Abstract: A correction method for transverse defocussing of paraboloid oriented relative to the source initially aligned with the focus consists of securing said paraboloid to first platform, articulating said first platform through hinge means jointed to second platform, itself articulated through further hinge means jointed to a stationary part, and then orienting said hinge means to said focus, while providing moving means for said platforms, said moving means being servocontrolled responsive to pointing error detector thereby to hold permanently said focus close to the source.Provision is also made of a parabolic antenna comprising means for carrying out said method. The system is applied to radio and TV broadcast apparatus aboard satellites.

Abstract: Rotary bodies possessing, in common, radially passive and axially active magnetic centering devices, eddy current dampers, emergency support systems, a drive motor and a motor switching sensor, and an axial velocity sensor to send correction signals to the axially active magnetic centering device with all of these members positioned at the maximum permitted axial limits, either inside or outside the rotor wall, whether the rotor is of an internal or external configuration.

Abstract: The invention relates to a rotary-wing aircraft rotor.The rotor comprises a hub 1 connected to each blade 7a by a rigid yoke 8-9 gripping the root of blade 7a and a spherical abutment 17 secured at its center C to radial arms 5a, 6a of hub 1 and bearing on its convex side against the inner end of yoke 8-9. According to the invention, an annular visco-elastic shock-absorber 20, constituting a frequency-matching device, is disposed between the yoke 8-9 associated with each blade 7a and the corresponding pitch control device 24-29.The invention is of use inter alia in the manufacture of fast helicopter rotors having a hub which is very compact and can therefore be easily streamlined.

Abstract: The present invention relates to the orientation of antennae on a satellite possessing at least one antenna comprising a horn rigidly connected to the body of the satellite, a movable reflector mounted on an orientable platform and at least one radio-frequency sensor in the horn using said antenna to control the orientation of said reflector. The invention consists of: using a signal characterizing the pivoting of the orientable platform with respect to the body of the satellite to orient said satellite correctly with respect to the reflector in order to limit the pivoting of said platform; using the signals from at least one earth sensor in the same way as the signals from the radio-frequency sensor to control said reflector, so as to orient the beam towards the point sighted on the earth. The invention is particularly useful for the control of the orientation of antennae, particularly on a satellite.

Abstract: The present invention relates to a foldable antenna reflector, particularly of large dimensions, for example adapted to fit out a telecommunications or direct television satellite.According to the invention, said reflector has a structure comprising a plurality of arms, each of which is articulated at the end of a frame element remote from the axis of the reflector, so that, when said frame elements are in opened out position, said arms project angularly with respect thereto so that said structure forms a sort of cradle in the concavity of which is disposed said opened out supple dish and, when the frame elements are in collapsed position, said arms are folded along the side of said frame elements inside the cradle, so that said structure then forms a sort of bundle of small diameter enclosing said collapsed supple dish.

Abstract: The present invention relates to a device for moulding cylindrical pieces, comprising, on the one hand, a tube made of a rigid, elastic material, split longitudinally and tending to expand transversely under the action of its inherent elasticity and, on the other hand, holding members capable, when they cooperate with said tube, of obliging the internal cavity thereof to take a reduced section corresponding to that of said pieces to be moulded and, when they do not cooperate with said tube, of allowing said internal cavity to take an expanded section. The invention is more particularly applicable to the moulding of tubular pieces, particularly from a laminate of supple fabric impregnated with polymerizable resin.

Abstract: Rotor assembly comprises a rotor and a bearing having inner and outer races with rolling elements disposed therebetween, one of the races being secured to the rotor and the other thereof being secured to a rotatable annular member concentric with the rotor. Magnetic means secured to each of the races cooperate to take up the axial clearance of the bearing, reducing it to virtually zero.

Abstract: The present invention relates to a process for making a magnetic armature of divided structure of annular shape and provided with a concentric annular groove, comprising the steps of winding a filamentary magnetic material on an annular mandrel, impregnating said winding with a hardening material, then cutting said winding along the equatorial plane of said mandrel, after said material has hardened. The invention is more particularly applicable to the production of divided magnetic armatures, especially for magnetic bearings.

Abstract: The present invention relates to a process for setting up a vertical gyroscopic device mounted on a moving craft, wherein the action of roll reset means is eliminated only with a delay time with respect to the rotation of the mass, this delay time being such that upon its expiration the kinetic moment of the mass in rotation is sufficient to ensure the stability thereof and the erector system is controlled in the sense of activation only with another time delay necessary to reduce the movement of precession of the device. The invention is applicable to the guiding or control of missiles or aircraft.

Abstract: The window is constituted by two parallel walls and a central space, a detonating fuse being inserted between the walls and mounted in such a manner as to produce anisotropic detonating action. As a result of detonation, breakage and ejection of the outer wall and embrittlement of the inner wall take place simultaneously along the cutting outline.

Abstract: Electromagnetic method and apparatus to accurately control the orientation of a platform according to two axes wherein pivoting of the platform about two orthogonal axes passing through its center is effected by electromagnetic means, with the servo-control being obtained by using a detector responsive to the angle of deviation from a reference direction, an amplifier, a low-pass filter, a phase lead filter and power amplifiers supplying currents to the electromagnetic devices. The method and apparatus is particularly adapted to the orientation of platforms carrying means such as aerials or inertia wheels intended for piloting a space vehicle.

