Abstract: A shock absorber including a cylinder (501), a rod (502) slidably mounted in the cylinder, and a piston (506) fixed to the rod and slidable inside the cylinder. The piston divides the cylinder into two oil-filled chambers (508, 514) and there is a third chamber (518) in the rod and including air to act as a hydraulic spring. Shocks tend to move the piston along the rod away from its equilibrium position therein, and the hydraulic spring tends to return the piston to its equilibrium position. Damping is provided by variable aperture channels between the first chamber (508) and the other two chambers (514 and 518). The channels comprise orifices (509 and 510) in a cylindrical wall of the first chamber (508) which overlap orifices in a movable cylindrical valve plate (527). A control shaft (540) leading out along the axis of the shock absorber serves to rotate the valve plate and to move it in axial translation.

Abstract: The present invention relates to shock absorber-actuators.The shock absorber-actuator is characterized essentially by the fact that it comprises at least one cylinder (101), a hollow rod (102) sliding in the cylinder (101), a gas chamber (153) delimited by a separating piston (141), and means (140, 156, 154) for positioning this piston between two stops (145, 147).The shock absorber-actuator finds a particularly advantageous application in aircraft and in particular helicopters.

Abstract: The undercarriage comprises: a leg (1) pivotally mounted about a first pivot axis (14) which is fixed relative to a rigid structure of the aircraft; a main side-brace (30) comprising at least two articulated levers (31 and 32) having first ends pivotally connected to each other about a fourth pivot axis (33), having respective other ends pivotally mounted about a second pivot axis (37) which is fixed relative to the rigid structure, and pivotally mounted about a third pivot axis (36) which is fixed relative to the leg; and a drive (40 to 48) for causing the levers to pivot relative to each other. The first, second, third, and fourth pivot axes are parallel to each other.

Abstract: This invention relates to landing gears. The described landing gear is characterized essentially by the fact that it comprises a leg (3) at one end of which is fixed a wheel (14 ) for rolling around a pivoting pin (11), a shock absorber (15) of which one end (22) is connected to leg (3), a strut (24) whose end is connected to leg (3) and links (39, 37, 41) connecting the end of strut (24) to the pivoting pin (11) so as to cause the wheel to pivot when the landing gear is retracted. This landing gear finds an advantageous application as a fuselage landing gear of the tripod type.

Abstract: The landing gear for aircraft comprises at least two rocker beams respectively carrying wheels, the rocker beams being connected rigidly and respectively to two points of the rigid structure of the aircraft, each rocker beam being connected to two other rigid points of the aircraft structure by an assembly composed of a lever and a shock absorber mounted rotatably on each other, and a connecting rod of constant length connecting two levers and an actuating cylinder to rotate at least one of the two said levers. The landing gear finds a particularly advantageous application as a fuselage landing gear with tandem mounted wheels.

Abstract: The present invention relates to landing gears retractable between two positions.The landing gear includes essentially a lever (14 ) mounted rotatably around an axis (5), a rocker beam (7) mounted rotatably on the same axis (5), a strut (21) including two links (22,23) pivoting in relation to each other, the strut being connected to the lever, a shock absorber (18) fixed respectively on the lever (14) and the rocker beam (7), and an actuating cylinder (32) for applying a pivoting force to the lever (14). This landing gear finds a particularly advantageous application in aircraft of the commuter type.CROSS REFERENCE TO RELATED APPLICATIONThe present application relates to application Ser. No. 354,010 filed on Mar. 2, 1982, and entitled "FUSELAGE LANDING GEAR WITH TANDEM WHEELS" by inventors Andre Turiot and Michel Derrien, our reference 4126.

Abstract: An oleopneumatic suspension with variable throttle orifices, particularly for aircraft landing gear comprising a rod (1) enclosing a pneumatic spring (2) and being fixed with respect to a piston (4) sliding in a cylinder (3), two valves (6) and (7) with permanent throttle orifices, the valve (6), which is of greater cross-section, throttling in the compression phase and the valve (7), which is of lesser cross-section, throttling in the extension phase, the suspension comprising in addition a throttle device, the section of whose orifice varies in dependence on the position and the direction of displacement of the piston (4) in the cylinder (3) so that over a given distance around a predetermined equilibrium position the orifices ensuring throttling in the compression and extension phases are of cross-sections respectively greater than the corresponding orifices over the remainder of the distance covered by the piston (4) in the cylinder (3).

