A buoy includes a surface unit comprising a sealed tank comprising an inflatable bag, a tubular wall of axis z and a bottom, the tubular wall and the bottom delimiting a volume referred to as the inner volume, the surface unit comprising at least one cartridge enclosing a compressed gas that can be released in such a way as to inflate the inflatable bag such that it functions as a float in an operational configuration of the buoy, and the sealed tank comprises a projecting container protruding from the bottom and extending out from the inner volume, from the bottom.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International patent application PCT/EP2018/059571, filed on Apr. 13, 2018, which claims priority to foreign French patent application No. FR 1700419, filed on Apr. 14, 2017, the disclosures of which are incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to buoys of the type comprising an inflatable bag and at least one cartridge enclosing a compressed gas that can be released such as to inflate the inflatable bag using the gas so that the inflated bag functions as a float.

The present invention relates notably to communication buoys of the type comprising at least one radioelectric antenna designed to be arranged above the surface of the water in order to allow communication with a remote base. The inflatable bag is equipped with a radioelectric antenna arranged such that, when the bag is inflated using the gas, the bag resurfaces such as to bring and to maintain the radioelectric antenna above the surface of the water. In a variant, the buoy may serve as a reference point or for maintaining an object immersed at a predetermined level.

BACKGROUND

These buoys may be deployed from a carrier located above the surface of the water or from a submarine.

These buoys generally comprise a stack of coaxial cylinders housing functional elements of the buoy. This stack is housed in a tubular receptacle prior to deployment of the buoy.

The size of the cylinders and of the internal equipment is greatly constrained by the size of the tubular receptacle.

Buoys conventionally comprise a surface unit comprising a sealed tank comprising the inflatable bag and a cylindrical casing forming one of the cylinders of the stack. The casing houses electrical equipment, including one or more electric circuits for processing signals originating from and/or destined for a radioelectric antenna and/or at least one battery for powering these electric circuits and/or the antenna.

The surface unit rises to the surface of the water when the inflatable bag is inflated, while the depth unit generally descends to a depth, for example to emit and/or to receive sound waves.

With a view to guaranteeing good radioelectric communication or enabling the buoy to be clearly seen even when the sea is rough, the inflatable bag must be able to reach a sufficient height above the level of the sea, which presupposes satisfactory inflation of the inflatable bag.

To that end, prior-art deployable buoys comprise a plurality of cartridges of similar volume enclosed inside the casing. These cartridges are arranged such that their longitudinal axes are perpendicular to the axis of the cylinder formed by the casing. The inner volume of the casing communicates with the inner volume of the inflatable bag. However, the size of the casing is increased fairly significantly for each added cartridge, this volume being greater than the volume of the cartridge and thereby leading to a fairly significant increase in the drag of the casing. In point of fact, the drag of the casing must generally be minimized in order thus to guarantee the positional stability of the surface unit by limiting the movements of the depth unit through the effect of antagonistic currents at the surface and at depth.

The same problems are encountered when it is desired to multiply or to increase the size of the equipment housed in the casing.

SUMMARY OF THE INVENTION

An object of the invention is to limit at least one of the aforesaid drawbacks.

To that end, a subject of the invention is a surface unit comprising a sealed tank comprising an inflatable bag, a tubular wall of axis z and a bottom, the tubular wall and the bottom delimiting a volume referred to as the inner volume, the surface unit comprising at least one cartridge enclosing a compressed gas that can be released in such a way as to inflate the inflatable bag such that it functions as a float in an operational configuration of the buoy. The sealed tank comprises a projecting container protruding from the bottom and extending away from the inner volume, from the bottom.

