Abstract: The invention relates to a latch device, in particular for latching an airplane landing gear or an airplane landing gear hatch, the device comprising a box containing a set of hinged elements mounted to pivot about respective parallel axes, said assembly including at least one hook and a locking lever connected to said hook by associated elastically deformable return means, said hook being capable of being unlocked by acting on said locking lever either via first actuator means in a normal mode of operation, or via a second actuator means in an emergency mode of operation when said first actuator means fails to unlock the hook. In accordance with the invention, the first actuator means associated with the normal mode of operation is a low power electromechanical actuator under independent electrical control.

Abstract: The wheel of the invention comprises a rim and side walls made of composite material and removable beading on at least one side and preferably likewise made of composite material. The beading is mounted on the rim via a metal mounting belt which is fixed to the rim.

Abstract: The steering apparatus of the invention comprises a body (4) containing a crank (8) with actuators (12) associated with the crank and free to pivot about respective pivot axes (14). The actuators co-operate with distribution members including feed circuits and return circuits carried by the body and opening out facing at least one actuator face (16) extending perpendicularly to the pivot axis (14) of the actuator, the face including at least one control orifice (17).

Abstract: The landing gear of the invention comprises a strut in which a sliding rod slides, the strut and the sliding rod are connected to each other by a scissors linkage having a top branch and a bottom branch which are connected to each other by articulated means capable of moving between a folded position in which the branches of the scissors linkage are adjacent to each other, and an unfolded position in which the branches of the scissors linkage are moved apart from each other, thereby causing the sliding rod to pivot about its own axis.

Abstract: The system in accordance with the invention provides braking while an aircraft (1) is being towed on the ground by a tractor vehicle (2) which is mechanically connected to the aircraft and which is fitted with a brake device under the control of a brake pedal (27), with the aircraft being fitted with a braking circuit. The system comprises a towing brake member (7) disposed in the aircraft's braking circuit line (34) for connecting the brake control member (27) of the vehicle to the towing brake member (7) of the aircraft.

Abstract: A pulse generator in which a magnetic circuit is closed by a portion of a wall (5) of a cylindrical part rotating about its axis and coupled at one of its ends to a drive member (7). The wall portion and a fixed part (1) together define an air gap which varies depending on the relative angular positions of the wall portion and the fixed part such that during rotation magnetic field variations are generated at a frequency proportional to the speed of rotation of the rotating part. The generator includes an electrically conductive winding (4) in which the field variations generate electrical pulses, and the rotating cylindrical part (5) includes at least one longitudinal slot (8).

Abstract: A device for steering the wheels fitted to the bottom end of the leg (1) of the nose landing gear of an aircraft, the wheels being steered about the axis of the leg, the leg (1) comprising a strut (2) hinged to the structure of the aircraft, a tube (4) mounted to rotate inside the strut (2) and projecting outside the strut, a rod (5) slidably mounted inside the tube (4) and carrying the wheels at its free end, and a scissor linkage (6) for constraining the tube (4) and the rod (5) to rotate together.

Abstract: The shock absorber of the invention comprises a struct (1) in which a sliding rod (4) is mounted, with an annular chamber (17) being defined between the strut and the sliding rod. According to the invention, the shock absorber includes at least one support bearing (10) between the strut and the sliding rod in the vicinity of the opening (3) in the strut, and a sealing bearing (12) at a distance from the support bearing (10) and disposed at a level which corresponds to the top portion of the sliding rod when the shock absorber is in its extended position, with the sealing bearing (12) also having a side which is in contact with the annular chamber (17) and spporting at least two sealing rings (14) which are separted by a groove (13) which is connected to the annular chamber via a balance channel (16) capable of being closed by a cock (19).

Abstract: A control mechanism according to the invention comprises a crank (13) constrained to rotate with the catapult bar (10), a catapult bar linkage comprising a link (14) and a lever (16) which are hinged to each other, and having a first end hinged to the crank (13) at a point distant from the pivot pin of the catapult bar, and a second end hinged about a pin (17) carried by the landing gear and distant from the pivot pin (11) of the catapult bar (10), and control means (18) for controlling the relative disposition of the link and the lever.

Abstract: A carbon disk brake rotor (1) has n trapezium-shaped drive notches (3) around its periphery and a plurality of reinforcing riders (2), with the drive faces (6) of each notch (3) being at an angle A of (360/2n) degrees relative to the midplane (3a) of the notch, and with the riders (2) completely covering the projecting portions (7) between consecutive notches (3) which have parallel fitting faces (9).

