Abstract: Single phase synchronous motor with a two-pole permanent-magnet rotor (5), coils (9) designed for nominal operation and a stator iron (7) which carries the coils (9) to produce a two-pole stator field between the stator poles (13). The rotor elements (19, 23) produce pulsating torques and are made of hard-magnetic and soft-magnetic materials, the pulsating torques comprising average-value and alternating components. The motor is constructed so that the alternating components are in phase opposition and tend to cancel each other during nominal operation. Elements producing the pulsating torques comprise a soft-magnetic central part and hard-magnetic permanent magnets arranged on opposite sides thereof.

Abstract: Two-pole single-phase synchronous motor comprising an electromagnetic exciter part and a driving unit. The exciter part comprises a stator member having a longitudinal axis and a pair of stator limbs. Each stator limb has a coil thereon and a free end with an end surface. Each end surface being similarly disposable at various angles relative to the longitudinal axis of the stator member. The driving unit comprises, in combination, a rectangular housing, a permanent-magnetic rotor, and a pair of pole-shoe members. The rotor is rotatably journalled in a bearing imbedded in the housing. The pole-shoe member are contained within the housing. Each pole-shoe member has a pole shoe. The pole shoes enclose the rotor inside the housing. The driving unit forms a separate constructional module which is coupled to the exciter part.

Abstract: A single-phase synchronous motor with a two-pole permanent-magnet rotor of a magnet material having a remanence B.sub.r, a specific density .rho., a rotor diameter d, a resulting detent torque of an amplitude M.sub.k1, and a mass moment of inertia J. In the single-phase synchronous motor, high-energy magnet materials are used for the rotor, which rotor material is characterized by the constant ##EQU1## The moment of inertia J and/or the detent torque M.sub.k1 should be influenced in such a way that the natural frequency ##EQU2## of the low-amplitude freely oscillating system comprising the rotor and the load is unequal to the mains frequency .omega..sub.e. In the design of a single-phase synchronous motor this may result in, for example, the air gap at the narrowest point being enlarged in comparison with the dimensions of conventional motors having rotors with conventional permanent magnet materials.

Abstract: A vibratory dry-shaving apparatus comprises a housing; a bipolar, uniphase, synchronous motor positioned within the housing and having a rotor and a stator; and a shaving head arranged on the housing and including a vibratory cutter part below a fixed cutter part. A wall separates the interior of the housing from the shaving head, such wall having a passage therethrough. A swing lever is driven by the rotor and engages the vibratory cutter part to drive the latter, the swing lever extending through the passage. An elastic sleeve surrounds the swing lever and seals the passage between the edge thereof and the swing lever. The elastic sleeve is asymmetrically designed so that, in a final end position of the vibratory cutter part where the magnetic fields of the rotor and the stator are parallel, no force resulting from deformation of the sleeve is exerted on the vibratory cutter part.

Abstract: A vibratory dry-shaver comprises a shear foil having two longitudinal edges, and respective means to clamp the two longitudinal edges in place to cause the shear foil to assume a natural curvature, the tangents to such curvature at the two clamping means forming an acute angle with each other. A cutter is reciprocatingly movable along and adjacent to the shear foil, the cutting edge of the cutter having a curvature corresponding to that of the clamped, curved shear foil. The curved shear foil and the cutting edge of the cutter each have a hyperbolic cosine curvature according to the formula:y=c.multidot.cosh x/cwhere y indicates the distances of the individual cutting edge points from the x-axis, x is the coordinate in the direction of the width of the cutter, and c is a constant derived from the width 2b of the clamped shear foil and the height of the curvature h of the clamped shear foil.

Abstract: A drive mechanism for a dry shaver comprising a shear foil and a cutter reciprocatory relative to the shear foil includes a single-phase synchronous motor having a drive shaft. A cam is mounted on the drive shaft, and a transmission roller is constantly in contact with the cam. The surface of at least one of the cam and the transmission roller is provided with a layer approximately 1 mm in thickness of an elastic material.

Abstract: The invention relates to an electric motor having a U-shaped stator iron such as a series-, split-pole- or single-phase synchronous motor. Between the free shank ends of the stator, pole shoes are formed, and on the shanks, induction coils are provided. The shanks of the stator iron in the area between the pole shoes and the coils are bent with respect to the central plane of the stator iron in such manner that the shaft of the rotor with the central plane of the stator iron encloses an angle differing from the perpendicular to the central plane.

Abstract: Electric motor, in particular series-, split-pole- and single-phase synchronous motor, having a bent stator iron, pole shoe shanks formed by the stator iron which form pole shoes at their free ends. Induction coils are provided on the pole shoe limbs. A rotatable, radially magnetized permanent magnetic rotor is present between the pole shoes. In this electric motor the oppositely located pole shoes are formed at the end faces of the pole shoe shanks. The rotor shaft intersects the central longitudinal line of the two pole shoe shanks. Finally, the parts of the pole shoe shanks facing away from the pole shoes are bent and interconnected in the form of a bridge.

Abstract: A self-starting single-phase synchronous motor without an auxiliary coil comprises a diametrically magnetized permanent-magnet rotor and a two-pole stator provided with exciter coils. A PTC resistor (5) is arranged in the circuit (1) of the exciter coils. The PTC resistor is proportioned so that its resistance will increase to a continuously permissible load resistance value after approximately 0.5 to 1 sec.

Abstract: Disclosed is a shaving apparatus having a shear plate provided with hair-entry apertures and a cutting member drivable relative to the shear plate. The cutting member is formed with cutters each having an associated lead cutter slidingly engaging the guide wall of its respective cutter. The end of each lead cutter has a projection terminating in a cutting edge for penetration into a hair, the thickness of such projection permitting only partial penetration of the lead cutter into the hair. Such penetration is advantageously further limited by forming the front wall of the lead cutter perpendicular to the end wall of its associated cutter.

Abstract: A pumping device for fluids, in particular for low-viscosity liquids such as washing suds or rinsing water, having a pump impeller whose flexible vanes rotate in an annular chamber, and a synchronous drive motor, the elasticity of the pump vanes being sufficient that the required accelerating moments during starting do not exceed the maximum torque produced by the motor, and the drive motor undergoes torsional vibrations during the starting phase.