Abstract: A system may include an electromagnetic actuator, a first coil configured to drive mechanical displacement of the electromagnetic actuator, a second coil configured to drive mechanical displacement of the electromagnetic actuator, and an inductance sensing subsystem having an inductance sensing path coupled to the first coil and the second coil.

Abstract: A solenoid valve comprising a magnetic drive having at least two parallel coils which are arranged with their end faces lying between two spaced apart magnetic yoke plates, a stationary magnetic plug and an axially movable magnetic core each being arranged in each coil which together with the magnetic yoke plates form a ferromagnetic circuit. At least one further magnetic element which is firmly connected to a respective yoke plate on two opposite ends is arranged between the magnetic plates.

Abstract: A micromechanical electromagnetic actuator may have two separate components: a flux-generating portion and a separate movable structure. The flux-generating portion may have a plurality of conductive coils wound around a magnetically permeable material. Each coil generates a magnetic field along its axis, which is different for each of the coils. The adjacent movable structure may include magnetically permeable features, one inlaid in the movable structure and other stationary features which focus the flux produced by the flux-generating mechanism across a gap between the stationary features. By energizing each coil sequentially, a push-pull motion in the actuator may result from the force of the magnetically permeable features. This push-pull actuator may be particularly effective when used as a pumping element in a drug delivery system, or other fluidic pumping system.

Abstract: An electromagnetic actuator has a yoke for guiding a magnetic flux, and a holding plate attached to an actuating member, the holding plate and yoke forming a first magnetic circuit. Furthermore a magnetic flux generation device is provided for generating a magnetic flux in the first magnetic circuit. The magnetic flux generation device has an under voltage release coil electrically connected to an auxiliary voltage source representing the value of a voltage to be monitored.

Abstract: A solenoid for a vehicle starter comprises a spool including a first coil bay, a second coil bay, and an interior passage defining an axial direction. A first coil is positioned in the first coil bay of the spool, and a second coil positioned in the second coil bay of the spool. A plunger is positioned within the interior passage of the spool and configured to move in the axial direction when the first coil is energized. The first coil bay is positioned adjacent to the second coil bay in the axial direction. The spool further includes two end flanges and a middle flange. The middle flange separates the first coil bay from the second coil bay.

Abstract: A solenoid arrangement includes a plunger configured to move in an axial direction and a coil wound radially outward from the plunger. The coil includes a first winding layer and at least one additional winding layer positioned radially outward from the first winding layer. The first winding layer includes a first portion wound in a first winding direction and a second portion wound in a second winding direction that is opposite the first winding direction. The at least one additional winding layer is wound in the second winding direction radially outward from both the first portion and the second portion of the first winding layer..

Abstract: A solenoid for a vehicle starter includes a pull-in coil made of a length of rectangular wire and a hold-in coil adjacent to the pull-in coil. A plunger is configured to move in an axial direction when the pull-in coil made of rectangular wire is energized. The pull-in coil and the hold-in coil are positioned on a spool with the plunger slideably positioned within a central passage of the spool. The plunger is configured to engage a plunger stop when the pull-in coil is energized. In at least one embodiment, the hold-in coil is separated from the plunger stop in the axial direction and the hold-in coil encircles the plunger stop.

Abstract: A solenoid for a vehicle starter includes at least one coil with a passage extending through the coil. A plunger is slideably positioned within the passage and configured to move in an axial direction between a first position and a second position. The plunger includes a substantially cylindrical outer surface portion with a circumferential notch formed in the outer surface portion. The at least one coil may include a pull-in coil and a hold-in coil wound on a spool. A plate member is positioned at one end of the spool and is separated from the plunger by a radial distance. The radial distance varies when the plunger moves in the axial direction as a result of the notch moving in relation to the plate member. A sleeve member may be coupled to the plunger such that the sleeve member covers the circumferential notch formed in the plunger.

Abstract: There is an electromagnetic switch for a starter includes a first and second electromagnet and a frame and a cover. The first and second electromagnets are set alongside in the frame. The first and second electromagnets are configured to change a position with respect to the cover by rotating about the axis with respect to the frame.

