PNEUMATIC FLAT INFLATION DEVICE

Abstract

Pneumatic Flat Inflation Device The present invention relates to an inflation device (1) for an inflatable safety vest comprising a storage casing (2) containing a first pressurized gas cartridge (4) and at least one second pressurized gas cartridge (5) arranged side by side to form a row, and a release casing (3) comprising a first perforation device (20) which, upon activation, punctures the first gas cartridge (4) to release the gas it contains in gaseous form, and a second perforation device (30) associated with each second gas cartridge (5) which, upon activation, punctures the latter to release the gas it contains in gaseous form. Fig 1

Description

Title of the invention: PNEUMATIC FLAT INFLATION DEVICE Technical field of the invention

[0001] The present invention relates to the field of prevention and reduction of injuries linked to a fall in general, in particular when practicing motorcycling, skiing or horse riding, and more particularly to an inflation device for an inflatable safety vest. State of the art

[0002] With the democratization of the practice of horse riding and skiing, and in particular so-called "extreme" skiing such as off-piste skiing, efforts have been made to develop systems intended to protect motorcyclists, riders or skiers during falls, and more specifically the most exposed parts of their bodies, such as, for example, the neck, thorax, spine, abdomen and hips.

[0003] Thus, so-called "intelligent" protections have been developed. This type of protection is traditionally made up of a very compact inflatable safety vest capable of being inflated very quickly by a gas, when the wearer falls, to prevent the latter from violently hitting the ground. The operation of this vest is similar to the operation of the "airbags" installed in vehicles.

[0004] Thus, the inflatable vest comprises a waterproof "airbag" pocket capable of being inflated and being integrated into a textile and distributed around the user's body so as to protect certain previously identified areas of the body, said pocket itself being able to be integrated in the form of a lining of a jacket. Said inflatable vest also comprises an inflation device capable of allowing the release of a gas, conventionally carbon dioxide CO2, contained in a liquefied gas cartridge, said inflation device further comprising a perforating member being movable and intended to perforate the end of said gas cartridge provided for this purpose.

[0005] After the wearer falls and the gas is released into the "airbag" pocket of the inflatable safety vest, the inflation device must be returned to its initial state so that it can be reused with the said inflatable safety vest.

[0006] The known inflation devices are certainly effective, but they have the major drawback, on the one hand, of comprising numerous parts making their design and manufacture complex and their reliability suboptimal and, on the other hand, of being difficult to restore to their initial state with a view to a new use. Summary of the invention

[0007] The aim of the present invention is therefore to overcome the drawbacks previously cited and to present an alternative to known inflatable safety vest inflation devices by proposing a reliable, resistant inflation device that is easy to implement and reset.

[0008] In accordance with the first subject of the invention, there is therefore proposed an inflation device for an inflatable safety vest comprising a storage casing containing a first pressurized gas cartridge and at least one second pressurized gas cartridge arranged side by side to form a row and a release casing comprising a first percussion device making it possible, in the event of activation, to perforate the first gas cartridge so as to release the gas that it contains in gaseous form and a second percussion device associated with each second gas cartridge and making it possible, in the event of activation, to perforate the latter so as to release the gas that it contains in gaseous form, said inflation device being remarkable in that said first percussion device comprises at least: - a cylinder whose lower end is non-permanently closed and whose upper end is partly blocked by a stop receiving the first gas cartridge on its upper part, - a piston provided with a perforating end oriented towards the upper end of said cylinder and sliding between a "normal" position in which its perforating end is not in contact with the first gas cartridge and an "activation" position in which said perforating end has perforated said first gas cartridge, - a thrust member capable of moving said piston from its "normal" position to its "activation" position, and - a retaining member allowing said piston to be kept in its "normal" position, in that said second percussion device comprises at least: - a cylinder whose lower end is partly closed and whose upper end is partly blocked by a stop receiving on its upper part the second gas cartridge, and comprising in the upper part at least one discharge orifice connecting the interior of said cylinder and the exterior of the inflation device, - a piston provided with a perforating end oriented towards the upper end of said cylinder and sliding between a "normal" position in which its perforating end is not in contact with the second gas cartridge and an "activation" position in which said perforating end has perforated said second gas cartridge, - a retaining member for holding said piston in its position "normal", and in that the release casing comprises a main conduit putting the upper part of the cylinder of the first percussion device into fluidic connection with the lower end of the cylinder of each second percussion device by means of a secondary conduit opening on one side under the lower end of said cylinder of each second percussion device and on the other into said main conduit in order to convey, in the event of activation, the gas from the first gas cartridge released by the piston to the underside of each piston so as to set it in motion from its "normal" position to its "activation" position.

