Abstract: The invention relates to a method for locking a mobile element (101) of an aircraft, such as a hold door or a landing gear, the mobile element being moved between a deployed position and a closed or retracted position by means of an actuator (200) having a sliding stem (3) coupled to the mobile element, the stem being mounted so as to be able to slide in a body (1) of the actuator between an extended position corresponding to the deployed position of the mobile element and a withdrawn position corresponding to the closed or retracted position of the mobile element. The method of the invention comprises the step of positively blocking the sliding stem of the actuator in the withdrawn position.

Abstract: The invention provides a method of moving an aircraft undercarriage comprising a leg (1) that is movable between a deployed position and a retracted position in which the leg is held stationary by means of a strut (2) held in an aligned position by a stabilizer member (4), the method including using a drive actuator (10) for raising the undercarriage from the deployed position to the retracted position. According to the invention, the actuator is coupled firstly to the leg and secondly to the stabilizer member in such a manner that on being activated the actuator begins by causing the stabilizer member to unlock and then moves the undercarriage leg towards the retracted position.

Abstract: The invention relates to a method of driving an aircraft undercarriage between a deployed position and a retracted position, the undercarriage comprising a leg (2) that is hinged to a structure of the aircraft in order to be movable between those two positions and being stabilized in the deployed position by means of a brace member (10) comprising two limbs (11, 12) that are hinged to each other, one of which is coupled to the leg and the other of which is coupled to the structure of the aircraft, the limbs being brought into an aligned position when the leg is in the deployed position. According to the invention, a rotary actuator (20) is arranged on the aircraft, which actuator comprises first and second cranks (22, 24) that are mounted to turn freely about a common axis of rotation but that have a relative angular position that can be controlled, and that are arranged to stabilize the limbs of the brace member in the substantially aligned position.

Abstract: An aircraft undercarriage includes a steerable bottom portion carrying one or more wheels and fitted with a steering device configured to turn the steerable bottom portion in response to a steering order. The steering device has a single electromechanical steering actuator having a steering electric motor driving, by a reduction gearing, an outlet pinion on an axis of the steering electric motor. The outlet pinion cooperates with a spur gear secured to the steerable bottom portion. A connection between the steering electric motor and the steerable bottom portion is reversible. The electromechanical steering actuator is fitted with a monitor configured to monitor at least one operating parameter of the steering device and to detect an actuator performance deterioration condition.

Abstract: The invention relates to a method of driving an aircraft undercarriage between a deployed position and a retracted position, the undercarriage comprising a leg (2) that is hinged to a structure of the aircraft in order to be movable between those two positions and being stabilized in the deployed position by means of a brace member (10) comprising two limbs (11, 12) that are hinged to each other, one of which is coupled to the leg and the other of which is coupled to the structure of the aircraft, the limbs being brought into an aligned position when the leg is in the deployed position. According to the invention, a rotary actuator (20) is arranged on the aircraft, which actuator comprises first and second cranks (22, 24) that are mounted to turn freely about a common axis of rotation but that have a relative angular position that can be controlled, and that are arranged to stabilize the limbs of the brace member in the substantially aligned position.

Abstract: The invention provides a method of moving an aircraft undercarriage comprising a leg (1) that is movable between a deployed position and a retracted position in which the leg is held stationary by means of a strut (2) held in an aligned position by a stabilizer member (4), the method including using a drive actuator (10) for raising the undercarriage from the deployed position to the retracted position. According to the invention, the actuator is coupled firstly to the leg and secondly to the stabilizer member in such a manner that on being activated the actuator begins by causing the stabilizer member to unlock and then moves the undercarriage leg towards the retracted position.

Abstract: An aircraft undercarriage leg having an orientation control for wheels that causes a sliding rod to pivot. The orientation control has a rotating member mounted on the strut assembly having a toothed sector forming a pinion and is rotationally coupled to the sliding rod, and a rack mounted to slide on the strut assembly along a sliding axis perpendicular to the pivot axis to mesh with the pinion, the rack being moved by drive means. The drive include a rotary drive inside the rack adapted to turn about the sliding axis and to cooperate via a helicoidal coupling with the rack, The rotary drive is immobilized axially by two opposite axial thrust bearings allowing angular tilting of the rotary drive. The thrust bearings are carried by at least one elongate support inside the rack having a proximal end fixed to an end of a cylinder in which the rack slides.

Abstract: A device for measuring a relative rotation speed and/or a relative angular position between a first rotating element (2) and a second rotating element (3). The device includes a structure for generating a magnetic field rotating at a magnetic rotation speed representing a rotation speed of the first rotating element and a sensor (5) mounted to rotate and adapted to produce from the rotating magnetic field a measurement signal representing the relative rotation speed and/or the relative angular position. The device also has a processor (11) positioned on the static part and intended to acquire the measurement signal. A transmitter is adapted to transmit the measurement signal to the processor from the sensor.