Abstract: A variety of systems, apparatus and methods for deflecting a particle beam are described. An apparatus comprises at least six electromagnetic portions disposed on a plane. Each of the at least six electromagnetic portions is aligned with a radius emanating from an axis normal to the plane and is distanced from the axis to form a volume about the axis. At least six coils are configured for affecting a dipole magnetic field in the volume in response to electrical currents applied to physically opposing coils where a particle beam entering the volume is deflected. Each of the at least six coils is disposed about a one of the at least six electromagnetic portions. A yoke structure is configured for returning a generated magnetic flux.

Abstract: A solenoid for a vehicle starter comprises a pull-in coil and a hold-in coil positioned axially adjacent to the pull-in coil. A plunger is positioned within the pull-in coil and configured to move in an axial direction when the pull-in coil is energized. The plunger is separated from a plunger stop in the axial direction by an air gap when the pull-in coil and the hold-in coil are not energized. When the pull-in coil and hold-in coil are energized, a shoulder of the plunger moves in an axial direction toward the plunger stop. The pull-in coil is positioned in the solenoid such that it is removed from the plunger stop in the axial direction. In contrast, the hold-in coil encircles the plunger stop.

Abstract: The present invention provides a cylindrical magnetic levitation stage which includes a cylindrical substrate used to form micro-patterns of various arbitrary shapes on a large-area semiconductor substrate or display panel substrate, a cylindrical substrate, a combination of a first permanent magnet array and a first coil array and a combination of a first permanent magnet array and a first coil array, which are coupled to the cylindrical substrate, so that levitation, axial translation and rotation of the cylindrical substrate can be made finely through the control of a magnetic force generated by the interaction between a magnetic field generated by electric current applied to the coil arrays and a magnetic field generated from the permanent magnet arrays corresponding to the coil arrays.

Abstract: A micromechanical electromagnetic actuator may have two separate components: a flux-generating portion and a separate movable structure. The flux-generating portion may have a plurality of conductive coils wound around a magnetically permeable material. Each coil generates a magnetic field along its axis, which is different for each of the coils. The adjacent movable structure may include magnetically permeable features, one inlaid in the movable structure and other stationary features which focus the flux produced by the flux-generating mechanism across a gap between the stationary features. By energizing each coil sequentially, a push-pull motion in the actuator may result from the force of the magnetically permeable features. This push-pull actuator may be particularly effective when used as a pumping element in a drug delivery system, or other fluidic pumping system.

Abstract: The invention relates to a tool that includes a tool holder, which has on its first end a tool holder recess that is adapted to the contours of a rotating spindle driver and a tool recess on a second end that lies opposite the first end. The tool holder also includes a tool head that can be inserted into the tool recess. For the optimal machining of a workpiece, attempts were previously made to provide an oscillating unit in the spindle of the machine, to initiate oscillations in the tool head. The disadvantage of said known constructions is that all available tools have to be synchronized with the oscillation unit. The invention overcomes said disadvantage by equipping the tool holder with an oscillating motor.

Abstract: Apparatus for inductive braking of a projectile are disclosed. Embodiments include a receiver that has a unidirectional conductor having a closed conductive pathway that encircles a passageway for a moving projectile. The unidirectional conductor permits current to flow through it in substantially only one direction around the passageway. As the projectile and its associated magnetic field move past the unidirectional conductor, the moving magnetic field induces a current flow through the closed conductive pathway, which in turn generates a magnetic field behind the projectile having the same polarity as the projectile's field. The two fields attract one another, which both exerts a braking force on the projectile and tends to align the two fields. Alignment of these fields centers the projectile away from the passageway wall.

Abstract: An electromagnetic control mechanism (1) with an actuating element (15) which can move longitudinally and can be retained in three stable positions. By way of two coils (3, 4), the actuating element (15) can be switched to a first or to a second stable position, namely, the two opposed end positions. The actuating element (15) comprises an actuator rod (7) with a permanent magnet (8) arranged on the actuator rod (7), such that the actuating element (15) can be retained magnetically in the third stable position by the permanent magnet (8).

Abstract: A magnetically driven tool includes a shaft having a bottom application end including a contacting surface, at least one support around a portion of the shaft for supporting components positioned outside the shaft that float with respect to the shaft. A first magnet is affixed to the shaft. An electromagnet secured to the support is positioned outside the shaft and floats with respect to the shaft above the first magnet. At least one bearing is provided for sliding the shaft in an axial direction and optionally rotating the shaft. For pushing operations, the direction of current through the electromagnet is applied so that like poles relative to the first magnet face one another to provide a repulsive force, while for pulling operations unlike poles face one another. The magnitude of the current sets a force applied by the contacting surface to a workpiece.

