Abstract: A device for generating in the ground longitudinal and transverse acoustic waves by a mass striking a target element coupled with the surface of the ground. The target element is recessed in a central part thereof and have an inner wall slanted with respect to the vertical in the form of, for example, a truncated cone. The mass is fixed to the end of an arm pivoting with respect to a support structure in the form of a parallelepipedic cage, which is movable by a cylinder between a high transport position and a low position in which the target element is coupled with the ground a drive causes raising of the mass by pivoting the arm with the geometry of the assembly being calculated so that the mass strikes the inner slanting faces perpendicularly thereto, and thus creates both P and S waves.

Abstract: The improved device for generating acoustic shear waves in the earth comprises a target member adapted to be coupled with the earth and provided with two lateral striking surfaces on which impinges a hammer pivotably mounted on a platform; the target member is connected through damping means to a cage supporting the platform, the hammer and its actuation means, said cage being displaceable with respect to the frame of a carrying vehicle between a position of contact with the earth of the target member and a lifted position thereof, the striking surfaces being inner walls of the target member.

Abstract: A supporting system for carrying apparatuses to be moved under water at a substantially constant submersion depth, when towed from a ship, including a platform made up of two elongate members interconnected through plates carrying the apparatuses, a depth regulating paddle foil or flap, automatically controlled by the variation of the hydrostatic pressure, and a float secured to the platform, through cross members, at a certain distance above the platform.

Abstract: A submerged device, carrying oceanography apparatuses, is adapted to be towed from a ship and provided with an automatic control of the submersion depth, which is made up of two hulls of positive buoyancy and interconnecting cross members with the device having a center of bouyancy substantially above the center of gravity, and at least one movable substantially airfoil shaped fin, which is actuated by the automatic control of the submersion depth which is sensitive to the depth of submersion of the device.

Abstract: The device includes two movable members interconnected at their periphery by a flexible membrane defining therewith a tight enclosure of variable volume, a piston slidable in a cylinder integral with one of the two movable members and hydraulically actuated, to move the members apart from each other, a second cylinder separated in two compartments by an inner valve and controlling the actuation of the piston in response to the pressure of the water feeding said second cylinder, two apertures intermittently freed by the valve for releasing the piston and at least one aperture for the discharge of the water from the tight enclosure to the external water body when the piston release allows the two movable members to be urged toward each other, thereby producing an implosion which generates a strong sonic wave.

Abstract: An optical recording device comprising a rigid arm carrying an optical system generating a light beam whose characteristics are varied in response and in relationship to a signal to be recorded. The arm is driven in an oscillatory movement by a motor of circular movement associated to a crank. The device further comprises a recording support unrolled along a direction orthogonal to that of the arm oscillatory movement, and means for synchronizing the control of the optical system with the movement of the arm.

Abstract: Device for controlling the submersion depth of an element moving through a body of water comprising a pivotable wing having an upper and a lower wall articulated to each other at one end and interconnected at the other end through a deformable incurved wall, the wing housing spacing elements, between the upper and the lower wall, which are compressed or expanded in response to the hydrostatic pressure variation, resulting from a depth variation of the element, thereby producing a space variation between the two walls, and a system for converting said space variation to a rotation of the wing with respect to the submerged element, in a direction at which the movement of the element tends to an opposite variation of the hydrostatic pressure.

Abstract: A device for generating acoustic waves in the earth by striking a mass, housed in a guiding tube, against a target member secured to the lower end of this tube and coupled to the earth in operating conditions, including means, such as an electromagnet, for holding said mass at the upper end of said tube and releasing it at will, and means to turn the tube upside down after each operation so as to reset the mass in position for a new operation.

