EP1228957B1 - Pneumatic floatation device, especially pneumatic liferaft, provided with a Venturi-type inflator means - Google Patents

Abstract

The float (R), with chambers (1, 2) designed to be inflated pneumatically on a liquid surface by a pressurised gas (4) has its inflation system fitted with Venturi nozzles (3) that draw in ambient air to assist inflation. The Venturi nozzles are covered by protectors which allow in ambient air but prevent liquid penetrating. The protectors are made with reinforcing members (6) supporting panels (8, 9) with offset apertures (10, 11) that form chicanes between the outside and the Venturi nozzles, while allowing access to close the nozzles at the end of inflation.

Description

The present invention generally relates to improvements made to floating pneumatic devices, and more particularly, although not exclusively, to those devices which have a large swelling volume.

The pneumatic devices are inflated from a pressurized gas source, generally constituted by one or more tanks or compressed gas cylinders on board or in the device when the latter is autonomous.

An important problem lies in the fact that the larger the device, the greater its volume of swelling and the more the source must be able to deliver a high volume of gas. Correlatively, elongated inflation times result, which is unacceptable when the pneumatic device is an emergency device (for example a liferaft) which must be able to be implemented as quickly as possible.

Another disadvantage due to the increase in the volume of gas required for inflation lies in the correlative increase in the number of gas cylinders required to inflate the increased volume of the large devices, and therefore in the considerable increase in the weight of the gas. this material.

In an attempt to overcome these disadvantages, it could of course be envisaged to use a gas under very high pressure, which, for a given inflation volume, would significantly reduce the number of necessary bottles, and therefore the corresponding weight. However, cylinders suitable for containing gas under very high pressure must be mechanically very strong and, having to be unduly heavy, must be made of special materials. Such bottles are therefore expensive, and this solution can not be retained for economic reasons, for example when it comes to survival equipment at sea.

It is already known (see for example US 3 158 314) to implement a venturi in the inflating means of pneumatic devices. During inflation, the flow of pressurized gas from the source creates, at the outlet of the venturi where the speed of the gas is greatly increased, a vacuum capable of causing a phenomenon of ambient air suction through a passage associated with the venturi. This air, driven by the jet of gas, contributes significantly or even predominantly to the inflation of the device so that the amount of gas necessary for the inflation of the device is greatly reduced: thus, the desired reduction in the number of cylinders is obtained. and their weight, at the same time that the inflation rate of the device is very significantly raised.

However, until now, venturi inflation means have been used only for terrestrial devices, or for inflated floating devices before launching. On the other hand, such venturi inflating means have never been practically implemented on floating devices to be inflated on the liquid surface, and in particular for liferafts, because of the presence of the passage of air associated with the venturi through which the water (water of sea, rain, spray) can penetrate widely into the interior of the device.

In addition, the rigid structure of the venturi inflation means disclosed in the aforementioned document does not allow the implementation of said means for a pneumatic liferaft housed, deflated and folded, in a container.

In addition, and there is a disadvantage that is not of less importance, the relaxation of the gas under very high pressure during inflation is accompanied by a sudden lowering of temperature resulting in the formation of ice which obstructs the passage of the gas: the inflation of the device is then interrupted. Especially for rescue devices such as life rafts, such a situation is absolutely unacceptable.

The object of the invention is therefore to improve floating-type pneumatic devices that must be inflated on the liquid surface so that the number of on-board bottles intended for this inflation can be substantially reduced in order to limit the cost and the weight of this equipment. However, this does not imply any allocation of the speed of inflation or the conditions of packaging of the device in the deflated and folded state in a container, and no more than it resulted in a significant increase in the cost of entire device.

For these purposes, the invention provides a floating pneumatic device to be inflated on the liquid surface according to the preamble of claim 1. which, being arranged in accordance with the invention, is characterized by the provisions set forth in the characterizing part of the invention. claim 1.

It is therefore thanks to the additional and combinatorial implementation of the protective means suitable for preventing the penetration of water while allowing the circulation of ambient air that venturi inflating means can be provided on floating pneumatic devices. to be inflated on the liquid surface according to the invention.

In addition, the fact that the armature is made of inflated tubes under pressure is particularly interesting because, in the storage situation of the device in the deflated and folded state (for example in a storage container), the armature is it - Even deflated and folded as the rest of the device: it does not result in significant additional volume to be integrated into the container and especially there is no rigid element likely to damage the fabric of the device.

