Abstract: A lead-lag damper arranged inside a blade of a rotor of a rotary wing aircraft. The lead-lag damper comprises an inner strength member provided with a cage in which a ball-joint connection is arranged, an outer strength member for securing to the blade, and an elastomer material member arranged between the two strength members. The two strength members and the elastomer material member extending beyond the zone around the cage so that the relative movements between two strength members resulting from the movements of the blade are damped by deformations of the elastomer material member, at least a portion of the lead-lag damper being designed to occupy a portion of the inside of the blade that is conventionally filled with foam.

Abstract: A rotorcraft rotor comprising a hub made up of a monolithic body of composite material obtained by stacking successive layers of carbon fiber fabric dusted with a thermoplastic resin and compressed while hot. The hub is provided with branches on which respective blades are mounted via hinge systems, each including a strength member bearing radially against a corresponding branch. The strength members are individually received in sockets defined on fabrication so that when the rotor is set into rotation at a predefined operating speed, the radial thrust seat for enabling the strength members to bear against the branches present bearing surfaces that are cylindrical, the radial thrust seats then being of shape complementary to a cylindrical bearing surface of the corresponding strength member.

Abstract: A lead-lag damper arranged inside a blade of a rotor of a rotary wing aircraft. The lead-lag damper (comprises an inner strength member provided with a cage in which a ball-joint connection is arranged, an outer strength member for securing to the blade, and an elastomer material member arranged between the two strength members. The two strength members and the elastomer material member extending beyond the zone around the cage so that the relative movements between two strength members resulting from the movements of the blade are damped by deformations of the elastomer material member, at least a portion of the lead-lag damper being designed to occupy a portion of the inside of the blade that is conventionally filled with foam.

Abstract: A rotor having a hub and a plurality of lift assemblies, the rotor having one lead/lag abutment mechanism per lift assembly. Each abutment mechanism includes an elastomer spacer strip and two C-shaped metal clips engaged respectively on a first base and on a second base of the strip. Two fastener pins each pass through a clip and the longitudinal projections of a base and through an orifice in the hub.

Abstract: A rotorcraft rotor comprising a hub made up of a monolithic body of composite material obtained by stacking successive layers of carbon fiber fabric dusted with a thermoplastic resin and compressed while hot. The hub is provided with branches on which respective blades are mounted via hinge systems, each including a strength member bearing radially against a corresponding branch. The strength members are individually received in sockets defined on fabrication so that when the rotor is set into rotation at a predefined operating speed, the radial thrust seat for enabling the strength members to bear against the branches present bearing surfaces that are cylindrical, the radial thrust seats then being of shape complementary to a cylindrical bearing surface of the corresponding strength member.

Abstract: A rotor having a hub and a plurality of lift assemblies, the rotor having one lead/lag abutment mechanism per lift assembly. Each abutment mechanism includes an elastomer spacer strip and two C-shaped metal clips engaged respectively on a first base and on a second base of the strip. Two fastener pins each pass through a clip and the longitudinal projections of a base and through an orifice in the hub.

Abstract: A concentrated-mass device including a main oscillating mass held radially in a horizontal plane by main resilient means inside a casing suitable for being secured to the hub is provided. The device includes a secondary main oscillating mass suspended by secondary resilient means inside a recess in said main oscillating mass to oscillate along a vertical axis perpendicular to the horizontal plane, the secondary oscillating mass being constrained to move in translation together with the main oscillating mass in the horizontal plane.

Abstract: The present invention relates to a rotorcraft blade (1) provided with at least one spar (3) and an outer covering (4), said blade (1) including a hollow sleeve (10) with a wall (11) that is provided at least with said outer covering (4) secured to said spar (3). The blade includes a rotary damper (20) provided with an inner tubular strength member (21) and an outer tubular strength member (22) that are coaxial and connected together by a ring (23) of viscoelastic material, said inner tubular strength member (21) being secured to said covering (4), and said outer tubular strength member (22) being provided with a fork (25) possessing first and second tines (26, 27) facing each other so as to be suitable for receiving a first ball joint (41) close to the pitch-variation axis (AX1) of said blade (1).

Abstract: The tightening clamps are multifunctional and ensure the transmission of the electric current generated by the fuel cell stack, the insulation of the different ducts and passage openings of the operation fluid of the fuel cell stack, and the tightening of the stack itself. Each clamp comprises a single part, the upper surface and the side surfaces of which, except for the conductors, are coated with an insulating material. Similarly, the supply and discharge openings (23) are also insulated. However, the tightening surface (29) is at least coated with a conductive deposit on a predetermined area corresponding to the conducting areas of the upper surface of the end of the stack. The invention can be used in PEM (“Proton Exchange Membrane”) fuel cells.

