S.a.m.m.-societe D'applications Des Machines Motrices

Societe D'applications Des Machines Motrices

Gerard L Devaud

Serge Grand

Arnaud Libault De La Chevasnerie

Marcel Bouveret

Serge David

Christian Valent

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).

Hydraulic directional valve for servocontrols of aircraft in particular

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.

Electrohydraulic actuator for controlling a vehicle gearbox of the type

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.

System for the assisted selection of the ratios of an automobile gearbox

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. This trim system makes it possible to prevent rolling and pitching during the phases of acceleration, braking and cornering, without affecting the comfort of the occupants.

Device for dynamically controlling the trim of a vehicle

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.

Hydraulic directional valve for an aircraft control

Electrohydraulic servovalve for the control of a hydraulic actuator, in

The invention provides a hydraulic servo-control device which performs the same functions as a conventional device but is much cheaper to manufacture and maintain. For this purpose, the control device comprises a cylinder device formed by a cylinder and a piston rigid with a rod and a hydraulic control unit whose body is rigid with the cylinder. The body of the hydraulic control unit defines a cavity for receiving the cylinder of the cylinder device and this cylinder is made in two main parts, namely a case partly received in the cavity and fixed to the body of the hydraulic control unit, and a tubular sleeve which is axially and radially positioned inside the case and the cavity and cooperates with the piston. Application in particular in the control of the pitch of the blades of a helicopter or the ailerons of a light aircraft.

Hydraulic control device

The device comprises a directional valve body which is movable with respect to guide means, and a spool which is slidably mounted in the body and connected to a control lever. The latter is pivotally mounted on a pin which is fixed relative to the body. This pin is carried by a support which is mounted on the body and means are provided for adjusting the position of the support relative to the body.

Servo-control device for aircraft flight control

The piston comprises two annular members which are mounted without clearance on a tubular rod. The main annular member receives in a counter bore the other annular member without clearance. The assembly is achieved by means of a mutual forming over of the two annular members which pre-stresses a rigid ring in a groove in the rod, this ring being interposed between the two annular members. The main annular member has a second formed over portion which is engaged in a groove in the rod and is capable of performing the function of the first mentioned forming over in the event of failure of the latter. Application in control cylinder devices of helicopters.

Piston and rod assembly for sliding in a cylinder

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.

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Paris, France

Gerard L Devaud