[0009] The first and second gas cartridges advantageously each comprise a perforable end in the form of a circular cover.

[0010] Advantageously, each discharge orifice is positioned under and as close as possible to the corresponding stop and in that the value of the surface area of ​​said discharge orifice is equal to at least the value of the surface area of ​​the cross-section of the perforable end of said second gas cartridge.

[0011] The cylinder of each second percussion device preferably comprises at least one degassing orifice connecting the interior of said cylinder and the exterior of the inflation device, in order to evacuate the gas between the lower end of said cylinder and the piston in the "activation" position and to allow the return of said piston to its "normal" position.

[0012] The sum of the values ​​of the surface area of ​​the degassing orifice of each second percussion device is advantageously equal to at least the value of the surface area of ​​the cross-section of the perforable end of the first gas cartridge.

[0013] Advantageously, a residual volume Ve remains between the stop of the first percussion device and the upper face of said associated piston in the "activation" position, this residual volume Ve having a height He at least equal to the value of the width of the cross-section of the perforable end of the first gas cartridge.

[0014] The main duct advantageously has an oblong cross-section and the sum of the values ​​of the surface area of ​​the cross-section of the secondary duct associated with each second percussion device is greater than or equal to the value of the surface area of ​​the cross-section of the main duct.

[0015] According to a preferred embodiment, the inflation device is such that the value of Vi / Vo is between 1 and 3, with Vo corresponding to the sum of the values ​​of the residual volume Ve, the volume Vcp of the main conduit and the volumes Vcs of the secondary conduits, and Vi corresponding to the sum of the values ​​of said volume Vo and the volumes Vtph occupied by the gas released in the cylinders of the second percussion devices when the corresponding pistons are in the "activation" position.

[0016] The value of the length of the respective pistons of the first and second percussion devices is advantageously greater than or equal to 1.5 times the value of the diameter of said pistons.

[0017] Preferably, the value of the stroke of the piston of each second percussion device is at most equal to the value of Lt-Lp-Hor, in which Lt designates the length of the cylinder, Lp designates the length of the piston, and Hor designates the height of the discharge orifice.

[0018] The retaining member of the first percussion device is advantageously a pin capable of being engaged simultaneously in a retaining orifice of the release casing and in an imprint provided in the piston to maintain it in the "normal" position, said pin being capable of being secured to a strap mechanically connecting said pin to a fixed point.

[0019] According to an advantageous embodiment, the thrust member of the first percussion device is a helical compression spring arranged between the piston and the lower end of the cylinder, the latter being closed non-permanently by a setting screw cooperating with a thread provided in the release casing under and in the extension of said cylinder.

[0020] The helical compression spring preferably has, on the one hand, a diameter smaller than the diameter of the piston of the first percussion device and, on the other hand, a stiffness and a relaxed length making it possible to obtain a potential energy Epr greater than the energy Epc4 necessary for the perforation of the first gas cartridge.

[0021] According to another advantageous embodiment, the thrust member of the first percussion device is a pyrotechnic charge. Brief description of the figures

[0022] Other advantages and characteristics will emerge more clearly from the following description of an embodiment of the invention with reference to the appended figures in which:

[0023] [Fig.l] is a front view of an inflation device according to the invention,

[0024] [Fig.2] is a horizontal sectional view of the inflation device along axis II - 11' of [Fig.l],

[0025] [Fig.3] is a partial front sectional view of the inflation device according to axis III -III' of [Fig.2]. Description of the embodiments

[0026] Referring to Figures 1 to 3, the inflation device 1 for an inflatable safety vest, not shown in the figures, is shown. Said inflation device 1 comprises a storage casing 2 containing a plurality of gas cartridges, conventionally pressurized carbon dioxide, arranged adjacent to each other. side of the others so as to form a row and a release casing 3 allowing, in the event of activation, that is to say in the example described in the event of the wearer of the inflatable safety vest falling, to perforate each of said gas cartridges so as to release the gas which they contain in gaseous form inside the inflatable safety vest in order to ensure its deployment.