Abstract: An enclosure to enclose the vertical electromagnetic repulsive elevation and manipulation of electromagnets is presented. The enclosure is capable of elevating the electromagnet to various heights and additionally horizontally repelling the elevated electromagnet from one elevated position to the next. The heights of the elevated electromagnet may vary depending on the voltage of the base electromagnets, the polarities of the electromagnets and the desired height of the elevated electromagnet.

Abstract: A switching contact, an electromagnetically operated electromagnet for driving the switching contact, and a drive power source device for driving the electromagnetically operated electromagnet. The electromagnetically operated electromagnet includes a movable core coupled to a movable contact of the switching contact, a fixed core located in a peripheral portion of the movable core, and coils wound around the movable core and the fixed core. Currents are supplied to the coils to drive the movable core. Capacitors store charges for supplying the current to the coils. Resistors are arranged in series with a path through which the capacitors are connected with the coils of the electromagnetically operated electromagnet and through which a current for closing operation flows. Capacitances of the capacitors and values of the resistors are controlled to adjust a supplied current characteristic to the electromagnetically operated electromagnet.

Abstract: A coil configuration having a tube-shaped coil brace of an electromagnetic drive is provided, particularly a two-stage starter solenoid switch, the coil configuration having a holding winding and a pull-in winding. The coil brace has at its one end a first delimitation and at its other end a second delimitation, between which the holding winding is situated. The first delimitation has on its side, facing away from its second delimitation, an axial recess for accommodating the pull-in winding.

Abstract: A coil configuration having a tube-shaped coil brace of an electromagnetic drive is provided, particularly a two-stage starter solenoid switch, the coil configuration having a holding winding and a pull-in winding. The coil brace has at its one end a first delimitation and at its other end a second delimitation, between which the holding winding is situated. The first delimitation has on its side, facing away from its second delimitation, an axial recess for accommodating the pull-in winding.

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: According to the invention, a system for adjusting the polarity of an antenna is disclosed. The system may include a spherical structure, at least one arm, and a coupling apparatus. The spherical structure may be at least partially spherical in shape about a central point and may include a first plurality of magnets. The at least one arm may be in proximity to the spherical structure, may include a second plurality of magnets, and may be coupled with the antenna. The coupling apparatus may be fixedly coupled with the antenna and rotatably coupled with the at least one arm. The coupling apparatus may include a third plurality of magnets, where at least a portion of the magnets may be configured to be selectively activated to rotate the coupling apparatus relative to the at least one arm.

Abstract: Provided is a two-axis driving electromagnetic actuator that includes a stage that is operative to be actuated about a first axis; an inner frame that that is disposed outside the stage and supports the stage by the first axis; an external frame that is disposed outside the inner frame and supports the inner frame by a second axis which is perpendicular to the first axis; a magnet that provides an electric field between the first axis and the second axis; a first driving coil that is formed on the inner frame and to which a first signal that actuates the stage in a direction of the second axis is applied; and a second driving coil that is formed on the inner frame and to which a second signal that actuates the stage and the inner frame in a direction of the first axis is applied, wherein the first driving coil and the second driving coil are electrically separated from each other.

Abstract: An electromagnetic actuator and a method for controlling the actuator comprising at least one armature (3) and two coils (1, 2). The voltage gradient at the two coils (1, 2) is measured during a sudden increase in voltage. From this measured data, a subtractor (16) computes a third voltage gradient (25) from which a logic unit (17) determines the position of the armature (3) without the use of an additional sensor.

Abstract: An eye module at least including a body, a magnetic element, a casing and a plurality of magnet windings is provided. The body is a globe. The magnetic element is disposed on the body. The body is disposed in the casing in a rotatable manner. A plurality of magnet windings are disposed at the back of the body. The body is rotated by driving the magnet windings to function on the magnetic element.

Abstract: The electromagnet includes a valve-opening side coil portion supplied with a current to thereby generate a first magnetic flux and generate electromagnetic force in a direction moving the valve-opening side moving element toward a valve-opening position, and a valve-closing side coil portion supplied with a current to thereby generate a second magnetic flux and generate electromagnetic force in a direction moving the valve-closing side moving element toward the valve-closing position. The valve-opening side coil portion and the valve-closing side coil portion are constituted of an identical connection. The electromagnet further has a sub-coil constituted of a separate connection from the valve-opening side coil portion and the valve-closing side coil portion. By the current supply to the sub-coil, a third magnetic flux reducing at least one of the first magnetic flux and the second magnetic flux is generated.

