Avalanche triggering system

Abstract

The invention relates to an avalanche triggering system (2), which comprises: helicopter-transportable equipment (3) comprising a gas storage device; and a support structure (4) configured to be attached to a mountainside and comprising a support (16) including a receiving location configured to receive the helicopter-transportable equipment (3), an explosion chamber (27) configured to be filled with an explosive gas mixture formed from fuel gas and oxidising gas coming from the gas storage device, a firing device configured to trigger the explosion of the explosive gas mixture, and a guiding device (22) configured to cooperate with the helicopter-transportable equipment (3) and to guide the positioning of the helicopter-transportable equipment (3) into the receiving location during an operation for mounting the helicopter-transportable equipment (3) on the support (16).

Description

[0001] DESCRIPTION

[0002] TITLE: Avalanche Triggering System

[0003] Domain

[0004] The present invention relates to the field of preventive avalanche triggering and more particularly concerns an avalanche triggering system.

[0005] State of the art

[0006] Preventive avalanche triggering is primarily aimed at securing ski areas, transport networks, or even homes.

[0007] The snowpack that forms on a slope comprises a series of snow layers deposited one on top of the other by precipitation. These different layers are often made up of different types of snow, resulting in a certain heterogeneity of the snowpack, which is often the cause of avalanches.

[0008] Preventive avalanche triggering involves creating a shock wave over an upper area of ​​the snowpack surface in order to cause a disruption of the snowpack's equilibrium in that area, before the accumulation of snow can cause a destructive natural avalanche.

[0009] Systems and techniques for intentionally triggering avalanches are already known.

[0010] One known technique involves having an operator place explosive charges precisely where the avalanche is to be triggered. This placement can be done either from a helicopter by dropping the charge or from the ground, where the explosive charge can be dropped, slid, or thrown to the appropriate location. In both cases, the charge is generally detonated using a slow-burning fuse or electrically. The risks inherent in this technique are significant. In addition to the risks directly related to handling explosives, the operator must, for the placement of explosive charges directly on the ground, access often steep areas with unstable snowpack.

[0011] To reduce the risks associated with an operator's presence in the firing zone, remote detonation techniques have been implemented. These techniques utilize military weapons such as rocket launchers or mortar launchers to trigger an explosion on-site. This type of device is not compatible with certain regulations, such as French law, which prohibits the storage of primed munitions.

[0012] One way to reduce the risks associated with handling explosives is to use explosive gases to generate a shock wave to trigger the avalanche. Document FR2636729 describes a remote avalanche triggering system that operates without explosives. Such a system includes a cannon mounted on a concrete base with an opening facing the snowpack surface, a filling circuit configured to fill the cannon with an explosive gas mixture, and a firing device configured to detonate the explosive gas mixture.

[0013] This type of avalanche triggering system includes a gas reserve sufficient for a season, installed in an adjacent technical room, and a remotely controlled ignition device. Thus, this type of avalanche triggering system offers complete autonomy and perfect safety for the operator. Furthermore, the fixed installation of this system guarantees sufficient, repeatable, and long-lasting power for the protection of large avalanche paths.

[0014] The main disadvantages associated with this type of system are the need to carry out a heavy installation requiring a major civil engineering operation for the system itself, the adjacent technical room and the connecting pipes linking them and the need to carry out its maintenance on the installation site which is, by definition, difficult to access.

[0015] Document FR2958739 discloses a remote avalanche triggering system comprising a support structure configured for attachment to a mountainside and a helicopter-transportable system that is electrically self-contained and configured for removable mounting on the support structure. The helicopter-transportable system specifically comprises a gas storage device configured to store an oxidizing gas and a combustible gas; an explosion chamber configured to be at least partially filled with an explosive gas mixture consisting of combustible and oxidizing gases from the gas storage device, the explosion chamber having a lower opening intended to face the snowpack; and a firing device configured to trigger the explosion of the explosive gas mixture contained within the explosion chamber.

