Abstract: A sonar device intended to be towed by a surface ship and includes a tow cable and a set of at least one towed device, comprising a towed body, intended to be towed by the surface ship via the tow cable, the towed body being elongate along a longitudinal axis from a first longitudinal end of the towed body as far as a second longitudinal end of the towed body, the towed body incorporating a first linear acoustic antenna comprising a plurality of electroacoustic transducers substantially aligned along the longitudinal axis, the towed device being configured and connected to the tow cable in such a way that the towed body is able, when it is being towed and is fully submerged, to exhibit an orientation the longitudinal axis extends substantially along a vertical axis defined by the force of gravity, at least one towed body of the set of towed bodies being connected to the tow cable by a first hanger and a second hanger of substantially the same length, a first end of the first hanger and a first end of the seco

Abstract: A handling device includes a winch comprising a frame, intended to be attached to a structure of the surface vessel and a first drum capable of turning relative to the frame about a first rotation axis and an assembly comprising at least one second drum which surrounds the first drum and is capable of turning relative to the frame about a second rotation axis substantially parallel to the first rotation axis, the winch being capable of being in a decoupled state wherein the first drum and the second drum are rotationally decoupled about the first rotation axis and the second rotation axis so as to allow a traction cable to be wound around the first drum during a first winding step wherein the first drum is rotated about the first axis, the second drum being capable of being in an open state wherein the second drum has a receiving opening that a towed body is capable of passing through in order to enter the interior of the space that surrounds the first drum and that is surrounded by the second drum, the winch

Abstract: Embodiments of the present invention relate to a linear submersible body including a plurality of rigid segments that are articulated and can adopt relative to one another an orientation making it possible to form a rectilinear body, or a curved body of which the radius of curvature is adapted to the drum of the winch onto which it is wound. The segments are associated with couplers and configured so that a vertical rectilinear posture is naturally obtained when the device is totally submerged and towed by the ship, while the curved posture is obtained naturally by the winding of the device onto the winch. Embodiments of the invention apply to the production of linear and vertical transmitting acoustic antennas.

Abstract: Embodiments of the present invention relate to the undersea mechanics of ship-towed linear bodies which preferably are towed in a vertical position and which, at rest, are designed to be stored on the drum of a winch. The linear submersible body is capable of adopting a rectilinear configuration in a vertical position when it is towed at a total immersion depth and of adopting a curved configuration at rest, having a radius of curvature allowing it to be wound onto the drum of a winch. The device according to the invention includes a plurality of rigid segments that are articulated and can adopt relative to one another an orientation making it possible to form a rectilinear body or a curved body, of which the radius of curvature is adapted to the drum of the winch onto which it is wound.

Abstract: The present invention relates to a device for the automatic hauling of very long elongate objects. This device in particular allows very long tubular objects of relatively flexible and delicate structure such as, in particular, underwater cables, pipes or alternatively linear sonar antennas of the “streamer” type to be handled. The device chiefly comprises traction means consisting of at least two running strips with rough surfaces which are pressed on each side of the object and drag it along in a traction movement and gripping means which constantly keep the running strips pressed against the object in order to ensure good adhesion. Another subject of the invention is means for actuating the traction means and the gripping means in a coordinated manner so that the object that is to be hauled experiences continuous traction throughout the hauling operation. The device according to the invention has the advantage of being mounted on a stationary chassis and therefore of not requiring an operating area.

Abstract: The present invention relates to a device for the automatic hauling of very long elongate objects. This device in particular allows very long tubular objects of relatively flexible and delicate structure such as, in particular, underwater cables, pipes or alternatively linear sonar antennas of the “streamer” type to be handled. The device chiefly comprises traction means consisting of at least two running strips with rough surfaces which are pressed on each side of the object and drag it along in a traction movement and gripping means which constantly keep the running strips pressed against the object in order to ensure good adhesion. Another subject of the invention is means for actuating the traction means and the gripping means in a coordinated manner so that the object that is to be hauled experiences continuous traction throughout the hauling operation. The device according to the invention has the advantage of being mounted on a stationary chassis and therefore of not requiring an operating area.

Abstract: The invention relates to acoustic transducers which comprise a ceramic ring formed from a pre-stressed set of segments. It consists in using, as screws for tightening pre-stressing wedges, screws with hexagonal heads and in placing on the inner face of these wedges a plate provided with recesses in which the cants of these screw heads become anchored. This plate comprises transverse channels allowing the passage of the power supply wires for the sectors. The central screw is removed after the desired pre-stressing has been obtained. It makes it possible to improve the manufacture of these transducers.

Abstract: The invention relates to acoustic transducers which comprise a ceramic ring formed from a pre-stressed set of segments.

Abstract: An underwater acoustic transducer configured to emit a low-frequency broadband acoustic signal. The underwater acoustic transducer includes a cap in the form of a cylinder closed on one side and open on the other side. A piezoelectric plate operating in flexion is fixed on the base of the cylinder outside the cylinder. The inside cavity defined by the cylinder is open freely toward the outside medium in which the acoustic waves are to be emitted. For identical dimensions, the underwater acoustic transducer makes it possible to decrease a central frequency of emission and to increase bandwidth.