[0027] Said storage casing 2 contains a first gas cartridge 4 and at least one second gas cartridge 5. Furthermore, with reference to the exemplary embodiment shown in the figures, said storage casing 2 advantageously contains a first gas cartridge 4 and three second gas cartridges 5.

[0028] The storage casing 2 is in the general shape of a hollow flattened parallelepiped comprising, advantageously on its lower face, fixing means 6 and is capable of entirely containing the first and second gas cartridges 4, 5 oriented so that their respective perforable end 7, 8 is positioned on the side of said fixing means 6.

[0029] The release casing 3 is in the general shape of a hollow flattened parallelepiped comprising, advantageously on its upper face, complementary fixing means 9 capable of cooperating with the fixing means 6 of the storage casing 2 to guarantee removable fixing of the storage casing 2 and release casing 3 to each other, said fixing also being sealed against the gas contained in said first and second gas cartridges 4, 5.

[0030] However, the storage 2 and release 3 casings may be slightly curved to adapt to the morphology of the human body, as shown in [Fig.2], without departing from the scope of the present invention.

[0031] Here, the term "lower" or "upper" refers to elements or parts of elements located below or above when the inflation device 1 according to the invention is used under normal conditions, that is to say fixed to a vest worn by an individual standing upright, the storage casing 2 then being placed above the release casing 3. These terms lower and upper will need to be adapted if the inflation device 1 is fixed differently under normal conditions.

[0032] Furthermore, here, the term "fixing sealed against the gas contained in said first and second gas cartridges 4, 5" denotes a fixing making it possible to obtain not necessarily an absolute seal which is difficult to achieve, but a seal sufficient to guarantee that the gas released from the first and second gas cartridges 4, 5 spreads into the associated safety vest in sufficient quantity to ensure its complete inflation and not outside the inflation device 1 according to the invention.

[0033] Advantageously, the fixing means 6 of the storage casing 2 and the complementary fixing means 9 of the release casing 3 are, for example, in accordance with those described in patent application FR 3 059 210 filed in the name of the applicant.

[0034] With reference to Figures 2 and 3, the release casing 3 comprises a first percussion device 20 associated with the first gas cartridge 4 and being capable of perforating the perforable end 7 of the latter, in the event of the wearer of the inflatable safety vest falling, so as to release the gas that it contains in gaseous form partly inside said inflatable safety vest in order to ensure its deployment. The gas cartridge 3 is advantageously arranged at one of the ends of the row of first and second gas cartridges 4, 5, but it may also be arranged in the row of first and second gas cartridges 4, 5, without departing from the scope of the present invention.

[0035] The first percussion device 20 advantageously comprises at least: - a cylinder 21 whose lower end is non-permanently closed and whose upper end is partly closed by a stop 22 receiving on its upper part the perforable end 7 of the first gas cartridge 4, - a piston 23 provided with a perforating end 24 oriented towards the upper end of said cylinder 21 and sliding between a "normal" position in which its perforating end 24 is not in contact with the first gas cartridge 4 and an "activation" position in which said perforating end 24 has perforated the perforable end 7 of said first gas cartridge 4, - a thrust member, not shown in the figures, capable of setting said piston 23 in motion from its "normal" position to its "activation" position, and - a retaining member 25 making it possible to maintain said piston 23 in its “normal” position.

[0036] The stop 22 is provided with a bore passing right through it and allowing the passage of the perforating end 24 of the piston 23 so as to perforate the perforable end 7 of said first gas cartridge 4. This stop 22 is furthermore mechanically reinforced to withstand the shocks generated during the perforation of the perforable end 7 of said first gas cartridge 4 by said perforating end 24 of the piston 23.

[0037] According to an advantageous embodiment, said thrust member is a helical compression spring arranged between the piston 23 and the lower end of the cylinder 21, the latter being closed in a non-permanent manner by a setting screw 10 cooperating with a thread 11 arranged in the release casing 3 under and in the extension of said cylinder 21, said setting screw 10 allowing said helical compression spring to be put in place and maintained under a predetermined pressure.

[0038] It is understood that the thrust member could be of a completely different type such as, for example, a pyrotechnic charge, without departing from the scope of the present invention.

