Abstract: This directional valve comprises a closing element (1) rotatively mounted in a fixed sleeve (5) disposed in a body (2) with interposition of an annular element (4) between the closing element and the sleeve. Means are provided for locking the annular element against rotation in normal use and for permitting the driving of the annular element by the closing element in the event of a seizing of the closing element in the annular element. These locking means comprise a device (12) having a push member (13) mounted laterally on the body at one end of the closing element (1) and extending in a direction perpendicular to the closing element (1), resilient means (15) being provided for biasing the push member against a rocker (30) inside the body, the thrust of which is applied to locking balls (21) which project from recesses (24) provided in an end of the annular element (4).

Abstract: This electrohydraulic actuator comprises a pair of hydraulic rams (12, 13) and a rocker (14) integral in terms of rotation with an input shaft (7) of the barrel, the rams are arranged parallel with one another in such a way as to be able to control the rotation of the rocker to make it adopt predetermined angular positions corresponding to the gears (R, N, 1, 2, . . . ) selected and this actuator also comprises solenoid valves for controlling the rams. The rocker (14) extends transversely to the shaft (7) and its ends are designed to be able to interact with respective pistons (17, 18) of the rams (12, 13), each ram comprises three pistons (24, 25, 17; 26, 27, 18) which are coaxial and have different cross sections, arranged in chambers (28, 29) of corresponding cross sections formed in the body (11). This electrohydraulic actuator permits extremely quick and easy control of gear selection for a structure which is relatively simple and has a modest cost of manufacture.

Abstract: This assisted selection system comprises an electrohydraulic actuator (12) which controls the input element of the gearbox and may itself be controlled by parameters provided by the engine control computer. The actuator (12) comprises a group of solenoid valves (34, 35, 37, 52, 53) connected to cylinders (15, 16, 41, 42) controlling a fork selecting shaft (13). The cylinders (15, 16) may cause the rotation of the shaft (13) by means of a rocker (14) for selecting the fork corresponding to the chosen ratio, and cause the shaft (13) to move in translation so as to engage the chosen ratio by displacement of the selected fork. This automatic selecting system, which is also applicable to gearboxes of the barrel type, permits, when coupled with the engine control computer, the driver to avoid effecting the declutching and clutching operations, while enabling him to fully master his selection of the speed, if he desires, with no loss due to slip.

Abstract: This device is intended for a vehicle in which the wheels (1) are each equipped with a damper (2) and with a suspension spring (3); it comprises, for each wheel, an actuator (4) interacting with the spring, and provided with a position sensor (5), an electro-hydraulic interface (6) for controlling the actuator, this interface being connected to the actuator, to a hydraulic unit (8) of the vehicle and to a source of electrical energy, and a computer (7) for trim management, connected to the interfaces, and programed to take account of each parameter of the driving of the vehicle, especially its speed and the angle of its steering wheel; on the basis of these parameters, the computer controls the interfaces (6) and the actuators within the context of loops for slaving the latter to reference output travels, corresponding to maintaining the vehicle in predetermined trim stored in the memory of the computer.

Abstract: This assisted selection system comprises an electrohydraulic actuator (12) which controls the input element of the gearbox and may itself be controlled by parameters provided by the engine control computer. The actuator (12) comprises a group of solenoid valves (34, 35, 37, 52, 53) connected to cylinders (15, 16, 41, 42) controlling a fork selecting shaft (13). The cylinders (15, 16) may cause the rotation of the shaft (13) by means of a rocker (14) for selecting the fork corresponding to the chosen ratio, and cause the shaft (13) to move in translation so as to engage the chosen ratio by displacement of the selected fork. This automatic selecting system, which is also applicable to gearboxes of the barrel type, permits, when coupled with the engine control computer, the driver to avoid effecting the declutching and clutching operations, while enabling him to fully master his selection of the speed, if he desires, with no loss due to slip.

Abstract: The damper comprises a fixed body (1A, 1B) provided with ports (3, 4) for the passage of hydraulic fluid, stacks (7) of flexible washers disposed in rigid deflectors (8) placed on each side of the body (1A, 1B) in facing relation to the ports (3, 4) and recesses and tubular inserts (5, 6) for allowing the passage of the fluid in only one direction for some ports (3) and in the opposite direction for the other ports (4). A disc (9) provided with at least two series of orifices (11, 12) having different diameters is disposed in the body. The orifices are arranged to be capable of coming into confronting relation with the ports (3, 4) of the body. The disc (9) is rotated through a given angle so as to place one of the series of orifices of the disc (9) in correspondence with the ports (3, 4) of the body. This arrangement permits adjusting the degree of damping so as to obtain the desired hardness or softness for the suspension in accordance with the utilization of the vehicle.

