Abstract: This invention relates to a monophase electromagnetic rotary actuator of angular travel between 70/N and 110/N degrees exhibiting a high torque/mass ratio and a torque that is approximately independent of the angular position of the rotor. A relation between the magnetized width Y.sub.a measured on the mean diameter of the magnets, the width of the angular arc C through which the rotor passes on the mean diameter of the magnets, the width S measured on the mean diameter of the magnets between two adjacent stator poles, the radial length of the magnets L, and the constant length E of the air gap is:Y.sub.a =C+S +2 E'where E' is between E/2 and E. Furthermore, C+2 E'/E >6 and L/E>0.75.

Abstract: An electrically-energized rotary actuator includes an annular stator ring having a plurality of slot-like magnetic flux obstructions spaced around the ring circumference. An associated rotor has two permanent magnets that are polarized along the rotor diameter to form a south pole at one point on the rotor periphery and a north pole on a diametrically-opposed point on the rotor periphery. Two pole pieces are located at diametrically spaced points on the stator ring, each pole piece having a magnetic winding so that, when the windings are energized, a north pole and a south pole will be established for interaction with the poles formed by the rotor magnets. The flux obstructions in the stator ring cause the rotor to be deflected in steps so that the rotor has various discrete positions centered on the flux obstructions. The rotor can maintain a stable position uninfluenced by minor variations in the current applied to the stator windings.

Abstract: A motor includes a permanent magnet rotor having opposed magnetic poles supported for rotation about an axis. A stator surrounds the rotor and consists of conductors extending parallel and uniformly around the rotor axis, in order to provide a uniform current sheet and a constant force per unit current acting on the rotor.

Abstract: A rotary actuator disk drive in which the rotary actuator is driven by a motor comprising a movable coil and a stationary permanent magnet structure producing a magnetic field which links the coil. The rotary actuator comprises a load beam arm stack and a voice coil arm of electrical insulating material such as a light weight plastic, all of which are axially stacked and swaged to a rotary actuator bearing hub which is rotatably mounted in the disk drive. The coil arm of electrical insulating material has a bobbin section on which the coil is directly wound. The coil arm is molded together with the coil arm mounting bushing, a latch pin of magnetic material and an actuator arm balance weight insert molded therein. The latch pin is linked by the permanent magnet field of the motor permanent magnet structure and functions with that structure to define mechanical limits of angular actuator movement and to magnetically latch the actuator in one angular limit when the disk drive is not in use.

Abstract: An electromagnetic exciter for use in powering vibratory equipment includes a plurality of deflectable elastomeric springs in a configuration that allows the spring system to achieve a vertical non-linear spring rate increase beneficial in dual mass electromagnetic feeder and conveyor systems.

Abstract: A reactionless scanning and positioning system is disclosed which includes a mirror scanning assembly coupled to a reaction mass having a rotational moment of inertia equal and opposite to that of the mirror assembly, so that the system is effectively reactionless. The overall mechanical design of the scanning system is optimized to require minimum power consumption by the actuators used to drive the scanning assembly. The scanning assembly is mounted on flexible pivots having a torsional stiffness which provides a mechanically resonant frequency such that a minimum amount of power is required to angularly position the mirror. A position encoder disc is used in both coarse positioning mode and in a relatively fast scanning mode to determine the position of the mirror. In the present invention, the position of the mirror is accurately determinable in a fast scanning mode due to the novel mounting of the mirror with respect to the position encoder disc.

Abstract: In the electromagnetic transducer disclosed herein, first and second magnetic core structures are oriented in opposition with a space therebetween. In the space between the core structures, an armature is provided for completing magnetic circuits for both of the core structures with respective gaps. Spring means normally centers the armature structure between the core structures so that the respective gaps are nominally equal. On each of the core structures there is provided a first winding and a second winding. The first windings are connected in series to a supply of direct current thereby to bias the magnetic circuits and the second windings are connected to a source of alternating current with the second windings being installed or phased so that one of them aids the corresponding first winding while the other opposes the corresponding first winding.