[0016] The use of such a helicopter-mounted unit, which is energy self-sufficient and carries the gas storage and firing devices, allows for all maintenance and refueling operations to be carried out at a more accessible site than the avalanche triggering system itself. By removing the unit from its support structure, all maintenance and refueling operations can be performed at a site more accessible than the avalanche triggering system's location. Furthermore, during the summer months, the helicopter-mounted unit can be detached from its support structure, thus minimizing visual impact on the operating site. Locating the gas storage unit on the helicopter-mounted unit, rather than in a separate technical room, also reduces the installation costs of such an avalanche triggering system.

[0017] However, given the shock wave generated by the explosion, the helicopter-portable equipment is likely to move relative to the support structure, which may change the orientation of the lower opening of the explosion chamber relative to the snowpack and impair the performance of the avalanche triggering system described in document FR2958739, unless the avalanche triggering system is equipped with a locking mechanism configured to lock the helicopter-portable equipment onto the support structure.

[0018] In addition, the fact that the explosion enclosure is carried by the helicopter-portable equipment increases the mass of the latter, which complicates the operation of mounting the helicopter-portable equipment onto the support structure using a helicopter.

[0019] Summary of the invention

[0020] The present invention aims to remedy all or part of these drawbacks.

[0021] The technical problem underlying the invention is therefore to provide an avalanche triggering system that is simple and economical in structure, while allowing for a less expensive and easier installation of helicopter-portable equipment belonging to the avalanche triggering system.

[0022] To this end, the present invention relates to an avalanche triggering system comprising:

[0023] - a helicopter-transportable unit comprising a support frame and a gas storage device supported by the support frame and configured to store an oxidizing gas and a combustible gas,

[0024] - a support structure configured to be fixed to a mountainside, the support structure comprising: o a support, such as a support platform, configured to accommodate and support the helicopter-portable equipment, the support having a receiving location configured to receive at least part of the helicopter-portable equipment, o an explosion chamber configured to be at least partially filled with an explosive gas mixture consisting of combustible gas and oxidizing gas from the gas storage device, the explosion chamber having a lower opening intended to face the snowpack, o a firing device configured to trigger the explosion of the explosive gas mixture contained in the explosion chamber,and a guidance device configured to cooperate with the helicopter-portable equipment and to guide the positioning of the helicopter-portable equipment at the receiving location during a mounting operation of the helicopter-portable equipment on the support, the guidance device comprising guide elements that are elongated and converge downwards, the guide elements being configured to guide the insertion of the helicopter-portable equipment into the receiving location during a mounting operation of the helicopter-portable equipment on the support and being configured to extend in relation to the external surfaces of the helicopter-portable equipment when the helicopter-portable equipment rests on the support.

[0025] Such a configuration of the support structure, and in particular the fact that the explosion chamber is provided on the support structure, ensures optimal positioning of the explosion chamber relative to the snowpack and therefore gives increased performance to the avalanche triggering system according to the present invention.

[0026] Furthermore, the fact that the support structure is equipped with a guidance device, capable of cooperating with the helicopter-portable equipment during an operation to mount the helicopter-portable equipment onto the support, greatly facilitates said mounting operation (which makes it possible to significantly reduce the installation costs of the helicopter-portable equipment) and also avoids the intervention of an operator near the support during this operation.

[0027] The avalanche triggering system may also have one or more of the following characteristics, taken alone or in combination.

[0028] According to one embodiment of the invention, the guide elements are configured to extend substantially vertically.

[0029] According to one embodiment of the invention, the guide elements are fixed to the support frame.

[0030] According to one embodiment of the invention, the guide elements extend upwards from the support frame.

[0031] According to one embodiment of the invention, the guide elements are arranged around the perimeter of the receiving location.

[0032] According to one embodiment of the invention, each guide element is equipped with guide rollers having axes of rotation configured to extend substantially horizontally. The presence of such guide rollers facilitates sliding of the helicopter-portable equipment relative to the guide elements during the mounting operation of the helicopter-portable equipment onto the support.

[0033] According to another embodiment of the invention, each guide element could be equipped, instead of guide rollers, with sliding pads.

[0034] According to one embodiment of the invention, the guide elements comprise a first guide element and a second guide element which are located substantially opposite each other, the first and second guide elements being configured to extend respectively opposite two external faces, and for example two external transverse faces, of the helicopter-portable equipment, which are located opposite each other, when the helicopter-portable equipment rests on the support.