In a simple way, we can make sure that the panels have a height that is less than that of the armature, the difference thus defining the aforesaid respective opening.

Also desirably, the panels are at least partially opening to give access to the venturi, in particular to allow it to be closed at the end of inflation.

In a concrete embodiment, the armature is substantially in the form of a dihedron, rectangular parallelepiped or truncated pyramid, which leads to simple form of beads that can easily inflate and especially that are simple to manufacture.

For certain applications or conditions of use, it may be that the initiation of inflation occurs when the device is partially or completely immersed (eg liferafts triggered from a ship that has just sank quickly). ). To be assured that the inflation using the venturi can be performed, or at least start properly without water intrusion, while the container is immersed, it is expected that the device is enclosed, in the state deflated and folded into a sealed pocket that can be opened during inflation only when the bag is on or above the liquid surface. In this case, the pneumatic device being folded into the sealed bag, this bag, during the initialization of the inflation, increases in volume and flushes the water having penetrated inside the container and thus accelerates the recovery of all on the surface. During this phase, the venturi remains protected against any entry of water. The container then opens after reaching the surface and the sealed bag is torn after opening the container. When tearing the pocket, the means of protection of the venturis or are already in place and functional.

Moreover, at the beginning of the inflation of the device on the liquid surface, the flaccid fabric extends at the height of the surface of the water or very little above so that the venturi, insufficiently raised, may allow penetration of water, and all the more so that it is necessary to wait until the entire device has begun to take shape, and therefore a certain amount of time has elapsed, so that the venturi is carried substantially above from the surface of the water. To avoid this disadvantage related to the inflation time, the device is provided with an internal gas-permeable buffer chamber into which the venturi inflating means open, whereby the buffer chamber inflates in the first place from the the venturi inflating means is thus actuated, which is thus raised above the liquid, being able to function without significant liquid introduction. Advantageously then, the buffer chamber is provided with at least one restricted passage communicating said chamber with the rest of the interior volume of the device.

Although all the provisions of the invention can be applied in any type of floating pneumatic device to be inflated on the liquid surface, a particularly interesting application of said provisions relates to inflatable liferafts, in particular large rafts and large capacity (eg one hundred or one hundred and fifty people) that are under development.

• la figure 1 est une vue en coupe transversale d'une partie d'un dispositif pneumatique flottant agencé conformément à l'invention ;
• la figure 2 est une vue en perspective de côté de la partie dudit dispositif illustrée à la figure 1 ;
• la figure 3 est une vue de face du dispositif des figures 1 et 2, montrant une variante de réalisation ;
• les figures 4 à 7 sont des vues schématiques partielles en coupe transversale illustrant diverses variantes de réalisation ;
• la figure 8 est une vue schématique en coupe d'un mode de mise en oeuvre spécifique d'une disposition de l'invention, illustrée dans le cas d'un radeau pneumatique de survie ;
• les figures 9A à 9C sont des vues schématiques partielles, en coupe, illustrant diverses variantes d'une autre disposition de l'invention ; et
• les figures 10A à 10C illustrent respectivement trois étapes de la phase initiale de déploiement d'un radeau de survie équipé conformément à l'invention.

The invention will be better understood on reading the detailed description of certain embodiments given only as non-limiting examples. In this description, reference is made to the accompanying drawings in which:

• Figure 1 is a cross-sectional view of a portion of a floating pneumatic device arranged in accordance with the invention;
• Figure 2 is a side perspective view of the portion of said device shown in Figure 1;
• Figure 3 is a front view of the device of Figures 1 and 2, showing an alternative embodiment;
• Figures 4 to 7 are partial schematic views in cross section illustrating various embodiments;
• Figure 8 is a schematic sectional view of a specific embodiment of an embodiment of the invention, illustrated in the case of a pneumatic liferaft;
• Figures 9A to 9C are partial schematic sectional views illustrating various variations of another embodiment of the invention; and
• FIGS. 10A to 10C respectively illustrate three stages of the initial deployment phase of a liferaft equipped in accordance with the invention.

Referring firstly to Figures 1 and 2, there is shown in a very simplified way, in cross-section, a portion of a floating pneumatic device R; it may for example be the peripheral float (consisting for example of two strands 1 and 2 superimposed) of a liferaft whose other components are not shown.

Each strand 1 and 2 is equipped with a venturi inflator 3, connected by a hose 5 to a source of pressurized gas 4, which is in practice one or several bottles of gas. The source 4 may be common to all the inflation members 3, or the inflation members 3 are associated with respective separate sources.

