Abstract: For braking a gyroplane rotor, a unit is proposed which comprises a disk brake equipped with a hydraulic actuator (26), which is integrated and has force amplification, as well as a mechanical transmission (54) connecting a control member such as a handle or lever (52) to the said actuator. The amplification effect is obtained by the section difference between a control piston (34) of the actuator directly connected to the mechanical transmission and a free piston (28) of the actuator by which the braking force is exerted.

Abstract: The blade has its lower-surface and upper-surface skins of its shell, its front and rear filling bodies and its spar made of a composite material having the same thermoplastic matrix, preferably made of PEEK, reinforced preferably with carbon fibres. The spar is extended outside the shell by an integrated rooting part with linkage attachment, in a loop or laminate, in the same thermoplastic composite. The method consists in assembling the spar with the skins, after manufacturing these components in the form of prefabricated elementary pieces, by injecting under pressure a fluidized thermoplastic composite with short reinforcing fibres moulding the filling bodies.

Abstract: A rotor head for a rotary wing aircraft having a plurality of rotor blades, such that each blade is coupled to the hub by an attachment assembly. The attachment assembly includes a thrust bearing device attached to the hub for allowing angular oscillations, and drag damping device coupled between the blade and the hub for damping movements of drag caused by rotation of the rotor head. The drag damping device has visco-elastic elements which are pivotable with respect to each other about a common axis. The damping device is also disposed to pivot in a flapping direction of the blade through a pivot joint.

Abstract: A device for linking a blade to the hub comprising a laminate attachment at the end of the rooting part with torsion bars of the blade, the laminate attachment being in abutment against the pins for holding on the hub. The opposite blades of the rotor may be arranged angularly offset with respect to the other blades.

Abstract: The invention relates to a cylindrical elastomeric bearing with wide angular deflection comprising three cylindrical elements: a central element (1) and two lateral elements (2, 3) arranged either side of the central element (1). Each torsible cylindrical element is made up of a deformable elastomeric central part, relatively flexible angularly and relatively rigid radially, which is rigidly locked to an inner armature and to an outer armature; the outer armature (6) of the central element (1) and the inner armature (8, 11) of each lateral element (2, 3) are rigidly locked together so as to form a single part, the common armature (13).

Abstract: A rotor head for a rotary wing aircraft rotor blades, such that each blade is coupled to the hub by an attachment assembly. The attachment assembly includes a thrust bearing attached to the hub for allowing angular oscillations, and drag damping device coupled between the blade and the hub for damping movements of drag caused by rotation of the rotor head. The drag damping device has hydro-elastic elements which are pivotable with respect to each other about a common axis. The damping device as also disposed to pivot in a flapping direction of the blade through a pivot joint.

Abstract: The hydraulic damper has at least one restricted communication passage (47) between its two working chambers (8, 9) whose cross section is controlled by a viscous restriction valve (51) positioned via a control pressure of a fluid of a control damper with at least one secondary chamber (41, 42) delimited in a secondary cylinder (39) by a control piston (40), which cylinder and control piston are integrally attached, one to the main body (1), the other to the damping piston (4) of the damper, such that the pressure law of the control fluid positioning said valve (51) is linked to the relative displacements of the main body (1) and damping piston (4).

Abstract: A joint is provided for connecting an end of a tube of composite material which is subject to relatively large axial stress to an annular metallic ferrule, and includes a composite tube composed of high strength fibers agglomerated by a polymerized synthetic resin having a wall and an annular metallic ferrule formed as a band. The ferrule has in cross-section the shape of a segment of a circle including a curved portion and a flat portion, the curved portion of the ferrule facing the composite tube. The ferrule is embedded in a receiving surface of the wall of the tube, and the flat portion of the ferrule is flush with adjacent regions of the receiving surface of the tube. An end member is included having an extending portion which engages the ferrule, and a complementary connecting device is disposed between the flat portion of the ferrule and the extending portion of the end member, for connecting the tube to the end member.