Abstract: A shock absorber comprising a strut (1), a sliding rod (3) mounted to slide inside the strut, at least one gas chamber (13, 17) under pressure, an oil chamber (6) associated with the gas chamber, and an expansion chamber (5) connected to the oil chamber via expansion throttling valve (8), the volume of the expansion chamber (5) varying as a function of the extent to which the sliding rod is received in the strut. The shock absorber also includes an expansion short circuit passage (18) between the oil chamber (6) and the expansion chamber (5), the expansion short circuit passage having a cross-section which is greater than the flow section of throttling valve (8), and the shock absorber includes controlled closure partition (32) for closing expansion short circuit passage (18).

Abstract: A hydraulic circuit for aircraft braking, the circuit including wheel brakes (11) fed with hydraulic fluid by servovalves (8, 22) mounted in a normal circuit and in an emergency circuit. The normal circuit and the emergency circuit are selectively connected to the wheel brakes by switching devices (9) and protected from excessive loss of hydraulic fluid by hydraulic fuses (6, 24). The servovalves of the normal circuit are associated in pairs. The hydraulic fuses (6) of the normal circuit are disposed upstream from the servovalves (8) on lengths of line (5) which are common to each pair of servovalves. The devices (9) for switching from the normal circuit to the emergency circuit are disposed downstream from the servovalves (8).

Abstract: The present invention relates to shock absorbers including a rod slidable in a cylinder and a piston for determining at least two variable volume chambers, one of the two chambers including a first resilient member at a first pressure, and the other chamber containing a second resilient member at a second determined pressure, the second resilient member being suitable for being displaced in translation en bloc by an actuator chamber.

Abstract: The present invention is concerned with tilting-beam undercarriages.The undercarriage is characterized in that the shock absorber means (7) comprise a hollow cylinder (11) entered by a plunger stem (14) at its first end (12) and by a piston (18) at its second end, while the hollow cylinder (11) has a hinge member (22) onto which the beam (8) is hinged at a point C differing from the center of it and the piston (18) is connected to the beam at a point D differing from the point of hinge C.

Abstract: Thermal insulators (40,50) are each made of a material based on carbon fibers and subjected to low temperature heat treatment. One insulator (40) is disposed between a thrust means actuator (18) and a first brake stator (28a), and the other insulator (50) is disposed between a last brake stator (28b) and a brake retaining plate (30). The insulator (40) associated with the first stator (28a) is of comparable size to the stator.

Abstract: The method of controlling braking on a wheeled vehicle (such as an aircraft during landing) is applied to at least one wheel of the vehicle, which wheel has brakes and means for measuring the wheel speed. The method consists in a repeated two-period cycle comprising:a measuring period (0-t1, t2-t3) in which the wheel brakes are not applied and in which the true speed (A) of the vehicle is measured by measuring the linear speed (D2) of the wheel; anda braking period (t1-t2, t3- ) in which the said measured true speed is used in conjunction with a decleration value to estimate an approximate value of the vehicle speed (B1, B2), and in which the wheel brakes are applied in such a manner that the linear speed (D1, D3) of the wheel is caused to be less than the estimated speed of the vehicle by a predetermined function.

Abstract: Each rocking arm (9, 10) hinged to a shock absorber (7, 8) has a lateral extension (13, 14) extending at an acute angle a to one side of the shock absorber (7, 8). This extension (13, 14) is connected by a telescopic strut (15, 16) to the opposite end (7A, 8A) of the same shock absorber (7, 8) in order to shorten said shock absorber when the landing gear is raised, thereby reducing the space it occupies in the raised position.

Abstract: The landing gear comprises: a rod including nested first and second tubes between which there slides a cylinder whose outer end supports a running gear; a strut surrounding the top of the rod and including a steering mechanism cooperating with a rotary tube disposed between the rod and the strut; and a fluid actuator constituted by at least one chamber between the strut and the rod and having a feed inlet only. The landing gear is particularly applicable to helicopters that are required to "kneel down" camel fashion, e.g., for storage in the hold of an aircraft carrier or a cargo plane.

Abstract: On a shaft (2) which carries a wheel there are mounted: firstly a toothed sector (3) which meshes with a rack (4) on a piston rod (5) which is a part of a double-acting hydraulic actuator (8); and secondly a cam (12) which acts on two rocking levers (13, 14) to apply a bolt (13B, 14B) against a stop face (10A, 10B) of the rod (5) when, by directly swivelling the wheel, the toothed sector (3) is disengaged from the rack (4).

Abstract: The low portion (9) of a landing gear strut (3) carrying running means such as a wheel (8) is capable of swivelling together with the running means relative to the strut. A system of cranks (17) receives the necessary force for swivelling the wheel during retraction and extension of the landing gear from a rod (13) which is fixed to the aircraft structure (2) at a point different from the point at which the strut (3) is fixed. The rod (13) is of variable length (piston and cylinder arrangement 31), and the crank system has a stop (33) against excessive swivelling. The arrangement is such that swivelling is restricted to a selected portion of the landing gear's travel, e.g. to ensure that the wheel enters the aircraft body at a particular degree of swivel.