[0039] The retaining member 25 is advantageously a pin capable of being engaged simultaneously in a retaining orifice 12 of the release casing 3 and in a recess 26 provided in the piston 23 to maintain it in the "normal" position, said pin being capable of being secured to a strap, not shown in the figures, mechanically connecting said pin to a fixed point of the motorcycle or the saddle of the horse. Thus, in the event of activation, that is to say in the event of the motorcyclist being detached from his motorcycle or the rider from his horse, the tensile force exerted by the strap will disengage the pin and release the piston 23, which under the effect of the thrust exerted by the thrust member will come into the "activation" position and pierce the first gas cartridge 4 so as to release the gas which it contains inside said inflatable safety vest in order to ensure its deployment.

[0040] Furthermore, the release casing 3 comprises a second percussion device 30 associated with each second gas cartridge 5 of the row of first and second gas cartridges 4, 5 and capable of perforating said associated second gas cartridge 5, in the event of the wearer of the inflatable safety vest falling, so as to release the gas that it contains in gaseous form inside said inflatable safety vest in order to ensure its deployment.

[0041] Each second percussion device 30 advantageously comprises at least: - a cylinder 31 whose lower end is closed and whose upper end is partly closed by a stop 32 receiving on its upper part the perforable end 8 of the second gas cartridge 5, - a piston 33 provided with a perforating end 34 oriented towards the upper end of said cylinder 31 and sliding between a "normal" position in which its perforating end 34 is not in contact with the second gas cartridge 5 and an "activation" position in which said perforating end 34 has perforated the perforable end 8 of said second gas cartridge 5, and - a retaining member for maintaining said piston 33 in its “normal” position.

[0042] The cylinder 31 of each second percussion device 30 comprises in the upper part at least one discharge orifice 35 connecting the interior of said release casing 3 and the exterior of the inflation device 1, in order to allow the passage of the gas coming from the second associated gas cartridge 5 towards the interior of said inflatable safety vest. To obtain optimal discharge allowing rapid deployment of the inflatable safety vest, it is understood that each discharge orifice 35 is advantageously positioned under and as close as possible to the corresponding stop 32.

[0043] Furthermore, the cylinder 31 of each second percussion device 30 comprises at least one degassing orifice 36 connecting the interior of the latter and the outside of the inflation device 1, in order to evacuate the gas between the lower end of said cylinder 31 and the piston 33 in the "activation" position and to allow the return of said piston 23 to its "normal" position while avoiding rebound effects.

[0044] According to an advantageous embodiment, the piston 33 of each second percussion device 30 is made from a ferromagnetic material and the associated retaining member is a magnet.

[0045] The respective perforating ends 24, 34 of the pistons 23, 33 are, in a conventional manner, needles of circular cross-section and the respective perforable ends 7, 8 of the first and second gas cartridges 4, 5 are circular covers.

[0046] Furthermore, the release casing 3 comprises a main conduit 13 in the overall shape of a J and putting the upper part of the cylinder 21 of the first percussion device 20 into fluidic connection with the lower end of the cylinder 31 of each second percussion device 30 by means of a generally vertical secondary conduit 14 opening on one side under the lower end of said cylinder 31 of each second percussion device 30 and on the other into said main conduit 13. The main conduit 13 and each secondary conduit 14 make it possible to convey the gas contained in the first gas cartridge 4 and released by the piston 23, when it passes from its "normal" position to its "activation" position, to the underside of each piston 33 in order to set said piston 33 in motion from its "normal" position to its "activation" position.

[0047] Given the need to obtain very rapid deployment of the inflatable safety vest, it is understood that the activation time of the inflation device 1 must be very short, the perforation of the second gas cartridges 5 having to conventionally take place within a time period of the order of 10 milliseconds following the perforation of the first gas cartridge 4. It is also understood that the configuration of the release casing 3 of the inflation device 1, of apparently simple design, requires extensive development and fine-tuning work.Indeed, to obtain the shortest possible activation time of the inflation device 1, it is necessary in particular that the pistons 33 of the second percussion devices 30 all have sufficient energy at the end of their stroke to optimally perforate the associated second gas cartridges 5, while guaranteeing reduced bulk and reliable and long-lasting operation of said inflation device 1.

[0048] First of all, if one wishes to maximize the gas flow rate during the perforation of the first and second gas cartridges 4, 5, one must seek to have the respective perforating ends 24, 34 of the pistons 23, 33 as wide as possible, in order to perforate almost all of the respective perforable ends 7, 8 of the first and second gas cartridges 4, 5, without harming the proper functioning of the device. inflation 1.