[0035] According to one embodiment of the invention, the receiving location is open upwards and is provided with a top insertion opening through which the helicopter-portable equipment is able to be at least partially inserted into the receiving location, the guide elements being configured to guide the insertion of the helicopter-portable equipment into the receiving location as the helicopter-portable equipment is inserted through the top insertion opening.

[0036] According to one embodiment of the invention, the upper insertion opening has a passage section greater than the maximum cross-section of the helicopter-portable equipment.

[0037] According to one embodiment of the invention, the upper insertion opening is generally rectangular in shape.

[0038] According to one embodiment of the invention, the support comprises a support frame, for example rectangular in shape, and a peripheral rail offset vertically from the support frame and delimiting the upper insertion opening, the guide elements mechanically connecting the peripheral rail to the support frame.

[0039] According to one embodiment of the invention, the peripheral rail is configured to extend substantially horizontally.

[0040] According to one embodiment of the invention, the guidance device comprises at least one pre-positioning element extending substantially vertically and beyond the upper insertion opening and against which an external lateral face, and for example an external longitudinal face, of the helicopter-portable equipment is able to bear, the at least one pre-positioning element being configured to pre-position the helicopter-portable equipment relative to the support before its insertion through the upper insertion opening and to guide the insertion of the helicopter-portable equipment through the upper insertion opening.

[0041] According to one embodiment of the invention, at least one pre-positioning element is configured to define a support plane which is substantially vertical and against which the helicopter-portable equipment is able to come to rest.

[0042] According to one embodiment of the invention, at least one pre-positioning element is configured to guide the helicopter-portable equipment substantially vertically and along the support plane during a helicopter-portable equipment mounting operation on the support.

[0043] According to one embodiment of the invention, the guidance device comprises two pre-positioning elements offset laterally from each other and extending substantially parallel to each other.

[0044] According to one embodiment of the invention, the guidance device comprises at least one third guidance element located substantially opposite at least one pre-positioning element. Advantageously, the third guidance element is configured to extend opposite an external longitudinal face of the helicopter-transportable equipment.

[0045] According to one embodiment of the invention, at least one pre-positioning element is equipped with guide rollers having rotation axes configured to extend substantially horizontally.

[0046] According to one embodiment of the invention, at least one pre-positioning element mechanically connects the guide rail to the support frame.

[0047] According to one embodiment of the invention, the guidance device is configured to cooperate with a lower peripheral edge of the helicopter-portable equipment, and for example a lower peripheral edge of the support chassis, said lower peripheral edge being chamfered.

[0048] According to one embodiment of the invention, the avalanche triggering system comprises a control unit carried by the helicopter-portable equipment and configured to control the operation of the avalanche triggering system.

[0049] According to one embodiment of the invention, the gas storage device comprises at least one fuel gas tank and at least one oxidizing gas tank.

[0050] According to one embodiment of the invention, the helicopter-portable equipment includes a fuel gas distribution circuit that is fluidly connected to the fuel gas tank, and an oxidizer gas distribution circuit that is fluidly connected to the oxidizer gas tank, and the support structure includes a fuel gas supply circuit that is fluidly connected to the blast chamber and configured to be fluidly connected to the fuel gas distribution circuit and to supply the blast chamber with fuel gas when the helicopter-portable equipment rests on the support, and an oxidizer gas supply circuit that is fluidly connected to the blast chamber and configured to be fluidly connected to the oxidizer gas distribution circuit and to supply the blast chamber with oxidizer gas when the helicopter-portable equipment rests on the support.

[0051] According to one embodiment of the invention, the oxidizing gas is dioxygen, ozone, hydrogen peroxide, halogens, or any other oxidizing gas.

[0052] According to one embodiment of the invention, the combustible gas is dihydrogen, methane, ethane, propane, butane, pentane, acetylene, or any other combustible gas.

[0053] According to one embodiment of the invention, the helicopter-portable equipment includes an electrical energy storage device, such as a rechargeable battery, configured to electrically power the helicopter-portable equipment and the firing device.

[0054] According to one embodiment of the invention, the helicopter-portable equipment comprises at least one energy production device, such as solar panels or a wind turbine. Advantageously, the energy production device is functionally coupled to the electrical energy storage device.