Advantageously, the buoy comprises one or more features, taken alone or in combination:

a larger dimension of the projecting container perpendicularly to the axis z being less than a smaller dimension of the tubular wall perpendicularly to the axis z,

the buoy is configured such that a front surface of a submerged part of the surface unit or of the sealed tank, when the buoy is in the operational configuration, comprises a part of the projecting container,

the buoy is configured such that a front surface of a submerged part of the surface unit or of the sealed tank, when the buoy is in the operational configuration, comprises a part of the tubular wall,

the buoy comprises at least one element of the buoy arranged in a volume surrounding the projecting container when the buoy is in a storage configuration in which the gas is confined in the cartridge,

said at least one element and the surface unit are inserted in one and the same receptacle when the buoy is in the storage configuration,

the buoy comprises a depth unit connected to the surface unit by a cable, the depth unit and the surface unit being connected, when the buoy is in a storage configuration in which the gas is confined in the cartridge, and separated when the buoy is in the operational configuration,

at least one of said at least one element forms part of the depth unit,

at least one of said at least one element is an active functional element,

at least one element comprises a tubular container surrounding the projecting container,

at least one element comprises a cable winding,

the buoy comprises a single cartridge,

the cartridge is arranged such that the gas is expelled from the cartridge upward, when it is released,

the projecting container is a part of the cartridge,

the buoy is arranged such that the cartridge comes into direct physical contact with the water when the buoy is submerged in the water,

the inner volume receives at least one electronic circuit and/or at least one electrical energy accumulator and/or a system for releasing the gas,

the projecting container delimits a volume communicating with the inner volume when the buoy is in a storage configuration in which the gas is confined in the cartridge,

the projecting container receives a part of at least one electronic circuit and/or of at least one electrical energy accumulator and/or of at least one system for releasing the buoy and/or the gas cartridge,

the buoy comprises a radioelectric antenna, the antenna being arranged such that the antenna is brought above the surface of the water when the bag functions as a float.

The same elements from one figure to another are denoted by the same numerical references.

FIGS. 1a,1b,1c,1dillustrate the deployment of a buoy according to the invention.

DETAILED DESCRIPTION

In the non-limiting example ofFIGS. 1ato 1d, the buoy1is a buoy that can be deployed from a carrier100located above the surface of the water. This carrier100is, for example, an aircraft, a helicopter or a surface structure. In a variant, the buoy is connected to a submarine and is designed to provide radioelectric communication between the submarine and a station located above sea level.

The buoy1may comprise, as shown inFIGS. 1ato 1d, a tubular receptacle4delimiting an inner volume of globally cylindrical form that has negative buoyancy and within which is housed a part, called the internal part, of the buoy in a storage configuration of the buoy shown inFIG. 1a. When the buoy1is in a storage configuration, the inflatable bag3is not inflated.

The inner volume is advantageously but not necessarily an axisymmetrical volume.

When the buoy is deployed from an aircraft100, as shown inFIG. 1b, a parachute7is deployed outside the receptacle4such as to slow down the fall of the buoy1into the water.

Once the buoy is submerged in the water, as shown inFIG. 1c, the inflatable bag3inflates, which has the effect of ensuring the detachment of the parachute7, and of causing the emergence of a casing6from the surface unit5of the receptacle4, and the rising of the surface unit5toward the surface S of the water, as shown inFIG. 1c, such as to bring the float3of the surface unit5to the surface of the water.

The internal part of the antenna comprises a stack of several units. This stack comprises the surface unit5and a depth unit8with negative buoyancy. The surface unit5and the depth unit8are connected when the antenna is in the storage configuration ofFIG. 1a. These elements are conventionally housed in the tubular receptacle of generally standard size prior to deployment of the buoy, i.e. when the buoy is in the storage configuration. The volume attributed to each unit is very restricted and it is essential to limit the volume occupied by the various elements within the tube.

The surface unit5is connected to a depth unit8by a cable9that unwinds upon inflation of the inflatable bag3such that the surface unit5rises toward the surface S while the depth unit8continues its descent toward the sea bed. When the surface unit5rises toward the surface S, the depth unit8continues to sink and thus separates from the surface unit5. The cable9is deployed or unwound during this phase until the depth unit8reaches a predetermined depth. The descent of the depth unit8is halted by stopping the unwinding of the cable9. The cable9is then under tension. The receptacle4with negative buoyancy continues to sink, thereby releasing the depth unit8. The antenna1is then in an operational configuration, shown inFIG. 1d.