[0049] Similarly, to ensure the perforation of the first cartridge 4, it is understood that it is necessary, on the one hand, that the piston 23 of the first percussion device 20 slides perfectly in the associated cylinder 21 and, on the other hand, that the thrust member of the first main percussion device 20, advantageously a helical compression spring, delivers a potential energy Epr greater than the energy Epc4 necessary for the perforation of the perforable end 7 of the first gas cartridge 4, the energy Epc4 being a known value because the first gas cartridge 4 is a commercial product. For this, tests have shown that, taking into account the speed of movement of said piston 23, the length of the latter must be greater than or equal to 1.5 times its diameter, in order to avoid any risk of arching.In addition, the helical compression spring must have, on the one hand, a diameter smaller than the diameter of the piston 23 of the first percussion device 20 and, on the other hand, a stiffness and a relaxed length making it possible to obtain a potential energy Epr greater than the energy Epc4. Finally, once the perforable end 7 of the first gas cartridge 4 is perforated, to allow the gas contained in said first cartridge 4 to escape through the main conduit 13, a residual volume Ve must remain between the stop 22 of the first percussion device 20 and the upper face of said associated piston 23 in the "activation" position, this residual volume Ve advantageously has a height He at least equal to the width of the perforable end 7 of the first gas cartridge 4, this width corresponding, where appropriate, to the diameter of the cover of the first gas cartridge 4.It is understood that this height He has an impact on the dimensions and characteristics of the piston 23 and the compression coil spring.

[0050] Furthermore, to guarantee the perforation of the second gas cartridges 5, it is clearly understood that it is necessary for the kinetic energy Ecg of the gas released by the first gas cartridge 4 and setting in motion the piston 33 of each second percussion device 30 to be greater than the energy Epc5 necessary for the perforation of the perforable ends 8 of the second gas cartridges 5, the energy Epc5 being at a known value because the second gas cartridges 5 are commercial products.

[0051] Numerous tests have shown that to obtain sufficient kinetic energy Ecg to perforate the perforable ends 8 of the second gas cartridges 5, the inflation device 1 must be shaped so that the value of Vi / Vo is between 1 and 3, with Vo corresponding to the sum of the values ​​of the residual volume Ve, of the volume Vcp of the main conduit 13 and of the volumes Vcs of the secondary conduits 14, and Vi corresponding to the sum of the values ​​of the volume Vo defined previously and of the volumes Vtph occupied by the gas released in the cylinders 31 of the second percussion devices 30 when the pistons 33 correspond The latching levers are at the upper end of the stroke, i.e. in the "activation" position.

[0052] Similarly, as mentioned previously, tests have shown that, taking into account the speed of movement of the piston 33 of each second percussion device 30, the length of said piston 33 must be greater than or equal to 1.5 times its diameter, in order to avoid any risk of buckling.

[0053] Concerning each secondary conduit 14, tests have determined that the sum of the values ​​of the surface area of ​​the cross-section of the secondary conduit 14 associated with each second percussion device 30 must be greater than or equal to the value of the cross-section of the main conduit 13. It is then clearly understood that this configuration makes it possible to have a reduction in section at the level of each secondary conduit 14, which has the consequence of increasing the speed of the released gas. Furthermore, the length of said secondary conduit 14 is advantageously reduced to a minimum so as not to increase the dimensions of the release casing 3 of the inflation device 1, but must nevertheless be sufficient to protect said secondary conduit 14 from the shock generated by the return of the corresponding piston 33, the volume of released gas contained in said secondary conduit 14 then acting as a gas shock absorber.

[0054] To limit the size of the release casing 3 and therefore of the inflation device 1, the cross-section of the main conduit 13 is advantageously of generally oblong shape to maximize said cross-section in a reduced size.

[0055] Concerning the discharge orifice 35 of each second percussion device 30, it has been demonstrated that, in order to efficiently discharge the gas released by the associated second gas cartridge 5 in order to quickly fill the airbag and avoid too sudden a return of the piston 33 after the perforation of said second gas cartridge 5, it is necessary that the value of the surface area of ​​said discharge orifice 35 be equal to at least the value of the surface area of ​​the cross-section of the perforable end 8 of said second gas cartridge 5. In addition, the discharge orifice 35 of each second percussion device 30 is preferably oblong.

