Abstract: An electromagnetic coil apparatus includes a ferrous coil frame having a first end and a second end opposite the first end. A coil assembly includes a conduit, a number of coils within the ferrous coil frame and being disposed on the conduit, and a ferrous plunger movable in the conduit. A first ferrous heel member is disposed proximate the first end of the ferrous coil frame. A second ferrous top plate member has an opening and is disposed proximate the second end of the ferrous coil frame. A magnetic flux enhancer is external to the conduit and is at least partially external to the ferrous coil frame. The magnetic flux enhancer includes a ferrous conduit coupled to the second ferrous top plate member and cooperates with the opening thereof to form a passageway. A portion of the ferrous plunger of the coil assembly passes through the passageway.

Abstract: A submersible vehicle for use in a body of liquid includes a vehicle body, a pair of fins coupled to the vehicle body on opposed sides thereof, and a dihedral angle control system. The dihedral angle control is system operative to vary a fin dihedral angle of each of the fins.

Abstract: A locking device for vehicles, especially for aeroplanes, comprising an actively driven drive element provided with an input shaft and an output shaft which is directly or indirectly connected to the input shaft. According to the invention, at least one permanent magnet is associated with the input shaft or the output shaft, the magnet interacting with at least one other external fixed element, especially a permanent magnet.

Abstract: An actuator has a resilient shape memory member 1 with superelasticity, a magnetic body 2, and a magnetic field generator 3. At least one of the magnetic body 2 and the magnetic field generator 3 is fixed to the resilient shape memory member 1 such that one of the magnetic body 2 and the magnetic field generator 3 is stationary while the other is movable, whereby the movable member is moved by a magnetic field provided from the magnetic field generator 3.

Abstract: An electrical switching apparatus accessory sub-assembly is for an electromagnetic coil including a movable stem. The electrical switching apparatus accessory sub-assembly includes a coil frame having a first end and an opposite second end. A housing includes a plurality of interior surfaces, a first end and an opposite second end. The second end of the housing has an opening structured to receive the movable stem of the electromagnetic coil. A number of the interior surfaces of the housing are structured to selectively hold the coil frame in either one of a first position in which the coil frame first end faces the housing first end and the coil frame second end faces the housing second end, and a second position in which the coil frame first end faces the housing second end and the coil frame second end faces the housing first end.

Abstract: The main body of the actuator structure is generally formed into a “pitchfork”shape. The middle bar of the pitchfork forms a Y-bend at its forward end. The Y-bend is disposed so that each tip of the bend is adjacent to the outer bar on each side of the pitchfork. At least a coil is fixed on each bar of the main body. The forward ends of the Y-bend abut against a movable member. In the structure above, applying a current to a coil generates minute movements in each tip of the Y-bend, thereby moving the movable member.

Abstract: A magnetic levitation system has a substantially circular levitation track that is magnetically repulsive and a substantially circular propulsion track adjacent the levitation track that is magnetically repulsive. The system further has an end effector, which has a first array of magnets positioned to magnetically interface with the levitation track and a second array of magnets positioned to magnetically interface with the propulsion track to create propelling magnetic forces. The system further has a rotation device for radially rotating the end effector over the levitation track until the end effector levitates and reaches a threshold speed such that the propelling magnet forces generated by the second array of magnets and the propulsion track tend to propel the end effector radially.

Abstract: An electromagnetic transmission device. A guide bar connects to a fixed base and includes magnetic-permeable material and a first central height plane. A coil connects to the fixed base. A support base movably fits on the guide bar. An annular magnetic member connects to the support base and is surrounded by the coil. A magnetization direction of the annular magnetic member is perpendicular to a moving direction of the support base and annular magnetic member. The annular magnetic member includes a second central height plane. The coil interacts with the annular magnetic member to generate a first force. When moving to separate the second central height plane from the first central height plane, the annular magnetic member interacts with the guide bar to generate a second force, driving the support base and annular magnetic member to move along a direction perpendicular to the magnetization direction of the annular magnetic member.

Abstract: The invention relates to a linear magnetic drive consisting of an iron core and a coil. A yoke and a constant magnet are connected to a movable armature. When the armature is placed in a first terminal position, it is supported by magnetic forces produced by the constant magnet and the yoke which is used as a bridge in the iron bore.