To protect the venturi inflators 3 against the water inlets, be it water from the liquid mass on which the device is floating or water suspended in the ambient air (rain, spray ), a protective structure 6 is put in place which covers the inflation member (s) 3 either individually or together as illustrated in FIGS. 1 and 2. This protective structure is fixed on the inflatable tubes 1, 2 and forms a cage protection arranged to allow free passage to the ambient air (arrows A) which is sucked by the venturi (s) while preventing liquid from being entrained.

As illustrated in FIGS. 1 and 2, the protective structure 6 is in the form of a cage or cowling which rests on the strands 1, 2 extending over the inflating means 3. This cowling comprises a rigid armature 7 by example in the form of two rectangular frames arranged dihedron. Each frame of the frame 7 supports panels 8, 9 which define openings 10, 11 mutually offset so as to form at least one baffle between the outside and the inflation members 3, a baffle which does not interfere with the passage of the air (arrows A).

In the embodiment illustrated in Figures 1 and 2, the two frames of the rigid frame 7 have a substantial thickness and the panels 8 and 9 are fixed on these frames on either side thereof, the outer panels 8 being mounted towards the base of the frames (the corresponding openings 10 being thus located towards the top of the frames), while the inner panels 9 are located towards the top of the frames (the corresponding openings 11 thus being located towards the bottom of the frames). Such an arrangement is sufficient to prevent a significant penetration of water into the venturi inflators 3.

The protective structure 6 can give rise to many embodiments. However it is desirable that it comprises no rigid element that could damage, including tearing, the canvas of the pneumatic device during deployment and inflation thereof. For this reason, the rigid armature 7 consists of pressure-inflated tubes and the panels 8 and 9 are constituted in the form of waterproof canvas panels stretched over the frames, as shown in FIGS. 1 and 2. The end walls 12 of the cowling thus formed are formed of a cloth or bib conforming to the outer contour of the rolls 1, 2 and integral with the two frames of the frame 7.

A protective structure 6 is thus formed which, in the deflated state of the armature 7, is flexible and can be folded together with the device R itself when it is enclosed in its container.

To be sure that the protective structure 6 performs its function of protecting the venturi inflation members 3 from the beginning of the inflation, it is necessary to ensure that this protective structure 6 is inflated first, before the inflation begins. device: for this purpose, it is possible to provide an independent gas source 13 (FIG. 1) and, since the volume of gas necessary for the inflation of the armature 6 is small, this auxiliary source 13 can consist of a small bottle of compressed gas that does not penalize, in cost and weight, the entire device.

Alternatively, it would also be possible to inflate the armature 6 from the main source 4 by implementing sequential distribution means such that the inflation of the rods 1, 2 only begins once inflated. 6 of the protective cover frame: such an arrangement is suggested in Figure 1 by a pipe 13a (shown in broken lines) connecting the head of the main bottle 4 to the frame 6.

In the example shown in Figures 1 and 2, the openings 10 and 11 forming baffle are defined by a dimension (height) of the fabric panels 8, 9 with respect to the corresponding dimension of the frame. Of course, other arrangements are conceivable (canvas panels of the same format as the frame and provided with drilling (s), for example).

In addition, various arrangements may be provided in connection with the implementation requirements of the pneumatic device, and in particular the venturi inflators.

Thus, it can be provided that the outer panels 8 are fixed, on the corresponding frame of the rigid frame 7, removably (at least along their two lateral sides) with means 14 for sealing and easy handling (eg "velcro" hook-and-loop strips, zipper, ...). As shown in Figure 3, which shows the hood in front view, the lifting of the outer panels 8 provides access to the venturi inflators 3 in particular to close (lock) them once the inflation is complete.

In addition to or replacing the preceding provision, each outer panel 8 may be provided with a flap 15 releasing a window 16 providing close access to the inflation members 3.

FIG. 4 illustrates an alternative embodiment in which the rigid reinforcement 6 is no longer in the form of a dihedral as shown in FIGS. 1 to 3, but in the form of a rectangular parallelepiped with two substantially parallel lateral frames 17 joined by a frame front panel 18. Two outer panels 19, supported by the side frames 17 and partially by the front frame 18, define between them, on the front frame 18, an opening 20 opposite which extends an inner panel 21 supported at least by the front frame 18. The path of the air is illustrated by the arrows A.

