Abstract: A position sensor, designed in particular for detecting a steering column torsion, including a first magnetic structure including a plurality of magnets and a second magnetic structure including two ferromagnetic rings having a plurality of teeth and defining an air gap. At least a magneto-sensitive element is placed in the air gap. The first and second magnetic structures are respectively integral with two parts in relative rotation. The two ferromagnetic rings are nested and have each a substantially tubular part forming axially oriented teeth connected by a flux-closing zone, the detecting air gap being delimited by the flux-closing zones.

Abstract: The invention concerns a position sensor, designed in particular for detecting a steering column torsion, consisting of a first magnetic structure including a plurality of magnets and a second magnetic structure including two ferromagnetic rings (6, 7) having a plurality of teeth (11, 12) and defining an air gap wherein is placed at least a magneto-sensitive element (15), the two magnetic structures being respectively integral with two parts in relative rotation. The invention is characterised in that the two ferromagnetic rings (6, 7) are nested and have each a substantially tubular part forming axially oriented teeth (11, 123) connected by a flux-closing zone (13, 14), the detecting air gap being delimited by said flux-closing zones.

Abstract: A position sensor including at least one stator structure defining a secondary gap wherein is housed at least one Hall probe, and a mobile magnet in a main gap. The stator structure includes stator parts defining at least one first secondary gap wherein is housed at least one first Hall probe delivering a signal which is a function of the displacement of the mobile magnet relative to a first degree of freedom, and at least one second secondary gap wherein is housed at least one second Hall probe delivering a signal which is a function of the displacement of the mobile magnet relative to a second degree of freedom.

Abstract: A a rotating electromagnetic actuator with limited stroke, including at least 2N poles on the stator, N being a whole number, energized by at least one energizer coil and N magnetized parts on the rotor arranged in an air gap of thickness E wherein each magnetized part is juxtaposed with at least one ferromagnetic part with a thickness e between 0 and E, defining one or two air gaps with a total length of E-e.

Abstract: A linear uniphase polarized electromagnetic actuator. The actuator includes a coiled stator and one part which is movable in the direction OX with the useful travel of Xc. The movable part is moved according to the current traveling in the coil and the direction of travel depends on the direction of the current. The movable part includes a yoke of soft magnetic material having at least one magnet coupled with the yoke. The magnet is partially set inside a cavity of the mobile yoke on the side of the stator poles at a depth e such that 0.1 L<e<0.9 L, where E is the distance measured perpendicularly to OX between the stator poles and the cavity end pole.

Abstract: This invention pertains to an incremental sensor of position and/or speed, of the type which includes a moving component made of a soft material that has at least one moving tooth in a direction OZ with respect to a permanent magnet magnetized along the direction OY, which is approximately perpendicular to the OZ axis, and a probe which is sensitive to the direction and strength of the magnetic field, such as a Hall-effect gaussmeter, arranged in the air gap between the magnet and the tooth of the moving component so that its axis of greatest sensitivity is approximately oriented along the OZ axis. The Hall-effect gaussmeter is located near a singular point of the OZ axis where the average value of the magnetic field is weak and preferably less than .+-.20 mT and approximately equal to the average value of the alternating field of the integrated circuit connected to the Hall-effect gaussmeter. The permanent magnet can also be laser trimmed to achieve the desired operation in the Hall-effect gaussmeter.

Abstract: A monophase electromagnetic actuator including at least a ferromagnetic part integral with a member movable along a direction Y, a fixed stator part made of soft magnetic material and including at least on electrical coil, and a thin transversely magnetized permanent magnet. The fixed stator part and the ferromagnetic part define between each other at least two air gaps arranged symmetrically with respect to the medial plane perpendicular to the axis of displacement of the movable member and passing through the middle of the permanent magnet. The length of the ferromagnetic part is approximately equal to the length of the permanent magnet.

Abstract: This invention pertains to an incremental sensor of position and/or speed, of the type which includes a moving component made of a soft material that has at least one moving tooth in a direction OZ with respect to a permanent magnet magnetized along the direction OY, which is approximately perpendicular to the OZ axis, and a probe which is sensitive to the direction and strength of the magnetic field, such as a Hall-effect gaussmeter, arranged in the air gap between the magnet and the tooth of the moving component so that its axis of greatest sensitivity is approximately oriented along the OZ axis. The Hall-effect gaussmeter is located near a singular point of the OZ axis where the average value of the magnetic field is weak and preferably less than .+-.20 mT and approximately equal to the average value of the alternating field of the integrated circuit connected to the Hall-effect gaussmeter.

