Abstract: An actuator comprising a body in which a rod is mounted to slide, the actuator including a screw extending inside the rod to co-operate with a nut secured to the rod, the screw being driven in rotation by a motor. The rod is associated with a piston that slides in a cavity of the body so as to define two chambers therein, the chambers being filled with hydraulic fluid and being put into communication via fluid transfer means fitted with at least one regulator member adapted to throttle the fluid expelled from one of the chambers, in at least one travel direction of the rod.

Abstract: A one-piece or otherwise unitary annular shim member made from a perforated metallic material is used to maintain a space between stacked annular preforms during a manufacturing process, such as densification. The metallic material used preferably can withstand at least the temperatures encountered during densification. The one-piece structure advantageously simplifies the arrangement of the preforms in a process chamber and causes less deformation in the preforms. In one example, the shim member is made from a metallic mesh and may utilize a crimped weave structure.

Abstract: A method of controlling power applied to an induction coil assembly used for densifying porous articles with a liquid matrix precursor. The control of applied power addresses dynamic changes in the electrical characteristics of the porous article being densified as it becomes denser. In particular, the power applied is controlled in accordance with changes in resonant frequency of the coupled system of the induction heating system and the porous article.

Abstract: The invention relates to a controlled-friction device comprising first and second elements mounted to move relative to each other in a sliding direction, wherein the device of the invention includes first and second friction members arranged symmetrically between the two elements in order to rub selectively against the second element, each of the friction members being urged towards a wedging position by a presser member, the first friction member being arranged, in a first direction of relative movement between the two elements along the travel direction, to tend to prevent relative movement between the two elements, and in a second direction to exert on the two elements an opposing friction force that depends on a stress applied against the first wedge member by the presser member; while the second friction member is arranged in the second direction to tend to prevent relative movement of the two elements, and in the first direction to exert on the two elements an opposing friction force that depends on a s

Abstract: The invention relates to a method for making a metal part that comprises a reinforcement (15) made of ceramic fibers. The method comprises the following steps: forming at least one annular-shaped insert (15) by assembling a bundle of metal-coated fibers; placing the insert into a hollow metal mold (10) such that the insert is spaced between the walls (10a, 10b) of the mold; filling the mold with a metal powder; generating vacuum in the mold and closing the same; hot isostatic compressing the assembly at a temperature and under a pressure sufficient for binding the powder particles between them and for binding the insert fibers between them; removing the mold and optionally machining to the desired shape.

Abstract: The invention relates to a method of powering at least one brushless DC electric motor having a plurality of phases for powering, the method including the steps of associating a static contactor with the motor for taking input voltage pulses and delivering polyphase voltage pulses to the motor in a manner that is servo-controlled to the angular position of the rotor of the motor, and for generating from a DC voltage source voltage pulses of frequency that is fixed and at a duty ratio that is controllable, thereby forming the input voltage pulses to the static contactor.

Abstract: A method for distributing braking energy between a group of the braked wheels numbered 1 . . . p and fitted to N undercarriages of an aircraft, each of the braked wheels having a brake furnished with a stack of discs to which a load is selectively applied so as to generate a torque for braking the wheel. Each brake is equipped with a unit for measuring a thickness of the stack of discs, and in which—the setting C j = E j E 1 + … ? + E p · N · C is an individual setting of braking to be generated by brake j, where p is the number of wheels concerned, C is the general setting of braking to be developed by the braked wheels of one and the same undercarriage, Ej is the thickness of the stack of discs of the brake of wheel j, and Cj the individual braking setting for wheel j. Each brake is controlled according to the individual braking setting thus determined.

Abstract: The invention relates to a hydraulic valve comprising a body in which a bore is formed in order to receive a sleeve that includes sealing seats that cooperate with a wall of the bore to define hydraulically isolated chambers that are connected to hydraulic ports in the body, the sleeve including connection holes in order to connect at least certain chambers with the inside of the sleeve and receiving a movable element that is slidable between two end positions in order to slide in leaktight manner against an inside wall of the sleeve, wherein the sleeve includes at least one regulator hole that opens out inside the sleeve in such a manner as to be the first bore to be uncovered or the last bore to be blocked by one of the fitted portions of the movable element when said element slides from one position to another, said fitted portion having at least one face portion that presents a setback that passes over the regulator hole.

Abstract: An aircraft undercarriage having a strut (1) hingedly mounted to the aircraft, and a bottom part (2) carrying the wheels and movable relative to the strut. The bottom part has a rod that slides in the strut and a scissors linkage between the strut and the rod. The undercarriage has a shortener for shortening the undercarriage between a deployed position and a raised position by causing the rod to enter into the strut (1). The shortener has coupled first and second members (11, 12), the first member (11) coupled to the bottom part (2) or to an element (5) that moves with the bottom part during its movement relative to the strut. The second member (12) is hinged to the aircraft so that while the undercarriage is raised, the second member abuts before the undercarriage reaches the raised position. The first member (11) is coupled to the scissors linkage.

Abstract: A process for manufacturing a metal part reinforced with ceramic fibers, in which: a housing is formed for an insert in a main metal body having an upper face; an insert formed from a bundle of fibers with a metal matrix is placed in the housing; a metal cover is placed on the main body so as to cover the insert; the cover is welded onto the metal body; a hot isostatic pressing operation is carried out; and the part obtained is machined to the desired shape. The housing has the shape of a notch of L-shaped cross section with a face perpendicular to the upper face and a face parallel to the upper face, the cover having an internal notch of L-shaped cross section, this having a shape complementary to that of the metal body with said insert, the cover being shaped on the outside so that the pressure forces are exerted perpendicular to said faces of the notch.