In the operational configuration, the inflatable bag3is supported by a casing6of the surface unit5. A part of the surface unit5is submerged in the water when the buoy is in the operational configuration.

The buoy1is, for example, but not necessarily, a communication buoy of the type comprising at least one radioelectric antenna2for emitting and/or receiving radioelectric waves. In this case, the buoy1is configured such that the radioelectric antenna2is maintained above the surface of the water when the buoy1is in the operational configuration so as to allow radioelectric communication of information between the buoy1and a remote station located above the level of the sea, for example on board the carrier100, when the antenna is located above the surface of the water.

The buoy1comprises, for example, one or more sensors that make it possible to measure a physical value, the buoy being configured such that the sensor is submerged in the water when the buoy1is in the operational configuration.

The buoy comprises, for example, one or more designed to measure underwater sound waves and/or one or more temperature sensors designed to be submerged in order to measure a temperature of the water.

A buoy comprising one or more hydrophones is an acoustic buoy, also known as a “sonobuoy” in English.

The buoy is, for example, designed to radioelectrically transmit, by means of the radioelectric antenna, information on the underwater sound waves detected by at least one hydrophone.

In a variant, or in addition to the one or more sensors, the buoy1comprises at least one sound wave emission antenna. The buoy is then said to be “active”.

At least one hydrophone advantageously belongs to the depth unit when the buoy comprises a surface unit and a depth unit.

FIG. 2illustrates a perspective view of principal elements of the surface unit5of the buoy1according to the invention when the buoy is in the storage configuration. InFIG. 3, the inflatable bag is protected by a cap13.FIG. 3shows a cross-sectional view of the buoy according to the invention in the storage configuration.

The surface unit5comprises a gas cartridge11enclosing a compressed gas.

This gas is, for example, air, carbon dioxide or nitrogen dioxide.

The gas confined in the cartridge can be released. In other words, it may be released from the cartridge11.

In the storage configuration of the buoy, shown inFIGS. 2 and 3, the gas is confined in the cartridge11, which is sealed. In other words, the inflatable bag3is not inflated. In the operational configuration of the buoy1, the inflatable bag3is inflated using the gas that was confined in the cartridge11in the storage configuration, and the inflatable bag3then functions as a float.

The gas contained in the cartridge can be released by means of a gas release system that will be described below. The gas release system is capable of forming an orifice in the cartridge in order to release the gas.

The cartridge11and the inflatable bag3are arranged such that, when the gas is released, the gas contained in the cartridge11inflates the inflatable bag3so that the bag3becomes a float. In other words, the inflatable bag3is connected to the cartridge11in a gas-tight manner and the inner volume of the cartridge is in communication with the inner volume of the inflatable bag3when the gas is released.

The casing6is, for example, produced from lightweight, inexpensive and possibly transparent plastics, but it may be produced from any other material.

Advantageously, the casing6does not substantially deform when the buoy passes from the storage configuration to the operational configuration.

The casing6delimits an inner volume60.

The surface unit5comprises a sealed tank1000. The sealed tank1000comprises the inflatable bag3and a casing6. The inner volume60delimited by the casing6forms part of the volume delimited by the sealed tank1000.

As shown inFIGS. 2 and 3, the casing6comprises a tubular lateral wall70of axis z and a bottom71transverse to the lateral wall70. The lateral wall70and the bottom71delimit an inner volume60of the casing6belonging to the inner volume delimited by the tank1000. In other words, the inner volume60extends from one side only of the bottom71on the axis z.

Advantageously, but not necessarily, the tubular wall70is cylindrical.

Advantageously, but not necessarily, the cylinder is axisymmetrical. In other words, it has a circular cross section.

The cylinder form is advantageously a form of the external face of the tubular wall, i.e. of the face turned toward the exterior of the inner volume60.

Advantageously, the bottom71comprises an external face, i.e. opposite the inner volume60extending principally perpendicularly to the axis z.

In the non-limiting embodiment of the figures, the volume is delimited by another wall76transverse to the wall70.

