Abstract: A position-controlled actuator includes a motor supplied with power by a power supply circuit controlled at least by an error signal. A speed reducer converts rotary movement of the motor into linear movement over a given travel. An output sensor indicates the position of the actuator and an error signal computation circuit compares a commanded position of the actuator to a calculated position. The output sensor supplies a binary position signal taking two different values according to the position of the actuator relative to its mid-travel position.

Abstract: An actuator suitable for autopilot control of a helicopter tail rotor comprises a direct current motor, a non-reversible gearbox, a speed reducer driving an output shaft, a friction device disposed between the non-reversible gearbox and the speed reducer and a friction exceeded sensing device adapted to cut off the supply of power to the motor.

Abstract: An autonomous kinematic measurement system for helicopters is disclosed. A helicopter comprises a lifting rotor, an anti-torque rotor, first means to control the cyclical pitch and the collective pitch of the rotor and second means to control the pitch of the anti-torque rotor. The system comprises means to measure the helicopter's ground speed, means to measure the longitudinal cyclical pitch of the lifting rotor blades, means to measure the lateral cyclical pitch of the lifting rotor blades, means to measure the collective pitch given to the lifting rotor blades, and means to measure the pitch of the anti-torque rotor. An inertial unit, provided with ancillary computing means, uses a direction signal and a helicopter attitude signal corresponding to the longitudinal acceleration signal and lateral acceleration signal of the helicopter's ground speed signal to establish the helicopter's longitudinal and lateral airspeed values, following a determination of the coefficients .alpha.,.beta.

Abstract: The invention relates to a signal generator with programmable variable frequency and comprises a reference oscillator, a first frequency divider receiving the signal emitted by the reference oscillator and delivering an instantaneous frequency signal (FS). A control chain for said first frequency divider comprises a second frequency divider and a first programmable integrator system, which controls the first frequency divider. A control chain for the second frequency divider comprises a second integrator system receiving the output signal (FS).

Abstract: The mirror comprises a cellular structure core having a stack of plies each constituted by fiber-containing polymerized resin fixed on at least one face thereof, with a reflecting surface being made on the stack, and with the fibers in each ply extending in one direction only. The invention enables ultralight-weight mirrors to be made having excellent mechanical properties.

Abstract: Equipment for providing protection against drowning, in particular for use by the driver of a motorized water vessel, the equipment comprising:a supply (110) of air under pressure, feeding a regulating pressure expander (130, 140);a face mask (210) including a breathe-in valve (211) and a breathe-out valve (212); andswitch means (160) for selectively connecting the breathe-in valve of the face mask either to the regulating pressure expander or else to the atmopshere, said switch means being constituted by an electrically controlled valve permanently powered via a safety inertia switch, such that the breathe-in valve of the face mask is connected to the surrounding air so long as the electrically controlled valve is fed with electricity, and that in the event of the inertia switch interrupting the supply of electricity to the electricity controlled valve, because of the vessel being subjected to a shock, the breathe-in valve of the face mask is immediately switched to the regulating pressure expander.

Abstract: A device for half-opening the door of a box containing safety equipment such as oxygen masks, said device enabling said door to be held in a partially open position for inspection purposes without releasing the safety equipment, said device being constituted by a half-opening member hinged to said door about a transverse axis, said half-opening member having an operating portion on one side of said axis and a latching portion on the other side of said axis, said operating portion, when in a normal position, closing an associated opening through said door, and said latching portion, when in an inspection position, co-operating with a latching member fixed inside said box.

Abstract: A gyroscope constructed in accordance with the present invention includes a flywheel (220) which can oscillate with at least two degrees of freedom about a central position in which the flywheel axis is aligned with the axis of a drive shaft (200), the flywheel being held radially and rotated relative to the body (100) of the apparatus. The gyroscope also includes a set of electrodes (101 to 104) for electrostatically controlling the position or for detecting the position of the flywheel. The electrodes are fixed relative to the body and face corresponding conducting surfaces of the flywheel. In accordance with the invention, the gyroscope further includes a rigid spinning casing (250) which encloses the flywheel in such a manner as to interpose a dielectric surface between the corresponding conducting surfaces of the flywheel and each electrode, the casing being fixed to the flywheel drive shaft but not having any degrees of freedom in oscillation relative to the body other than being free to spin.

Abstract: A spherical indicator for use on board an aircraft comprises one or more pointers supported by members which are mounted to rotate in front of a sphere of the indicator. The member which supports a pointer is mounted to rotate about an axis which passes through the center of the sphere.

Abstract: A gyroscope comprises a rotor driven by a motor shaft through the intermediary of an intermediate ring connected to the motor and to the rotor by torsion bars at 90.degree. with respect to each other and precession motors for applying to the rotor, precession torques in planes containing the axis of rotation of the drive shaft. Precession motors are fixed electromagnets exerting a force of attraction on the rotor. A system for supplying current to the electromagnets is provided, reacting to a control by an electrical control signal, this system having a response such that the attraction torque exerted by a pair of diametrically opposed electromagnets is a linear function of a parameter of the signal for controlling the current applied to the electromagnets.The gyroscope may have an elastic suspension and be intended to rotate at high speed.

Abstract: The invention relates to the aiming of an optical illuminator on a target. The direction in which is seen the maximum light of the illuminator reflected by the target is detected, the angle formed by this direction and the direction of sight is measured and the result of this measurement is employed for controlling an orientation of the optical axis of the illuminator or of the optical axis of the sighting system, with the result that the direction in which is seen this maximum coincides with the optical axis of the sighting system. The invention is particularly applied to the sending of a moving body, provided with an optical, self-directing system, onto a target.

Abstract: An optical sighting device consists of a hood with two windows which can transmit radiation within predetermined wavelength ranges to a rotatable reflecting device. The reflecting device receives radiation from one or other of the windows and the hood is rotatable subject to the rotation of the reflecting device. The radiation reflected by the reflecting device is received by two dichroic mirror plates which are suitable for transmitting or reflecting thermal infra-red radiation, visible radiation and near infra-red radiation towards suitable corresponding detectors.