Abstract: The actuation system including a control system, an actuator comprising a drive part and a step motor comprising a rotor and a stator with at least one electric phase, an actuated system comprising a controlled element coupled to the drive part, and an elastic part capable of generating an elastic return force on the rotor of the motor or on the drive part. The control system comprises means for measuring an induced electric parameter on the phase of the stator after switching off the current of said at least one phase of the stator to detect a return of the rotor resulting from elastic return force when a mechanical clearance is overtaken.

Abstract: The actuation system including a control system, an actuator comprising a drive part and a step motor comprising a rotor and a stator with at least one electric phase, an actuated system comprising a controlled element coupled to the drive part, and an elastic part capable of generating an elastic return force on the rotor of the motor or on the drive part. The control system comprises means for measuring an induced electric parameter on the phase of the stator after switching off the current of said at least one phase of the stator to detect a return of the rotor resulting from elastic return force when a mechanical clearance is overtaken.

Abstract: A linear actuator (1) comprising a housing (6), a motor (2) comprising a stator with coils (4), a screw-nut system, and a rotor (5) axially and radially supported on the motor side by a bearing (11). The bearing comprises a ball (14) rigidly attached to the rotor, a cylindrical cavity (15) formed or positioned in the housing into which the ball (14) is inserted. A stop (17) is positioned in the cavity, supported in an axial direction of the rotor, against the ball (14) in essentially one point.

Abstract: A hydraulic control valve system comprising a hydraulic valve block with a plurality of control valve segments arranged in a juxtaposed manner, each control valve segment comprising a first line, for example a pump line, a second line, for example a return line, and a displaceable valve rod adapted to open and close the first line, respectively close and open the second line to varying degrees depending on a position of the valve rod. The valve system further has a plurality of actuators arranged in a juxtaposed manner, one actuator for each valve segment, each actuator comprising an electrical motor connected to a respective said valve rod through a coupling mechanism.

Abstract: A linear actuator (1) comprising a housing (6), a motor (2) comprising a stator with coils (4), a screw-nut system, and a rotor (5) axially and radially supported on the motor side by a bearing (11). The bearing comprises a ball (14) rigidly attached to the rotor, a cylindrical cavity (15) formed or positioned in the housing into which the ball (14) is inserted. A stop (17) is positioned in the cavity, supported in an axial direction of the rotor, against the ball (14) in essentially one point.

Abstract: A hydraulic control valve system comprising a hydraulic valve block with a plurality of control valve segments arranged in a juxtaposed manner, each control valve segment comprising a first line, for example a pump line, a second line, for example a return line, and a displaceable valve rod adapted to open and close the first line, respectively close and open the second line to varying degrees depending on a position of the valve rod. The valve system further has a plurality of actuators arranged in a juxtaposed manner, one actuator for each valve segment, each actuator comprising an electrical motor connected to a respective said valve rod through a coupling mechanism. Each motor has a rotor and a stator, whereby a ratio DS/HS of an average diameter DS of coils of the stator divided by an overall height HS of the coils in a direction parallel to an axis of rotation of the rotor is greater than four.

Abstract: A hydraulic control valve system comprising a hydraulic valve block with a plurality of control valve segments arranged in a juxtaposed manner, each control valve segment comprising a first line, for example a pump line, a second line, for example a return line, and a displaceable valve rod adapted to open and close the first line, respectively close and open the second line to varying degrees depending on a position of the valve rod. The valve system further has a plurality of actuators arranged in a juxtaposed manner, one actuator for each valve segment, each actuator comprising an electrical motor connected to a respective said valve rod through a coupling mechanism.

Abstract: A vehicle headlight positioning device comprising a pivoting headlight support and a linear actuator comprising a housing (16), an electric stepping motor with a rotor having a part in the form of a nut, and a linear-movement screw engaging the nut part of the rotor. The screw has a coupling portion arranged at one of its ends and is intended to transversely engage a coupling portion part integral with a pivotable headlight support.

Abstract: A linear actuator for displacing a member or a set of movable members, having an electric stepping motor (7) with a rotor having a portion in the form of a nut (9), and a linear-movement screw (12) engaging the nut portion of the rotor. The screw has a coupling portion (19) disposed at an extremity and intended to engage a coupling portion (5) of the movable member to be displaced.