Abstract: An aircraft undercarriage leg having an orientation control for wheels that causes a sliding rod to pivot. The orientation control has a rotating member mounted on the strut assembly having a toothed sector forming a pinion and is rotationally coupled to the sliding rod, and a rack mounted to slide on the strut assembly along a sliding axis perpendicular to the pivot axis to mesh with the pinion, the rack being moved by drive means. The drive include a rotary drive inside the rack adapted to turn about the sliding axis and to cooperate via a helicoidal coupling with the rack,. The rotary drive is immobilized axially by two opposite axial thrust bearings allowing angular tilting of the rotary drive. The thrust bearings are carried by at least one elongate support inside the rack having a proximal end fixed to an end of a cylinder in which the rack slides.

Abstract: A device for measuring a relative rotation speed and/or a relative angular position between a first rotating element (2) and a second rotating element (3). The device includes a structure for generating a magnetic field rotating at a magnetic rotation speed representing a rotation speed of the first rotating element and a sensor (5) mounted to rotate and adapted to produce from the rotating magnetic field a measurement signal representing the relative rotation speed and/or the relative angular position. The device also has a processor (11) positioned on the static part and intended to acquire the measurement signal. A transmitter is adapted to transmit the measurement signal to the processor from the sensor.

Abstract: The invention relates to a method for locking a mobile element (101) of an aircraft, such as a hold door or a landing gear, the mobile element being moved between a deployed position and a closed or retracted position by means of an actuator (200) having a sliding stem (3) coupled to the mobile element, the stem being mounted so as to be able to slide in a body (1) of the actuator between an extended position corresponding to the deployed position of the mobile element and a withdrawn position corresponding to the closed or retracted position of the mobile element. The method of the invention comprises the step of positively blocking the sliding stem of the actuator in the withdrawn position.

Abstract: A telescopic actuator comprising a cylinder having a structure for coupling the cylinder to a first external element a rod mounted to slide telescopically in the cylinder along a sliding axis and including a structure for coupling it to a second external element and a lead screw mounted to rotate in the cylinder about the sliding axis and extending inside the rod to co-operate with a nut secured to the rod, such that rotating the lead screw causes the rod to slide. There also is a drive structure for driving the lead screw in rotation and a retention structure for axially retaining the lead screw. The retention structure holds a bearing of the lead screw captive in an axial direction and is arranged to retain the bearing of the lead screw with axial clearance suitable for absorbing movements imparted to the rod relative to the cylinder.

Abstract: The invention relates to a telescopic actuator comprising a body (1) defining a cylindrical cavity of longitudinal axis (X); a rod (3) mounted to slide telescopically in the cylinder along the said axis; a nut (7) secured to the rod; a lead screw (4) mounted on the cylinder to extend along and rotate about the said axis (X) and collaborate with the nut in such a way that a rotation of the lead screw causes a telescopic movement of the rod in the cylinder; means (8, 9, 10) for driving the rotation of the lead screw. According to the invention, the nut is mounted on the rod to be axially retained thereon by retaining means (12, 13, 14; 30 to 38) which can be made to release the nut axially from the rod.

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 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 telescopic actuator comprising a body (1) defining a cylindrical cavity of longitudinal axis (X); a rod (3) mounted to slide telescopically in the cylinder along the said axis; a nut (7) secured to the rod; a lead screw (4) mounted on the cylinder to extend along and rotate about the said axis (X) and collaborate with the nut in such a way that a rotation of the lead screw causes a telescopic movement of the rod in the cylinder; means (8, 9, 10) for driving the rotation of the lead screw. According to the invention, the nut is mounted on the rod to be axially retained thereon by retaining means (12, 13, 14; 30 to 38) which can be made to release the nut axially from the rod.

Abstract: The invention relates to a telescopic actuator comprising: a cylinder having means for coupling it to a first external element; a rod mounted to slide telescopically in the cylinder along a sliding axis and including means for coupling it to a second external element; a lead screw mounted to rotate in the cylinder about the sliding axis and extending inside the rod to co-operate with a nut secured to the rod, such that rotating the lead screw causes the rod to slide; drive means for driving the lead screw in rotation; and retention means for axially retaining the lead screw, which means hold a bearing of the lead screw captive in an axial direction; wherein the retention means are arranged to retain the bearing of the lead screw with axial clearance suitable for absorbing movements imparted to the rod relative to the cylinder.

Abstract: The invention provides a locking device for locking together first and second elements that are movable relative to each other in an axial direction, the device comprising firstly a bushing secured to first element and including catches that are cantilevered-out in an axial direction and that are elastically deformable, and secondly an anchor portion secured to the second element and including an annular setback to receive hook-shaped ends of the catches, the device also including 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, such that: when the sleeve is in a first angular position corresponding to the release position, the gaps are in register with the catches which are therefore free to flex under the effect of the a

Abstract: The invention relates to 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. According to the invention, 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: The invention relates to an actuator comprising a body with a cylindrical cavity, and a rod extending through one end of the cavity, being secured with a piston mounted to slide axially in the cavity so as to define therein two hydraulic chambers, the actuator including additional means for extending the rod, which comprise: means for preventing the rod from rotating relative to the body of the actuator; a nut rigidly secured to the rod; a screw extending axially inside the cavity and co-operating with the nut; a drive shaft extending axially inside the cavity and being free to turn, the screw being mounted to slide without rotation along the shaft; and rotary drive means for driving the drive shaft.