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: 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: 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: 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.