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: 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: An electromagnetic device, specifically a linear or rotary single- or multi-phase motor or generator comprising, for each phase, at least two relatively-movable sets of teeth of soft magnetic material, one set of teeth being associated with the stator and the other with the rotor, the size of the device being such as to enable it to generate a maximum magnetic potential Umax of at least 1.7×10−4 J/&mgr;0 ampere turns. The width E of the minimum air-gap between teeth of the rotor and of the stator as measured in the direction perpendicular to the degree of freedom is approximately equal to or greater than 0.7 &mgr;0Umax/J where &mgr;0 is the permeability of free space, Umax is the maximum generated magnetic potential difference for causing the magnetic field to pass through the air-gap E, and where J is the maximum polarization of the soft magnetic material used for making the teeth.

Abstract: The invention concerns a magnetic position sensor for delivering an electric signal proportional to the position, including of a mobile part having at least a thin permanent magnet movable in a main air gap. The air gap is defined by two ferromagnetic parts and, the ferromagnetic parts defining between them a secondary air gap including a sensor sensible to magnetism. The mobile part is arranged such that penetration on the magnetic part into the main air gap is partial over part of the useful travel so that the sensor sensible to magnetism delivers a signal proportional to the degree of engagement of the magnetic parts in the main air gap.

Abstract: An electromagnetic actuator including a fixed stator having two poles. The stator includes one or two excitation coils. The actuator further includes a mobile part provided with thin permanent magnets magnetized along an air gap direction. The mobile member includes at least two independent elements which are each mobile along directions parallel to the air gap plane intersection and the fixed stator median plane, in opposite directions. Each of the mobile parts has three thin magnets alternately magnetized, which are either integral or not with a yoke made of soft material. The thin magnets of the mobile elements are magnetized along a direction opposite to the corresponding thin magnets of the second mobile element or of the adjacent element, the yokes defining with a fixed stator part a yoke.

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: This invention relates to a position sensor featuring a stator defining an air gap inside of which a mobile magnet integral with a coupling shaft moves. The sensor features a Hall probe for measuring the variation of the induction in an air gap. The stator is formed of a first stationary part and a second part which is either stationary or mobile, the two parts defining between them a main air gap in which the part of the mobile element moves. The mobile element exhibits at least two adjacent thin parts magnetized crosswise in alternate directions, the magnetized parts being made of a material exhibiting in the entire working area a practically linear demagnetization characteristic and reversible permeability close to that of the air. The stationary part exhibits at least two secondary air gaps approximately perpendicular to the main air gap in which the mobile element moves. The Hall probe is housed in one of the secondary air gaps.

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: A movable member of the present driving device comprises a magnetized part, or more than one magnetized parts having all the same direction of magnetization, which is perpendicular to the direction of movement. Each magnetized part is moving in at least two air-gaps of a closed magnetic circuit coupled with en energizing coil. The material of the magnetized parts has a linear demagnetization characteristic up to temperatures at least equal to 100.degree. C. and at least up to a negative value of the flux density equal, in absolute value, to 0.5 times the remanence of the magnetic material. The driving device is dimensioned so that the mean operating point of each magnetized part lies at a flux density value smaller than 0.5 times the value of the remanence of the magnetic material used. The volume of magnetic material can be substantially reduced for a given force or torque to be delivered.

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: A magnetic position sensor having a thin tubular-shaped permanent magnet that is integral with a coupling shaft. The permanent magnet is mobile in rotation in a main air gap between two parts made of a soft magnetic material. One of the parts is formed by a stator having a secondary air gap in which a Hall probe is housed. The stator is placed coaxially on the inside of the tubular-shaped permanent magnet, with the other magnetic part including a coaxial tubular yoke with the tubular-shaped permanent magnet and defining, with the stator, a cylindrical main air gap.

Abstract: A linear oscillating motor capable of assuring a consistent and effective feedback control of keeping a constant oscillation amplitude with varying load conditions. The linear oscillating motor comprises an oscillator carrying a permanent magnet, and a stator with an electromagnet. The electromagnet is supplied with an electric power to develop an electromagnetic drive force of moving the oscillator in a linear direction relative to the stator. A spring is provided to apply a restoring force to the oscillator for providing a linear oscillating motion to the oscillator. A photo-sensor monitors the linear motion of the oscillator and outputs a signal to a reverse-point detector which determines right and left reverse points of the oscillator. A controller applies the electric power to the electromagnet at the drive points respectively defined subsequent in time to the reverse points and in a varying amount for keeping a constant oscillation amplitude of the oscillator.

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: This invention relates to a position sensor featuring a stator (1) defining an air gap inside of which a mobile magnet (3) integral with a coupling shaft (4) moves. The sensor features a Hall probe (12) for measuring the variation of the induction in an air gap (10). The stator (1) is formed of a first stationary part and a second part (2) which is either stationary or mobile, the two parts defining between them a main air gap (5) in which the part of the mobile element moves. The mobile element exhibits at least two adjacent thin parts magnetized crosswise in alternate direction, the magnetized parts being made of a material exhibiting in the entire working area a practically linear demagnetization characteristic and a reversible permeability close to that of the air. The stationary part exhibits at least two secondary air gaps (10, 11) approximately perpendicular to the main air gap (5) in which the mobile element moves. The Hall probe (12) is housed in one of the secondary air gaps (10, 11).

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).