Abstract: A torque motor for a servovalve, said torque motor comprising a set of pole pieces comprising a first pole piece and a second pole piece. An armature is also provided between the first pole piece and the second pole piece, said armature configured to provide air gaps (AG1-AG4) between the armature and the first pole piece, and the armature and the second pole piece. The armature is configured to rotate about a centre point (CP). The set of pole pieces is also adapted to rotate around the centre point (CP) such that the air gaps (AG1-AG4) can be adjusted.

Abstract: An electromagnetic drive for a valve includes a housing comprising at least one electromagnetic circuit comprising a coil wound onto a coil support, a valve closing member, at least one core, at least one magnetizable reflux member, an armature having an annular shape at least on a side facing away from the valve closing member, an adjustment device having an adjustment screw, and a device to fix the armature in a non-energized state. The armature moves between a first end position and a second end position so as to act at least indirectly on the valve closing member. The adjustment device adjusts a magnetic force. The adjustment screw is insertable through the at least the magnetizable reflux member or through the core into the armature. Supplying the coil with an electric current causes the armature to move into the first end position or into the second end position.

Abstract: An electromagnetic drive for a valve includes a housing and at least one electromagnetic circuit comprising a coil wound onto a coil carrier, a valve closing member, an armature movably supported between a first and a second end position which acts on the valve closing member. A device fixes the armature in a currentless state. A core is disposed at an end of the electromagnetic drive directed toward the valve closing member. A magnetizable reflux device has an adjusting bore and a circumferential recess in an area of the adjusting bore on a side facing the coil. An adjustment device has an adjusting screw and adjusts a magnetic force. The adjusting screw influences a course of magnetic field lines and is insertable into the adjusting bore in a direction of the armature. Supplying the coil with a current moves the armature into the first or the second end position.

Abstract: When a pulley and an armature are coupled with each other, first and second permanent magnets place the movable member at a location where a magnetic resistance of an attracting magnetic circuit, which generates an attracting magnetic force to couple between the pulley and the armature, is reduced. In contrast, when the pulley and the armature are decoupled from each other, the movable member is placed at a location where the magnetic resistance of the attracting magnetic circuit is increased, and a magnetic resistance of a non-attracting magnetic circuit is reduced. Thereby, a coupled state or a decoupled state of the pulley and the armature can be maintained without an erroneous operation.

Abstract: Method and apparatus are described for a variable force solenoid for controlling the flow of a fluid in a housing having a bore for receiving the fluid flow, at least one port for exhausting the fluid flow, and a seat extending between the port and the bore. The solenoid includes a valve member disposed in the housing. In a closed position, the valve member is engaged with the seat, preventing fluid flow from the bore to the port. In an open position, the valve member is not engaged with the seat, allowing fluid flow from the bore to the port. A subassembly is disposed in the housing and surrounds a portion of the valve member for moving the valve member to its closed position. The subassembly has a movable armature for engaging the valve member, an annular member for attracting the armature, and a gap defined between the armature and the annular member. The gap is maintained by engagement of the armature by the valve member. A coil is disposed in the housing radially outward from the subassembly.

Abstract: An electromagnetic actuator includes a core made of a soft magnetic material, a permanent magnet located between a pair of ends of the core, the permanent magnet being supported for movement, and an electrically conductive coil wrapped about a portion of the core. The reluctance of the core is adjustable to alter movement of the permanent magnet as a function of time upon application of electrical current to the coil of the electromagnetic actuator.

Abstract: An electromagnetic solenoid includes a housing enclosing an electromagnetic coil assembly. An armature is disposed within the electromagnetic coil assembly. An end of the housing is provided with an annular groove. A nut is selectively received by the groove for varying the magnetic path of the coil assembly. Adjustment of the nut thereby sets the solenoid at a predetermined armature activation force accounting for manufacturing tolerances of the solenoid components as well as variations in the electric current supplied to the coil assembly.

Abstract: A variable force solenoid operated pressure control valve of the type having a force balanced spool moveably controlled energization of the solenoid for modulating the discharge pressure of the valve at its control outlet when the valve is supplied at its inlet with fluid of a supply pressure. The spool is moved to bleed fluid through an exhaust port to a sump for controlling the pressure supplied to the control outlet. The spool has a dashpot and piston in one end for providing hydraulic dampening of spool oscillations. In one embodiment a cylindrical piston is used and in an alternate arrangement a ball is employed in the dashpot.

Abstract: A write head magnetizes magnetic-ink characters for a MICR system. A magnetic assembly defines a first pole in a first location and an opposite pole in a second location. A first pole piece and a second pole piece, spaced by a gap therebetween, are provided, the first pole piece disposed adjacent the first location and adapted to conduct a magnetic field from the first pole to the gap. A selectably positionable member is disposed between the second location and the second pole piece, the positionable member being adapted to affect a magnetic field from the second location through the second pole piece to the gap, thereby facilitating selectable alteration of a magnetic field profile across the gap.

Abstract: An improved torque motor includes a supporting body (3) having a U-shaped cross-section and formed of a magnetizable material, includes at least two magnet structures (7, 8) adapted to be mounted on the body, includes first polepieces (10-13) mounted on the magnet structures, and includes an armature (5) mounted for movement in working air gaps (16, 17) between the first polepieces. Permanent magnets (10, 11) are mounted on the first polepieces. A second polepiece is spaced from the armature by the presence of a non-working air gap (21). At least one control coil (20) surrounding the second pole between the magnet structures (7, 8).

