element 43 and is thus delimited internally by an oblong circumference in order to be able to cooperate in locking with the reversible locking element 42. This oblong circumference is therefore of substantially rectangular shape, and it has along its length two rectilinear longitudinal edges and along its width two arcuate lateral edges; the arcuate lateral edges following a circular contour of substantially the same diameter as that of the arcuate lateral sides. Thus, when coupling the pyrotechnic percussion device 3 to the coupling device 5, the oblong stop element 43 is aligned with the complementary locking hole 50 (as illustrated in Figures 3, 8, 9, 11 and 12) to be able to pass through, then the pyrotechnic percussion device 3 is turned a quarter turn (90 degrees) in order to lock it (as illustrated in Figures 4 and 13).

[0092] A boss 59 may be placed behind the plate 55 and have a concave bearing surface, having an arcuate shape complementary to that of the arcuate lateral sides of the oblong stop element 43, so that once locked by a quarter turn, one of these arcuate lateral sides is housed and wedged on this concave bearing surface of the boss 59 (as visible in Figure 13), thus making the pyrotechnic percussion device 3 more reliable to be held in position and locked.

[0093] In variants not shown, the reversible locking element and the complementary locking hole are shaped to together form a bayonet locking means, a screw locking means, or a snap-in locking means.

[0094] With reference to Figures 14 and 15, such an inflatable protection system may be integrated into a belt 6 adapted to be worn around the wearer's waist, thus forming a personal safety device 7 for protection of the wearer's pelvis or hips during inflation of the airbag 1. The airbag 1 may be folded or rolled up to occupy a restricted space within the belt 6.

[0095] In this pelvic or hip protection application, it is conceivable, as in the illustrated example, to have two such inflatable protection systems 1, on the right and on the left.

Claims

DEMANDS 1. Pyrotechnic percussion device (3), for a pyrotechnic gas generator (4), comprising a body (30) internally housing a pyrotechnic charge (31) and a perforator (32), said body (30) being extended by a proximal tip (34) delimiting an internal channel (35) suitable for communication with a gas cartridge (2), in which said proximal tip (34) has an external circumferential section (37), framed by two seals (38), at least one radial exhaust hole (40) being provided in said external circumferential section (37) between the two seals (38), the at least one radial exhaust hole (40) opening into said internal channel (35).

2. Pyrotechnic percussion device (3) according to claim 1, wherein the outer circumferential section (37) has a peripheral groove (39) in which at least one radial escape hole (40) is provided.

3. Pyrotechnic percussion device (3) according to claim 1 or 2, wherein the proximal tip (34) has internally a coupling portion (36) shaped for coupling to a mouthpiece (20) of the gas cartridge (2), for example a screw coupling.

4. Pyrotechnic percussion device (3) according to any one of claims 1 to 3, wherein the body (30) is extended by a distal tip (41), opposite the proximal tip (34), said distal tip (41) having a reversible locking element (42) to allow reversible locking of the pyrotechnic percussion device (3) onto a complementary locking orifice (50) of a coupling device (5) for an airbag (1).

5. Pyrotechnic percussion device (3) according to claim 4, wherein the reversible locking element (42) is a rotational locking element comprising an oblong stop element (43) adjacent to a peripheral groove (44), such as, for example, a quarter-turn rotational locking element.

6. Pyrotechnic percussion device (3) according to claim 4, wherein the reversible locking element is selected from a bayonet locking element, a screw locking element, a snap-locking element.

7. Pyrotechnic gas generator (4) comprising a gas cartridge (2) and a pyrotechnic percussion device (3) according to any one of claims 1 to 6, said gas cartridge (2) containing a gas under pressure and having a mouthpiece (20) internally provided with a sealing element (21), in which said mouthpiece (20) is mounted in the proximal end (34) of the pyrotechnic percussion device (3) to be in communication with its internal channel (35), and the perforator (32) is adapted to pierce said sealing element (21) upon activation of the pyrotechnic charge (31) to bring the gas under pressure into communication with the internal channel (35) for escape through at least one radial escape hole (40).

8. Coupling device (5) for coupling between an airbag (1) and a pyrotechnic percussion device (3) according to any one of claims 1 to 6, said coupling device (5) comprising: - a connecting interface (51) having an interface opening (52) shaped for a tight connection with an inflation valve (10) of the inflatable cushion (1), - a mounting sleeve (54) integral with the linking interface (51), extending along a principal axis and adapted to internally receive the external circumferential section (37) of the proximal tip (34) of the pyrotechnic percussion device (3); in which the mounting sleeve (54) comprises a cylindrical wall traversed by at least one exit orifice (56) in communication with the interface opening (52).

