Abstract: An electric motor having a permanent magnet rotor and a stable with two poles and two windings and electronic switching for controlling commutation. To ensure that the motor starts under heavy load conditions, commutation is delayed during a predetermined period of time while the rotor is travelling in a forward direction of rotation to suppress the associated braking torque.

Abstract: A small motor having a two-pole permanent-magnet rotor and a U-shaped laminated stator having a pair of limbs with end portions that form magnetic poles for the rotor. The limbs carry alternately energized exciter coils including three nested winding layers arranged in two winding groups, of which the outer winding layer and the inner winding layer of the first limb and the second limb, respectively, and the central winding layer of the second limb and the first limb, respectively, are connected in series with one another.

Abstract: A charging device for accumulator-operated small electrical appliances, for example, electric dry-shavers, which are energized by rechargeable accumulators (24) which can be charged by means of a charging device (15) including solar cells (11). The charging device includes an energy buffer (20) which is connected parallel to the solar cells for buffering the solar energy when the charge capacity of the solar cells is below the charge current threshold of the accumulator. The buffered solar energy is supplied to the accumulator when a discharge current of the energy buffer exceeds the charge current threshold of the accumulator and flows until the discharge current falls below the charge current threshold.

Abstract: The invention relates to an epilating device having epilating rollers which are drivable in opposite directions, at the periphery have a wave-shaped cross-sectional profile, mesh together at their periphery by their cross-sectional profiles and are drivable by means of a motor, a single-phase synchronous motor without a non-reverse mechanism being provided for the purpose of driving an uneven number of epilating rollers.

Abstract: The invention relates to a rotor (10) for an electric motor, in particular for a multi-phase or single-phase electric motor, comprising a permanent-magnetic ceramic rotor cylinder (1) made of an imperforate solid material and provided with moulded-on plastic elements (5) on at least the cylinder end faces (3), which elements carry axially projecting shaft portions (6) for rotatably journalling the rotor (10), the cylinder end faces (3) being formed with recesses and the moulded-on plastic elements (5) engaging in the recesses (4).

Abstract: The invention relates to a two-pole single-phase synchronous motor having a permanent-magnet rotor (11), a magnetic detent torque, which viewed over one revolution exhibits positive and negative values with resulting stable and unstable rest positions, the stable rest positions being offset in the positive direction relative to the average direction of the stator field (39) by the asymmetry angle (.gamma.), and a critical detent torque (M.sub.K1kr) being active in the parallel position of the stator field (9) and the rotor field (41), and a starting device provided with rotational backlash between a driving member connected to the rotor (11) and a load member, and with a directional blocking device (22).

Abstract: The invention relates to a small electric household utensil for the production of foods by mixing by stirring from original components which are slightly liquid at the start of work, in the preparation of which foods the production temperature deviates from the ambient temperature, the temperature change in the original components which is required during the production process being achieved by means of a thermal energy dispenser, the thermal energy dispenser (6) bringing the inner wall (4a) of a pot-shaped container (4, 24) to the production temperature and a stirring tool (10) intermixing the production components during the production process.

Abstract: A domestic vibration apparatus, in particular a dry-shaver or hair trimmer, in which rotary movements of a two-pole permanent magnet (9) forming a rotor are converted into vibratory movements of a vibration tool by means of a lever system (13) which preloads the drive in such a way that the rotor (9) can oscillate about a rest position,t he two-pole permanent-magnet rotor (9) without pole-pieces being arranged in the U-shaped stator of a single-phase synchronous motor.

Abstract: The invention relates to a rotary shaving head (2) for an electric shaving apparatus, the shaving head comprising a rotary cutter (23) which is driven by an electric motor (3) and which comprises a cutter disc (54) whose periphery is provided with an annular configuration of cutter blades (52) which are offset from the plane of the disc and whose cutting edges (59) co-operate along a cutting plane with a shear plate (24) formed with hair entry apertures (57). The rotary cutting (23) and the shear plate (24) are constructed for rotation of the rotary cutter (23) in both directions of rotation and the rotary cutter (23) is adapted to be driven by a single-phase synchronous motor (3, 3') having a permanent-magnet rotor (9, 65).

Abstract: An electrically driven vibrating apparatus such as a dry shaver comprises a single-phase synchronous motor having a drive shaft, together with a part to be reciprocated. A cam is rotated by the motor drive shaft, and a lever is journalled about a pivot and is in contact with the part to be reciprocated. A pressure roller is mounted on the lever and is in constant contact with the cam profile. A compression spring acts on the lever to urge the pressure roller towards the cam.

Abstract: An eddy-current intermediate rotor (13) is fixed to the motor shaft (9) and is arranged to be rotatable between the stator-iron poles and the permanent-magnetic rotor (15) which is mounted for free rotation on the motor shaft (9). The rotor (15) and the eddy-current intermediate rotor (13) are disc-shaped and form a disc assembly (23) which can be axially magnetized via the stator-iron poles (3) on each side of the disc-assembly (23). A centrifugal coupling is provided, which acts to couple the rotor (15) to the eddy-current rotor when the disc assembly has come up to speed.