Abstract: A solenoid includes a stator core, a plunger, a ring core, and a magnetic circuit component. The stator core has a fixed axial end and a free axial end. The free axial end is unfixed. The stator core is formed of a magnetic material. The plunger is slidable along an inner surface of the stator core. The plunger is formed of a magnetic material. The ring core surrounds an outer surface of the free axial end of the stator core. The ring core is formed of a magnetic material. The magnetic circuit component is adjacent to the stator core. The magnetic circuit component conducts magnetic flux with the stator core. The ring core radially conducts radial magnetic flux with the stator core. The ring core axially conducts axial magnetic flux with the magnetic circuit component.

Abstract: A shielded solenoid for a solenoid operated valve having a solenoid body and an annular coil of electrical wire in the solenoid body. An armature of magnetic material is rectilinearly movable with respect to the body. A magnet holder is fastened to the armature and has a permanent magnet fixedly oriented thereon. A shield member covers the magnet holder and the permanent magnet. The shield member is configured to shield a Hall effect sensor from any significant electromagnetic field produced by the coil when effecting rectilinear movement of the armature. The hollow shield member has a non-metallic plug closing one end thereof. The plug has the Hall effect sensor oriented therein to closely oppose the magnet on the magnet holder so that movement of the armature and resulting corresponding movement of the magnet will cause the Hall effect sensor to produce a signal indicative of movement of the armature.

Abstract: An actuator has a resilient shape memory member 1 with superelasticity, a magnetic body 2, and a magnetic field generator 3. At least one of the magnetic body 2 and the magnetic field generator 3 is fixed to the resilient shape memory member 1 such that one of the magnetic body 2 and the magnetic field generator 3 is stationary while the other is movable, whereby the movable member is moved by a magnetic field provided from the magnetic field generator 3.

Abstract: A solenoid plunger for use in solenoid driven multi-line embossing systems is constructed of magnetic steel laminations that are attached to a center block which is machined to mount a solenoid shaft and anti-rotate pins. The laminations are attached to the center block with screws and vacuum epoxy glued for a very high cycle life. The laminated steel construction dramatically reduces eddy currents, which allows the magnetic field to rise and fall much more quickly than a conventional steel plunger. It also increases the magnetic force in the solenoid. This reduction in solenoid plunger eddy currents and increase of magnetic force in the solenoid structure itself operates to increase embosser throughput. The laminated steel construction further reduces embosser solenoid heating which also contributes to improved embossing control.

Abstract: Illustrated is a cartridge type solenoid valve with a coil-actuator structure which employs O-ring seals to inhibit harsh environment entry into the coil-actuator and allows for metal to metal contact with the frame to increase the flux density and path for flux when the valve is in operation. A plastic over mould is encapsulated over the metal frame (in one embodiment a sleeve) which is shaped to provide efficient magnetic flux carrying capability, as well as abut a flux connector, e.g. a disc adapted to capture an O-ring. The O-ring is in sealing contact with a capture element, e.g. a nut on the projecting extended end of an insertable cartridge having an internal plug, environmentally sealing the coil. When the capture nut is assembled on to the plug, in sealing engagement with the O-ring and simultaneously engaging the plug, an increased efficiency flux path is created. The lead wire termination version includes cold forming or latched caps over lead wires to provide environmental (or dunk) sealing.

Abstract: A bi-stable actuator comprises a chamber 40 having a fluid inlet 34 and first and second fluid outlets 36, 38, a valve member 42 movable between a first position in which it co-operates with a first seat to close the first outlet 36 and a second position in which it co-operates with a second seat to close the second outlet 38, and an electromagnetic actuator 48 operable to drive the valve member 42 between its first and second positions, wherein the valve member 42 has a first surface 44 against which the fluid pressure within the chamber 40 acts when the valve member 42 is in its first position to resist movement of the valve member 42, and a second surface 46 against which the fluid pressure within the chamber 40 acts when the valve member 42 is in its second position to resist movement of the valve member 42.

Abstract: An improved MEMS thermal actuator has a cantilevered beam and a conductive circuit having two driving arms, an inner arm adjacent to the cantilevered beam, and an outer arm adjacent to the inner arm. Current flows through the inner and outer arms to heat the conductive circuit, causing it to expand relative to the cantilevered beam. A tether ties the conductive circuit to the cantilevered beam, so that upon expansion, the conductive circuit causes the cantilevered beam to deflect about its anchor point. However, only the inner arm of the driving beam is coupled to the cantilevered beam. Since the outer arm of the conductive circuit is not coupled to the cantilevered beam, the overall stiffness of the actuator may be decreased. In addition, serpentines may be placed in the outer arm of the conductive circuit, in order to further decrease the stiffness of this beam. The actuator may therefore be made more efficient, in that the deflection of the cantilevered beam may be increased for a given input current.