Abstract: A toothbrush which includes a toothbrush body (12) and a lever arm (14) having toothbrush bristles (18) at one end thereof. The lever arm (14) is mounted for pivotal movement at a pivot member (16) which is in the vicinity of the other end of the lever arm (14). In one embodiment, a pair of permanent magnets (44, 46) are provided at the other end of the lever arm (14), positioned side-by-side with opposite polarities. An electromagnet (24) is provided to the rear of the lever arm (14). The electromagnet (24) includes an E-core having top, bottom and center legs (30, 31, 33) with a coil (36) wound around its center leg (33) which receives an alternating current driving signal from an oscillator/battery section (38). The frequency of operation is in the range of 150-400 Hz. The action of the alternating current in the electromagnet (24) causes the lever arm (14) to move about the pivot member (16), first in one direction and then in an opposing direction to provide the desired vibrating effect.

Abstract: A method of the present invention for stabilizing the resonant frequency of a resonant scanner is that thermal energy of the same amount as the heat generated in an optical scanning mode is applied to the scanner section in a non-scanning mode to insure that the variation of the temperature of the resonant light deflector will lie within a predetermined range, whereby the resonant frequency of the oscillation of the reflecting mirror is stabilized. The resonant scanner of the present invention in which the scanner section is heated in the non-scanning mode by supplying the drive coil with an electric current that has a non-resonant frequency or with the heater is constructed. The resonant scanner using the method is capable of achieving precise optical scanning that has an improved dimensional precision in the sub-scanning direction.

Abstract: A fine tracking miniature galvanometer actuator is used as a fine tracking positioner for a read/write head in the optical disk drive of an information storage and/or retrieval system. An efficient magnetic circuit is used in conjunction with a small and lightweight rotor design which offers high performance characteristics in terms of frequency response and sensitivity. No mechanical springs or torsion bars are necessary to maintain the rotor in a neutral or zero position. The present invention is also useful in other systems using electro-optical transducers including reflecting-type galvanometer recording systems used for producing variable-area sound tracks .

Abstract: A vibrating toothbrush which includes a toothbrush body (12) and a lever arm (14) having toothbrush bristles (18) at one end thereof. The lever arm (14) is mounted for pivotal movement at a pivot member (16) which is in the vicinity of the other end of the lever arm (14). In one embodiment, a pair of permanent magnets (44, 46) are provided at the other end of the lever arm (14), positioned side-by-side with opposite polarities. An electromagnet (24) is provided to the rear of the lever arm (14). The elecromagnet (24) includes an E-core having top, bottom and center legs (30, 31, 33) with a coil (36) wound around its center leg (33) which receives an alternating current driving signal from an oscillator/battery section (38). The frequency of operation is in the range of 150-400 Hz. The action of the alternating current in the electromagnet (24) causes the lever arm (14) to move about the pivot member (16), first in one direction and then in an opposing direction to provide the desired vibrating effect.

Abstract: A miniature device for moving a reference plane or point on an axis in rotational or x-y directions, particularly useful for two dimensional beam scanning. The device consists of a ferromagnetic ring surrounding a magnetic core which is flexibly mounted and suspended within it. Electric current at various frequencies is supplied to coils wrapped about and mounted within the ring. The core provides a magnetic field within the ring which defines its coordinates with respect to the ring and its coils and interacts with current applied to the coils to produce torque. The flexible mount suspending the core within the coils permits relative movement therebetween in response to the varying current.

Abstract: A unique electromagnetic brake which, when pulsed with a D.C. current, will latch and hold in either of two extreme positions; on position and off position. A continuous current is not necessary to maintain either position which eliminates power loss from a limited power supply and heat dissipation problems.

