Patent Application
20130019994
The present invention relates to a portable device for rapidly inflating an inflatable bag such as, for example, an avalanche airbag.
The device according to the invention, which might be of elongate overall shape, may comprise at least one inlet intended to be connected to a source of compressed gas at high pressure, in order to allow this gas to expand into an air intake chamber, the inlet being associated with a mechanism that triggers the release of the compressed gas to the air intake chamber. The latter may have an opening allowing atmospheric air to be admitted and an outlet intended to be connected to the bag that is to be inflated.
Devices of this type have already been disclosed, for example in patent U.S. Pat. No. 6,220,909 B1. That document describes an avalanche airbag inflation device intended to operate notably using a cartridge of nitrogen compressed to 200 bar. The cartridge is assembled with a control mechanism that allows the gas to be released in response to a user action. The gas, once released following the piercing of the cartridge, is conveyed to two inflation mechanisms, by pipes, each inflation mechanism being associated with an inflatable bag.
The gas is injected into a cylindrical air intake chamber provided in each of the inflation mechanisms by an injection nozzle arranged substantially in line with the central axis of the air intake chamber. This chamber comprises a plurality of openings in its lateral wall so that atmospheric air can be sucked in in response to the injection of the high-pressure gas. The air sucked in is accelerated by a Venturi effect to inflate the corresponding inflatable bag quickly with a sufficient volume, by applying a multiplication factor (volume of air/volume of compressed gas) to that of the volume of compressed gas available, thanks to the addition of the air.
Each of the inflation mechanisms further comprises a nonreturn check valve to prevent the corresponding inflatable bag from becoming deflated via the inlet when it is fully inflated.
As an alternative to nitrogen, it is also known practice to use compressed air as the compressed gas at high pressure.
In general, the multiplication factor applied in the known devices is not very high, of the order of 2 to 3 (which means that the volume of atmospheric air injected into the airbag is of the order of 2 to 3 times the volume that the gas represents in the airbag once it has expanded) and entails the use of a significant volume of compressed gas in order to be able to inflate the airbag.
The space occupied by the compressed-gas cartridge thus contributes significantly to the overall space occupied by the inflation device, and this is why the abovementioned US Patent proposes a design of the device that comes in modular form, which means to say that allows the various component parts of the device to be located at different parts of a pack for example.
However, in that case, getting the device into or out of a backpack, for example, is a complicated matter because each of its component parts has its own means of attachment that have to be done up or undone.
It will also be noted that, aside from the requirement that has to be observed regarding the airbag inflation volume, it is absolutely essential that the airbag be inflated quickly. As a general rule, an avalanche airbag needs to be inflated in around 2 to 4 seconds.
A main objective of the present invention is to alleviate the disadvantages of the inflation devices known from the prior art by proposing such a device that may effectively meet the abovementioned demands, and notably that may allow an airbag to be inflated within the required timeframe and that may occupy a smaller amount of space and is easier to fit/remove.
To this end, the invention relates more specifically to an inflation device of the type mentioned above, further comprising an intermediate distribution chamber for the compressed gas, which chamber may be arranged between the inlet and the air intake chamber in order to connect the one to the other, and a plurality of ejection holes arranged so as to open into a lateral wall of the air intake chamber in order to connect the latter to the intermediate distribution chamber.
By virtue of these features, the device according to the invention is more effective at admitting atmospheric air, and this means that it is able to achieve a higher multiplication factor than the known devices and that it is therefore possible to make use of compressed-gas cartridges of smaller size.
Preferably, the intermediate distribution chamber may be at least partially annular in overall shape and may be arranged at the periphery of the intake chamber. Furthermore, the lateral wall of the intake chamber into which the ejection holes open may be located between the opening and the outlet.
According to one preferred embodiment, the device may comprise a first cylindrical tube the internal wall of which defines the lateral wall of the intake chamber, and a second cylindrical tube, coaxial with the first tube and arranged at least partially around it in order between them to define the intermediate distribution chamber. At least two seals may be provided to delimit this chamber in an axial direction.
The first and second tubes may advantageously be joined together by screw-fastening or by a bayonet mechanism.
Such a design makes it possible to guarantee a simplified method of manufacturing the various component parts of the device, and for assembling or dismantling them, for example for servicing operations.
Moreover, the ejection holes may preferably be inclined more or less by between 10 and 20 degrees with reference to the longitudinal direction of the device, and have a diameter more or less of between 0.2 and 1 mm, preferably between 0.5 and 0.8 mm.
The device may advantageously comprise between 2 and 10 ejection holes.
As a preference, the inlet may have an attachment member for attaching a sealed cartridge containing a compressed gas at high pressure. Further, the trigger mechanism may comprise a first needle controlled by a drive mechanism that a user can actuate so that it can move between at least a first position and a second position and pierce the sealed cartridge in order to release the compressed gas therefrom.
The attachment member may advantageously comprise a tapped thread that can be screwed-together with a male screwthread provided on the sealed cartridge.