Abstract: In an electric motor with a damping device incorporating a disc-shaped damping mass which is freely rotatable and axially movable in relation to the driven element and consists at least partially of a mangetizable material, the damping mass is located within the range of a stray magnetic field (31) of the motor (11) and is pressed against a friction plate (28) located between the rotor (14) of the motor and the damping mass and rotating with the driven element as a result of the magnetic force of the stray field acting upon the mass.

Abstract: The invention relates to a device for improving the stability of rotation of the rotor of a single-phase synchronous motor mounted in an apparatus housing. The motor exhibits an average motor torque on which strong alternating torques are superimposed and which drives a preferably rotating load. The rotating load may be a small domestic appliance such as a citrus-juice extractor, a knife sharpener, or a dry-shaver with rotatary cutters.

Abstract: A method for making the shaving head of a dry-shaving apparatus with an effective shaving area of a desired shape, in which a shear foil is mounted in an arcuate condition in a shaving-head frame without the cutter so that the foil assumes a free clamping curvature which is not influenced by the cutter, a normal-pressure distribution is applied perpendicular to the foil curvature which simulates the pressure distribution between the cutter and the foil in conformity with a desired effective shaving area, so that the shear foil experiences in said effective shaving area a deformation relative to the free clamping curvature, the simulated pretension curvature thus obtained corresponding to the desired normal-pressure distribution on the cutter in the desired effective shaving area relative to the shear foil.

Abstract: Two drive motors (251) drive the shaft of a load via a common drive wheel (19), either directly or via further gear wheels. The rotor shafts of the drive motors are constructed as two-pole single-phase synchronous motors having permanent-magnet rotors. The gear wheels mounted on the rotor shafts are oriented in such a way relative to the direction of magnetic polarization of the rotor magnets that when the arrangement is assembled and in mesh, the magnetic orientation of both rotors (27) relative to the main direction of the stator fields is the same for a positive stator current.

Abstract: A drive mechanism for a domestic vibration-type apparatus is provided, in which the rotor shaft (19) of a single-phase synchronous motor drives a cam-and-follower mechanism which converts the rotary motion of the rotor into a vibratory motion, the rotor and the stator having a main field direction (22) and (16), respectively. The longitudinal axis of the mirror-symmetrical cam extends at an angle to the main field direction (22) of the rotor. Rollers (31, 31a) which follow the cam (21) are arranged on a pivotal arm which is pivot about its central portion and a vibratory part (39) to be driven is arranged on the driving end (35) of this pivotal arm. As they cooperate with the cam the rollers are constantly in contact with the cam profile.

Abstract: A domestic ice-cream maker comprises a refrigerated bowl-shaped container for an ice-cream mass; a rotatable stirring tool associated with such container for scraping off ice-cream freezing at a refrigerated surface of the container; and a single-phase synchronous motor for rotating the stirring tool, such motor having a maximum permissible operating temperature for making the ice-cream. A transmission path including a reduction mechanism extends between the synchronous motor and the stirring tool. Backlash is provided in the reduction mechanism as overload protection for the synchronous motor, the backlash acting in both directions of rotation of the motor and corresponding in each such direction of rotation to at least 10 revolutions of the motor, the motor, upon being blocked in either direction of rotation, reversing its direction of rotation and passing through the range of the backlash without exceeding its maximum permissible operating temperature.

Abstract: A small domestic appliance is driven by means of a single-phase synchronous motor (2) whose drive shaft (5) drives a load (9), the work function being independent of the direction of rotation of the motor and the operating noise and vibrations produced by the motor being dependent on the direction of rotation of the motor. In the transmisson system a unidirectional blocking device (41) forces the rotor to start in the optimum direction of rotation. In particular, the single-phase synchronous motor (2) including its transmission path to the load (9) is constructed that the optimum operating noise is obtained in that direction of rotation in which the torque exerted on the rotor (3) by the stator current becomes zero before the magnetic detent torque has become zero, when the stator coils (4d) are not energized. This has led to a stable rest position.

Abstract: A single-phase synchronous motor comprises a two-pole permanent-magnet rotor (5) between two electromagnetically excited stator coils (9). At the location of the median plane (33) parallel to the direction of magnetization (37) parallel to the direction of the permanent-magnet rotor (5) has a shape which deviates from a cylindrical shape and the dimension of the permanent-magnet rotor (5) in the direction of magnetization (37) is largest near the median plane (33).

Abstract: A protection against overheating not only of the heat transmitting component (2), but also of the components (3) surrounding said component is achieved. A latent heat store (1) is provided between the heat transmitting component (2) or a part thereof and a component (3) to be protected from overheating or a part thereof. The latent heat store (1) comprises a latent heat storing agent, whose melting-point T is between the operating temperature of the heat transmitting component (2) and the maximum permissible temperature of the component (3) to be protected. The quantity is proportioned so that the storage capacity of the latent heat store (1) is sufficient for the amount of heat maximally to be transmitted by the heat transmitting component (2). Between the heat transmitting component (2) and the latent heat source (1) and between the latent heat store (1) and the component (3) to be protected a thermal insulation (4,5) is provided.