Abstract: An individual pitch control device for the blades (7) of a rotor of a rotor craft employing respective rotating linear jacks (29) for controlling the pitch of the rotor blades. The linear jacks are implanted in a rotating support (25) which is driven in rotation with the rotor. The jacks (29) include rods (31) which are connected via additional rods (33) to drive pitch control levers (24) for each respective blade. The jacks (29) are linear, electrohydraulic, dual-action jacks having at least one body, and are supplied by control servovalves (36) which are also mounted in a rotating reference system. The servovalves (36) are supplied from a hydraulic circuit in a fixed reference system positioned on the rotor craft, having at least one hydraulic collector (27) which is at least partially rotating.

Abstract: The resilient return strut is of the elastic-hydraulic type with incorporated linear damping by throttling a high-viscosity fluid, and comprises a damper (1) mounted between two return springs (2, 3) in elastomer-based sleeves (17, 18), undergoing a shearing action and sealing the chambers (34, 35) set off within the body of the damper (12) by a transverse wall (10) which marks off a permanent throttling passage around a central brace (23). Limiting valves equipped with spring-leaves (45) sealing the holes (40) bored in the wall (10) increase the throttling section. A compressed-air system (52), mounted in a spring (2), compensates for thermal expansion of the fluid. The device is used with helicopter rotors.

Abstract: In this elastic strut incorporating a hydromechanical resonator having a weight/spring system of the type providing a hydraulic amplification of the displacement of the beating weight (7), the weight mounted between two opposed return springs constitutes a double-sided hollow piston slidably mounted on two coaxial opposed cylinders (6) in a closed chamber filled with a liquid (10) in an inner tubular element (1) disposed in an outer tubular element (2) with which it defines, at each end, a chamber (18, 26) filled with liquid onto which opens one of the cylinders (6), the elements (1, 2) constituting the body of the strut being coaxially movable relative to each other and fixed together at each of their ends in a sealed and elastic manner by bearings composed of an elastomer material.

Abstract: The invention relates to a control device for monocyclic pitch in a fixed reference system and multicyclic pitch in a rotating reference system, for the blades (7) of a rotor craft.In addition to conventional swashplates (27, 38), one (38) of which rotates (39) on the other (27) held in rotation by a nonrotating compass (28), but which slides axially (4) and oscillates (25) about the rotor mast (1), through the action of pilot control (30), it comprises multicyclic jacks (45) in a number equal to the blades (7), and each of which is implanted in the rotating plate (38) and directly drives a pitch control rod (44) of a corresponding blade (7). Each multicyclic jack (45) is a dual-action, hydraulic linear jack controlled by a servovalve (49) also implanted on the rotating plate (38).

Abstract: A hydraulic device for the individual control of the pitch of a helicopter rotor blade by a rotary hydraulic jack, the stator vanes of which are integral with a sleeve fitted on the hub. The jack rotor carries rotor vanes movable relative to the stator vanes and delimiting with these chambers of variable volume fed by a servo-distributor controlled as a function of pilot signals and signals from a detector of the angular position of the blade about its pitch axis. The jack is integrated in a pitch bearing and in an elastic ball joint integrated in a rotary hydroelastic shock absorber with vanes for lamination of a viscous fluid. The shock-absorber rotor is connected rigidly in terms of rotation about the pitch axis to the rotor of the jack and is connected to the blade by a rigid cuff.

Abstract: Contact link for flight controls of aerodynes, especially helicopters. The link comprises a rod (2) mounted axially slideably over a limited stroke under tension and under compression in a body (1). A leaf spring (35) subjected to compressive buckling prestress is accommodated in a recess (27) of the rod (2) between two supports (36, 37) pushed against stops of the rod (2) and stops of the body (1). Under any axial tensile or compressive force higher than the prestress of the leaf spring (35), one of the supports (36, 37) is brought nearer to the other, so that the leaf spring (35) works by buckling, and its central part increases its deflection to an extent amplified in relation to the axial stroke of the rod in the body and shifts radially a movable contact member (55) actuating an electrical contactor (45) fastened in the recess (27) of the rod (2). The contact link is used for equipping flight controls for cutting in or cutting out an automatic pilot.