Abstract: An air conditioning valve actuator for a motor vehicle operating on an electric step motor with a permanent magnet capable of delivering mechanical power at least equal to 50 mW, and a reduction unit for decreasing the amplitude of the angular pitch and increase the output torque. The motor is defined by the following relationship: 10?6<?2/R0<, wherein: ? is the torque constant, proportional to the magnet volume and, R0 is the characteristic coefficient of the volume of copper and the length of the average turn of the coils, in which R0=?.Lsp/(Scu.?), ? being the resistivity of copper, Lsp being the length of the average turn of a coil, Scu being the copper section of a coil and ? the filling coefficient of a coil. A controller is cooperative with the motor power supply enabling to accelerate gradually the frequency of the supply of the windings.

Abstract: An airflow control device for air streams in a motor vehicle air-conditioning system includes an installation frame with pivotable lamellae (2) that are driven by an electric motor via a gear mechanism arranged on the outside of the frame. The gear mechanism comprises a plurality of cylindrical gearwheels (9 to 12) arranged one above the other, so as to be very narrow and such that the overall dimensions of the housing (5) for the gear mechanism do not exceed the width and height dimensions of the frame (1). This novel arrangement allows integration of the drive as a whole and minimizes the amount of space required.

Abstract: A two-phase motor formed by a stator part excited by electric coils and a magnetized rotor. The rotor has N pairs of poles which are radially magnetized in alternate directions, N being equal to 3 or 5. The stator part has at least two W-shaped circuits comprising each an electric coil surrounding the central leg. The "W" circuits are so arranged that when one of the central legs faces a magnetic transition, the other central leg faces a magnetic pole. The polar opening outs of the legs of a "W" circuit are angularly spaced by .pi./4. The polar opening outs of the central legs of the two "W" circuits belonging to different phases are angularly spaced apart by an angle which is substantially equal to .pi./2.+-.k..pi./N, where N is the number of pairs of magnetic poles, that is 3 or 5, and k is equal to 0, 1 or 2.

Abstract: An electromagnetic actuator has four positions which are stable in the absence of a current and moves rapidly between these positions when acted upon by a current. The actuator has a thin, rotatable magnet (3) with two pairs of magnetic poles transversally magnetised in alternate directions, and a stator member having four pole pieces (9-12, 34-37, 48-51) of developed length P, each with an excitation coil. Two consecutive poles of the thin magnet (3) are spaced by a distance d. The thin magnet (3) is movable in an airgap of width E. wherein the size ratio P:E and P:d is greater than 8. The invention is useful for driving a device such as a valve or a switch.

Abstract: A timepiece includes a date indicator with inner teeth moving angularly by one step per day. An indication control star meshes with the inner teeth of the indicator. A pinion that is integral and coaxial with the star drives an indicator wheel on which an indication arbor is centrally disposed. The rotary indicating structure is driven by the date indicator through the indication arbor and is intended to indicate cyclic parameters such as the date, the phase of the moon, the user's "cash balance," etc. Various types of indication, all controlled by the date indicator, make it possible to produce a wide range of watches of simple design with different display combinations.

Abstract: A method by means of which the damping of the rotor and of the load of a multiphase motor can be increased when it is desired to stop the rotor and the load in a certain position consists in measuring the voltages induced by the movement of the rotor in the different stator phase windings and modifying the currents applied to these windings as a function of the measurements made, so as to produce an electromagnetic-type damping torque. A device for carrying out this method comprises circuitry for measuring the induced voltages in the phase windings and circuitry by means of which currents depending on such measurements of the induced voltages can be applied to these phase windings.

Abstract: A simple, inexpensive, and effective linear actuator design comprises a motor adjacent to a speed-reducer, with the driven stem of the speed-reducer passing through the rotor of the motor. The stem has one bearing at one end of the reducer and its second bearing at the end of the motor, in a bearing part likewise serving as a bearing for the rotor. The distance between the two bearings is increased, and the second bearing includes a socket which has a radial elasticity owing to the fact that it is monolithically joined to the fixed bearing part via a thin portion. This second bearing part is advantageously of synthetic material. The rotation of the stem actuates a driven linear-motion part, which is prevented from rotating and which executes a translatory movement.

Abstract: An electrical drive device comprising a stator arrangement of the claw pole type surrounding a stator chamber or compartment and producing therein at least one magnetic field containing at least one rotary field component. There is provided a permanent magnet-rotor arranged in such rotor chamber in such a manner that it rotates in synchronism with such magnetic field and a hysteresis magnetic coupling, the driving part of which is form-lockingly connected with such rotor and the driven part of which is force-lockingly secured to a shaft constituting the power take-off shaft of the drive device. The stator arrangement, the rotor, the driving part of the hysteresis magnetic coupling and the driven part of such coupling are all housed in a common housing.