[0055] According to one embodiment of the invention, the firing device is disposed at least in part within the explosion chamber.

[0056] According to one embodiment of the invention, the ignition device comprises a spark plug. Advantageously, the spark plug is configured to generate a spark capable of igniting the explosive gas mixture.

[0057] According to one embodiment of the invention, the helicopter-portable equipment includes an attachment device, such as an attachment ring, to which an attachment element, such as a fixing hook, provided at a lower end of a helicopter sling, is suitable for being attached.

[0058] According to one embodiment of the invention, the explosion chamber has an overall cylindrical shape.

[0059] According to one embodiment of the invention, the explosion chamber is configured to be located at a lower altitude than the helicopter-portable equipment when the helicopter-portable equipment is received at the receiving location.

[0060] According to one embodiment of the invention, the support structure comprises a mast configured to be anchored to the ground and to extend substantially vertically, the support being fixed to, and therefore supported by, the mast. Advantageously, the explosion chamber is fixed to the mast.

[0061] According to one embodiment of the invention, the helicopter-portable equipment includes at least one protective cover configured to cover and protect the gas storage device.

[0062] According to one embodiment of the invention, the helicopter-portable equipment has an overall parallelepiped shape. In such an embodiment of the invention, the helicopter-portable equipment comprises two opposing external longitudinal faces and two opposing external transverse faces.

[0063] According to one embodiment of the invention, the support includes a centering member projecting upwards from the receiving location, the centering member being configured to cooperate with a receiving housing, provided on the helicopter-portable equipment and opening into the underside of the helicopter-portable equipment, so as to center the helicopter-portable equipment relative to the support.

[0064] According to one embodiment of the invention, the centering member is generally in the shape of a trapezoidal prism.

[0065] Brief description of the figures The invention will be well understood with the aid of the following description with reference to the attached schematic drawings representing, by way of non-limiting examples, one embodiment of this avalanche triggering system.

[0066] Figure 1 is a side view of an avalanche triggering system according to the present invention.

[0067] Figure 2 is a perspective view of a mast and blast chamber belonging to a support structure equipping the avalanche triggering system of Figure 1.

[0068] Figure 3 is a perspective view of a helicopter-portable piece of equipment belonging to the avalanche triggering system of Figure 1.

[0069] Figure 4 is a perspective view of a support belonging to the support structure of Figure 2.

[0070] Figure 5 is a partial perspective view of the helicopter-portable equipment in Figure 3.

[0071] Figure 6 is a partial perspective view of the helicopter-portable equipment in Figure 3.

[0072] Figure 7 is a perspective view of the helicopter-portable equipment of Figure 3 mounted on the support of Figure 4.

[0073] Figure 8 is a partial top view of the avalanche triggering system in Figure 1.

[0074] Figure 9 is a perspective view showing an initial phase of an operation to mount the helicopter-portable equipment of Figure 3 onto the support of Figure 4.

[0075] Figure 10 is a perspective view showing an intermediate phase of an operation to mount the helicopter-portable equipment of Figure 3 onto the support of Figure 4.

[0076] Figure 11 is a perspective view showing the helicopter-portable equipment of Figure 3 connected to a helicopter sling.

[0077] Figure 12 is a schematic partial view of the avalanche triggering system of Figure 1.

[0078] Detailed description

[0079] Unless otherwise stipulated, the term "substantially" means, in this document, "exactly or to within 10% or to within 10°".

[0080] Figures 1 to 12 represent an avalanche triggering system 2, according to the present invention, comprising more particularly a helicopter-portable device 3, a support structure 4 configured to be fixed to a mountainside and to support the helicopter-portable device 3, and a control unit 5 (see Figure 3) configured to control the operation of the avalanche triggering system 2. Advantageously, the control unit 5 is carried by the helicopter-portable device 3, and includes a microprocessor capable of generating control instructions.

[0081] According to the embodiment shown in the figures, the helicopter-portable equipment 3 has an overall parallelepiped shape, and includes in particular two external longitudinal faces 3.1 opposed to each other, two external transverse faces 3.2 opposed to each other, a lower face 3.3 and a upper face 3.4.