Advantageously, the transverse wall76comprises an external face, i.e. opposite the inner volume60extending principally perpendicularly to the axis z.

The inner volume60is delimited by the walls70,71,76.

In the non-limiting embodiment of the figures, the casing6is globally cylindrical.

The inflatable bag3is affixed in a sealed manner to the casing6, for example by means of at least one seal78, and such that the volume delimited by the casing is in communication with the inner volume delimited by the inflatable bag.

It is possible to house equipment that has to be protected from the water in the sealed tank1000.

Advantageously, at least one electronic circuit61and/or at least one energy accumulator62and/or at least one system102,104for releasing a gas is housed in the sealed tank1000, for example in an inner volume60delimited by the casing6. An electronic circuit is, for example, embodied in the form of an electronic card.

These elements may comprise at least one electronic circuit61(for example, embodied in the form of an electronic card) allowing the processing of information originating from and/or destined for the hydrophones or, more generally, sensors located in the depth unit8, and/or allowing the processing of information destined for and/or originating from the radioelectric antenna.

The energy accumulator is, for example, designed to provide electric power to the electronic circuit(s) and/or the radioelectric antenna and/or a device for actuating a gas release system to be described below.

According to the invention, the sealed tank1000comprises a container, referred to as a projecting container,17protruding from the bottom71and extending away from the inner volume60, from the bottom71.

In other words, the projecting container17extends from that side of the bottom that is opposite the inner volume60.

This configuration makes it possible to house supplementary elements in the sealed enclosure without increasing the height of the cylindrical casing6, which makes it possible to limit the drag thereof and is beneficial in terms of optimizing the occupation of the volume inside the tubular receptacle4. Indeed, it is possible to house equipment other than those items that have to be housed in the sealed enclosure, around the projecting container17, and thereby to optimize the occupation of the volume delimited by the receptacle4, as will be seen below.

This configuration makes it possible to limit the size of the front surface of the submerged part (the part in the water) of the sealed tank1000or of the surface unit5, and thus their drag, while the buoy is in the operational configuration, when a front surface of a submerged part (a part in the water) of the sealed tank or of the surface unit comprises a part of the projecting container and a part of the tubular lateral wall70. When an object is submerged in a liquid, the term “front surface” of this object is applied to the surface projected in accordance with the trajectory of the liquid over a plane perpendicular to this trajectory. In other words, it is the surface that the object presents to the water. In the present case, the axis z is substantially vertical in the operational configuration. The sea currents are globally perpendicular to the axis z.

For example, it is possible to make provision for a cartridge containing 38 g of CO2, with a casing having a cylindrical part 10 cm in height on the axis z and 17 cm in diameter perpendicularly to the axis z and a cartridge forming a protuberance 10 cm in height on the axis z and 3 cm in diameter perpendicular to the axis z. By providing two cartridges each containing 16 g of CO2and thus 32 g of CO2in total, it is necessary to provide a casing 13 cm in height and 17 cm in diameter, which represents a larger front surface.

In the non-limiting example of the figures, the wall70and the projecting container17are submerged in the operational configuration.

Advantageously, a larger dimension d of the projecting container17perpendicularly to the axis z being less than a smaller dimension D of the tubular wall70perpendicularly to the axis z. This makes it possible to limit the size of the front surface formed by the casing and the projecting container.

Advantageously, the casing is completely submerged in the operational configuration.

In the non-limiting example ofFIG. 3, this projecting container17is a part of the cartridge11called the “projecting part” of the cartridge.

Thus, the cartridge11is at least in part located outside the inner volume60.

In other words, the cartridge11comprises a projecting part17extending in the continuation of the cylinder formed by the wall70and the bottom71, on the axis of the cylinder in the case of a cylinder.

The sealed tank1000comprises a sealed wall turned toward the exterior of the tank comprising a wall12of the cartridge11. In other words, the cartridge11is involved in the closure of the sealed volume delimited by the tank1000. This makes it possible to avoid isolating the cartridge from the water, notably by the casing6(which is very advantageous when the casing is made from plastics) and the air contained in the inner volume of the casing.

