Abstract: The device for coupling a tachometer and an airplane wheel includes an elastically deformable sleeve defining, at each of its axial ends, a drive recess suitable for co-operating with a complementary endpiece fitted in the recess.

Abstract: Method and device for determining the weight and/or a characteristic value of the position of the center of gravity of an aircraft standing on the ground by means of a plurality of undercarriages, each undercarriage including at least one structural element exhibiting a variable level of stresses depending on the fraction of the weight of the aircraft transmitted to the ground through the undercarriage. The method includes the steps of a) measuring on each undercarriage at least one parameter representing the stress level of the element; and b) evaluating the characteristic value and/or the weight according to the parameters measured in step a). At least one parameter measured in step a) is a magnetic or electrical characteristic of the structural element of the undercarriage.

Abstract: Disclosed is an arrangement in which the main landing gear assemblies of a large commercial airplane are each joined to the airplane at four attachment points. Two of the attachment points connect the landing gear side brace and drag brace to the airplane. The two remaining attachment points are aft and forward trunnions that are mounted to the airplane wing. The aft trunnion pivotally connects one side of the landing gear shock strut to the airplane and carries both vertical and torsional loading. The forward trunnion is pivotally connected to the other side of the shock strut by a trunnion link. An actuator is coupled between the shock strut and the trunnion link. When the landing gear is down and locked the actuator is not activated and the trunnion link does not have the rigidity and stiffness required to transfer vertical loads to the forward trunnion.

Abstract: The invention relates to a brake system for braking aircraft wheels, the brake system being of the type which, for each wheel, comprises a stator central portion coaxially surrounding a wheel axle on which a rotor annular portion is mounted to rotate, and a succession of brake disks disposed between the stator central portion and the rotor annular portion with alternate disks being constrained to rotate with one and the other of said portions, said stator central portion being provided with a brake collar equipped with a plurality of sets of pistons and, rigidly secured to said collar, a torsion tube internally provided with a transverse annular web, a centering bearing being interposed between the annular web and the axle. According to the invention the centering bearing has structural characteristics that vary circumferentially in a distribution configuration suitable for generating different bearing stiffnesses along two orthogonal axes contained in a plane that is perpendicular to the axis of the axle.

Abstract: A transverse fiber sheet is lapped by being guided in a substantially radial direction back and forth along a path between circumferentially outer and inner edges of the sheet, with the transverse sheet being reversed at each end of its path, the width of the transverse sheet being narrowed between the outer circumferential edge and the inner circumferential edge, the transverse sheet being held in place as it is lapped. Substantially mutually parallel yarns or tows are pulled to form a helical longitudinal sheet of density per unit area that decreases between its outer edge and its inner edge. The transverse sheet and the helical longitudinal sheet are superposed and advance continuously in flat rotation, and they are assembled together to form a helical two-dimensional sheet which is removed.

Abstract: The equipment for measuring the speed of rotation of a vehicle wheel (14) carried by a wheel axle (12) comprises a tachometer (30) having a stator (32) suitable for being secured to the wheel axle (12), a rotor (34) suitable for being rotated by the wheel (14), and a connector (110) secured to the stator (32) for electrical connection of the tachometer. The connector (110) includes a set of connection terminals (114A). The equipment further comprises an information transmission member (82) carried by the tachometer stator (32) and suitable for co-operating with a complementary information transmission member (74) constrained to rotate with the wheel (14). Said tachometer connector (110) includes additional connection terminals (114B) to which said information transmission member (82) is connected for transmitting said information.

Abstract: A damper for an airplane landing gear leg comprises a main strut (11) and a rod piston (13) co-operating with the strut (11) to define a main chamber (15) and annular chamber (16) for hydraulic fluid, and presenting internally two adjacent chambers (19, 20) that are isolated from each other by a separator piston (21). The damper (10) further comprises a first secondary strut (26) telescopically slidable on the above-mentioned rod piston (13), and a second secondary strut (37) telescopically slidable on the other end of the first secondary strut (26). The two second annular chambers (31, 40) as defined in this way are respectively connected to associated control circuits thus enabling the total length of the damper to be shortened or lengthened respectively for the purpose of causing the landing gear to contract or to be extended.

Abstract: A one-piece or otherwise unitary annular shim member made from a carbon material or a metallic is used to maintain a space between stacked annular preforms during a manufacturing process, such as densification. The one-piece structure advantageously simplifies the arrangement of the preforms in a process chamber and causes less deformation in the preforms. The carbon composition also provides beneficial thermal effects that improve the densification process. A debonding coating is provided on the carbon annular shim member in order to facilitate separation of the annular preforms from the shim members. The metallic annular shim member does not require a debonding coating.

Abstract: Heat treatment is performed on preforms placed in an enclosure accompanied by sweeping with an inert gas under reduced pressure, and with a gaseous effluent being exhausted continuously via a first effluent outlet connected to an effluent exhaust circuit. At the end of the heat treatment, the first gaseous effluent outlet is closed so as to isolate the effluent exhaust circuit from the enclosure, sweeping of the enclosure with the inert gas is interrupted, and the heat-treated preforms are left in the enclosure and are subjected to densification by admitting a reagent gas into the enclosure via at least one reagent gas admission duct opening out into the enclosure, with gaseous effluent being exhausted via a second effluent outlet separate from the first, said second outlet being closed during the heat treatment step. Advantageously, metal, in particular sodium, contained in the gaseous effluent exhausted from the enclosure during the heat treatment step is neutralized.