Moreover, according to a preferred embodiment, the device may comprise a second inlet similar to the first inlet and intended to accept a second sealed cartridge of compressed gas and which is associated with an additional trigger mechanism comprising a second needle designed to be operated substantially at the same time as the first needle and to pierce the second sealed cartridge in order to release the compressed gas therefrom.
By virtue of these features, carbon dioxide cartridges can be used. Now, carbon dioxide is a gas which is highly compressible, which means that a large potential volume of it can be stored in a cartridge of the kind used in current airbags. This is one of the reasons, aside from its low cost, why this gas is generally used for inflating lifejackets in vehicles of the boat or aeroplane type, for example.
However, the expansion of this gas consumes a great deal of energy, which causes it to cool rapidly as it expands and carries with it the risk of it freezing. A device having the above characteristics however makes it possible to avoid these difficulties which are specific to carbon dioxide and to harness all the advantages of its use with reference to the other gases.
Furthermore, it is also possible, as a preference, to plan that the intake chamber may comprise an acceleration cone arranged between the ejection holes and the outlet, preferably having a length more or less of between 60 and 150 mm.
Moreover, the device may advantageously comprise a reversible-attachment member for reversible attachment to an inflatable bag, this member preferably being arranged some distance from the outlet so that the acceleration cone can be at least partially housed in the inflatable bag in the use configuration.
The present invention also relates to an assembly comprising a device corresponding to the above features and an inflatable bag, possibly with at least one sealed high-pressure compressed-gas cartridge.
Other features and advantages of the present invention will become more clearly apparent from reading the detailed description of a preferred embodiment which follows, given with reference to the appended drawings provided by way of nonlimiting examples and in which:
The device of
Advantageously but without implying any limitation, the cartridges 2 may be standard carbon dioxide cartridges, preferably each containing 33 grams of carbon dioxide, at a pressure of the order of 200 bar and available more or less worldwide at a very modest cost. These cartridges are actually generally used, for example, to inflate the lifejackets found on aeroplanes.
The cartridges 2 are assembled with a central body 4 of the device. The latter bears an air intake cylinder 6 on a first side and an air ejection tube 8 on the other side. It is preferable to position a filter, not illustrated, around the air intake cylinder 6 to prevent a large-sized element from blocking the latter.
Moreover, first and second levers 10 which are intended to be pivoted in response to an action by a user to release the compressed gas are assembled with the central body 4.
What is more, the central body 4 here has a threaded cylindrical support portion 12 onto which airbag retaining washers 14 are screwed. What happens is that a circular opening may be provided in the airbag into which to insert the air ejection tube 8 and one of the two washers 14, the other washer then being screwed against the first one in order to trap the periphery of the opening in the airbag, thereby immobilizing it.
Of course, a person skilled in the art will have no particular difficulty in implementing alternative means for attaching the inflation device to the airbag without departing from the scope of the invention.
It is clear from
Each lever 10 bears a cam 18, produced as one piece with the lever in this instance by way of illustration, and designed to act on a needle 20 mounted with the freedom to effect a translational movement in a matched bore 21 of the central body, with the interposition of a seal 22 and a spring 24, the functions of which will be explained later on.
The ejection tube 8 comprises a main first portion 26 intended to be screwed into the central body 4 and intended to support a cylindrical end portion 28 defining the outlet of the device into the airbag.
The main portion 26 has a first part 30, of cylindrical overall shape, intended to define the inlet of an air intake chamber 32 at its centre and an intermediate distribution chamber in communication with the central body 4, as will become apparent from the detailed description of
The first part 30 also has a male screwthread 34 so that it can be screwed into the central body, with the interposition of two seals 36 or O-rings, distant from one another in the longitudinal direction of the device.
A second part 38 extends the first and has a conical overall shape. The main function of this second part is to accelerate the air introduced via the inlet of the air intake chamber 32, by a Venturi effect, in the known way, so that it can be injected into the airbag and inflate the latter.
The second part 38 bears a cylindrical male screwthread 40 at the end of the large-diameter conical part, onto which the end portion 28 can be screw-fastened.
A non return membrane 42 is interposed between the second part 38 and the end portion 28 and is clamped between these two elements.
The nonreturn membrane here is produced in the form of a disc having a circular slot near its periphery extending over a little less than 360 degrees, so as to define a central disc held on the periphery by a thin tongue of material.
Thus, the central disc is able to pivot with respect to the peripheral portion in order to allow air to pass in one direction, but is blocked against the second portion 38 in the other direction in order to prevent the gas and the air from leaving the airbag.
The nonreturn membrane offers optimum dependability and robustness for a low number of components.
It will be noted that a thin rod 44 may be provided, in the second portion 38 as a safety measure, to define an end stop for the pivoting disc and prevent the nonreturn membrane from deforming in the airbag outlet direction, something which could happen if a high and sudden pressure were applied to it were such a stop not present.
Each cartridge 2 is screwed to an inlet 46 of the inflation device, along the axis of movement of the needles 20.