Abstract: An axially magnetized linear force motor employs an exteriorly faced armature (4) having a first exterior face (14) and a second exterior face (16), wherein said first face (14) is acted upon by a first axial magnetic field established by a first annular, axially polarized, permanent magnet (22) and said second face (16) is acted upon by a second axial, magnetically opposing, magnetic field established by a second annular, axially polarized, permanent magnet (26). Actuation of a coil (32) affects the first and second fields oppositely causing an imbalance of net magnetic forces. The force imbalance causes the armature (4) to displace to a point where the net magnetic force equals a counter force established by a spring (10). Positionable ferromagnetic slugs (36, 37) alter the ratio of displacement of the armature (4) to the magnitude of a signal used to actuate the coil (32).

Abstract: In a preferred embodiment, an oscillating stepping motor having only one stator phase. What would otherwise be a second stator phase is a magnet fixedly disposed with respect to the rotor to produce a detent position of the rotor. When the stator is energized, the field of the fixed magnet is at least partially overcome and the rotor steps to a first predetermined position. When the stator is de-energized, the rotor returns to the detent position. Alternately energizing and de-energizing the stator causes the rotor to oscillate between the two positions. Alternatively, an angle of oscillation twice that produced above may be provided by reversing the stator field to oscillate the rotor between the first predetermined position and a second predetermined position produced by reversing the stator field.

Abstract: A swing-type actuator comprising (a) a housing comprising two yokes and permanent magnets attached to the yokes with their different magnetic poles opposing each other, a magnetic gap existing between the opposing permanent magnets; and (b) a swingable arm having one end to which a movable coil is fixed and the other end to which a function member is fixed, such that the movable coil is swingable in the magnetic gap, the movable coil being integrally fixed to the arm by a hold member made of a thermoplastic resin having a modulus of 10.sup.5 kg/cm.sup.2 or more.

Abstract: Described herein is a moving coil type rotary actuator for a disk drive, which essentially includes: a rotary arm supporting transducer means at one end thereof, and rotatably supported for rotation about an axis; a first york arranged in a first plane perpendicular to the rotational axis; a second york arranged in a second plane in a spaced relation parallel with the first york and perpendicular to the rotational axis; a first permanent magnet mounted on the surface of the first york to produce a first magnetic field between the second york and itself; a second permanent magnet mounted on one surface of the second york in staggered relation with the first magnet on the first york to produce a second magnetic field between the first york and itself; and a moving coil supported by the rotary arm at the other end thereof and having first and second coil portions positioned within the first and second magnetic fields, respectively.

Abstract: A torque motor for rotatably driving a rate sensor (10, 100) which includes a permanent magnet (30) that is magnetically coupled to an upper rotor (18, 106) and a lower rotor (44, 110). At three sites, the upper rotor includes an upper tab (60), which is centered between two electromagnetic coils (56, 58). Similarly, at each site, the lower rotor includes two lower tabs (62) that extend adjacent opposite faces of the electromagnetic coils. With no electrical current flowing through the electromagnetic coils, flexures (46) that connect the upper and lower rotors to a base (12) provide a spring bias force sufficient to maintain the upper tab centered in a slot (66) and thus, equidistant between each of the two lower tabs. As the electric current flows through the electromagnetic coils, distribution of the magnetic flux produced by the permanent magnet changes so that the upper tab is attracted toward one of the electromagnetic coils and repelled from the other.

Abstract: A diaphragm pump intended to pump gases or highly-volatile liquids include a vibrating arm (6) acting on a diaphragm (5) placed into oscillation by a fixed electromagnet (7) fed with alternating or direct electric current. The vibrating arm (6) is composed of a single piece of plastic material, with an enlarged head (11) integrally molded with at least one permanent magnet (9) located opposite electromagnet (7). Opposite the head (11), the vibrating arm (6) has an elastically deformable part (12) attaching the arm to pump housing (1).

Abstract: A voice coil motor includes an upper yoke having a lower surface, and a lower yoke having an upper surface. Two upper side yokes are attached to the lower surface of the upper yoke respectively at laterally opposite end positions on the lower surface of the upper yoke. Two lower side yokes are attached to the upper surface of the lower yoke respectively at laterally opposite end positions on the upper surface of the lower yoke. A central yoke has two distal end portions respectively sandwiched between the upper side yokes and the lower side yokes. An upper magnet is attached to the lower surface of the upper yoke and located above the central yoke. A lower magnet is attached to the upper surface of the lower yoke and located beneath the central yoke. A rotary arm is pivotally mounted on the upper yoke. The rotary arm has a coil wound around the central yoke with a spacing being maintained therebetween so that the rotary arm is allowed to pivot along the central yoke.