9. Coupling device (5) according to claim 8, comprising a plate (55) integral with the linking interface (51) and spaced from the mounting sleeve (54) along the main axis, said plate (55) being provided with a complementary locking orifice (50) centered on the main axis and adapted to cooperate with a reversible locking element (42) of the pyrotechnic percussion device (3) to allow reversible locking of the pyrotechnic percussion device (3) on said plate (55).

10. Coupling device (5) according to claim 9, in which a slot (58) is provided in the plate (55) to open into the additional locking orifice (50) in order to allow passage of at least one connecting cable (33) coming out of the pyrotechnic percussion device (3).

11. Coupling device (5) according to claim 9 or 10, wherein the additional locking orifice (50) is internally delimited by an oblong perimeter so as to be able to cooperate in locking with the reversible locking element (42) which is a rotational locking element comprising an oblong stop element (43) adjacent to a peripheral groove (44).

12. Coupling device (5) according to claim 9 or 10, wherein the additional locking orifice (50) is shaped to be able to cooperate in locking with the reversible locking element selected from a bayonet locking element, a screw locking element, a snap-locking element.

13. Coupling device (5) according to any one of claims 9 to 12, wherein the plate (55) is connected to the mounting sleeve (54) by a channel (57) which extends the mounting sleeve (54) to the plate (55).

14. Coupling device (5) according to any one of claims 8 to 13, wherein at least one outlet orifice (56) extends radially with respect to the main axis.

15. Coupling device (5) according to any one of claims 8 to 14, wherein the connecting interface (51) comprises a base (53) having an upper face (530) from which the mounting sleeve (54) protrudes, and a lower face (531) opposite the upper face (530) and in which the interface opening (52) is provided in communication with at least one output orifice (56) of the mounting sleeve (54).

16. Inflatable protection system comprising a coupling device (5) according to any one of claims 8 to 15 and an inflatable cushion (1), wherein the linking interface (51) of the coupling device (5) is secured to an inflation valve (10) of the inflatable cushion (1) such that said inflation valve (10) is in a sealed connection with the interface opening (52) and with at least one outlet orifice (56).

17. An inflatable protection system according to claim 16, further comprising a pyrotechnic percussion device (3) according to any one of claims 1 to 6, wherein the outer circumferential section (37) of the proximal tip (34) of the pyrotechnic percussion device (3) is mounted in a sealed manner in the mounting sleeve (54) of the coupling device (5), so that at least one radial exhaust hole (40) is in communication with at least one outlet orifice (56) and therefore with the inflation valve (10) of the airbag (1).

18. Inflatable protection system according to claim 17, wherein the pyrotechnic percussion device (3) conforms to claim 4 and the coupling device (5) conforms to claim 9, such that the distal tip (41) of the pyrotechnic percussion device (3) is held and locked onto the plate (55) of the coupling device (5) for translational locking along the main axis, by cooperation between the reversible locking element (42) of said distal tip (41) and the complementary locking orifice (50) of said plate (55).

19. Inflatable protection system according to claim 18, wherein the coupling device (5) conforms to claim 10, and the pyrotechnic percussion device (3) comprises at least one connecting cable (33) which exits from its distal tip (41) and which is engaged through the slot (58) formed in the plate (55).

20. Inflatable protection system according to any one of claims 17 to 19, further comprising a gas cartridge (2), said gas cartridge (2) containing a pressurized gas and having a mouth (20) internally provided with a sealing element (21), in which said mouth (20) is mounted in the proximal tip (34) of the pyrotechnic percussion device (3) to be in communication with its internal channel (35), and the perforator (32) is adapted to pierce said sealing element (21) upon activation of the pyrotechnic charge (31) to bring the pressurized gas into communication with the internal channel (35) for escape through at least one radial exhaust hole (40) in order to inflate the airbag (1).

21. Personal safety device (7) comprising a personal accessory (6) suitable for being worn on a wearer, said personal accessory (6) supporting at least one inflatable protection system conforming to claim 20.

22. Personal protective device (7) according to claim 21, wherein said personal accessory (6) is a belt suitable for being worn around the waist of the wearer, for protection of the pelvis or hips of the wearer during inflation of the airbag (1) of at least one inflatable protection system.

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