Abstract: Retractable landing gear for an aircraft, the landing gear being of the type that is raised vertically, and comprising a plurality of independent legs, each leg comprising a structural part rigidly secured to a structure of the aircraft, a pivoting rocker beam supporting a pair of wheels, and a shock absorber. In accordance with the invention, the shock absorber of each leg is extended by a positioning portion enabling the total length of the extended shock absorber to be shortened in order to collapse the leg, and each leg further comprises a positioning actuator connected in hinged manner to the extended shock absorber and arranged to lengthen relative to a normal use position in order to lengthen the corresponding leg. This makes it possible to shorten and/or lengthen one or another of the legs of the landing gear while the aircraft is stationary or taxiing slowly.

Abstract: The subject of the invention is a deep hole boring head capable of rotating about a central axis (A-A), comprising a body (2) whose front part (4) has at least one cutting edge (8a, 8b, 8c, 8d) followed by a recess (10a, 10b) which leads to a duct (12) inside the said body (2), this duct allowing the chips formed during the boring to be cleared away rearwards, characterized in that it comprises at its front end and at its centre a pilot bit (20) capable of guiding the said head during boring. Use for the boring of a production piece made of titanium, the ratio L/D between the depth L of the hole bored and the diameter D of the latter being greater than or equal to 10, and the diameter D being greater than or equal to 65 mm.

Abstract: The invention relates to an architecture for a hydraulic circuit associated with actuators (100), such as actuators for airplane brakes, the architecture comprising a main hydraulic circuit (C) having hydraulic components (4, 5 101, 6) and adapted to convey hydraulic fluid pressurized by at least one pressure generator (2) associated with a main supply (1) to the actuators (100). The architecture includes an emergency system comprising an auxiliary supply (8) permanently fed by a return circuit (R) collecting the returns from all of the hydraulic components (4, 5,101, 6), the auxiliary supply (8) being connected to the main supply (1) via a relief valve (9). The emergency system further comprising an electrically driven pump unit (10) arranged to take fluid from the auxiliary supply (8) and to inject it into the main circuit (C) downstream from a general check valve (3).

Abstract: An installation for measuring the pressure of at least one tire of a wheel of an aeroplane includes: at least a pressure measuring sensor associated with a tire; a unit operating on the pressure measurement provided in the aeroplane; and radio-frequency transmission elements including for the or each sensor, a revolving antenna borne by the wheel and connected to each measuring sensor and to a fixed antenna connected by a conductive cable to the unit operating on the pressure measurement. The fixed antenna is adapted to be borne by the aeroplane structure away from the or each wheel at least in an upper part of the shock strut of the landing gear bearing the wheel.

Abstract: The invention relates to landing gear including a shock absorber having fist and second elements slidable relative to each other, the slidable elements defining an inside volume which is filled in part with hydraulic fluid so as to leave a first chamber filled with gas under pressure and located at the end of one of the slidable elements. According to the invention, a vessel filled with gas under pressure is housed in the end and is provided with a shutter member that is initially in a closed state and that is suitable for taking up a stable open state when the pressure in the first chamber exceeds the pressure in the vessel by a predetermined threshold amount.

Abstract: A method for verifying a hydraulic fluid level in a shock absorber, having a first portion and a second portion that are slidably movable relative to each other, includes using a first transmitter located on the first movable portion to transmit a first wave suitable for propagating without a physical medium, towards the second movable portion. A first receiver is disposed on the first movable portion and is used to receive the first transmitted wave after the transmitted wave has been reflected on a mechanical part secured to the second movable portion. The method further encompasses deducing a theoretical level of hydraulic fluid in the shock absorber from a measured characteristic of the first wave received in this way. This method further includes an airplane undercarriage having a shock absorber that has been fitted with two transceiver assemblies.

Abstract: A method for densification of porous by CVI in which substrates are loaded into a loading zone of an oven and heated to a temperature at which a desired matrix material is formed from a precursor gas(es). A reative gas containing the precursor gas(es) is admitted into the end of the oven and heated upstream from the loading zone of the substrates. The reactive gas is also preheated prior to entering the oven so that, upon entering the oven, it is brought to an intermediate temperature between ambient temperature and the temperature to which the substrates are heated. In this manner, a very small temperature gradient is obtained throughout the loading zone.

Abstract: The invention relates to a method of managing a braking system architecture for an airplane fitted with brakes having electromechanical actuators, in which some of the actuators are connected to a battery assembly of the airplane and other actuators are not connected to the battery assembly of the airplane, which method comprises a step of controlling at least one of the actuators that is not connected to the battery assembly to cause it to exert a force equal to a unit holding force, which force is determined independently of any braking demand from the pilot. The invention also provides an architecture specially adapted to implement the method.

Abstract: A landing gear includes a shock absorber having first and second elements slidable relative to each other, the slidable elements defining an inside volume which is filled in part with hydraulic fluid so as to leave a first chamber filled with gas under pressure and located at the end of one of the slidable elements. A vessel filled with gas under pressure is housed in the end and is provided with a shutter member that is initially in a closed state and that is suitable for taking up a stable open state when the pressure in the first chamber exceeds the pressure in the vessel by a predetermined threshold amount.