Abstract: A system is disclosed which comprises an electrical actuator (2), a current source (35), a actuating unit (37) having a limited operating range, and a control unit (41). The actuator comprises a first actuator body having two diametrially opposed magnetic poles, and a soft-magnetic second actuator body, which is coaxial with the first actuator body and which preferably comprises three circumferentially equi-spaced teeth, which each carry an energizing coil (29, 30, 31). The first actuator body and the second actuator body cooperate with one another via an air gap and are pivotable relative to each other through a specific angle about a pivotable axis. The control unit is constructed to divide the operating range of the actuating unit into a plurality of sub-ranges and, depending on said sub-ranges, to controllably feed a current through one of the energizing coils, through two of the energizing coils, and through all the energizing coils, respectively.

Abstract: Disclosed is a direct drive servovalve which includes a drive motor mounted upon a housing for a reciprocally disposed spool valve wherein the rotor of the drive motor engages the spool valve. The rotational motion of the rotor is converted into linear motion in the spool-valve. The rotor of the drive motor carries a cam shaped flat washer which has surfaces engaging stop means defined by the valve housing.

Abstract: Disclosed herein is a swing-arm type linear d.c. brushless motor, wherein at least one coreless type armature coil such as an air-core armature coil is arranged on the inner wall of a linear motor body and a field magnet is formed by magnetizing a magnet member with a single pair of N/S poles so as to permit the generation of thrust in a predetermined direction face to face with only one active conductor of said at least one armature coil and which does not contribute to the generation of reverse thrust. The field magnet is opposite through an air-gap in the axial direction to only the active conductor portion, and is supported relatively and swingably through the air-gap. It is suitable for use in small, economical and high-speed magnetic head positioner mechanisms more useful in small-capacity magnetic disk units and the like and capable of performing position detecting, feed control, etc.

Abstract: This electrical resolver has an arcuate stator with a concave inner side concentric to a convex side of an angularly rotatable arcuate rotor limited to rotation within outer ends of the stator. The stator and rotor have arcuate magnetic cores with transverse slots in which are embedded windings made of insulated wire. Rotation of the rotor causes changes in voltages induced in the stator windings corresponding to the extent of angular position of the rotor. The stator windings include trimming coils which generate bucking voltages to reduce errors in determining angular position of the rotor. In an operating range of .+-.10.degree. from a centered position, magnitudes of rotor position can be determined with an accuracy of 5-10 arc seconds maximum, with a considerable savings in space, weight, cost, simplified installation, and increased stability over the operating temperature range.

Abstract: A cyclically varied magnetic field extending from a pole piece interacts with the repelling field of a superconductive member while conducting electrical current therethrough to generate a force transmitted to a frame which mounts the pole piece and the superconductive member in spaced relationship to each other forming a flux gap therebetween within which the magnetic fields interact. A power control unit regulates the variation of the magnetic field by means of an electromagnetic assembly mounted on the pole piece and controls cyclic interruption of current through the superconductive member.

Abstract: An improved rotary actuator for torque linearization in a disk drive recording system is described. A notch is formed in the actuator frame at a point midway along one of the sidewalls of a pair of circumferential slots which define a centerpole member therebetween. These slots house the actuator coil. The notch increases the air gap between the coil and the frame at the midpoint of the data stroke. This reduces the flux density at the midpoint of the data stroke which linearizes the torque of the actuator as a function of the angular position of the coil (i.e., the coil arc). In addition, the dimension of the centerpole member which extends beyond the sweep of the coil during a data stroke is widened to decrease the air gap in these regions.