Each cam 18 has a cam lobe 48 intended to apply pressure to the corresponding needle against the force of the spring 24 kept in abutment in the central body.
Thus, when the lever is pivoted, the cam lobe 48 pushes against the needle which pierces the corresponding gas cartridge in order to release the compressed gas.
As the lever continues to turn in the direction for activating the device, the cam offers the needle a smaller-diameter portion so that the needle can retreat and thus allow the gas to be released more quickly.
It will be noted that the levers 10 are mounted top to tail to limit the amount of torque applied to the device when a user activates it.
Each needle 20 is housed in a matched bore 21 of the central body 4.
Recesses 52 are formed in the bore to allow the compressed gas to be released even if the needles 20 remain in their depressed position. The bevelled shape of the needles offers an additional safety feature with regard to dependability.
Further, each bore communicates with the inside of the central body via an oblique passage 54 formed near the corresponding inlet 46. The simplicity of this construction means that it retains good durability.
When the air ejection tube 8 is assembled with the central body 4, these two tubular elements between them define an annular cavity that forms an intermediate distribution chamber 56 for the compressed gas, into which chamber the oblique passages 54 open. This intermediate chamber is delimited by the internal wall of the central body, the external wall of the first part 30 of the main portion 26 of the ejection tube, and the two seals 36, in the longitudinal direction of the device.
Ejection holes 58 are provided to cause the intermediate distribution chamber 56 to communicate with the air intake chamber 32 and inject the compressed gas into the latter.
When the compressed gas is injected into the air intake chamber 32, it creates a depression which causes an inrush of atmospheric air through that opening of the intake chamber that is connected to the air intake cylinder 6.
The mixture of gas and air is then driven into the second part 38 of the main portion 26 of the ejection tube, before emerging therefrom via the end portion 28, after activating the nonreturn membrane 42, in order to inflate the airbag.
It will be noted that the first and second tubes, namely the central body and the ejection tube, may as an alternative be secured to one another by a bayonet mechanism, for example.
The design described hereinabove makes it possible to guarantee a simplified method of manufacturing the various component parts of the device, and for assembling or dismantling them, for example for servicing operations.
Moreover, the ejection holes 58 preferably have an inclination more or less of between 10 and 20 degrees with reference to the longitudinal direction of the device, preferably of the order of 15 degrees, and a diameter more or less of between 0.2 and 1 mm, preferably of between 0.5 and 0.8 mm.
The device advantageously comprises between 2 and 10 ejection holes, preferably between 4 and 8 and more preferably still, 6.
The applicant company has taken measurements based on the above information and which have revealed that a multiplication factor of the order of 4 to 5 can be achieved with carbon dioxide, for an inflation time of the order of 2 to 4 seconds. A high multiplication factor makes it possible to limit fluctuations in the inflated volume of the airbag as a function of temperature, which fluctuations are connected with the high thermal expansion coefficient of carbon dioxide.
The use of two small-volume cartridges rather than one cartridge of a larger volume means that the time taken to empty a cartridge can be reduced, thus eliminating any risk of icing which could impair the rate at which the airbag is inflated.
Advantageously, the airbag comprises a drain bung (not visible).
The pocket comprises, by way of non-limiting illustration, two D-rings 72 the relative distance between which is kept fixed by a reinforcing bar 74.
Moreover, a first piece 76 of Velcro (registered trademark) is arranged in the pocket 70 and intended to collaborate with a second piece of Velcro (numerical reference 78 in
Thus, the airbag 60 can be installed in the pocket 70 with the two pieces of Velcro engaging with one another, as is clear from
It will be noted that the inflation device/airbag assembly forms a self-contained assembly that can easily be fitted in or removed from a backpack or transferred from one pack to another. Further, the construction of this assembly minimizes the dynamic stresses that might arise between the inflation device and the airbag and which could detract from the operational effectiveness of the assembly.
The foregoing description corresponds to a preferred embodiment of the invention which has been described nonlimitingly. In particular, the shapes depicted and described for the various constituent parts of the inflation device are not limiting.
Thus, it is possible to foresee various alternative forms of embodiment, notably as far as the piercing mechanism is concerned. The cam lobes 48 which pierce the cartridges by acting on the needles may, for example, be formed on a rod that can be moved from a rest position to a piercing position by means of a single operating lever, without departing from the scope of the present invention. The lever could in particular collaborate with a pin secured to the rod to move it translationally in response to an action from the user. With such a construction, the reliability of the piercing mechanism is improved insofar as having just one lever means that only one cable for operating it need be provided. Furthermore, the cam lobes may be formed on the rod in such a way that they act on the corresponding needles with a slight offset over time, thus reducing the force needed to pierce the two cartridges as compared with the force required for simultaneous piercing.
The device according to the present invention makes it possible to create an inflation device/airbag assembly as a single unit which is at once compact, lightweight, and easy to fit or remove.
| Number | Date | Country | Kind |
|---|---|---|---|
| CH01212/11 | Jul 2011 | CH | national |