Abstract: This hydraulic directional valve for an aircraft servo-control, for example for controlling the air brake flaps of the wings of an aircraft, comprises a plug 12 rotatively mounted in a fixed liner 13 disposed in a body 15 and connected to a control device, and an annular sleeve 14 interposed between the plug 12 and the liner 13, ports 19, 23, 26 for the inlet under pressure and the outlet of a hydraulic fluid being provided in the liner 14 and the sleeve 13, and passages being provided on the periphery of the plug 12 for ensuring the circulation of the hydraulic fluid. According to the invention, the sleeve 14 is rotatively mounted in the body 15 and projects outside the body 15 and is connected to rotate with a lateral lever 32 associated with a feedback device constituting a feedback loop which is capable of causing the sleeve 14 to copy automatically the angular position of the plug 12 after the pilot of the aircraft has commanded a rotation of the plug 12.

Abstract: This unit is provided with two hydropneumatic jacks (2) having parallel vertical axes X--X and comprising bodies (5) adapted to be rigidly connected by a plate (3) and mounted slidably on rods (6) fixed to the chassis (7) of the vehicle. The plate (3) is sufficiently wide to allow if desired the passage of a transmission for the corresponding wheel. This arrangement improves the guiding of the wheels by holding them in fixed planes and enables them if desired to be made into driving and/or steered wheels.

Abstract: Shock absorber (31) for a hydropneumatic vehicle suspension element, comprising a disk (32) fastened in an outer casing having ports (30, 38) for the passage of the hydraulic fluid, first elements (48, 49, 37a, 37b) allowing this passage in only one direction for some ports (30) and in the opposite direction for the other ports (38), and second elements (53, 54, 55) for fastening the first elements to the disk; the abovementioned first elements comprise, mounted on the two opposite faces of the disk (32), stacks (46, 47) of elastically flexible metal washers (46a-46c; 47a-47c) arranged in rigid annular deflectors (48, 49) located opposite the hydraulic-fluid passage ports (30, 38). The deflectors protect the flexible washers against any damage caused by the very high peaks of hydraulic pressure which occur on uneven ground.

Abstract: The hydropneumatic jack comprises a tubular body (14) closed at one end and open at the other end. A hollow rod (9) is slidably mounted in the body (14) in a sealed manner and in the rod is formed a first chamber (18) containing a freely slidable piston (19) which divides the chamber into two compartments (18a, 18 b) which are sealed off from each other, a second chamber (23) being defined between a transverse end wall (21) constituting the end of the hollow rod (9) and the inner wall of the body (14). The transverse end wall (21) is provided with a nozzle (22) putting the second chamber (23) in communication with the neighbouring compartment (18b) of hollow rod (9). The compartment (18b) and the second chamber (23) are filled with a hydraulic liquid under pressure and the second compartment (18a) is filled with a pressurized gas. This jack automatically and instantaneously corrects the decreases in tension of the track (1) in the static state, subsequent to wear or expansion of the track and rollers.

Abstract: The servovalve has in combination:(a) a rotary torque motor (1) having a limited angular movement;(b) a hydraulic distributor (2) capable of supplying fluid to the actuator and comprising a rotary shaft (10) coaxially connected to the torque motor (1);(c) a detector (3) of the angular position of the shaft (10) coaxial with said shaft, so that the motor (1), the distributor (2) and the detector (3) have their rotating parts (7, 10, 3a) coaxial and connected to rotate together; and(d) an adder (4) associated with an electronic amplifier (5) connected to the torque motor (1) and capable of receiving a given control voltage (E), the output of the detector (3) being connected to the input of the adder (4).This arrangement permits giving the same rotating movement to all the moving parts of the servovalve and consequently has the advantage of eliminating the play and friction which have an adverse effect on the precision and reliability of prior mechanisms.

Abstract: Rotary hydraulic actuator comprising a vane (1) which is mounted rotatably and sealingly in a chamber (2) made in a body (3) and on the faces of which a hydraulic fluid pressure is exerted, the vane being fixed mechanically to an element to be driven in rotation; the vane (1) comprises two parts (4, 5) extending radially on either side of its axis of rotation (XX), and these two parts are each movable in a chamber (8, 9) extending over an angular sector less than half a circumference, this chamber being divided into two compartments by the said part (4, 5); the actuator has a hydraulic circuit for feeding the chambers (8, 9), which is designed so as to be capable of driving the vane (1) in rotation in one direction or the other. This arrangement reduces the overall size of the actuator and increases its reliability.

Abstract: The valve comprises a hollow body (36, 37, 40) provided with a first inlet or outlet opening (38) and a second outlet or inlet opening (41) for a hydraulic fluid, and the following elements:(a) a hollow slide (58) slidably mounted inside a hollow sleeve (56) slidably mounted in the body and coaxial with the slide (58);(b) an elastic element (61) bearing against the body (40) and biasing the slide into abutment against an annular end of the sleeve and the sleeve (56) into abutment against an annular seat (58) of the body;(c) and the annular bearing section (59) of the slide (58) on the sleeve (56) is less than the annular bearing section (57) of the sleeve on its seat (58), the sleeve being moreover provided with apertures (66) communicating with the first opening (38).This valve avoids deterioration of the suspension of a heavy vehicle travelling at high speed over uneven ground.