Abstract: Limited angle torque motor includes a secondary magnetic flux path of relatively small cross-sectional area which increases the rotational and torque gains of the motor in a localized area about the motor null as if the magnetic air gap of the motor were substantially reduced so that when properly matched with a direct drive valve having significant valve overlap, a desired linear valve flow gain can be achieved. As the motor flux increases with applied current, the secondary flux path saturates, whereby further increases in current above a specified level are directed into the main pole structure magnetic flux path as if the secondary flux path did not exist.

Abstract: A high torque AC stepping motor is provided. The motor includes a stator with six radially spaced coils. Spaced radially extending arms on an armature core are positioned adjacent the coils. The armature is mounted by a torsional shaft assembly including two concentric torque tubes. the torsional action of the tubes serves to return the armature to a home position after each current pulse. A one way sprag clutch is driven by the output shaft connected to the armature to turn an output gear or the like. A timer controls the AC power source to provide the precise rotary output. A system for precisely feeding webs of material for processing utilizing the stepping motor is also disclosed.

Abstract: A rotating head wheel for a recorder is displaceable in the direction of its axis of rotation. The displacement is produced by mounting the head wheel on a threaded spindle using a nut arrangement. The spindle rotates in the same direction as the head wheel and its rate of rotation is variable. The nut arrangement includes two nuts disposed along the same axis. A spring, disposed between the two nuts, pushes the nuts in opposite directions. The nuts are capable of moving in the direction of the axis but cannot be twisted relative to each other. In this way, the threads of the nuts make continuous contact with the thread of the spindle to compensate for a backlash between the spindle and the nuts.

Abstract: An element that moves resonantly has its resonant frequency dynamically tuned to a desired frequency by two components that cooperate via magnetic fields, one component being mounted for motion with the moving element.

Abstract: A vibrator (2) comprising:a massive, magnetic member (16) arranged for movement about a reference position; andelectromagnetic actuator means (12) for causing said member to move; andmagnetic suspension means (8, 10) arranged on either side of said member for suspending said member therebetween.

Abstract: In a rotary actuator including a voice coil motor having a coil fitted to the other end portion of a carriage fixed to a rotary shaft and having a load at one of the end portions thereof, the rotary actuator of the present invention is characterized in that the rotation on the coil side and the rotation on the load side with respect to the rotary shaft are balanced. The weight of the coil is adjusted by forming the coil by at least two kinds of coil wires having different specific gravities, and where a plurality of coils are disposed on the outer side of the rotary shaft, the weight of the coil on the load side is made smaller than that of the coil on the opposite side.

Abstract: A vibrator conveyor system, for example in the form of a circular or linear conveyor, has a reciprocating plate adapted for carrying a container, and electromagnetic oscillating armature motors for moving said plate along a primary advancement direction or vector; each motor has a stationary stator, an armature secured to the reciprocating plate, and an excitation coil driven by alternating current or pulsating direct current, the coil being disposed on a pole piece the stator, the pile piece having a stator pole surface cooperating with an armature pole surface. The reciprocating plate is elastically supported by spring elements in a manner limiting its vertical and horizontal motion. The elongated spring elements are aligned along at least a portion of the rim of the plate with equal inclination with respect to a plane containing the conveyor advancement vector, and are fastened to the plate.

Abstract: The present invention relates to a 3-position rotational actuator which obtains three stable points by two pairs of field poles, in which the magnetic flux to a rotor due to one pair of field poles of a stator for maintaining the rotor at the first stable point is substantially equal to the magnetic flux to the rotor due to the other pair of field poles of the stator for rotating the rotor from the first stable point. The magnetic flux density of the other pair of field poles of the stator applied to the rotor is set to be smaller than the magnetic flux density of the one pair of field poles of the stator. Therefore, the detention torque can be maintained to the same degree and the drive torque can be improved.