The invention makes it possible to free up a space inside the casing6and thus to reduce the volume of the casing6as compared to a configuration in which the cartridge is housed entirely in the casing6of substantially cylindrical form. It also makes it possible to provide a cartridge11of greater volume than that of cartridges arranged in the casing without increasing the volume of the casing6, since the size of the cartridges is no longer limited by that of the casing. For one and the same volume of gas stored in the cartridges, this makes it possible to reduce the number of cartridges used without increasing the size of the casing.

This configuration makes it possible to bring the radioelectric antenna2to a greater altitude above the level of the sea and thereby to ensure better performance levels in terms of communication, even when the sea is rough, or, alternately, to make provision for sonar emission antennae and/or hydrophones offering better acoustic performance levels and thus greater mass, without reducing the altitude of the antenna above the level of the water.

This configuration also makes it possible to reduce the total volume occupied by the surface unit5for one and the same quantity of gas and thereby to reduce its drag. Indeed, owing to a free volume left between the elements, the volume by which the volume of the casing has to be increased in order to house a gas cartridge is greater than the volume of the cartridge. The limitation on the drag of the surface unit makes it possible to limit the antagonistic drift of the surface unit and of the depth unit through the effect of antagonistic currents (at the surface and at the level of the depth unit8), which allows stabilization of the depth unit8.

When the buoy1is submerged in the water, water comes into direct contact with the cartridge11, whereas in the prior art the cartridges housed in the casing are thermally insulated from the water by the casing and by the air contained in the casing. Thus, when the gas is released from the cartridge, the gas cartridge being directly in physical contact with the water, the drop in the temperature of the gas is limited, which limits the likelihood of condensation and of freezing of the gas and the consequences thereof described previously.

Indeed, upon the release of the gas to inflate the inflatable bag, the gas, hitherto contained in the cartridge, expands rapidly, which leads to a reduction in its temperature and of that of the wall of the cartridge, giving rise to condensation of the water vapor from the air contained in the casing, which may thus damage an electronic circuit housed in the casing. The drop in the temperature of the gas may also give rise to the freezing of this gas, which may then block, at least partially, an orifice for the discharge of the gas from the cartridge, thereby delaying, until the temperature has risen sufficiently to vaporize the gas, the inflation of the inflatable bag and the arrival of the inflatable bag at the surface of the water. Lastly, the drop in the temperature of the gas gives rise to a reduction in its volume, which also delays this arrival at the surface. The greater the drop in temperature and the longer the period of time taken by the gas to attain its maximum expansion volume since the gas has to return to ambient temperature in order to attain this maximum expansion volume. Thus, the proposed configuration makes it possible to accelerate the inflation of the inflatable bag and to limit the likelihood of damage to electrical equipment arranged in the casing.

Thus, the gas confined in the cartridge11is to be kept apart from the water by a single wall12, which is a wall of the cartridge11. In other words, a face of the wall12is turned toward a permeable volume. In other words, the cartridge11is not completely surrounded by a sealed tank when the buoy is submerged in the water.

Advantageously, the wall12is metallic. It is, for example, made from steel in order to withstand significant pressures.

Advantageously, the cartridge11is arranged such as to come into direct physical contact with the water when it is submerged in the water, in the storage configuration. Thus, the thermal exchange between the cartridge11and the water occurs when the release of the gas commences.

Advantageously, when the buoy1is in the storage configuration the cartridge11is surrounded by a permeable tank allowing the water to come into direct contact with the cartridge11when the cartridge11is submerged. In other words, the tank delimits a volume, receiving the cartridge11, which is not closed in a sealed manner.