Abstract: An alignment apparatus moves an X-Y slider together with X and Y beams. Electromagnetic guides (electromagnetic mechanisms) are interposed between the X-Y slider, the X beam, and the Y beam. The electromagnetic guides include alignment and acceleration electromagnets attached to the X-Y slider, and targets attached to the X and Y beams. The alignment electromagnet is feedback controlled, whereas the acceleration electromagnet is feedforward controlled.

Abstract: An apparatus includes an electromagnetically conductive assembly including a first member having a first end and a second end and a second member disposed between the first end and the second end of the first member. The second member and the first end of the first member define a first gap. The second member and the second end of the first member define a second gap. A movable member moves with respect to the conductive member. A first magnet is coupled to the movable member and is disposed a distance from the first gap. A second magnet is coupled to the movable member and is disposed a distance from the second gap.

Abstract: A MEMS switch includes a substrate, at least one signal line and at least one electrode formed on the substrate, and a moving beam disposed in a spaced-apart relation with respect to the substrate above the substrate so as to be connected with or disconnected from the signal line according to an operation of the electrode. The moving beam includes at least one body, and at least one support to support the body. The body has a modulus of elasticity larger than that of the support. The MEMS switch prevents the moving beam from being stuck and increases a contact force generating between the moving beam and the signal line, thereby enabling a signal to be stably transmitted.

Abstract: An inertial actuator for active vibration control utilizes a single cylindrical actuator module of the “voice coil” type. A moving armature assembly, including a soft iron shell with a tubular sleeve coaxially surrounding a core with two permanent magnets and corresponding pole plates, is suspended compliantly by a flexure assembly including a multiple-stack array of shaped flexure strips and a pair of end support flexure plates mounted to a base. Two magnetically charged annular air gaps at the pole plates in the moving armature traverse two corresponding annular coils wound in a tubular bobbin that extends as a heat-sinking mounting column attached to the base. This form of inertial actuator provides cost benefits along with improved performance and reliability due to the stability of the moving parts and uniformity of linear motion.

Abstract: The solenoid is capable of generating great thrust and having broad-ranging thrust characteristics. The solenoid of the present invention comprises: a guide pipe formed into a cylindrical shape and provided inside of an excitation coil; a movable element having a small diameter section and a large diameter section; a first yoke part covering one end face of the excitation coil, the first yoke part having a first facing surface, which faces an outer circumferential face of the small diameter section of the movable element, and a second facing surface, which faces one end face of the small diameter section; and a second yoke part covering the other end face of the excitation coil, the second yoke part having a third facing surface, which faces an outer circumferential face of the large diameter section of the movable element, and a fourth facing surface, which faces one end face of the large diameter section.

Abstract: An electrical short stroke actuator, comprising an annular filed collar and a composite plunger for travelling therethrough. In its simplest form, the plunger comprises two permanent magnets with like poles facing, and which are housed within a thin walled tube, and separated by a central spacer. By judicious choice of the spacing of the magnets, and the length of the field coil, a substantially constant thrust profile is achieved over a pre-selected stroke of the field coil relative to the plunger. The thrust may be augmented by fabricating the means used for spacing the magnets wholly or in part from ferromagnetic material, and also adding collars, similarly fabricated, onto the outside face of each of the permanent magnets.

Abstract: A solenoid having a housing and a coil disposed in the housing for generating a magnetic field when an electric current passes through the coil. A center pole is disposed within the coil, and the center pole is made of a ferromagnetic material. A rod assembly is movably disposed in the housing for movement between a rest position and an energized position. The rod assembly has a portion thereof disposed in the center pole, and includes a magnet having a polarity causing the magnet to be repelled from the center pole when an electric current passes through the coil. The magnet is encapsulated by an elastomeric material that contacts a stop surface when in the rest position to reduce noise resulting from shifting of the rod assembly from the energized position to the rest position.

Abstract: A linear motor is provided including a stator having at least one electromagnetic coil and a rotor having at least one permanent magnet. The rotor is movable toward at least a first position when least one electromagnetic coil is energized and solely magnetically biased to a neutral position when the at least one electromagnetic coil is de-energized.