[0056] Concerning each degassing orifice 36, the sum of the values ​​of the surface area of ​​the degassing orifice 36 of each second percussion device 30 must be at least equal to the value of the surface area of ​​the perforable end 7 of the first gas cartridge 4, that is to say, where appropriate, to the value of the surface area of ​​the corresponding seal. The dimensions of the degassing orifice 36 of each second percussion device 30 make it possible to reduce as much as possible the rebound effect of the associated piston 33, this phenomenon being due to the residual pressure of the gas released by the first gas cartridge 4 present under said piston 33 and greatly impairing the discharge time of the gas released by the second gas cartridge 5.

[0057] Concerning its position, the degassing orifice 36 of each second percussion device 30 is positioned such that after the perforation of the perforable end 8 of said second corresponding gas cartridge 5, the associated piston 33 must quickly clear the discharge orifice 35 to allow the deployment of the inflatable safety vest associated with the inflation device 1. For this, the pressure under said piston 33 must decrease to allow the latter to descend, the degassing orifice 36 must therefore not be obstructed. However, the degassing orifice 36 must not be too low, because the associated piston 33 would then risk returning too quickly to abut against the lower end of the cylinder 31 and damaging the latter.

[0058] Therefore, it is clear that the position of the degassing orifice 36 of each second percussion device 30 is related to the values ​​of the stroke and length of the associated piston 33. Indeed, even if increasing the stroke of the piston 33 makes it possible to increase the perforation performance of its perforating end 34, the stroke of said piston 33 remains limited by the position of the degassing orifice 36, and also by the dimensions of the release casing 3 and therefore of the inflation device 1.

[0059] Tests have shown that the value of the stroke of the piston 33 of each second percussion device 30 must advantageously be at most equal to the value of the following relationship: Lt-Lp-Hor, in which Lt designates the length of the cylinder 31, Lp designates the length of the piston 33, and Hor designates the height of the discharge orifice 35. In this configuration, the stroke of the piston 23 corresponds to the distance between the lower end of the cylinder 21 and the bottom of the degassing orifice 36. Thus, when the piston 23 passes above said degassing orifice 36, the gas released by the first gas cartridge 4 begins to deploy in the inflatable safety vest and the pressure under said piston 33 decreases.

[0060] It is understood that the inflation device 1 according to the invention is preferably used for the deployment of an inflatable safety vest in the event of a fall by a motorcyclist or rider. However, it is obvious that the inflation device 1 according to the invention can be adapted and used to release gas for other purposes such as, for example, fire protection.

[0061] Finally, it goes without saying that the examples of inflation device 1 in accordance with the invention which have just been described are only particular illustrations, in no way limiting of the invention.

Claims

Claims

1. Inflation device (1) for an inflatable safety vest comprising a storage casing (2) containing a first cartridge (4) of pressurized gas comprising a perforable end (7), and at least two second cartridges (5) of pressurized gas arranged side by side to form a row and a release casing (3) comprising a first percussion device (20) allowing, in the event of activation, to perforate the first cartridge (4) of gas so as to release the gas which it contains in gaseous form and a second percussion device (30) associated with each second cartridge (5) of gas and allowing, in the event of activation, to perforate the latter so as to release the gas which it contains in gaseous form,said first percussion device (20) comprising at least: - a cylinder (21) whose lower end is non-permanently closed and whose upper end is partly closed by a stop (22) receiving on its upper part the first gas cartridge (4), - a piston (23) provided with a perforating end (24) oriented towards the upper end of said cylinder (21) and sliding between a "normal" position in which its perforating end (24) is not in contact with the first gas cartridge (4) and an "activation" position in which said perforating end (24) has perforated said first gas cartridge (4), - a thrust member capable of setting said piston (23) in motion from its "normal" position to its "activation" position, and - a retaining member (25) making it possible to maintain said piston (23) in its "normal" position,said second percussion device (30) comprising at least: - a cylinder (31) whose lower end is partly closed and whose upper end is partly closed by a stop (32) receiving on its upper part the second cartridge (5) of gas, and comprising in the upper part at least one discharge orifice (35) connecting the interior of said cylinder (31) and the exterior of the inflation device (1), - a piston (33) provided with a perforating end (34) oriented towards the upper end of said cylinder (31) and sliding between a "normal" position in which its perforating end (34) is not, not in contact with the second gas cartridge (5) and an "activation" position in which said perforating end (34) has perforated said second gas cartridge (5), said inflation device (1) being characterized in that the release casing (3) comprises a main conduit (13) putting the upper part of the cylinder (21) of the first percussion device (20) into fluidic connection with the lower end of the cylinder (31) of each second percussion device (30) by means of a secondary conduit (14) opening on one side under the lower end of said cylinder (31) of each second percussion device (30) and on the other into said main conduit (13) in order to convey, in the event of activation, all the gas from the first gas cartridge (4) released by the piston (23) to under each piston (33) so as to set it in motion from its "normal" position to its "activation" position,in that the sum of the values ​​of the surface area of ​​the cross-section of the secondary conduit (14) associated with each second percussion device (30) is greater than or equal to the value of the surface area of ​​the cross-section of said main conduit (13), and in that a residual volume Ve remains between the stop (22) of the first percussion device (20) and the upper face of said piston (23) associated in the "activation" position, this residual volume Ve having a height He at least equal to the width of the cross-section of the perforable end (7) of the first gas cartridge (4).,