Abstract: The present invention relates to an electromagnetic actuator comprised of a stator structure made of soft magnetic material which is unsaturated in rated operating conditions, comprising two stator parts (1 and 2) at least one of the stator structures (1) presenting a central pole (5) having a length Y.sub.C and two side poles (6,7) having a length Y.sub.L said stator parts (1,2) delimiting an air gap E inside which there is arranged a rotor movable member comprising two pairs of poles having a length Y.sub.R comprised of thin permanent magnets (10 and 11) which are transversely magnetized, characterized in that the length Y.sub.C of the central stator pole (5) is longer or equal to the stroke Y of the rotor movable member increased by a length substantially equal to the length E of the air gap, the length Y.sub.

Abstract: A position sensor which includes a stator presenting a slot forming a main air-gap inside which is positioned a permanent magnet, and including a sensor which features a magnetism-sensitive probe for measuring magnetic flow formed in a secondary air-gap. The permanent magnet is of a bipolar type and is movable inside the main thin air-gap delimited by ferromagnetic parts joined by non-magnetic connecting parts. The length of the main air-gap as measured along the direction of displacement of the movable magnet is at least 2(C+E), C designating the travel of the magnet and E designating the width of the main air-gap, the length of the magnet further being at least equal to (C+E) and its travel being at least .+-.C/2 with respect to the secondary air-gap perpendicular to the main air-gap.

Abstract: The present invention concerns a two-phase, stepping or synchronous motor. The rotor (6) includes five pairs of poles and the stator consists of two identical stator components (1,2) made from a low retentivity material, each having two stator poles (19,20) and (21,22) linked by a median part (23,24) surrounded by a winding (3,4) of a length substantially equal to the width of the opening of the stator component (1,2), the median lines (25 to 28) of said stator poles (19 to 22) being spaced apart by approximately 108.degree.. The second stator part (5) is composed of a low retentivity material for closing the magnetic circuit.

Abstract: A constant-torque single-phase electromagnetic actuator including a stationary device including a first magnetic stator circuit made of a high-permeability material and excited by at least one field coil (10), and a movable device (1) including an axially magnetized disc (3) having 2N pairs of magnetic poles magnetized in alternate directions, wherein the magnetization is substantially uniform. The magnetized disc (3) is attached to a second magnetic circuit (6) made of a high-permeability material, and the movable device is provided with a coupling shaft (7). The connection between the stationary device (1) and the movable device (2) allows at least some axial play of the coupling shaft (7) away from the stationary stator device (2), and the diameter of the magnetized disc (3) is substantially identical to that of the poles of the stator circuits. Play between the stationary (2) and Movable (1) devices is compensated by the magnetic attraction exerted by the stationary device on the movable one.

Abstract: Electromagnetic actuator comprising a stationary stator (I) with a central pole (3) of length X.sub.c and two lateral poles (4,5) of length X.sub.L, said stator including an exciting coil (6). The actuator further comprises a moving part (2) with thin permanent magnets (12,13,22,23) magnetized in the direction of the air gap. It is characterized in that the moving member (2) consists of at least two independent elements (10,20) each movable in the parallel directions to the intersection of the air gap plane and the stationary stator median plane (1), in opposite directions. Each of the moving parts (10,29) has a pair of thin magnets (12,13,22,23) magnetized in alternate directions, integral with a yoke (11,21) of soft material. The thin magnets (22,23) of one of the moving elements (20) are magnetized in the opposite direction to the corresponding thin magnets (12,13) of the adjacent moving element (10), the yokes (11,21) defining with the stationary stator part the air gap (E).

Abstract: A compact electromagnetic actuator having at least one stable position in the absence of current and an area of constant torque or force under a constant current. The actuator includes a movable member having at least one thin portion magnetized normal to the displacement direction thereof, as well as a stator structure defining an air gap therebetween. The stator structure includes first and second magnetic circuits separated by an air gap. The first magnetic circuit includes at least one energization electric coil and polar portions. At least one of the polar portions has a side bevelled strip inducing an adjustment for displacements near limit-stop of the movable member.

Abstract: An angular single-phased electromagnetic actuator including a stator structure constituted of a first magnetic stator part and a second magnetic stator part connected exclusively by a non-magnetic spacer. A movable member including a thin magnetized portion is provided within an air gap between the stator parts. Stator parts are selected so as that: ##EQU1## where, S.sub.fer is the section of the stator part as measured in any radial plane included in the area scanned by the movable radial plane defined by the radius between the two adjacent poles of the magnetized portions,S.sub.a is the surface of one among the 2N pairs of poles as measured in the plane normal to the magnetization,B.sub.fer is the induction within the stator,B.sub.a is the induction within the magnet, with ##EQU2## B.sub.r is the remanent induction of the magnet, L is the magnet thickness, andE is the distance between the stator poles, in the absence of the magnetized portion.