Abstract: Electromagnetic actuator for operating at least one movable contact of a switch into a switched-on position or a switched-off position. The electromagnetic actuator (1) has a first magnetic circuit for making a movable (3) and a fixed (4) pole body move towards one another and a second magnetic circuit, separate from the first magnetic circuit, with a permanent magnet (9) and a retaining plate (10). A switching-off coil (15) operates to counteract the magnetic field in the second magnetic circuit so that the actuator (1) can return to a switched-off position. In the axial direction of the actuator (1), the switching-off coil (15) is positioned Gloser to the retaining plate (10) than the permanent magnet (9), as a result of which more effective operation of the actuator is possible. Furthermore, the actuator is constructed from cylindrical elements that are easy to produce and to assemble.

Abstract: A common rail fuel injector comprises a three-way control valve that controls the flow of high-pressure fuel to a fuel cavity for fuel injection. Specifically, when the control valve is transitioning to a first, on position, from a second, off position, high-pressure fuel is provided to both the fuel cavity and to a check control cavity, thereby preventing fuel injection until the control valve seats in the first, on position. Once seated in the first, on position, the control valve only provides high-pressure fuel to the fuel cavity allowing fuel injection to occur. To stop injection, the control valve is moved from the first, on position to the second, closed position. Once again, while the control valve is in the transition location between the two positions, high-pressure fuel is provided to both the fuel cavity and to the check control cavity thereby terminating injection.

Abstract: An actuator assembly comprised of: a first coil and a second coil, each with a bore and a producing a magnetic flux when subject to an electric signal; a tube extending through the bores such that coils are coaxial; a magnetic pole piece within the tube and generally between the first bore and the second bore; a magnetic ring set outside of the tube and between the coils, in which the magnetic flux paths both travel through the magnetic pole piece and the magnetic ring to complete their respective magnetic paths; and a first and second axially translatable movable member within the tube and wherein the movable members each axially translate towards the magnetic pole piece in the presence of the magnetic flux such that by controlling the electric signal, proportionality can be achieved.

Abstract: An electromagnetic valve actuating mechanism for an internal combustion engine has an axially displaceable control element with an armature plate, for opening or closing a valve. Two solenoids are arranged behind one another in the displacement direction and spaced with respect to one another. One solenoid is arranged on the side of the armature plate close to the valve and the other is on the side away from the valve. Two springs are arranged behind one another in the displacement direction, one of the springs being arranged on the side of the armature plate close to the valve and the other being arranged on the side away from the valve. The control element, which is held in a neutral position when the solenoids are currentless, is deflectable from its neutral position by energizing the solenoids.

Abstract: What is disclosed is a lifting magnet assembly for a servo valve or control valve comprising a proportional magnet which acts on a valve spool of the control valve or servo valve through a tappet. Between the spool and the proportional magnet a failsafe magnet is provided which is penetrated or encompassed by the tappet of the proportional magnet.

Abstract: A system for electronically actuating valves in an engine. The system includes first and second voltage sources, and a plurality of valve actuator subsystems coupled therebetween. Each valve actuator subsystem has a valve actuator and a switch configured to selectively control application of voltage to the valve actuator to thereby selectively control energization of the valve actuator. The system also includes a dissipation switch operatively coupled with the valve actuator subsystems, the dissipation switch being selectively operable to control dissipation of energy from any of the valve actuators.

Abstract: A system for electronically actuating valves in an engine. The system includes a first voltage source, a second voltage source, and plural valve actuator subsystems coupled between the first voltage source and the second voltage source. Each valve actuator subsystem has a valve actuator and a switch. One of the actuator subsystems is configured so that current flows from the first voltage source through the valve actuator of the subsystem when the switch is in a first position, and when the switch is in a second position, current is permitted to flow from the valve actuator toward the second voltage source. Another of the valve actuator subsystems is configured so that current flows from the second voltage source through the valve actuator of the subsystem when the switch is in a first position, and when the switch is in a second position, current is permitted to flow from the valve actuator toward the first voltage source.