Abstract: This device comprises two movable elements of rigid material tightly interconnected by means of a deformable membrane forming therewith a tight internal enclosure, means for varying abruptly the volume of said enclosure by successively moving the two elements away from each other, maintaining them in spaced relationship and allowing them to be urged toward each other by the effect of the external hydrostatic pressure, in which the means for moving the two elements away from each other includes two cylinders and at least one piston slidable in one of said cylinders, associated to one of said movable elements and also to a push-member slidable in one of the cylinders and bearing on the other movable element and means for feeding said cylinder with pressurized fluid so as to maintain the elements in spaced relationship or to release them.

Abstract: A device for transmitting acoustic waves through a liquid medium in which it is submerged comprising two movable assemblies including respectively members provided with first contact walls and delimiting with a sealing membrane a water tight enclosure, and members provided with second contact walls which are the armatures of an electro-magnet, the respective members being so arranged that when the first contact walls are in contact, the second contact walls are spaced apart and conversely, pressure actuated means for moving the first contact walls apart from each other and releasable locking means including an energizing coil for maintaining the armatures of the electro-magnet in spaced apart relationship.

Abstract: Device for towing a submerged member from a ship, along a direction parallel to the ship route, and laterally shifted with respect thereto, comprising a submerged deflector, including a series of parallel paddles inclined with respect to the longitudinal axis of the device and whose generatrices are perpendicular to the plane of flotation, the deflector being solid with a floating element on the water surface.

Abstract: A device for generating shear waves in the earth for seismic prospectives, comprising a target member coupled with the earth, a vehicle carrying a mass and means for driving and guiding the mass along a direction perpendicular to the striking surface of the target member and parallel to the earth surface, said means comprising a toothed wheel in mesh with a driving chain and a counterweight for balancing the mass. According to a particular embodiment, the target member is so designed that at least a part of the vehicle weight can be applied thereon.

Abstract: This device comprises two movable elements of rigid material tightly interconnected by means of a deformable membrane forming therewith a tight internal enclosure, means for varying abruptly the volume of said enclosure by successively moving the two elements away from each other, maintaining them in spaced relationship and allowing them to be urged toward each other by the effect of the external hydrostatic pressure, in which the means for moving the two elements away from each other includes two cylinders and at least one piston slidable in one of said cylinders, associated to one of said movable elements and also to a push-member slidable in one of the cylinders and bearing on the other movable element and means for feeding said cylinder with pressurized fluid so as to maintain the elements in spaced relationship or to release them.

Abstract: Device for generating shear waves in the earth for seismic prospecting, comprising means for striking with a mass a target-member coupled to the earth, said means including means for lifting and shifting said mass with respect to the target member, an electromagnet for intermittently locking it in an upper position and releasing it abruptly and means for adjusting the stroke of the mass from its upper position to its lower position where it impinges the target member.

Abstract: Device for generating acoustic waves in a fluid medium by implosion, comprising a main cylinder, a main piston slidably mounted thereinto, said piston having a hollow cylindrical portion housing another cylinder solid with the main one and, through the bottom of which passes the hollow rod of another piston, actuated by hydraulic means and which drives in translation the main piston. By means of an annular valve, solid with the main piston, and further hydraulic means, the main piston may be locked in a position of spaced relationship with respect to the main cylinder and abruptly unlocked, thereby generating an implosion.

Abstract: A method and apparatus for determining the position of a plurality of seismic echo receivers on a towed cable by interpolating values obtained by measuring, by means of at least one device positioned among said receivers, the angle between the tangent to the cable and a fixed and known direction. The measuring device can also include apparatus for measuring its depth and its distance from a generator of seismic waves. This provides for more effective use of processes which involve the addition of seismic traces in marine seismic prospecting.

Abstract: Shock absorber comprising a casing delimiting an inner recess having two portions of different diameters and containing a liquid, a piston assembly consisting of two pistons of slightly different diameters mounted on the same rod and slidable into said recess, the larger of said pistons being traversed by a channel for liquid passage, a liquid reservoir either inside the rod or outside the casing, in communication with the inner recess through a further channel, sealing structure tightening the recess from the external medium and an element in the reservoir which is compressed or expanded in response to a change in the pressure of the liquid contained in the reservoir.