[0082] As shown in Figures 5 and 6, the helicopter-borne equipment 3 comprises a support frame 6 and a gas storage device supported by the support frame 6 and configured to store an oxidizing gas and a fuel gas. The gas storage device more specifically comprises a fuel gas tank 7, such as a fuel gas cylinder, and one or more oxidizing gas tank(s) 8, such as oxidizing gas cylinders. Advantageously, the fuel gas tank 7 and the oxidizing gas tank(s) 8 are removable to allow for their replacement when empty.

[0083] The oxidizing gas contained in the oxidizing gas tank(s) 8 can, for example, be dioxygen, ozone, hydrogen peroxide, or halogens, and the fuel gas contained in the fuel gas tank 7 can, for example, be dihydrogen, methane, ethane, propane, butane, pentane, or acetylene.

[0084] The helicopter-portable equipment 3 further includes one or more energy production devices 9, such as solar panels or a wind turbine, and an electrical energy storage device 10, such as a rechargeable battery, configured to electrically power the avalanche triggering system 2. Advantageously, the energy production device is functionally coupled to the electrical energy storage device.

[0085] As shown in Figures 3 and 11, the helicopter-portable equipment 3 includes an attachment device 11, such as an attachment ring, to which an attachment element 12, such as a fixing hook, provided at a lower end of a sling 13 of a helicopter, is suitable for attachment.

[0086] According to the embodiment shown in the figures, the helicopter-portable equipment 3 includes in particular two protective covers 14 which are removably attached to the support chassis 6 and which are configured to cover and protect respectively the fuel gas tank 7 and the oxidizing gas tank(s) 8.

[0087] As shown in Figures 1 and 2, the support structure 4 comprises a mast 15, for example tubular, configured to be anchored to the ground and to extend substantially vertically, and a support 16 fixed to a portion of the upper end of the mast 15 and configured to accommodate and support the helicopter-portable equipment 3. Advantageously, the support 16 is in the form of a support platform, and includes in particular a rectangular support frame 17.

[0088] The support 16 more particularly includes a receiving location 18 in which the helicopter-portable equipment 3 can be housed at least partially. The receiving location 18 is advantageously open upwards, and is provided with a top insertion opening 19 through which the helicopter-portable equipment 3 can be at least partially inserted into the receiving location 18. Advantageously, the top insertion opening 19 is generally rectangular in shape, and has a passage area greater than the maximum cross-section of the helicopter-portable equipment 3.

[0089] According to the embodiment shown in the figures, the support 16 has a peripheral rail 21 which is offset vertically from the support frame 17 and which delimits the upper insertion opening 19.

[0090] The support structure 4 also includes a guide device 22 configured to cooperate with the helicopter-portable equipment 3 and to guide the insertion of the helicopter-portable equipment 3 into the receiving location 18 during a mounting operation of the helicopter-portable equipment 3 onto the support 16. The guide device 22 is more particularly configured to cooperate with a lower peripheral edge 23 of the support frame 6, and said lower peripheral edge 23 is advantageously chamfered.

[0091] According to the embodiment shown in the figures, the guide device 22 includes guide elements 24 which mechanically connect the peripheral rail 21 to the support frame 17 and which are configured to guide the insertion of the helicopter-portable equipment 3 into the receiving location 18 during a mounting operation of the helicopter-portable equipment 3 onto the support 16.

[0092] As shown in Figures 4, the guide elements 24 are elongated, extend upwards from the support frame 17, and are arranged around the perimeter of the receiving location 18. Advantageously, the guide elements 24 converge downwards, and are configured to extend in relation to the external surfaces of the helicopter-portable equipment 3 when the helicopter-portable equipment 3 rests on the support 16.

[0093] According to an embodiment shown in the figures, the guide elements 24 comprise a first guide element 24.1 and a second guide element 24.2 which are located substantially opposite each other, and which are configured to extend respectively opposite the two external transverse faces 3.2 of the helicopter-portable equipment 3. Advantageously, the guide elements 24 further comprise a third guide element 24.3 and a fourth guide element 24.4 which are laterally offset from each other and which are configured to extend opposite the same external longitudinal face 3.1 of the helicopter-portable equipment 3. Each guide element 24 is advantageously equipped with guide rollers 25 having axes of rotation configured to extend substantially horizontally.The presence of such guide rollers 25 promotes a sliding of the helicopter-portable equipment 3 relative to the guide elements 24 during an operation of mounting the helicopter-portable equipment 3 on the support 16. However, according to an alternative embodiment of the invention, each guide element 24 could be equipped, instead of guide rollers 25, with sliding pads.