In the non-limiting example ofFIG. 3, the cartridge11is surrounded by a receptacle14, referred to as the “cable container”, delimiting a volume housing the cable9in the stored position. This cable container14is arranged in the receptacle4. The tank surrounding the cartridge11is permeable. Indeed, at least one of the ends of the receptacle4is open such as to enable the internal part of the buoy1to emerge from the receptacle4. Furthermore, the cable container14delimits a volume receiving the cartridge11, and this volume is not closed in a sealed manner. It is not, for example, connected in a sealed manner to the casing6and/or to the receptacle4. In this way, water penetrates inside the receptacle4and the cable container14such that the water comes into direct physical contact with the cartridge11. In other words, the water is contiguous with the wall12.

As may be seen inFIG. 3, the casing6comprises an opening63formed in the bottom71. This opening63is traversed by the cartridge11.

The casing6is in part closed by the cartridge11when the buoy1is in the storage configuration. This makes it possible to avoid insulating the cartridge from the exterior environment by means of the casing6(which is very advantageous when the casing is made from plastics) and the air contained in the inner volume of the casing.

The cartridge11is affixed to the casing6in a sealed manner, for example by means of at least one seal77.

Advantageously, but not necessarily, the casing6comprises a return81having a form that substantially complements that of the cartridge11and is affixed to the cartridge11in a sealed manner, for example by means of a seal77. This promotes the sealing of the connection between the cartridge and the casing.

In a variant shown inFIG. 5, the casing600comprises a cylindrical part601and a protuberance617forming the protruding container. This protruding container is made as a single piece with the cylindrical part of the casing6. In a variant, it is affixed to the casing. This protuberance617delimits an inner volume618that is in communication with the inner volume619delimited by the cylindrical part601when the buoy is in the storage configuration and in the operational configuration.

The cylindrical part is delimited by a tubular wall620and two transverse walls621,622, including the bottom621from which the protuberance forms a projection extending away from the inner volume619, from the bottom621, on the axis z.

It is, for example, possible to house, in this part, at least a part of one of the items of equipment housed in the sealed enclosure. It is, for example, possible to house therein a part of an electronic card and/or at least a part of a cartridge and/or at least a part of an electronic circuit and/or at least a part of an electrical battery and/or at least a part of a gas release system of the cartridge. This makes it possible to free up slightly the space delimited by the cylindrical part601, without increasing the height thereof.

The cartridge11is, for example, entirely housed in the volume delimited by the sealed enclosure. In other words, the cartridge11is fully surrounded by the sealed enclosure.

According to a non-limiting embodiment, the inflatable bag3extends on one side of the casing6on the axis z and the projecting container17extends on the other side of the casing relative to the inflatable bag on the axis z. In other words, the projecting container17extends away from the inflatable bag3from the bottom71. According to the non-limiting embodiment of the figures, the inner volume of the cartridge11is in communication, when the gas is released, with the inner volume of the inflatable bag3via the casing6. In a variant, the cartridge11is arranged such that the gas is expelled directly into the inner volume of the inflatable bag3. These two cases can be envisaged when the cartridge11is fully delimited by the sealed enclosure.

Communication between the inner volume of the inflatable bag3and the inner volume of the casing6is, for example, achieved via at least one orifice79.

The orifice79is, here, provided in an electronic card61closing an opening provided in the casing6.

The buoy1comprises a system for releasing the gas contained in the cartridge. This release system is, for example, a system of perforation of the cartridge11. The cartridge11comprises, for example, a film101, visible inFIG. 3, that closes an opening103made in the cartridge11and, more particularly, in the wall12. The release system comprises a perforator102provided with a point102b. The release system comprises an actuating device104configured such as to actuate the perforator102so that the point102bperforates the film101such as to form an orifice in the cartridge11(by opening at least a part of the opening), when a gas release status is verified. The actuating device104comprises, for example, a resistor and a source of electrical power to the resistor. The actuating device104is configured such as to supply electricity to the resistor when the gas release status is verified in such a manner as to release the perforator102so that it perforates the film101. The perforator102is, for example, a lever held in a standby position, as shown inFIG. 3, by a thread that is burned by the resistor which heats up when it is powered such that the lever rocks in order to perforate the film101. This actuating system is in no way limiting. In a variant, the release system comprises, for example, an actuating device of the pyrotechnic or hydrostatic type.