2. Inflation device (1) according to claim 1 characterized in that the first and second gas cartridges (4, 5) each comprise a perforable end (7, 8) in the form of a circular cover.

3. Inflation device (1) according to claim 2 characterized in that each discharge orifice (35) is positioned under and as close as possible to the corresponding stop (32) and in that the value of the surface area of ​​said discharge orifice (35) is equal to at least the value of the surface area of ​​the cross-section of the perforable end (8) of said second gas cartridge (5).

4. Inflation device (1) according to any one of claims 1 to 3 characterized in that the cylinder (31) of each second percussion device (30) comprises at least one degassing orifice (36) connecting the interior of said cylinder (31) and the exterior of the inflation device (1), in order to evacuate the gas between the lower end of said cylinder (31) and the piston (33) in "activation" position and to allow the return of said piston (33) to its "normal" position.

5. Inflation device (1) according to claims 2 and 4 characterized in that the sum of the values ​​of the surface area of ​​each degassing orifice (36) of each second percussion device (30) is equal to at least the value of the surface area of ​​the cross-section of the perforable end (7) of said first gas cartridge (4).

6. Inflation device (1) according to any one of claims 1 to 6 characterized in that the main conduit (13) has an oblong cross section.

7. Inflation device (1) according to any one of claims 1 to 6, characterized in that it is such that the value of Vi / V0 is between 1 and 3, with Vo corresponding to the sum of the values ​​of the residual volume Ve, of the volume Vcp of the main conduit (13) and of the volumes Vcs of the secondary conduits (14), and Vi corresponding to the sum of the values ​​of said volume Vo and of the volumes Vtph occupied by the gas released in the cylinders (31) of the second percussion devices (30) when the corresponding pistons (33) are in the "activation" position.

8. Inflation device (1) according to any one of claims 1 to 7 characterized in that the value of the length of the respective pistons (23, 33) of the first and second percussion devices (20, 30) is greater than or equal to 1.5 times the value of the diameter of said pistons (23, 33).

9. Inflation device (1) according to any one of claims 4 to 8 characterized in that the value of the stroke of the piston (33) of each second percussion device (30) is at most equal to the value of Lt-Lp-Hor, in which Lt designates the length of the cylinder (31), Lp designates the length of the piston (33), and Hor designates the height of the discharge orifice (35).

10. Inflation device (1) according to any one of claims 1 to 9, characterized in that the retaining member (25) of the first percussion device (20) is a pin capable of being engaged simultaneously in a retaining orifice (12) of the release casing (3) and in an imprint (26) provided in the piston (23) to maintain it in the "normal" position, said pin being capable of being secured to a strap mechanically connecting said pin to a fixed point.

11. An inflation device (1) according to any one of the claims- indications 1 to 10 characterized in that the thrust member of the first percussion device (20) is a helical compression spring arranged between the piston (23) and the lower end of the cylinder (21), the latter being closed in a non-permanent manner by a setting screw (10) cooperating with a thread (11) arranged in the release casing (3) under and in the extension of said cylinder (21).

12. Inflation device (1) according to claim 11 characterized in that the helical compression spring has, on the one hand, a diameter smaller than the diameter of the piston (23) of the first percussion device (20) and, on the other hand, a stiffness and a relaxed length allowing to obtain a potential energy Epr greater than the energy Epc4 necessary for the perforation of the first cartridge (4) of gas.

13. Inflation device (1) according to any one of claims 1 to 10 characterized in that the thrust member of the first percussion device (20) is a pyrotechnic charge.

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