Abstract: The present invention relates to a motorized electric control device provided with a joystick (14), characterized in that it comprises two electrtic torque motors (4, 5) whose axes of rotation are at right angles to one another, two forks (9, 10) coupled at one end to the respective torque motor shafts and offset relative to said shafts, the joystick being mounted for pivoting in relation to the point of intersection of the axes of rotation of the torque motors, resilient means for returning the joystick to a vertical position, rotary potentiometers (22) whose axis of rotation is fixed to the other ends of the forks (9, 10) and whose electric outputs constitute the control outputs of the device, and an electric circuit (30) connected to the outputs of the potentiometers and to the electric inputs of the torque motors in order to produce a resistant torque opposite and proportional to the inclination of the joystick (14) in the vertical position.

Abstract: A shock absorber having a hollow slide slidably mounted in a fixed member disposed in a sleeve inside the body, separated from the latter by an annular gap and having an opening which communicates with a conduit opening into an a hydraulic chamber. The fixed member is mounted with clearance in the sleeve and is provided with radial ports communicating with the interior of the slide which is biased against the fixed member by an elastic return member bearing on the body. The slide is arranged in such manner as to be capable of occupying alternately a first position, in which it closes any communication between the annular gap and the interior of the slide when the suspension element is subjected to a low frequency oscillation less than .sqroot.

Abstract: The element comprises a tubular body connected to the hub of a wheel and pivotally connected to the base of the chassis (5) by an arm. This body is slidably mounted on a rod (4) pivotally connected to the chassis (5) of the vehicle, the tubular body containing a gas chamber (11) and a hydraulic liquid chamber (13) divided into two compartments by a central ring (25) fixed to the rod (4). According to the invention, there is provided a device (15) for drawing the hydraulic liquid and disposed outside the tubular body (2) which is slidably mounted on the rod (4) by two fluidtight bearings (42, 55) forming the ends of the hydraulic chamber (13) and spaced apart by a constant distance. The drawing device (15) permits the dissipation to the exterior of the hydraulic chamber (13) of the heat stored by the oil during the reciprocating motions of the suspension element and thus avoids the disadjustment of the ground clearance of the vehicle.

Abstract: The corrector comprises a hydraulic distributor having a slide member (23) rotatively mounted in a body (39), the slide member (23) extending through a sleeve (41), a hydraulic circuit maintaining the ground clearance of the chassis of the vehicle being formed in the sleeve (41) and in the body (39), the hydraulic circuit maintaining the ground clearance at a pre-set value by the angular position of the sleeve (41) in the body (39), the slide member (23) being provided with means (34) for controlling the rotation of the slide member and associated with the chassis.

Abstract: An electric device for driving a rotatable mass having a high inertia, said device comprising an electric motor supplied with power by a low-voltage dc source through an electronic energy converter supplying power to the armature (11) of the motor; the field system of the motor (12) comprises magnets (14) and excitation coils (16), the electric conductor of a coil being wound around its pole piece (18) along surfaces parallel to the corresponding yoke portion (19); this device further comprises an electronic system for regulating the current in the coils (16) and capable of maintaining during accelerations and decelerations a maximum output voltage of the converter within a wide range of speeds and therefore a maximum power; the increase in the intensity of the current in the coils (16) progressively decreases the torque coefficient of the motor which is maximum when the coils (16) are not supplied with power.

Abstract: An oleopneumatic vehicle suspension element in particular for a heavy vehicle, comprising a piston (29) movable in a cylinder (28), a gas accumulator (26), a shock absorber (36) immersed in oil (37) filling the volume between the piston (29) and a diaphragm (27). According to the invention, the suspension element comprises a caloduct (50) connecting the shock absorber (36) to a cold source formed by a free surface (42) of the housing (33) of the suspension element (25), the caloduct (50) containing a fluid which evaporates in contact with the shock absorber (36) heated by the oil, then travels to the cold source (42) where it is condensed and returns thereafter to the shock absorber (36) where it again evaporates. This cooling device enables the temperature of the oil to be limited to the maximum acceptable value and maintains the ground clearance of the vehicle constant.

Abstract: An annular element which is stationary under normal operating conditions is interposed between a stationary sleeve and a central rotary plug. The annular element is provided with peripheral passages and radial openings, said radial openings being located in the line of extension of bores formed in the stationary sleeve. In the event of accidental seizure of the rotary plug, the annular element is automatically released and driven in rotation, thus permitting progressive transfer of the hydraulic fluid from one bore of the stationary sleeve to the adjacent bore via the peripheral passages.