Abstract: An alignment apparatus moves an X-Y slider together with X and Y beams. Electromagnetic guides (electromagnetic mechanisms) are interposed between the X-Y slider, the X beam, and the Y beam. The electromagnetic guides include alignment and acceleration electromagnets attached to the X-Y slider, and targets attached to the X and Y beams. The alignment electromagnet is feedback-controlled, whereas the acceleration electromagnet is feedforward-controlled.

Abstract: The invention relates to an actuator for actuating a valve installed in a hydraulic or compressed air system comprising a coil support which can be displaced by means of air space induction in a magnetically conducting housing on a magnetic cylinder composed of a permanent magnet and a cylinder pole disk. The invention is characterized in that the dimensions of the permanent magnet and the pole disk correspond to each other in such a way that the diameter of the front surface of the permanent magnet is at least the same size as the circumferential surface of a neighboring pole disk and that the width of the coil associated with the pole disk exceeds the width of the pole disk by the lift amplitude of the coil support.

Abstract: A two-axis actuator having a large stage area and including includes a substrate, an anchor unit having sides approximately in a rectangular shape, fixed on the substrate, a plurality of first actuating parts actuating in a first direction and separated from the substrate within regions of both sides of the anchor unit, a plurality of second actuating parts actuating in a second direction between the first actuating parts, a rectangular shaped stage that actuates in the second direction, disposed above the second actuating parts, a third actuating part formed on the first actuating part, and elevated at a predetermined distance from the stage and the anchor unit, first direction deformable springs that support the first actuating part in inner parts of the anchor unit, and second direction deformable springs formed to fix the second actuating part in an inner part of the third actuating part.

Abstract: An electrical structural part with an electrical or electronic structural element provided on a basic body and with an encapsulation enclosing the structural element tightly and free of voids, the material structure of the encapsulation being intimately fused with the material structure of the basic body.

Abstract: An electromagnetic valve (1, 21) includes a coil (2) which is fixedly connected to an iron core (3). An armature plate (5) is movably journalled in the direction of the coil longitudinal axis (22) relative to the iron core (3). At least two flow channels (8, 9; 26, 27, 28, 29) open at the armature plate (5) and are fluidly separated from each other when a current flows in the coil (2). A small structural size with a simple manufacture of the electromagnetic valve (1, 21) is achieved in that a flow channel (8; 26, 27, 28) opens in the peripheral region (32) of the armature plate (5) at the end (33) of the armature plate (5) facing toward the coil (2).

Abstract: Provided is a solenoid which is easier to assemble and which is improved in terms of operability. The solenoid is provided with a snap ring 22 which helps to integrate the molded coil 2 and the solenoid main body 3 into one, whereby it is possible to finally integrate the molded coil 2 and the solenoid main body 3 with each other after various operation processes; by finally attaching the molded coil 2, the lead wire 9 extending from the molded coil 2 constitutes no obstacle, and the assembly is facilitated, thus achieving an improvement in terms of operability.

Abstract: An active device for damping vibration comprises an actuator comprising a magnetically permeable armature and a coil associated with a magnetically permeable yoke sliding along a displacement axis under the effect of a magnetic field generated by a current conveyed by the coil. Displacement of the coil relative to the armature is generated by forces corresponding to magnetic field lines generated by the coil, concentrated in the armature and the yoke, and directed essentially through an airgap situated between the armature and the yoke.

Abstract: A relatively rugged and simple solenoid-actuated valve (100) is disclosed having a coil assembly (150), including a bobbin (152), a winding (160) for generating a magnetic field, and a flux path bracket (162). A fixed pole piece (110) extends into the axial volume defined by the bobbin. The coil assembly may be encased in a plastic outer body (101). An armature (120) is slidably disposed in the axial volume and a valve seat (130) closes the opposite end of the axial volume. A conical spring (140) biases the armature toward a first position against the valve seat. An inlet fitting (106) and an outlet fitting (104) fluidly connect to the axial volume. The armature is movable by the magnetic field generated by the winding from the first position to a second position away from the valve seat, such that the valve can be selectively opened and closed.

Abstract: A latch type solenoid switch including a frame, a permanent magnet providing magnetic force to the frame, a coil unit which offsets the magnetic force of a permanent magnet when power is supplied, and a moving part which adheres to and detaches from the frame depending on the power supply to the coil unit. Anti-corrosion coating is applied to the surface of the frame and the moving part. The plating thickness on the contact surfaces between the frame and the moving part is thinner than on the other surfaces of the two bodies.