In Figure 5, the rigid armature 6 is shaped as a truncated pyramid with the two side frames 17 converging towards one another. The outer panels 19 extend only along the side frames 17, while the inner panel 21 extends over the entire dimension of the front frame 18 by returning to the side frames 17 partially facing the outer panels 19.

The arrangements according to the invention are not dependent on the conformation of the pneumatic device R, and in particular are not dependent on the number of the constituting flanges of the float. The preceding examples of FIGS. 1 to 5 have been illustrated in relation with a float formed of two superimposed rolls 1, 2. In FIG. 6 is illustrated the embodiment of the cowling according to the invention shown in the associated FIG. , to a float formed of three superposed strands 1, 2, 22. Similarly, in FIG. 7 is illustrated the embodiment of the cowling according to the invention. shown in Figure 4 associated here with a float formed of a single coil 1.

In the uninflated and folded state, the pneumatic device can be enclosed in a protective shell or container. This is particularly the case with inflatable life rafts. However, the tightness of the containers is not perfect. As a result, water can enter the container, especially when it is thrown into the water and floats for some time before inflating the raft is ordered, or even during the rapid sinking of a container. ship in which the raft is driven underwater before being released by a hydrostatic system triggered to a predetermined depth. Under these conditions, the penetration of water into the container may result in water penetration into the raft, through the venturi inflators.

To avoid this disadvantage, it is planned to enclose the raft deflated and folded in a sealed pouch made of an extensible material.

As illustrated in FIG. 8, the deflated raft R is folded, for example so as to envelop the source 23 of pressurized gas necessary for inflation, the latter being connected by at least one hose 5 to at least one inflation device. venturi (not visible). The assembly is enclosed in a sealed pouch 24, which in turn is enclosed in the container 25. A halyard 26 for triggering the firing pin of the source 23 passes through the container 25 and in a sealed manner the pouch 24. It can also be connected directly to the firing of the striker of the source 23 if it crosses tightly pocket 24. During inflation, the pocket 24 tears under the thrust of the raft being dilated.

To further improve the efficiency of the venturi inflation means arranged in accordance with the invention, it is desirable that, from the beginning of inflation, the inflation member (s) be hoisted above the level of the water so as to be assured that water can not penetrate, through the venturi (s), into the pneumatic device during inflation.

For these purposes, it is expected that the inflation gas delivered into the or each coil 1, 2 of the pneumatic device is retained, locally and temporarily, in the portion of the coil 1, 2 adjacent to the inflation member 3. Therefore, a relatively small volume buffer chamber 27 into which the inflation element 3 opens, said buffer chamber 27 communicating with the remainder of the coil 1, 2 by a restriction which restricts the flow of the gas. As a result, from the beginning of the inflation, the buffer chamber 27 is put under overpressure and immediately inflates, hoisting the venturi inflator over the water and allowing it to assume its function in the best conditions.

The realization of the buffer chamber 27 may give rise to various variants.

Thus, as illustrated in FIG. 9A, the buffer chamber 27 may be constituted by a closed chamber 28 inserted inside the coil (1 for example) and into which the venturi inflation device 3 connected via a pipe 5 opens. to the cylinder of pressurized gas 23.

The enclosure 28 has an end wall 29 which is provided with calibrated holes 30 providing a braked flow of gas from the chamber 27 to the remainder of the coil 1. The other end wall 31 may be equipped in the same manner as the wall 29 and / or can, as illustrated, be equipped with a pressure relief valve 32 for safety.

In Figure 9B is illustrated an alternative embodiment similar to that of Figure 9A, except that the chamber 27 is defined by a section of the coil 1 itself which is delimited by two transverse partitions 29 and 31 secured to the wall of the coil 1 and equipped as described above with regard to FIG. 9A.

Of course, the braking of the flow of the gas can be provided by any appropriate means, such as, besides the aforementioned calibrated holes, the only pressure relief valve, a porous fabric, a system of baffles, etc. As an example is shown in Figure 9C a multi-compartment arrangement delimited by adjacent bulkheads 33 a, 33 b, 33 c, ... provided with calibrated holes 34 a, 34 b, 34 c, ... respectively of increasing total section. On the left-hand side of FIG. 9C, there is shown an arrangement with integral partitions of the coil 1 and in the right-hand part of FIG. 9C, there is shown an enclosure arrangement 28 that is attached and provided with a plurality of successive walls.

In the same way, the transverse partitions integral with the bead can have any desired shape (spherical cap, frustoconical, ...), and likewise the enclosure 28 introduced inside the bead 1 can have any desired shape (cylindrical, biconic, spherical, ...).