Abstract: The present invention relates to a blade profile for rotary wing of an aircraft, comprising, between the leading edge and the trailing edge, a convex upper surface and a non-concave lower surface, wherein, at the point of maximum curvature of the leading edge, the radius of curvature Ro is approximately defined by the expression Ro=1.7 C. e.sub.max.sup.2, in which C represents the chord and e.sub.max the relative thickness of said profile and the portion of lower surface adjacent the leading edge extends to about 20% of the chord from said leading edge and presents a very small general curvature decreasing continuously in the direction of the trailing edge up to the point of minimum curvature of the lower surface. The invention is more particularly applicable to obtaining rotary wings, for example for helicopters, capable of very high performances both when hovering, and in high speed flight, as well as during manoeuvres.

Abstract: This invention relates to a digital-analog interface for insertion between the control circuit of a moving element and a transmitter of digital control signals.This interface comprises an inductive detector of the actual position of the moving element. The inductive detector has a single primary winding directly connected to an a.c. source and two secondary windings. The detector secondary windings are connected in parallel to one input of a summing circuit, through a first resistance of fixed value and through a second resistance of adjustable value, respectively. Means responsive to the transmitter digital control signals are provided to adjust the value of the second resistance. The output of the summing circuit is connected to the control circuit of the moving element.

Abstract: The present invention relates to a system for guiding remote-controlled missiles, enabling these missiles to be fired by bursts, comprising a sighting device, an angular deviation measuring (ADM) device and a device for controlling the path; according to the invention, partial, individual and separate fields are defined in the field of the ADM device, said fields corresponding to various zones where successive missiles may be addressed, and said control device is designed for simultaneously guiding a plurality of missiles on a plurality of distinct predetermined standby courses spaced apart with respect to said line of sight. The invention finds particular application in the guiding of ground-ground, ground-air, or air-ground missiles.

Abstract: Rotary-wing aircraft rotor comprising a rigid hub coupled to the root of each blade in which a trailing return brace comprises a stack of metal plates alternating with plates of visco-elastic material the ends of which being coupled via a ball joint respectively to the root of one blade and to a place of the hub such that the brace is always slightly inclined.

Abstract: A method and device for balancing magnetically suspended bodies wherein at the axial ends of the bodies are included two centering devices on the rotor side constituted by centered and excentric magnetic rings facing two centering devices on the stator side with centered and excentric magnetic rings, the magnetic field in the air gaps between the pairs of rings being made variable according to signals received from correction sensors of the axes and of the alignment.

Abstract: A rotor blade, specially for a helicopter rotor, which blade is made of reinforced plastics and a process for making this blade in a single molding operation.This blade comprises: a solid one-piece leading edge spar embodied by strands of glass fibre filaments extending lengthwise over the whole length of the blade; a core made of a lightweight cellular substance and placed contiguous with the spar rear face; a thick sheet-like member extending around the spar and the core and comprising at least one layer of a fabric consisting of parallel glass fibres disposed askew of the blade longitudinal axis so as to form a torque-tube; a rear filling element, and a covering extending around the torque-tube and the rear filling element. The airfoil portion of this blade is centered substantially in the front quarter of the chord of the blade cross-section and it has a very high torsional stiffness.

Abstract: The invention relates to a process for multiplying a stochastic value at the most equal to 0.5, by a number 1+K, with 0<K.ltoreq.1, which stochastic value is physically represented by a sequence of logic 0 and 1 levels, such that in a certain interval of time, N logic 1 levels appear, according to which process, a first auxiliary sequence is formed from said sequence, comprising KN logic 1 levels, then a second auxiliary sequence comprising N logic 1 levels, each logic 1 level of each of the two auxiliary sequences being on the one hand deducted from a logic 1 level of the initial sequence and on the other hand temporally opposite a zero level of the other auxiliary sequence, after which said auxiliary sequences are added to each other. The invention is more particularly applicable to the stochastic processing of information.

Abstract: The present invention relates to a process for fitting a connecting member at one end of a control rod, wherein a sleeve of resistant fibres impregnated with polymerizable resin is applied substantially against the inner wall of the end, the end is flattened at least until the portions of inner face of the sleeve, disposed on either side of the plane of flattening, are applied against one another, substantially completely obturating the section of the flattened portion of the tubular end, and the resin impregnating the sleeve is polymerized after flattening. The invention is more particularly applicable to the obtaining of light, resistant connecting rods, especially for aircraft.

Abstract: The present invention relates to a process for making a connecting rod for controlling or transmitting efforts, comprising a rod provided at at least one of its ends with a connecting member, wherein a tubular element is firstly made of high strength fibers impregnated with polymerizable resin, said end is then flattened so that it is obturated, after which the resin impregnating said element is polymerized, then said connecting member is arranged in the hardened, flattened part of said element. The invention is more particularly applicable to the manufacture of connecting rods for controlling and transmitting efforts, particularly for aircraft, helicopters, etc. . . .