Abstract: An electromagnetic oscillation motor has an asymmetrical four-pole stator with an a.c. winding including two paths connected in parallel. Each path includes two serially connected coils received on the adjacent poles of the stator. The poles of the stator forming one pair are offset in opposite directions away from each other, while the poles forming the other pair are offset toward each other relative to the symmetry axes of their corresponding poles of the armature, through a distance equalling one half of the angular width of the stator winding. The oscillation motor further comprises a four-pole symmetrical armature, its poles being provided with a d.c. winding. The coils of this winding are connected in pairs in the matched-series fashion, while the pairs themselves are interconnected in opposition.

Abstract: The natural resonant frequency (and phase) of a resonant mechanical system (having an spring structure that includes a material whose elastic properties change with temperature, e.g., by at least 0.05% per .degree.C.) is tuned to a desired value by changing the temperature of at least part of the spring structure. A two-dimensional image is generated on a surface by tunign a resonant driver (having such a temperature sensitive element) to a natural resonant frequency in coordination with modulation of a beam that is raster scanned on the surface by the resonant driver.

Abstract: The present invention provides an optical scanner including a horizontally arranged base plate, a light source unit rigidly mounted on the base plate and adapted to emit a beam of light, an optical scanning unit for scanning the light beam in a repetitive cycle and an optical system unit for conducting the scanning beam to a desired surface to be irradiated, the optical scanning unit including a unit base, a torsion bar rigidly supported on the unit base at the opposite ends, a rotor rigidly mounted on the twistable portion of the torsion bar and having a mirror for reflecting the light beam, an electromagnetic drive mechanism for applying a rotational drive force to the rotor and a unit-side mirror for further reflecting the reflected light from the mirror, the optical scanning unit being arranged such that the torsion bar is disposed parallel to the base plate, the light beam being scanned along a plane perpendicular to the base plate on the rotation of the rotor and the reflected beam being scanned along a

Abstract: An air powered generator having only one moving part and no bearing surfaces comprises a whistle, an electric coil diagonally attached to the walls of the whistle, and a magnetic means which moves freely in a two-dimensional plane within the whistle. As air is forced into the whistle, the magnetic means oscillates back and forth with respect to the diagonally oriented electric coil to create an electric current in the same manner as an electric current is induced by passing a magnet in and out of a loop of wire.

Abstract: Limited angle torque motor includes a rotor assembly having one or more permanent magnets which are magnetized in the diametrical direction and a stator assembly including a pair of circumferentially spaced stator magnetic pole pieces, each having a stator pole flange at the opposite end thereof. Each stator pole piece has a greater circumferential width in the region of the respective stator pole flanges to increase the amount of magnetic material in such region where the flux density is the highest. Surrounding the stator assembly is a magnetic housing which desirably effectively has no air gap therein.

Abstract: An electromagnetic motor constituted by a movable member, a flexible support member, a first fixed magnetic pole, and a second fixed magnetic pole. The movable member is magnetized to form N and S poles on opposing surfaces. One end of the flexible support member is connected to the movable member, and the other end thereof is connected to a base. The first fixed magnetic pole is so arranged as to apply a magnetic force in a direction parallel to the N and S poles of the movable member. The second fixed magnetic pole is so arranged as to apply a magnetic force in a direction perpendicular to the N and S poles of the movable member.

Abstract: A rotary actuator in which there is a freely rotatable permanent magnetic armature between two stators. At least one of the stators produces an asymmetrical magnetic flux field that acts upon the magnetic field of the armature to cause the same to rotate.

Abstract: A control device (30) for controlling the supply of power to the coils (16A, 16B) of a drive motor (3) for a compressor unit of the resonant-piston type (1). The control device comprises a power-supply circuit (44) for energizing the motor coils from a direct voltage source (45), means (46, 47, 48; 46, 60) for determining a measure (P, .phi.), which indicates whether the power consumption of the motor as a function of the frequency of the energizing current is at least approximately maximal, and means (40, 42, 43; 61, 42, 43) for adjusting the frequency of the energizing current, depending on the derived measure (P, .phi.), to a value for which said measure indicates that the power consumption of the motor (3) is maximal.