Abstract: The present invention relates to landing gears. The landing gear includes essentially two legs (1, 2) comprising respecitvely two arms (10, 28) and two rocker beams (3, 24), a bar (21) forming with the two arms (10, 28) a deformable parallelogram, a strut (37) consisting of two levers (23, 38) placed on a diagonal of the parallelogram, two locking links (50, 51) cooperating with the strut (37), these two rotatably mounted links being rotated by an actuator (70) and a spring (60). The landing gear finds its application in commuter aircraft fitted with tandem type landing gears.

Abstract: The invention concerns a landing gear. The landing gear is characterized essentially by the fact that it comprises at least one shock absorber (15), this shock absorber being mounted in the leg (1) and casing (2) assembly by means of two convex surfaces (22, 31) made on the cylinder (16) of the shock absorber (15) and cooperating with two concave surfaces (25, 32) integral respectively with the leg (1) and the casing (2). This landing gear finds an application as a nose gear of the rocker-beam type.

Abstract: A main undercarriage train for an aircraft which is retractable substantially laterally, the train comprising two undercarriages which comprise identical legs each having a plane of symmetry which passes through its pivot mounting axis which is inclined relative to the plane of symmetry of the aircraft.

Abstract: An aircraft landing gear including a leg member supporting at least one wheel, the leg having a first point of attachment around a first axis of rotation about a first point on the aircraft, a strut including a rod and a lever pivotally mounted on one another around a third axis, the rod having a second axis of rotation on a second point of attachment to the aircraft and the lever being pivoted about a fourth axis on the leg, and an operating jack applying at least one rotational torque to the strut and the leg wherein one end of the jack is connected to a third point on the leg and the other end of the jack is connected to a fourth point on the strut, the third and fourth points being located substantially near the first and second points of attachment.

Abstract: A main landing gear with swing-bar and lateral lifting for aircraft. Two undercarriages are provided which are positioned symmetrically on either side of the longitudinal plane of symmetry of the aircraft, each one having a leg 1 articulated around a lifting axis 5, and a swing bar 16 around a transverse axis 18. The swing bar 16 carries a wheel 21 pivotally mounted around an axis of rotation 19. The maneuvering of the undercarriage and the bracing thereof are insured by a bracing jack 13, and the deflections of swing-bar 16 are damped by a shock absorber 10. The leg 1 of the undercarriage has a first plane of symmetry (X,X) perpendicular to the lifting axis 5 and the longitudinal plane of symmetry of the aircraft and the swing-bar 16 has a second plane of symmetry (Y,Y) defined by the transverse axis 18 of the axis of rotation 19.

Abstract: A hydraulic braking device for a load subjected to shocks and vibrations for the stabilization of loads in thermal or nuclear generating stations.The braking device has a cylinder 1 in which there slides the piston 4 of a rod 7 bearing two flap valves 18 and 19 to brake the passage at high speed of hydraulic fluid from one chamber 15 or 16 to the other. These valves communicate with a reservoir 17, pressurized by springs 31 to 34 and accumulate the expansions of the fluid. A secondary rod 29 which has displacements with respect to rod 7 which are reduced relative to the displacement of piston of reservoir 27 with respect to this rod 7 serves as a leak indicator.Application to the stabilization of loads such as high-temperature steam conduits in thermal or nuclear generating stations.

Abstract: A retractable fuselage mounted undercarriage comprising a leg casing mounted to pivot on a main universal joint about an axis which extends longitudinally of the aircraft, the leg casing mounting a wheel assembly which can pivot on the leg casing, a lateral deflection shock absorber and a manoeuvreing and wind bracing jack each connected to the leg casing by a joint and each connected to the fuselage by a joint, the main universal joint being mounted to pivot on the fuselage about an inclined retraction axis which does not pass through the point where the shock absorber is connected to the fuselage, so that, during lowering and retraction of the undercarriage effected by extending or retracting the manoeuvreing and wind bracing jack, the shock absorber acts as a directer bar and orientates the axis of the leg casing, which leg casing is rotated as the main universal joint pivots on the fuselage about the inclined retraction axis.

Abstract: A landing gear undercarriage which attaches to and retracts into the fuselage of an aircraft. The undercarriage has left and right matching portions, each of which includes a forward strut and a rearward hydraulic jack, both of which are coupled to the fuselage by cardan joints. A shock absorber is mounted on the fuselage outside of the strut and converges downwardly towards the strut to which it is coupled at the bottom by a cardan joint. A cylindrical sleeve is mounted at the bottom of the strut, and a spindle which supports a landing wheel is rotatably mounted in the sleeve. The bottom of the hydraulic jack is coupled to the spindle, and the arrangement is such that as the jack causes the undercarriage to retract into the fuselage, the spindle and wheel are rotated into a flat position in which they may be stored in a relatively small landing gear well.