Abstract: Disclosed is an electrodynamic transducer designed to emit acoustic waves in a sea environment while being capable of withstanding external explosions. The lower pole piece of such a transducer is drilled with vertical holes enabling air to circulate inside the transducer in order to efficiently cool the coil that makes it work. Light metal masses that are good heat conductors, attached between the magnets which excite the pole pieces, furthermore drain the heat out of the transducer. The efficiency of such a transducer is increased by at least 4.

Abstract: Disclosed is an electrodynamic transducer designed to emit acoustic waves in a sea environment while being capable of withstanding external explosions. The lower pole piece of such a transducer is drilled with vertical holes enabling air to circulate inside the transducer in order to efficiently cool the coil that makes it work. Light metal masses that are good heat conductors, attached between the magnets which excite the pole pieces, furthermore drain the heat out of the transducer. The efficiency of such a transducer is increased by at least 4.

Abstract: Acoustic transmitting antennas in the form of circular rings. Several circular rings which can be dismantled of a known type are superimposed in a stack. The stack is terminated at each end by two profiled annuli. The threaded tie-rods traverse the stacks of the pre-stressing keys of the rings by the intermediary of holes drilled in these keys. The threaded tie-rods make it possible to ensure the holding of the assembly. Two jackets, inside and outside, made of rubber, cover the inside and outside faces of the stack and are anchored in grooves formed in the profiled annuli. Thereby, annular transmitting antennas can be provided which can be dismantled entirely and whose active mass to inactive mass ratio is particularly large.

Abstract: A method for controlling the navigation of a towed linear acoustic antenna. Birds equipped with variable-incidence wings are fixed onto the antenna. Through a differential action, the wings allow the birds to be turned about the longitudinal axis of the antenna so that a hydrodynamic force oriented in any given direction about the longitudinal axis of the antenna is obtained. Power and control signals are transmitted between the antenna and the bird by rotary transformers. The bird is fixed to the antenna by a bore closed by a cover. The bird can be detached automatically as the antenna is raised so that the antenna can be wound freely onto a drum. This method allows the full control of the deformation, immersion and heading of the antenna.

Abstract: Disclosed is an electrodynamic transducer designed to emit acoustic waves in a sea environment. The dome of a transducer such as this is provided with a horn sliding in the body of the transducer with an adjutage whose clearance is extremely small. This reduces the effects of a shock wave coming from a possible external explosion and prevents the tearing of the tight-sealing membrane between the horn and the body. Radial ribs increase the stiffness of this mobile structure. A toroidal, elastic air chamber provides compensation for the effects of the hydrostatic pressure and of gravity on the mobile structure. The disclosure provides transducers that are resistant to external explosions.

Abstract: Method for fabricating thermally cooled electronic cards. A card of any kind is covered with a rigid heat sink shaped to fit the card and is attached thereto. The heat sink is formed in such a way that it fits as closely as possible the shape of the printed circuit. The printed circuit has components on one or both faces so that it is possible to increase the surface thermal coupling between the sink and the board. An optical sensor using a laser beam may be used.

Abstract: The invention relates to air-launched buoys intended to be launched from a flying aircraft. It consists, in a buoy the body of which is small and has neither flaps nor inflation opening, in making the connection between the balloon which makes the buoy buoyant and the body leaktight and in placing on the lower part of this balloon a beak of triangular shape allowing air to be caught as the buoy falls towards the water. An opening is made in the wall of the balloon below the beak to allow the air thus caught to enter this balloon in order to inflate it. A non-return valve makes it possible to keep the balloon inflated. It makes it possible to improve the inflation of the balloon and limit the speed at which the buoy falls.

Abstract: An airborne buoy droppable from an aircraft into water, comprising, as a float, a balloon which inflates during its fall. Before being dropped the balloon is protected by a hood locked by a bent blade bearing on a wedge. During the fall, the scoop-shaped mechanical parts lift up, a cloth placed below an opening in the scoops inflates and frees the hood by drawing back the wedge fixed on the tongue forming an extension of the cloth.

Abstract: A radio buoy which can be jettisoned from an aircraft by a cable and which is intended to float on the surface of the ocean connected to a submerged hydrophone. During the drop a balloon is inflated by a forced intake of air through holes as a result of articulated openings in the form of scoops, the scoops unlocking by a bar the protective casing of the balloon and the safety device of the container, which is detached after impact with the water, the submerged container being linked with the electronics by a cable. The buoy can be used for underwater monitoring at depths up to 2,000 meters.

Abstract: A buoy capable of being dropped onto water from an aircraft, comprising a balloon which inflates during the descent through a forced intake of air through adjustable openings at the base of the balloon. Inside the balloon there is a flexible membrane allowing the air to enter through holes, the balloon remaining inflated to the maximum pressure encountered during the descent. Pockets with openings are traversed by the air and prevent the balloon from rotating during its descent.

Abstract: A heat sink for components which dissipate large amounts of heat which enables operating temperatures to be held within predetermined limits.This heat sink consists of a stack of connecting members (34, 38), cooling members (35, 37), "press pack" type components (36) and pressure members (33) which are arranged between two cross-pieces (21, 22) which are held together by ties (24, 25) to form an assembly frame.The device is applicable in particular to the cooling of power thyristors.