Abstract: Disclosed is a solenoid type electromagnetic operating device which needs a relatively large current only for a limited short period at an excitation start initial stage and is adapted to achieve the speeding up at an excitation start stage and an improvement in responsiveness as well as power saving without increasing a power load on each of a drive circuit and power supply.

Abstract: A system and method for controlling an internal combustion engine provide valve actuation that selectively couples an energy storage device to a launching coil to recover energy stored in the magnetic field and valve spring of the launching coil, decouples the energy storage device during a valve opening or closing event to control energy supplied to the catching coil, and couples the energy storage device to the catching coil to transfer energy from the storage device to the catching coil to provide a repeatable soft landing. A nonlinear feedback controller incorporates a feedforward system with an observer to control the rate of energy into the magnetic field of the catching coil while compensating for system losses and work to overcome gas forces within the combustion chamber. Feedback linearization techniques improve stability of the control system.

Abstract: A controller for an electromagnetic actuator comprises a pair of springs acting on opposite directions, and an armature connected to the springs. The armature is held in a neutral position given by the springs when the armature is not activated. The actuator also comprises a pair of electromagnets for driving the armature between two end positions. In response to a release of the armature held in one of the end positions, the controller applies brake to the armature according to a load condition of the armature. In high-load conditions, the valve can surely be opened without additional electric power. In low-load conditions, the armature is prevented from colliding with a yoke of the electromagnet. The application of brake includes over-excitation operation, flywheel operation and suspension of power supply. In the over-excitation operation, voltage is applied to the electromagnet corresponding to one of the end positions from which the armature is released for a first period.

Abstract: An actuator assembly operates a device in a normally open mode and a normally closed mode. The actuator assembly includes a bobbin around which a coil is wound. The coil receives an electrical current to induce a magnetic field thereabout. A rod extends along the longitudinal axis. The rod is movable along the longitudinal axis in response to the magnetic field. The actuator assembly also includes a plunger extending through a portion of the bobbin. The plunger is movable with respect thereto in response to changes in the magnetic field. The plunger includes a rod receptacle for fixedly securing the rod therein allowing the rod to move with the plunger. The plunger also includes an opposing rod receptacle allowing the rod to be received thereby when the actuator assembly is in the normally closed orientation.

Abstract: A quick-return electro-mechanical actuator (20) broadly includes a cocking solenoid (21) and a holding solenoid (22). Each of the solenoids has an armature (24, 31) and a rod (26, 33). The rods are adapted to contact one another when the actuator is energized. However, after the second rod has been moved to its extended position, the cocking coil is de-energized.

Abstract: An actuator (10) for a fuel injector having a dual coil solenoid. The solenoid coils (14, 16) are connected in parallel and have windings that are wound in opposite directions. The actuator (10) of the present invention defines three air gap surfaces (22, 24, 26), one of which (24) is located in the space shared between the two coils (14, 16). The shared air gap surface (24) has a high flux density due to the additive nature of the magnetic forces between the oppositely wound coils (4, 16). The dual-coil solenoid of the actuator (10) of the present invention creates a very high force and a low inductive load which results in fast injector response times.

Abstract: An injector for supplying fuel into the combustion chamber of an internal combustion engine comprising an injector body having a fuel supplying port connected to a fuel rail, a nozzle port injecting the fuel and a fuel passage connecting the fuel supplying port and the nozzle port; two solenoids are mounted in the injector body along the fuel passage; and two spools elastically supported by two springs are mounted in each of the solenoid 10, 20 respectively and opens or closes selectively the fuel supplying port 110 and the nozzle port 120; wherein, when the fuel is supplied from the fuel rail into the injection body, one spool for supplying the fuel opens the fuel supplying port and the other spool for injecting the fuel closes the nozzle port, whereas when the fuel is injected into the combustion chamber, the spool for supplying the fuel closes the fuel supplying port and the other spool for injecting the fuel opens the nozzle port.

Abstract: A fuel injector comprising a valve needle which is slidable within a bore, a surface associated with the valve needle defining, in part, a control chamber which communicates, through a restriction, with a supply passage. The fuel injector also includes an injection control valve controlling communication between the control chamber and a low pressure reservoir, and a drain valve controlling communication between the supply passage and the low pressure reservoir. The injection control valve and the drain valve include respective armatures moveable under the influence of a common electromagnetic actuator.