Abstract: A solenoid apparatus compises an encasement defining a longitudinal axis. The reluctance of the encasement is variable by movement of a potion of the encasement relative to the longitudinal axis.

Abstract: A latching solenoid device comprising an encasement, a portion of which is manually translatable in order to vary reluctance in a magnetic circuit which extends through the encasement, thereby providing the device with manual override capability.

Abstract: An improved electrically actuated solenoid is used to regulate the function of a hydraulic flow control valve. The solenoid directs a control valve to generate a predetermined output pressure as a function of the solenoid input current. The working air gap surface area is increased by locating it at a greater circumferential radius than the pole piece to increase the air gap permeance, thereby increasing the output force obtainable from a solenoid of relatively small physical dimensions and low cost.

Abstract: An electromagnetic fuel injector is calibrated for dynamic flow by creating a blind hole in a stationary pole piece passing through the solenoid coil. The blind hole can be created by drilling, or by partially filling a pre-existing hole.

Abstract: A printer head comprising a plurality of driving arms provided corresponding to a like plurality of printing elements and a like plurality of electromagnetic driving devices for driving the corresponding driving arms independently. Each of the electromagnetic driving devices includes a movable yoke fixed to a corresponding driving arm, a core piece facing the yoke and having a coil mounted around the core piece, and a magnet adjacent to the core piece. Each of the magnetic circuits includes an adjusting member for adjusting the magnetic reluctance thereof.

Abstract: A matrix print head is provided with electromagnetic circuits coordinated to individual dot-print elements (10), where the dot-print elements (10) are attached in each case to spring armatures (11). The armatures are in each case disposed opposite to a coil core (12) of an electromagnetic coil (14), and the armature (11), the coil core (12), a back plate (16), a permanent magnet (17), and a yoke plate (18) form a main-series magnetic circuit (19), where the armature (11) rests in its rest position on the coil core (12). In addition, a shunt magnetic circuit (20) is coordinated to each main-series magnetic circuit (19), where the shunt magnetic circuit is formed by the back plate (16), by the permanent magnet (17), the yoke plate (18), and by a shunt ring (21).

Abstract: An electromagnetic valve assembly for fluid flow control is disclosed wherein the fluid flow through the assembly is hermetically sealed. The assembly provides a means to calibrate the power (i.e., voltage or amperage) level where fluid will flow through the valve at a predetermined pressure differential across the armature. The calibration means includes an annular washer with cam-like segments at its outer edge which segments cooperate with slots of a housing to define an air gap, that may be varied over the range defined by the cam-like segment. The assembly, the annular washer, housing, central core and armature cooperate to provide an electromagnetic flux path. The relative magnitude or strength of this flux path provides control of the armature to seal flow through such valve assembly, which magnetic strength is in part a function of the air gap distance at a given power input and fluid pressure.

Abstract: An actuator element having a fixed end and a magnetizable deflection end is releasably held in spring loaded condition at a non-operative position by an electromagnetic operator. In the preferred form, the actuator element is an elastic beam of magnetically permeable material. The operator comprises first and second permanent magnets for generating separate magnetic fields of the same polarity proximate the magnetizable deflection end of the actuator element and a magnetic core combined with the permanent magnets to form at least first and second magnetic holding circuits with the deflection end of the actuator element through a common return path. A winding on the return path of the core when energized generates flux in opposition to the flux from the permanent magnets to release the actuator element for movement to an operative position. Upon de-energization of the winding, the deflection end of the actuator element is retracted and held by the permanent magnets in spring loaded condition.

Abstract: Magnetic actuator arrangement in which the actuator or armature is retained in a cocked position by unidirectional magnetic flux having a density that cyclically varies in magnitude with time and is released by selective energization of a bucking coil to counteract the retention flux when the flux density is less than maximum. The modulated retaining flux may be made sufficient at its maximum density to retract the released actuator to the cocked position.

Abstract: Magnetic actuator apparatus in which the armature is held in a restrained position on a magnetic core by magnetic flux whose density is cyclically varied in time, and the armature is selectively released by a bucking coil that is energized only when the armature retention flux is at low holding value. The flux source is a permanent magnet that is reciprocated or rotated to vary the armature retaining force.

Abstract: Electromagnetic actuator, especially for actuating a hydraulic servo-control valve, which comprises a magnetic shell constituting a body of revolution and a concentric armature-forming permanent magnet, at least one annular field coil, the field coil and the armature being adapted to move axially in relation to each other. The movable member (field coil or armature) is caused to move by the resultant electromagnetic force resulting from the energization of the field coil to which a control direct current is applied and by the antagonistic force of a repulsion member incorporated in the magnetic shell. The field coil is longer than the armature so that the electromagnetic force is independent of the movement of the movable member and proportional to the control direct current. The movable member is caused to perform simultaneously a cyclic motion superposed to the axial movement in order to eliminate the friction hysteresis of the hydraulic valve.

Abstract: A system for a relay is disclosed having a permanent magnet for bias and electromagnetic energization for changing the disposition of an armature. A magnetic shunt path is provided for the permanent magnet serving as a basic load on the magnet, in that the magnetic resistance of magnet plus parallel shunt is lower than the resistance of the remainder of the magnetic circuit. The shunt has preferably resistance that declines with field strength and the flux at the work point (external excitation zero) plus field as set up by the magnet times its permeability should exceed 6000 Gauss.