[0094] As shown in Figures 4 and 7, the guide device 22 further comprises two pre-positioning elements 26 which are laterally offset from each other and which extend substantially vertically and beyond the upper insertion opening 19. The guide device 22 is more particularly configured such that, during a mounting operation of the helicopter-portable equipment 3 on the support 16, an external longitudinal face 3.1 of the helicopter-portable equipment 3 is able to come into contact with the pre-positioning elements 26.

[0095] According to the embodiment shown in the figures, the two pre-positioning elements 26 are located substantially opposite the third and fourth guide elements 24.3, 24.4 respectively, and each pre-positioning element 26 mechanically connects the peripheral rail 21 to the support frame 17. Advantageously, each pre-positioning element is equipped with guide rollers 25 having axes of rotation configured to extend substantially horizontally.

[0096] The two pre-positioning elements 26 are more specifically configured to pre-position the helicopter-portable equipment 3 relative to the support 16 before its insertion through the upper insertion opening 19, and then to guide the insertion of the helicopter-portable equipment 3 through the upper insertion opening 19 and into the receiving location 18. Such a configuration of the guidance device 22 makes it possible to stabilize the helicopter-portable equipment 3 relative to the support structure 4 before its insertion into the receiving location 18, which further facilitates the operation of mounting the helicopter-portable equipment 3 for the helicopter pilot.

[0097] According to the embodiment shown in the figures, the two pre-positioning elements

[0098] 26 are configured to define a support plane which is substantially vertical and against which the helicopter-portable equipment 3 is able to come to rest, and are configured to guide the helicopter-portable equipment 3 substantially vertically and along said support plane during an operation to mount the helicopter-portable equipment 3 onto the support 16.

[0099] As shown in Figure 1, the support structure 4 further includes an explosion chamber 27 attached to the mast 15 and located below the support 16. Thus, the explosion chamber

[0100] 27 is configured to be located at a lower altitude than the helicopter-portable equipment 3 when the helicopter-portable equipment 3 is received in the receiving location 18. According to the embodiment shown in the figures, the blast enclosure 27 has a generally cylindrical shape, and is provided with a lower opening 28 intended to be turned towards the snowpack.

[0101] The explosion enclosure 27 is configured to be at least partially filled with an explosive gas mixture consisting of combustible gas and oxidizing gas from the gas storage device.

[0102] For this purpose, the helicopter-portable equipment 3 includes a fuel gas distribution circuit 29 which is fluidly connected to the fuel gas tank 7, and a oxidizer gas distribution circuit 31 which is fluidly connected to the oxidizer gas tank 8, while the support structure 4 includes a fuel gas supply circuit 32 which is fluidly connected to the explosion chamber 27 and which is configured to be fluidly connected to the fuel gas distribution circuit 29 and to supply the explosion chamber 27 with fuel gas when the helicopter-portable equipment 3 rests on the support 16, and a oxidizer gas supply circuit 33 which is fluidly connected to the explosion chamber 27 and which is configured to be fluidly connected to the oxidizer gas distribution circuit 31 and to supply the explosion chamber 27 with oxidizer gas when the helicopter-portable equipment 3 rests on the support 16.

[0103] The fuel gas distribution circuit 29 may, for example, successively comprise a first pressure regulator, a first solenoid valve, and a first check valve, and the combustion gas distribution circuit 31 may, for example, successively comprise a second pressure regulator, a second solenoid valve, and a second check valve. The control unit 5 is specifically configured to control the opening and closing of the first and second solenoid valves belonging to the fuel gas distribution circuit 29 and the combustion gas distribution circuit 31.