Abstract: The invention concerns a device to convey and/or spray free-flowing media, in particular fluids, which works in accordance with the energy storage principle and is designed as an electromagnetically-powered reciprocating pump with at least one armature device as a drive element, whereby the armature device includes at least two armature elements and the armature elements are assigned magnetically corresponding yoke elements.

Abstract: An attraction coil, a repulsion coil and a plunger are disposed in a magnetic path of an electromagnetic device. An starting flux generating section is disposed between the attraction coil and the repulsion coil in the magnetic path. A magnetic flux of the starting flux generating section is repulsed magnetically by a magnetic flux of the repulsion coil at a part of the magnetic path to start the plunger. The plunger is attracted to one of first and second magnetic path parts by electromagnetic forces generated from magnetic fluxes of the attraction coil and the repulsion coil.

Abstract: A rotary solenoid for stabilizing performance is provided. A rotary solenoid 10 includes a pair of the first yoke 21 and the second yoke 22 placed oppositely in a rotor 24 providing a pair of magnetic poles by a permanent magnet, a core 23 enclosed by the first yoke 21 and the second yoke 22, and a coil 25 wound around the core 23 and forming a pair of magnetic poles in the first yoke 21 and the second yoke 22 by supplying electricity. These first yoke 21, second yoke 22, core 23, and coil 25 are resin-molded. A projecting portion 26a is provided in an outer surface on the opposite side of enclosing the core 23 by the first yoke 21 and the second yoke 22.

Abstract: An electromagnet a coil, a movable iron core adapted to move on the center axis of the coil, and a stationary iron core provided so as to cover the upper and lower surfaces and the outer peripheral surface of the coil. A permanent magnet is arranged in a gap surrounded by the movable iron core and the stationary core.

Abstract: An electromagnetic actuator is provided that comprises a housing, a solenoid coil, and an armature. The armature is movably disposed in an interior cavity defined by the housing. Irregular gaps are formed between the armature and the housing to increase the initial force of the actuator and to improve the latching force of the actuator after the actuator has been actuated.

Abstract: A magnetism property of an armature is increased by including a moving core of sintered metal of 1LSS to 3LSS, and a shaft of a ferromagnetic material. By contrast, a stator core contains 0.005 to 0.1 weight % resin powder, whose particle diameter is set to 50 ?m or less, in particular, 25 ?m or less, so as to decrease a core loss and increase a magnetism property. The stator core thereby becomes approximately equivalent to the armature in a direct current magnetism property, so that an electromagnetic actuator and a fuel injection valve that are excel in suction force and response are provided.

Abstract: An actuator is described having two fixed magnetic structures, and a mobile magnetic part able to move towards either one of the two ends of the magnetic structures. The actuator can be in the form of a microactuator, and can be used in the fabrication of microrelays, microvalves, and micropumps.

Abstract: An electromagnetic actuator for actuating a gas-reversing valve on a piston internal combustion engine includes two electromagnets. Each electromagnet includes a one yoke body presenting a pole face. The pole faces of the two electromagnets face each other at a distance. Each yoke body has two parallel grooves that are open toward the pole face and form a coil window with a coil disposed in the coil window. An armature is arranged to move back and forth between the pole faces counter to the force of at least one restoring spring. The two electromagnets each have a different load profile.

Abstract: The invention relates to an electromagnetic actuator comprising an actuator member (6) connected to an armature (8) which is movable under drive from a drive member comprising at least one coil (1) for generating magnetic flux in a core (2) having a face facing a face of the armature (8), at least one of the facing faces including at least one set-back portion (10), the armature (8) and the core (2) being arranged, in a first zone (12) of the armature (8) and of the core (2) including the set-back portion, to define a first magnetic path which is interrupted by an air gap that is not less than the setback of the set-back portion (10) when the armature (8) bears against the core (2), and in a second zone (13) of the armature (8) and of the core (2) excluding the set-back portion, to define a second magnetic path which is interrupted solely by a residual air gap when the armature (8) bears against the core (2), the total area of the set-back portion being no greater than an area that would bring the magnetic fl

Abstract: A relay for switching an electrical signal includes switching elements, an actuator for closing the switch, and an actuator for opening the switch, the latter two of which are mechanically decoupled when the relay is in a mechanical rest position. When a relay close signal is applied, the closing actuator electrostatically drives the switching elements to complete a signal path between two terminals for the switched signal. In the process of closing the switch, the opening actuator remains stationary, i.e., no mass is displaced. Application of a switch open signal electrostatically drives the opening actuator, optionally in combination with a mechanical restoring force on the closing actuator, to open the switch to break the signal conduction path for the switched signal.