Abstract: The present invention relates to a concentrated-mass device including a main oscillating mass held radially in a horizontal plane by main resilient element inside a casing suitable for being secured to the hub. The device includes a secondary main oscillating mass suspended by secondary resilient element inside a recess in the main oscillating mass to oscillate along a vertical axis perpendicular to the horizontal plane, the secondary oscillating mass being constrained to move in translation together with the main oscillating mass in the horizontal plane.

Abstract: The present invention relates to a rotorcraft blade (1) provided with at least one spar (3) and an outer covering (4), said blade (1) including a hollow sleeve (10) with a wall (11) that is provided at least with said outer covering (4) secured to said spar (3). The blade includes a rotary damper (20) provided with an inner tubular strength member (21) and an outer tubular strength member (22) that are coaxial and connected together by a ring (23) of viscoelastic material, said inner tubular strength member (21) being secured to said covering (4), and said outer tubular strength member (22) being provided with a fork (25) possessing first and second tines (26, 27) facing each other so as to be suitable for receiving a first ball joint (41) close to the pitch-variation axis (AX1) of said blade (1).

Abstract: A rotorcraft rotor with hinged blades, includes: a hub; a plurality of blades hinged to flap relative to the hub; bottom abutments of the hub, and bottom abutments of the blades suitable for co-operating with the bottom abutments of the hub; and top abutments of the hub, and top abutments of the blades suitable for co-operating with the top abutments of the hub; the top abutments of the hub being movable between a deployed position in which they extend facing the top abutments of the blades, and a retracted position in which they are offset angularly away from the top abutments of the blades. The rotor also includes elements for locking the top abutments of the hub in the deployed position, and inertial means for releasing the top abutments of the hub and for deactivating the locking means.

Abstract: A rotorcraft rotor with hinged blades, includes: a hub; a plurality of blades hinged to flap relative to the hub; bottom abutments of the hub, and bottom abutments of the blades suitable for co-operating with the bottom abutments of the hub; and top abutments of the hub, and top abutments of the blades suitable for co-operating with the top abutments of the hub; the top abutments of the hub being movable between a deployed position in which they extend facing the top abutments of the blades, and a retracted position in which they are offset angularly away from the top abutments of the blades. The rotor also includes elements for locking the top abutments of the hub in the deployed position, and inertial means for releasing the top abutments of the hub and for deactivating the locking means.

Abstract: On the rotor, between each blade and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held above that one of the two blade pins which is the pivot pin about which the blade can be folded by pivoting, once the other blade pin has been removed. This holding is provided by a cradle formed in a cable support connected to the pivot pin, and by a collar articulated to one edge of the cradle and which can be folded down into the closed position onto the opposite edge of the cradle, to which this collar can be connected detachably by at least one detachable retaining element. The section of cable is manually released from the collar and from the cradle before the removal of the removable pin, which precedes folding, so that this section of cable deforms naturally, following the pivoting of the blade.

Abstract: On the rotor, between each blade integral with its folding mount and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held, in any position of the blade about the folding axis, above the mount and the radially outer end of the link member on which the mount pivots, in an off-centered position with respect to the folding axis and on the side towards which the blade is designed to be folded. This holding is provided by a cable support tied to the folding pivot and on which an arm, receiving the held part of this section of cable, is mounted in cantilever manner on the folding side.

Abstract: On the rotor, between each blade and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held above that one of the two blade pins which is the pivot pin about which the blade can be folded by pivoting, once the other blade pin has been removed. This holding is provided by a cradle formed in a cable support connected to the pivot pin, and by a collar articulated to one edge of the cradle and which can be folded down into the closed position onto the opposite edge of the cradle, to which this collar can be connected detachably by at least one detachable retaining element. The section of cable is manually released from the collar and from the cradle before the removal of the removable pin, which precedes folding, so that this section of cable deforms naturally, following the pivoting of the blade.

Abstract: On the rotor, between each blade integral with its folding mount and the member for linking with the hub, an electrical connecting cable comprises a first section of which one part is held, in any position of the blade about the folding axis, above said mount and the radially outer end of the link member on which the mount pivots, in an off-centered position with respect to the folding axis and on the side towards which the blade is designed to be folded. This holding is provided by a cable support tied to the folding pivot and on which an arm, receiving the held part of this section of cable, is mounted in cantilever manner on the folding side.

Abstract: A gearbox with a transmission input shaft and an output shaft mounted parallel in a gearbox housing and includes several pairs of engaged pinions to shift in a corresponding number of forward transmission ratios. A reverse gear axle is mounted in the housing parallel to the input and output shafts, with two idler gears freely rotatable on the shaft, one gear engaging a fixed gear on the input shaft, the other engaging a fixed gear on the output shaft. A reverse synchronizing device is located between the two idler gears for engaging reverse gear ratio. The synchronizer includes a jaw clutching sleeve splined to one of the idler gears, and is slidable towards the other idler gear to actuate a synchronizing clutch. The clutch has radially inward facing champfered blockers which engage corresponding slots in the sleeve. A synchonization initiation device in the form of a snap ring is also provided.