Advantageously, as shown inFIG. 3, the gas release system102,104is housed in the sealed enclosure, for example in the inner volume60. In a variant, the gas release system is housed in the projecting container17.

Advantageously, the buoy1comprises a single cartridge11of gas that can be released such as to inflate the inflatable bag3. This makes it possible to reduce the drag of the surface unit5and to limit the complexity and the number of release devices. Furthermore, the free space in the casing6being greater than when the cartridges11are housed in the casing6, only one lever is needed to release the gas and there is no need to provide a return cam in order to limit the volume occupied by the actuating device104.

In a variant, the buoy1comprises several cartridges of gas that can be released in order to inflate the inflatable bag3.

Advantageously, as shown inFIG. 3, an assembly of at least one element of the buoy is arranged in a volume V surrounding the projecting container17when the buoy is in the storage configuration, in which the gas is confined in the cartridge11.

This element is arranged in the receptacle4when the buoy is in the storage configuration. In other words, the tubular volume is surrounded by the receptacle4in the storage configuration. The projecting container17is, for example, surrounded by a cable winding9.

Advantageously, as shown inFIG. 3, a tubular container14surrounds the projecting container17when the buoy is in the storage configuration. This tubular container14is housed in the receptacle4when the buoy is in the storage configuration.

The tubular container14is adjacent the transverse wall71on the axis z of the tube.

In the non-limiting example ofFIG. 3, the projecting part17is surrounded by a winding surrounding the projecting part17of the cartridge11and by the cable container14surrounding the winding. A cable wound on itself such as to form a coil necessarily leaves a cylindrical volume free because the radius of curvature of the cable cannot go below a minimum radius of curvature corresponding to the radius of the free cylindrical volume. Thus, this configuration makes it possible to optimize the occupation of the volume of the container by occupying a volume that is naturally left free.

The cable container14has a globally tubular form. It is in the continuation of the casing6on the axis z.

The cable container14advantageously comprises an external surface (turned toward the receptacle4or the environment outside the buoy) which is globally cylindrical and preferably axisymmetrical, i.e. it has a circular cross section. Advantageously, the cable container14and the lateral wall70are coaxial in the storage configuration. The external surface of the cable container14has, for example, the same diameter as the casing6, i.e. the same diameter as the external surface of the lateral wall70of the casing6.

The cable container14advantageously lies against the casing6and a part of the depth unit140. Thus, it makes it possible to limit the transmission of forces between the casing6and the part140via the cable during storage.

In a variant, the buoy1does not comprise a cable container14.

Advantageously, at least one active functional element of the buoy is arranged in a tubular volume surrounding the projecting container17when the buoy is in the storage configuration in which the gas is confined in the cartridge11. “Active functional element” is understood to mean an electrical or optical element, i.e. an element to be powered electrically or optically, transmitting electrical or optical energy, i.e. comprising at least one electrical wire or an optical fiber, or delivering, accumulating, transforming (such as, for example, an electric transformer) or modulating electrical or optical energy.

The cable forming the winding is, for example, an active element.

The cable9may make it possible to transmit information from the surface unit5toward the depth unit8and/or, conversely, is an active functional element. This is an electrocarrier cable.

The cable9comprises two parts, a first part15of which is attached to the depth unit8and of which the length is fixed, and a second part16of which comprises a tensioning device or elastic cable allowing insulation of the depth unit from the movements of the surface unit5upward and downward through the effect of the waves. In the storage configuration, these two units are separated by a partition75in the example ofFIG. 3.

The surface unit5and the unit8are connected by connecting means comprising the cable.

The cable9is, for example, connected to the surface unit5by means of wires74of the connecting means, for example three wires74of which only two are visible inFIG. 4, showing the buoy in the operational configuration. The wires74attached to the casing over the periphery of the casing6on the one hand and to the cable9on the other such as to ensure a force take-up at the center of the casing6.

In a variant, the cable9is a passive element.

Instead and in place of the cable and/or in addition to the cable and/or an electrical transformer may be arranged in the tubular volume surrounding the projecting container17. The transformer may surround the projecting container. A transformer generally has a ring or U form delimiting a free space in which the projecting container17may be inserted.