[0104] Advantageously, the helicopter-portable equipment 3 includes a first connection fitting 34 which is fluidly connected to the fuel gas distribution circuit 29, and a second connection fitting 35 which is fluidly connected to the oxidizer gas distribution circuit 31, and the support structure 4 also includes a third connection fitting 36 which is fluidly connected to the fuel gas supply circuit 32 and which is suitable for connection to the first connection fitting 34 when the helicopter-portable equipment 3 is received in the receiving location 18, and a fourth connection fitting 37 which is fluidly connected to the oxidizer gas supply circuit 33 and which is suitable for connection to the second connection fitting 35 when the helicopter-portable equipment 3 is received in the receiving location 18.

[0105] As shown in Figure 12, the support structure 4 further includes a firing device 38 configured to trigger the explosion of the explosive gas mixture contained in the explosion enclosure 27. The control unit 5 is more specifically configured to remotely control the firing device 38.

[0106] According to one embodiment of the invention, the ignition device 38 comprises an ignition plug 39 disposed in the explosion chamber 27 and configured to generate a spark capable of igniting the explosive gas mixture. However, according to a variant of the invention, the ignition device 38 could comprise an electric detonator, a slow-burning fuse, a NONEL®-type detonator, a device for generating a naked flame, a preheating candle, or any other device enabling the explosion of the explosive gas mixture, and in particular the heating of the explosive gas mixture beyond a predetermined temperature, for example, above 450°C.

[0107] The operation to mount the helicopter-portable equipment 3 onto the support 16 is carried out as follows.

[0108] The helicopter-portable equipment 3 is attached to the lower end of a helicopter sling by means of a mounting hook. The helicopter-portable equipment 3 is then brought over the support 16. During this approach, the pilot uses, for example, positioning devices arranged around the support 16 to place the helicopter-portable equipment 3 precisely over the upper insertion opening 19, provided on the support 16, and against the pre-positioning elements 26. The helicopter-portable equipment 3 is then lowered along the pre-positioning elements 26 with friction reduced to a minimum by the presence of the guide rollers 25 provided on the pre-positioning elements 26. During this descent, the insertion of the helicopter-portable equipment 3 into the receiving slot 18 is guided by the guide elements 24.The helicopter-portable equipment 3, thus put in place, can for example be detached from the sling either automatically by lowering the sling and therefore the fixing hook relative to the fixing ring (if the attachment device used conforms to that described in document FR3007009), or by electrically controlling the opening of the fixing hook from the helicopter, or by the intervention of an operator who, using the ladder present on the support structure 4, comes to manually open the fixing hook.

[0109] When a controlled avalanche is triggered by the avalanche triggering system 2, an operator, safely located at a distance from the installation site, sends a trigger command signal to the avalanche triggering system 2, and more specifically to a remote communication system 40 carried by the helicopter-mounted equipment 3 (see Figure 5). This command signal is processed by the control unit 5, which, based on this command signal, opens the first and second solenoid valves of the fuel gas distribution circuit 29 and the oxidizer gas distribution circuit 31 for a predetermined duration. The blast chamber 27 is thus supplied with a predetermined quantity of fuel gas and a predetermined quantity of oxidizer gas, and an explosive gas mixture is formed within the blast chamber 27.When the desired explosive gas mixture is reached, the control unit 5 activates the firing device 38 to trigger the explosion of the explosive gas mixture. The shock wave generated by the explosion is transmitted to the snowpack, dislodging the snow and triggering a controlled avalanche.

[0110] Of course, the present invention is in no way limited to the embodiment described and illustrated, which has been given only by way of example. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

DEMANDS 1. Avalanche triggering system (2) comprising: - a helicopter-transportable equipment (3) comprising a support frame (6) and a gas storage device supported by the support frame (6) and configured to store an oxidizing gas and a combustible gas, - a support structure (4) configured to be fixed to a mountainside, the support structure (4) comprising: o a support (16) configured to accommodate and support the helicopter-portable equipment (3), the support (16) having a receiving location (18) configured to receive at least part of the helicopter-portable equipment (3), o an explosion chamber (27) configured to be at least partially filled with an explosive gas mixture formed from combustible gas and oxidizing gas from the gas storage device, the explosion chamber (27) being provided with a lower opening (28) intended to be oriented towards the snowpack, o a firing device (38) configured to trigger the explosion of the explosive gas mixture contained in the explosion chamber (27),and a guidance device (22) configured to cooperate with the helicopter-portable equipment (3) and to guide the positioning of the helicopter-portable equipment (3) in the receiving location (18) during a mounting operation of the helicopter-portable equipment (3) onto the support (16), the guidance device (22) comprising guide elements (24) that are elongated and converge downwards, the guide elements (24) being configured to guide the insertion of the helicopter-portable equipment (3) into the receiving location (18) during a mounting operation of the helicopter-portable equipment (3) onto the support (16) and being configured to extend in relation to the external surfaces of the helicopter-portable equipment (3) when the helicopter-portable equipment (3) rests on the support (16).