Abstract: A magnetic motion device is disclosed, wherein a permanent magnet slides back and forth along a pivoting rail due to the interaction between the slide's magnetic field, the magnetic fields produced by a permanent/electromagnet combination at each end of the rail, and gravitational force. The ends of the rail thereby move up and down in a reciprocating, “see-saw” fashion. Power-take-off mechanisms can be connected in any suitable manner to the device, so that the motion of the rail can power an external device such as a pump.

Abstract: An actuator for applying force along an axis to a body, comprising an annular body arranged along the axis, an annular magnetic field source within and substantially coaxially with the annular body, a substantially cylindrical central member arranged substantially coaxially within the annular body in a fixed relationship with a gap formed between the central member and the annular body and an armature comprising a substantially cylindrical hollow member extending at least partially into the gap between the central member and the annular body. The hollow member has first and second spaced coils positioned at either side of the magnetic field source when the armature is at rest, such that the areas of the gap in which the first and second coils are positioned are magnetic flux gaps, and the armature and the annular body are translationally relatively moveable when the first and second coils are energised with opposite currents.

Abstract: A solenoid arrangement has at least one excitation coil and an armature arranged concentrically relative to the excitation coil and axially movable when the at least one excitation coil is supplied with current. A magnetizable cup-shaped housing part open at a first axial side is provided, wherein the at least one excitation coil is at least partially surrounded by the magnetizable cup-shaped housing part. A magnetizable yoke covers the first axial side for closing the magnetic circuit. A housing cover covering the solenoid arrangement is formed of plastic material, wherein the plastic material has at least one attachment flange for mounting the solenoid arrangement on other parts.

Abstract: A proportional pressure control valve (1) for controlling the pressure level in a hydraulic circuit having a push rod (5) as a connection between a control element (13) arranged in the hydraulic circuit and a proportional magnet located in a housing (10), which comprises a magnetic core (2), a magnetic anchor (3), and a magnetic coil (4), the magnetic coil (4) and the magnetic core (2) are securely connected to the housing (10), and the magnetic anchor (3) can be moved axially back and forth between two end positions by means of a magnetic force. At least one part of the magnetic anchor (3, 3?) is arranged so as to be movable relative to the anchor rod (6) in dependence upon the magnetic flow, so that in this way either the gaps (11, 14) are enlarged and/or an additional second gap (8) is produced.

Abstract: An electromagnetic actuator has a movable core, a housing that holds the movable core so that the core may freely reciprocate, and an attractive part that applies a magnetic force to pull the movable core in one of the reciprocating directions. The electromagnetic actuator further has a stator that constitutes a magnetic circuit along with the movable core. At least one of the sliding faces of the housing and the movable core in contact with each other is subjected to gas soft nitriding, salt-bath soft nitriding, sulfo-nitriding, or nitriding treatment. The surface roughness of such a nitrided face is controlled to be within a prescribed range, so that the wear of the sliding faces of the movable core and the housing can be reduced.

Abstract: The invention relates to an actuator for actuating a valve installed in a hydraulic or compressed air system, comprising a coil support which can be displaced by means of air space induction in a magnetically conducting housing on a magnetic cylinder composed of a permanent magnet and a cylinder pole disk. The invention is characterised in that the dimensions of the permanent magnet (16) and the pole disk (17) correspond to each other in such a way that the diameter of the front surface of the permanent magnet (16) is at least the same size as the circumferential surface of a neighbouring pole disk (17) and that the width of the coil (23) associated with the pole disk (17) exceeds the width of the pole disk (17) by the lift amplitude of the coil support (19).

Abstract: A displacement control device (1) is adapted to move a member (23) relative to a body (7). The displacement control device includes a drive means (2, 3) and an emergency actuator(8) arranged mechanically in series with the member. The actuator includes a housing (16) and a spring (14) arranged to act between the housing and the member. The improvement comprises: the actuator including a toggle linkage (9) acting between the housing and the spring, the toggle linkage having two pivotally-connected links (10, 11) that are adapted to be selectively moved between a collapsed position at which the links are arranged at an acute included angle, and an extended position at which the links are arranged at an obtuse included angle slightly less than 180°. The toggle linkage is arranged such that the spring will be more greatly compressed when the links are in the extended position than when the links are in the collapsed position.