Abstract: The invention relates to a shock absorber for an aircraft undercarriage, the shock absorber comprising a main cylinder in which a rod is mounted to slide telescopically, the shock absorber having one or more pneumatic chambers filled with gas, a supply of hydraulic fluid, and throttle means for throttling the hydraulic fluid such that when the shock absorber is shortened, the gas in the pneumatic chamber(s) is compressed and the hydraulic fluid is throttled, in which the pneumatic chamber(s) is/are fully contained in one or more auxiliary cylinders external to the main cylinder, and in each of which a sealed piston is slidably mounted to separate a pneumatic chamber contained in said external auxiliary cylinder from a fluid chamber in fluid flow communication with the main cylinder. According to the invention, the throttle means are disposed at the inlet of a fluid flow connection between the main cylinder and the auxiliary cylinder(s).

Abstract: The invention provides a telescopic member comprising a cylinder in which a rod carrying a piston is mounted to slide telescopically, the telescopic member including internal abutment means that are overridable over a predetermined force when the rod comes into abutment inside the cylinder in the shortening direction, wherein the internal abutment means comprise an abutment piece extending in an open bore within the rod and projecting therefrom, the abutment piece being held to the rod via a pin.

Abstract: The invention relates to a method of fabricating a composite material connecting rod, the method comprising the step of cutting out a pattern presenting two opposite edges from a composite fiber fabric made up of a plurality of superposed primary plies that are bonded together in such a manner that the primary plies can slide relative to one another, rolling the pattern into a tube in such a manner that the primary plies slide relative to one another to give a chamfer shape to the two edges, and joining together the chamfer-shaped edges so that they overlap.

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.

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: 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: 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: 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: 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 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.

Abstract: An aircraft landing gear includes a leg having a strut receiving a telescopic rod to slide on a sliding axis, the strut being hinged to an aircraft structure and being capable of pivoting about a pivot axis that is highly offset from the sliding axis. The landing gear further includes a connection structure essentially formed by two panels connecting two axially separate points of the strut to a common axis structure extending along the strut pivot axis. In the gear-down position, the panels are one above the other, the top panel being connected to the strut via a high attachment which is rigid in twisting, while the bottom panel is connected to the strut via a low attachment which tolerates twisting, thereby enabling the strut to warp to some extent when the aircraft is turning while taxiing.

Abstract: The invention relates to aircraft landing gear of the type comprising a leg constituted by a strut receiving a telescopic rod to slide on a sliding axis, said strut being hinged to an aircraft structure and being capable of pivoting about a pivot axis that is highly offset from the sliding axis. In accordance with the invention, the landing gear includes a connection structure essentially constituted by two panels connecting two axially separate points of the strut to a common axis structure extending along the strut pivot axis. In the gear-down position, the panels are one above the other, the top panel being connected to the strut via a high attachment which is rigid in twisting, while the bottom panel is connected to the strut via a low attachment which tolerates twisting, thereby enabling the strut to warp to some extent when the aircraft is turning while taxiing.

Abstract: An aircraft landing gear includes a leg having a strut receiving a telescopic rod to slide on a sliding axis, the strut being hinged to an aircraft structure and being capable of pivoting about a pivot axis that is highly offset from the sliding axis. The landing gear further includes a connection structure essentially comprising two panels connecting two axially separate points of the strut to a common axis structure extending along the strut pivot axis. In the gear-down position, the panels are one above the other, the top panel being connected to the strut via a high attachment which is rigid in twisting, while the bottom panel is connected to the strut via a low attachment which tolerates twisting, thereby enabling the strut to warp to some extent when the aircraft is turning while taxiing.

Abstract: The invention relates to an aircraft landing gear having a retractable leg, in which the leg comprises a strut with a telescopic rod, the strut being hinged to a structure of the aircraft in order to pivot between a gear-up position and a gear-down position, said strut also being connected to the structure of the aircraft via hinged brace elements. According to an essential aspect of the invention, the landing gear includes an independent low-noise fairing system that serves, when the leg is in the gear-down position, to cover the front of at least a portion of the hinge between the brace elements, said low-noise fairing system comprising a hinged fairing of two complementary portions connected to each other via a hinge whose axis is parallel to the axis of the corresponding hinge portion of said brace elements.

Abstract: The invention relates to a method of forming the inside wall of a support bearing of given height H and suitable for receiving a cylindrical portion of a cylindrical element for co-operating with the inside wall, said method comprising the steps of estimating a deflection f taken up by the cylindrical element between the center and one of the ends of the support bearing, estimating a nominal radius R using the relationship R=H2/8f, determining an inside wall for the support bearing that occupies a toroidal surface having a throat diameter equal to a diameter of the cylindrical element, ignoring predetermined clearance, and having a meridian radius lying in a range of ±15% about the nominal radius R, and machining the support bearing in such a manner that its inside wall occupies the toroidal surface as determined in this way.

Abstract: The invention relates to an aircraft landing gear having a retractable leg, in which the leg comprises a strut with a telescopic rod, the strut being hinged to a structure of the aircraft in order to pivot between a gear-up position and a gear-down position, said strut also being connected to the structure of the aircraft via hinged brace elements. According to an essential aspect of the invention, the landing gear includes an independent low-noise fairing system that serves, when the leg is in the gear-down position, to cover the front of at least a portion of the hinge between the brace elements, said low-noise fairing system comprising a hinged fairing of two complementary portions connected to each other via a hinge whose axis is parallel to the axis of the corresponding hinge portion of said brace elements.