2. Avalanche triggering system (2) according to claim 1, wherein the guide elements (24) are configured to extend substantially vertically.

3. Avalanche triggering system (2) according to claim 1 or 2, wherein the guide elements (24) are arranged around the perimeter of the receiving location (18).

4. Avalanche triggering system (2) according to any one of claims 1 to 3, wherein each guide element (24) is equipped with guide rollers (25) having axes of rotation configured to extend substantially horizontally.

5. Avalanche triggering system (2) according to any one of claims 1 to 4, wherein the guide elements (24) comprise a first guide element and a second guide element which are located substantially opposite each other, the first and second guide elements being configured to extend respectively opposite two external faces of the helicopter-portable equipment (3), which are located opposite each other, when the helicopter-portable equipment (3) rests on the support (16).

6. Avalanche triggering system (2) according to any one of claims 1 to 5, wherein the receiving location (18) is open upwards and is provided with a top insertion opening (19) through which the helicopter-portable equipment (3) is able to be at least partially inserted into the receiving location (18), the guiding elements (24) being configured to guide the insertion of the helicopter-portable equipment (3) into the receiving location (18) as the helicopter-portable equipment (3) is inserted through the top insertion opening (19).

7. Avalanche triggering system (2) according to claim 6, in which the support (16) comprises a support frame (17) and a peripheral rail (21) offset vertically from the support frame (17) and delimiting the upper insertion opening (19), the guide elements (24) mechanically connecting the peripheral rail (21) to the support frame (17).

8. Avalanche triggering system (2) according to claim 6 or 7, wherein the guidance device (22) comprises at least one pre-positioning element (26) extending substantially vertically and beyond the upper insertion opening (19) and against which an external lateral face of the helicopter-portable equipment (3) is able to bear, the at least one pre-positioning element (26) being configured to pre-position the helicopter-portable equipment (3) relative to the support (16) before its insertion through the upper insertion opening (19) and to guide the insertion of the helicopter-portable equipment (3) through the upper insertion opening (19).

9. Avalanche triggering system (2) according to any one of claims 1 to 8, wherein the guidance device (22) is configured to cooperate with a lower peripheral edge (23) of the helicopter-portable equipment (3), said lower peripheral edge (23) being chamfered.

10. Avalanche triggering system (2) according to any one of claims 1 to 9, wherein the gas storage device comprises at least one fuel gas tank (7) and at least one oxidizing gas tank (8).

11. Avalanche triggering system (2) according to claim 10, wherein the helicopter-portable equipment (3) comprises a fuel gas distribution circuit (29) which is fluidly connected to the fuel gas tank (7), and an oxidizer gas distribution circuit (31) which is fluidly connected to the oxidizer gas tank (8), and the support structure (4) comprises a fuel gas supply circuit (32) which is fluidly connected to the blast chamber (27) and which is configured to be fluidly connected to the fuel gas distribution circuit (29) and to supply the blast chamber (27) with fuel gas when the helicopter-portable equipment (3) rests on the support (16),and a combustion gas supply circuit (33) which is fluidly connected to the blast enclosure (27) and which is configured to be fluidly connected to the combustion gas distribution circuit (31) and to supply the blast enclosure (27) with combustion gas when the helicopter-portable equipment (3) rests on the support (16).

12. Avalanche triggering system (2) according to any one of claims 1 to 11, wherein the helicopter-portable equipment (3) comprises an electrical energy storage device configured to electrically power the helicopter-portable equipment (3) and the firing device (38).

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