Abstract: An electrical park latch actuator for the automatic transmission selector lever of a road vehicle, the actuator including a support member, first and second electromagnet windings carried by a common electromagnet core of the support member, and first and second plungers moveable relative to the support member, and responsive to energization of the first and second electromagnet windings respectively, said first and second plungers being positioned with their movement axes parallel and part of said second plunger being slidably received within said first plunger.

Abstract: An electromagnetic valve has a first and a second electromagnetic coil and an armature. The first electromagnetic coil generates a magnetic filed to cause the armature to move a valve for closing. The second electromagnetic coil generates a magnetic filed to cause the armature to move the valve for opening. The first electromagnetic coil is energized to generate the magnetic field. Measurement of time at a first moment is started before the valve is moved to a first position at which the first electromagnetic coil is temporarily de-energized and to output a first signal after a predetermined period of time has passed from the first moment. The temporarily de-energized first electromagnetic coil is energized in response to the first signal. The first electromagnetic coil is de-energized when the valve is fully closed. The second electromagnetic coil is energized to generate the magnetic field after the first electromagnetic coil is de-energized.

Abstract: A polarized relay with an electromagnet which consists of an exciter coil and a coil core mounted in the exciter coil. On each of two end sides of the electromagnet is a permanent magnet displaceable along its magnetic axis. The same pole, for example, the north pole (N), of each of the two permanent magnets face the end sides of the electromagnet. The relay is capable of tri-stable behavior, that is, it can switch between three states, with only one exciter coil. Preferably, the tri-stable function of the relay controls a commutator motor between "rest," "clockwise running," and "counter-clockwise running" states.

Abstract: A single or double relay is provided. The relay has a base and a coil body. Each relay has a coil with an axis parallel to the bottom side of the base, an angled yoke and a plate-shaped armature. The armature is connected to a contact spring that is split into two fork-like legs. A contact leg carries a movable contact and a terminal leg that is connected to a spring carrier in the region in front of the movable armature end. With the double relay, the two armatures lie parallel at opposite ends of the base. The design yields a simple assembly with good heat dissipation particularly for a double relay for high switching currents.

Abstract: An electromagnetic relay and methods for its manufacture are provided. The relay has a coil body with flanges and with at least one winding disposed between the flanges. A rod-shaped core is respectively arranged axially inside each winding. The yoke is secured against motion in the longitudinal direction and against pivotal movement in a coil flange by mounting elements. In addition, the first end of the core is connected on the side surface of the first yoke leg by welding or soldering. A double relay with first yoke legs disposed next to each other in parallel fashion is preferably created, whereby the core-yoke connection is produced in a simple manner and a good magnetic transition is ensured.

Abstract: A method of recognizing armature impingement in an electromagnetic actuator having an electromagnet including a solenoid, an armature movable toward and away from the electromagnet and return means for exerting a force on the armature. The method includes the steps of maintaining a solenoid current at a predetermined magnitude I.sub.max during a predetermined period T.sub.A for capturing the armature at the electromagnet; switching off the solenoid current at a moment t.sub.1 upon lapse of the period T.sub.A ; upon lapse of a period T.sub.1 running from moment t.sub.1, oscillating the solenoid current between a lower holding current threshold I.sub.H1 and an upper holding current threshold I.sub.H2 ; detecting a current course from moment t.sub.1 ; and deriving a signal from such current course.

Abstract: A multiple coil, multiple armature solenoid is disclosed. The solenoid has; multiple armatures slidably disposed on a common slip shaft, with separate coils disposed about the corresponding armatures. The conductor coils, through magnetic induction, displace the armatures through respective linear strokes along the slip shaft. By varying the stroke length of the various armatures, it is possible to use an armature that travels through a short stroke length to generate kinetic energy that is transferred through the slip shaft to actuate an armature that must travel through a longer stroke length. In this manner, the problem of a high breakaway force associated with a long stroke armature is resolved.

Abstract: There is provided a mechanism for engaging a power takeoff employed primarily to drive a load from a truck engine having a solenoid with a high energy coil that is energized for a short interval to produce engagement of the power takeoff and a low energy coil to maintain engagement of the power takeoff. The mechanism includes an armature movable from a retracted to an activated position to move the power takeoff engagement mechanism to a power takeoff engaged position and a high rate spring which is compressed if the power takeoff does not engage whereby to return the armature to its retracted position upon de-energization of the high energy coil. A second lower rate spring moves the armature to its retracted position upon de-energization of the lower energy coil.