Abstract: A control motor for a servo-valve. Adjacent to the control coil of the control motor a dampening coil is located and short-circuited, so as to provide for an improvement of the frequency characteristic of the control motor.

Abstract: An improved rotary-type read-write head actuator assembly for use in a rotating disc data storage device is provided. The head actuator assembly includes an elongated actuator arm pivotally mounted at one end and having flexible read-write head support arms at the other end. The elongated actuator arm includes a coil internally mounted within an open cavity at the center of percussion of the actuator arm. The portion of the actuator arm supporting the coil moves within a magnetic field to form a voice coil motor to drive the actuator arm.

Abstract: The limited angle rotary force motor includes an inner pole member having multiple permanent magnets disposed on the exterior thereof and a longitudinal bore in which a rotor shaft is journaled for rotation. An annular low inertia coil assembly is positioned in spaced relation around the permanent magnets by sets of spoke-like arms extending from the rotor shaft through transverse openings in the inner pole means. An annular ferritic stainless steel outer pole sleeve is located in spaced relation around the coil assembly to complete the magnetic circuit and withstand hydraulic system pressure to which the motor components are exposed. The outer pole piece is part of the casing or housing for the servovalve.

Abstract: A spherical motor particularly adapted for robotic control. The motor comprises a stator housing defining a semispherical socket having an opening of generally polar cap form with a spherical rotor rotatably received in the socket for rotation therein about three axes intersecting at the center of the rotor with one of the axes projecting through the opening and the other two axes being orthogonal thereto. A motion transmitter is carried by the rotor and aligned generally along one axis to project through the opening, and windings are carried by the stator housing in encompassing and in opposed relation to the rotor for rotating the rotor about the axis. A polyphase control selectively controls relative phase and energization of the windings to rotate the spherical rotor a substantially unlimited amount about one axis and in limited amounts about the other axes so as to maintain the motion transmitting member within the confines of the opening.

Abstract: An air pump for an aquarium includes a power source, first and second electromagnetic coils, and a circuit powered by the power source and coupled to the coils for energizing the coils in an alternating manner at a selected frequency, the circuit including an arrangement for varying the selected frequency. The air pump also includes a mechanical pump mechanism having two magnets which are each movably supported near a respective one of the coils and move in response to energization of the coils, and a pump arrangement which is responsive to movement of the magnets for effecting flow of a fluid.

Abstract: An apparatus comprising a rocker with a curved base, and an activating base supporting and continuously activating the rocker. Two magnets, whose north poles point in opposite directions, one upward and the other downward, are respectively disposed on either side, towards which rocker rocks, of the center of gravity of the curved base. A first induction coil is set within the activating base and under the rocker so as to produce induced a current when the rocker is rocking in the direction of one of the two magnets. An operational amplifier integrated circuit (OP AMP IC) is provided within the activating base so as to amplify the induced current. A second induction coil, which is connected to the output of the OP AMP IC, is provided so as to induce a magnetic field. This magnetic field applies an attractive force on the magnet when it moves closer to the activating base, and a repelling force on the other magnet moving away from the activating base so as to activate the rocking means.

Abstract: A pivoting armature which functions as part of an electric control motor is rotatably supported on a shaft in a housing of the electric control motor and has a pole carrier on which pole shoes are mounted, the pole shoes being joined to the pole carrier in a rotationally fixed manner. The pole shoes can be produced by sintering or welding on a pole shoe ring that is pressed onto the pole carrier, or by stacks of laminates.

Abstract: A motor-compressor unit comprises a motor including a magnetizable stator; an armature oscillatable about the motor shaft axis; two coils arranged opposite each other on the stator; and a magnetizable core extending between the coils. The stator has opposed sections spaced from each other and arranged to define air gaps between such stator sections and the core at the end faces of the coils remote from each other, such air gaps being concentric about the motor shaft axis. A permanent magnet is disposed between each stator section and the core, a pole of each magnet facing the core. A plurality of pole elements is associated with the armature and is arranged such that oscillation of the armature causes one pole element to move into its respective air gap and another pole element to move out of its respective air gap.