At least one hydrophone may be arranged in the tubular volume surrounding the projecting container17. The hydrophone is, for example, supported by an arm designed to extend longitudinally substantially parallel to the axis of the tubular wall70when the buoy is in the storage configuration. This makes it possible to provide arms of significant length.

Advantageously, at least one arm is arranged in the tubular volume surrounding the projecting container17. This arm extends, for example, longitudinally, substantially parallel to the axis z when the buoy is in the storage configuration, and the inclination thereof relative to the axis z varies between the storage configuration and the operational configuration.

In a variant, for example when the buoy is designed to be deployed from a submarine, a float, for example a foam float, may surround the projecting part17. The foam float may have an annular form surrounding the projecting part. Thus, this float enables the buoy to rise naturally toward the surface when the buoy is deployed. The inflatable bag is not inflated until it is near the surface.

The float surrounds, for example completely surrounds, the projecting container17in the storage configuration.

Advantageously, the buoy1is configured such that the relative arrangement between the projecting container17and the element(s) arranged in the volume V surrounding the buoy is modified between the storage configuration and the operational configuration of the buoy1.

Advantageously, the buoy is configured such that a front surface of a submerged part (a part in the water) of the projecting tank or of the surface unit when the buoy is in the operational configuration comprises a part of the projecting container17. This configuration offers the advantage of limiting the drag of the surface unit.

Advantageously, a part of the depth unit8surrounds the projecting container17in the operational configuration. Thus, the projecting container penetrates a part of the depth unit8in the storage configuration of the buoy, which is counter intuitive but makes it possible to optimize the occupation of the space in the receptacle4. In other words, at least one element of the buoy of the assembly of at least one element belongs to the depth unit.

In the particular example of the figures, the cable container14forms part of the depth unit8such that it separates from the surface unit upon inflation of the inflatable bag, i.e. when the surface unit rises toward the surface of the water. The cable9connecting the surface unit and the depth unit unwinds such as to release the cartridge.

In a variant, a part of the surface unit5is arranged in the tubular volume surrounding the projecting container17. For example, the cable container14is integral with the casing6such as to be entrained by the casing toward the surface of the water when the casing6rises toward the surface of the water. This embodiment is less advantageous from the drag standpoint.

Advantageously, the projecting container17extends longitudinally parallel to the axis z. The projecting container17advantageously comprises a cylindrical part, the axis of which is parallel to the axis z and is, for example, coaxial with the casing6and/or the cable container14(in the storage configuration).

Advantageously, the gas cartridge11is oriented with its head at the top. In other words, the cartridge11is arranged such that the gas is expelled upward from the cartridge, on a vertical axis relative to the earth when the buoy is deployed and submerged in the water. When the buoy is deployed into the water, it adopts a natural orientation dependent on the position of its center of gravity and its center of hydrostatic thrust.

Thus, the cartridge is advantageously arranged such that the orifice103through which the gas escapes is located at the top of the cartridge11when the buoy is deployed and submerged when the buoy is in the storage configuration. This makes it possible to limit the likelihood of damage to the casing. Indeed, as the gas molecules are in the liquid state in the lower part of the cartridge and in the gaseous state in the upper part of the cartridge, upon release of the gas, when the cartridge is turned so that its head is at the bottom or when the cartridge is lying on its side there are risks of gas molecule droplets being projected through the effect of the pressure exerted by the gas on the liquid. These droplets, which are at a very low temperature (owing to the expansion of the gas), can exert mechanical stresses that may damage the casing. They may also damage the electronic circuits. The “head upward” arrangement of the cartridge makes it possible to limit this risk.

In the embodiment of the figures, the cartridge comprises a neck121delimiting the opening103closed by the film101in the storage configuration.

In the embodiment of the figures, the depth unit8comprises the cable container14and an operational unit140. The operational unit comprises at least one active functional element of the antenna.

The operational unit is advantageously substantially cylindrical and of axis z in the storage configuration.