As has already been mentioned above, the arrangements in accordance with the invention find a preferred, although not exclusive, application in life rafts, and especially in high-capacity life rafts, that is, say able to embark a large number of people (for example 100 to 150 people) and to do so having large dimensions and therefore a large volume of swelling.

To make clearer the interest of the provisions explained above, FIGS. 10A to 10C illustrate three stages of the initial deployment phase of a life raft equipped in accordance with the invention.

In FIG. 10A, the container containing the raft has been thrown into the water and floats on the surface. The arrangement may be that indicated above with respect to FIG. 8 and illustrated on the latter.

By pulling (automatic or manual) on the halyard 26, the firing pin of the control head of the bottle 23 of gas under pressure, which initiates the inflation process.

The half-shells 25a, 25b of the container 25, for example articulated to one another around a hinge 35, move away from each other (FIG. 10B) and release the raft which starts to inflating inside the flexible waterproof pouch 24. The amplitude of the sealed pouch 24 and the coefficient of elongation of its constituent material are such that, under the pressure of the raft at the beginning of swelling, the pouch defines a large volume protected from water tightly. In addition, it is the buffer chambers 27 which begin to inflate, before the gas spreads in the rest of the tubes.

Finally, when the distended pouch ends up tearing along a weakened line for this purpose, the buffer chambers 27 of the strands 1, 2 are inflated, although the remainder of the strands 1, 2 is still in the non-state. inflated and flaccid as shown in Figure 10C. The buoyancy of the part of the raft associated with venturi inflators are sufficient for the venturis 3 to be above the water and unable to suck water.

At this time, the protective structure 6 is inflated and in place to protect the venturi inflators 3: the air sucked by the venturis is thus protected from any contact with water. As shown in FIG 10C, the half-shells 25 a, 25 b of the container float on water. However, in the case where the swelling of the raft is initiated by a hydrostatic release device (case of a sinking ship quickly, in particular), the half-shells 25 a, 25 b can quickly flow and the buoyancy of the structure is R provided by the beginning of swelling inside the sealed pouch bringing the structure R to the surface.

The torn pouch 24 gradually releases the still uninflated portion of the raft, which then completes to inflate completely.

Claims (8)

1. A floating inflatable device (R) having to be able to be inflated on the surface of liquid and which for this purpose comprises inflation means including an on-board source of pressurized gas (4) and a venturi supplied by the source of pressurized gas (4) and capable to induce a flow of ambient air which contributes to the inflating of the device, said venturi inflation means (3), being mounted on a wall of said device, being protected by protective means (6, 8, 9) covering them in such a way as to define at least one chicane between the outside and the venturi inflation means and to allow ambient air to pass freely while at the same time preventing liquid from gaining entry to the device to any appreciable extent, characterized in that the protective means (6, 8, 9) comprise a cowling which rests on the adjacent surface of the device and which comprises a substantially rigid framework (6) consisting of pressurized inflated tubes (7) and panels (8, 9) of watertight fabric stretched over the framework which respectively define mutually offset openings (10, 11) and constitute said chicane.
2. Floating inflatable device according to Claim 1, characterized in that the panels (8, 9) have one of their dimensions shorter than the corresponding dimension of the framework, thus defining said respective opening (10, 11).
3. Floating inflatable device according to Claim 1 or 2, characterized in that the panels (8, 9) are at least partially openable (14) so as to give access to the venturi, particularly so as to allow it to be plugged at the end of inflation.
4. Floating inflatable device according to any one of Claims 1 to 3, characterized in that the framework (6) is appreciably in the shape of a dihedron, a right-angled parallelepiped or a pyramid frustum.
5. Floating inflatable device according to any one of the preceding claims, characterized in that it is enclosed, in the deflated and folded state, in a watertight pouch (24) which can be opened during inflation only when the pouch is at the surface of the liquid.
6. Floating inflatable device according to any one of the preceding claims, characterized in that it comprises an interior gas-permeable buffer chamber (27) into which the venturi inflation means (3) open,
   whereby the buffer chamber (27) inflates first as soon as the venturi inflation means (3) come into operation, which means are thus raised above the liquid thereby being able to operate without the appreciable ingress of liquid.
7. Floating inflatable device according to Claim 6, characterized in that the buffer chamber (27) is equipped with at least one passage with a restriction (30) causing the said chamber to communicate with the remainder of the interior volume of the device.
8. Inflatable life raft, characterized in that it is constructed according to any one of the preceding claims.

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