Abstract: The torsible, flexible linking arm with integrated flexion damping according to the invention includes, between two rigid end portions, a flexible central portion constituted by a peripheral bundle (6) of rods (8) of fibres with high mechanical strength encapsulated in a flexible, vulcanized elastomer (9), and by a central damping core (7) with a strip (13) shearing a damping gel (12) filling a tight, flexible bladder (11) embedded in the elastomer (9). When deformations occur in the plane of the strip (13), the latter shears the gel (12), which produces damping that is added to that resulting from the deformation remanence of the elastomer (9). Application to the linking of two rigid bodies such as a rotor blade and its hub.

Abstract: The shock absorbing jack of the invention includes essentially a rod in which a sliding piston defines an extension chamber and which itself slides in a body by means of a piston defining a retraction chamber, the body including a throttling device and, on the side opposite the rod, two high and low pressure gas chambers, these chambers being separated by a membrane bearing, at rest, on a support with hemispherical perforated bottom.

Abstract: The invention relates to a combined bearing device for a rotorcraft rotor or a rotor equipped with such a bearing device. In the rotor, each blade is held on the hub by a flexible arm surrounded without contact by a rigid stub sleeve by a combined bearing device including a cylindrical plain angle of attach bearing, a spherical ball joint with visco-elastic element for resiliently returning the blade under flapping and drag conditions, and with an integrated damper for damping the angular oscillations of the blade under drag conditions, of the hydraulic rotation damper type with vanes for laminating the hydraulic fluid and compensation chambers for the expansion of this latter, the hydraulic damper being integrated in the spherical thrust bearing and its compensation chambers belonging to a hydraulic automatic play take-up device for the plain bearing.

Abstract: A device comprising cyclic plates driven by flexible blades for controlling a helicopter rotor. The device comprises upper flexible curved blades pivotably mounted on the rotor shaft, above the rotary plate, and pivotably mounted by a ball joint on the rotary plate, so as to cause it to rotate with the rotor shaft and at least one lower flexible curved blade, pivoting on an element of the structure of the helicopter and pivotably mounted by a ball joint on the non rotary plate, so as to secure it against rotation. The transverse stiffness of the blades ensures centering of the plates whereas the longitudinal flexibility of the blades and their end pivot point allow the blades to follow the axial translational and tilting movements imparted to the plates by pilot controls pivotably mounted to the non rotary plate, and transmitted to levers controlling the angle of attack of the rotor blades by means of links pivotably mounted to the rotary plate.

Abstract: The present invention relates to a suspension for a set of two wheels of a vehicle comprising two arms oscillating about an axis X--X transverse to said vehicle and each bearing one of said wheels, elastic means and damper means being associated with said arms respectively to counteract and dampen the vertical movements of said wheels and said elastic means comprising an assembly of two concentric tubes made of a composite fibre-synthetic resin material coaxial to said transverse axis X--X about which the arms oscillate. According to the invention, the tubes are fast with each other near the center of their length; said arms are fast with the ends of the outer tube; said ends of the outer tube may rotate at least in limited manner about said transverse axis X--X, and the inner tube is connected to the chassis of the vehicle by its two ends.

Abstract: The present invention relates to a suspension for a train of two wheels of a vehicle, comprising two arms oscillating about an axis transverse with respect to said vehicle and each bearing one of said wheels, elastic means and damper means being associated with said arms respectively to dampen the vertical movements of said wheels, wherein the transverse shaft for oscillation of said arms is itself mounted to oscillate parallel to the longitudinal direction of the vehicle. The invention is more particularly applicable to improving passenger comfort in the vehicle and for improving the road-holding qualities of said vehicle.