Abstract: The invention relates to a method of fabricating a structural part comprising a tubular portion from which there projects a structural element made of composite material, the method comprising the steps of: shaping a plane preform comprising a stack of a plurality of superposed fiber plies such that over at least a fraction of the preform that is to form a structural portion, the plies are secured to one another, and over at least another fraction of the preform that is to form a portion for connecting to the tube, the plies are separable so as to form two facing sheets; inserting a tube between the sheets of the connection portion so that the sheets surround the tube at least in part; and bonding the tube to the preform such that the tube forms the tubular portion and the preform forms the structural element of the structural part.

Abstract: The invention relates to a shock-absorber for aircraft landing gear, the shock-absorber having two elements mounted to slide telescopically one in the other and defining an internal volume that is filled with hydraulic fluid and with gas, the internal volume being separated into at least two chambers by a separation including at least one throttling orifice through which the hydraulic fluid passes from one chamber to the other while the shock-absorber is being compressed. According to the invention, the separation includes at least one degassing orifice to enable gas to be transferred from one chamber to the other when the landing gear is in the deployed position, the degassing orifice being offset vertically relative to the throttling orifice so as to be located above it when the landing gear is in the deployed position.

Abstract: A process for manufacturing a metal part reinforced with ceramic fibers, in which: a housing for an insert is machined in a metal body having an upper face; an insert formed from a fiber bundle having a metal matrix is placed in the housing; a metal cover is placed on the metal body so as to cover the insert; the cover is welded onto the metal body; the assembly including the metal body with the cover undergoes a hot isostatic compression treatment; and the treated assembly is machined to obtain the part. The insert is a rectilinear insert and the housing forms a rectilinear groove that extends beyond the insert and is open at each end, the groove being filled by a tab when the cover is placed on the metal body.

Abstract: A circular needling table for needling a textile structure made from an annular fiber preform, the table including: a horizontal annular platen for having the annular fiber preform placed thereon; drive means for driving the fiber preform in rotation about the axis of the platen; a needling device having a needling head extending over an angular sector of the platen and driven in vertical motion relative to the platen; and guide means for guiding the fiber preform under the needling head.

Abstract: A method and apparatus are disclosed for improving densification of porous substrate using a film boiling process. In particular, the disclosed method and apparatus permit more complete densification of a substrate (i.e., densification closer to the surface of the substrate) by selectively providing a sort of barrier that reduces cooling of the surface of the substrate being densified caused by contact with the relatively cool boiling liquid precursor of the densifying material, such as carbon. In particular, contact between the substrate and the liquid precursor is reduced using one or both of physical barriers (such as a mesh material) or structures that promote the formation of an insulating gaseous layer between the substrate and the liquid precursor (such as a plate closely spaced apart from the surface of the porous substrate). The barrier is moved into operational position before the applied power level increases sharply (as is known) near the end of the film boiling densification process.

Abstract: The invention provides an aircraft wheel-and-brake set, the wheel including a rim mounted to rotate on an axle of the aircraft about an axis of rotation, and the brake including a stack of disks extending into the rim in service, and a support carrying brake actuators facing the stack of disks in order to selectively press said disks together, wherein the support carries at least one rotary drive member for driving the wheel in rotation, which drive member is carried in such a manner that it extends outside said wheel.

Abstract: A locking device for locking together first and second elements that are movable relative to each other in an axial direction. The device has a bushing secured to a first element and catches that are cantilevered-out in an axial direction and are elastically deformable. The device also has an anchor portion secured to a second element and an annular setback to receive hook-shaped ends of the catches. The device also has a locking sleeve mounted to move relative to the catches between a release position in which the catches are free to flex, and a blocking position in which the catches are prevented from flexing, wherein the locking sleeve is movable in rotation relative to the catches and includes a circumferential succession of gaps and of obstacles.

Abstract: The invention relates to a bar for an aircraft wheel, the bar comprising an oblong body (2) extended at each end by respective endpieces (4, 5) extending parallel to the body and parallel to each other, the endpieces being offset relative to each other. The invention also relates to a wheel specially adapted to receive such a bar.

Abstract: A method for producing a metallic part including inner reinforcements of ceramic fibers, according to which: at least one recess for an insert is machined in a metallic body having an upper surface; at least one insert of ceramic fibers in a metallic matrix is arranged in the recess; the insert is covered with a cover; the gap around the insert is placed under a vacuum and hermetically sealed; the entire metallic body with the cover is treated by hot isostatic compaction; and the treated assembly is machined to produce the part. The insert is rectilinear, and the recess for the insert in the metallic body forms a rectilinear groove, the cover being dimensioned so as to be able to placed on the insert in the recess after having been shrunk by cooling and to establish a tight fit in the groove by dilation such as to close the space.

Abstract: The invention provides a method of taxiing an aircraft having at least one nose undercarriage at the front of the aircraft and main undercarriages, each undercarriage having wheels, the method comprising the steps of: fitting at least one of the wheels carried by the nose undercarriage with a main taxiing motor member, and fitting at least one of the wheels carried by the main undercarriages with an auxiliary taxiing motor member; and in response to a taxiing order, powering the main taxiing motor member to cause the aircraft to taxi, and in particular if the driving force developed by the main taxiing motor member on the aircraft is insufficient, powering the auxiliary taxiing motor member, as required.