Abstract: In the production of press molded articles, such as permanent magnets made from anisotropic powder materials, a more nearly uniform distribution of the particles is obtained by the forming of a preliminary series of articles, each being only a fraction of the length of the final product, after which the preliminary articles are combined under lengthwise pressure in a mold. Pressure may be applied as each preliminary article is added in the mold and the final article may be sintered or a plastic binder may be added and cured by heating.

Abstract: A rotor for small motors, or generators, having circumferentially arranged segmental poles which extend over the entire axial length of the rotor can be fabricated by molding a pair of elements from particulate magnetic material of high coercivity with a binder in the shape of identical crown gears; the rotor being completed by arranging the elements on a shaft with the toothed portions facing each other in interfitting engagement. Other modifications are disclosed in which the pole pieces may be formed separately from, or integrally with, a radial pole carrier, and the pole carrier may be in the shape of a spool with the segmental pole pieces assembled thereon.

Abstract: A low-leakage pot magnet system for moving-coil loudspeakers having two permanent magnets of opposite polarity is accomplished by spacing the lower permanent magnet away from the bottom of the screen pot by an appropriate support which includes a disk or plate of nonmagnetic material arranged between the lower permanent magnet body and the bottom of the screen pot.

Abstract: The magnetic field which is required to hold image-forming toner particles on the tubular carrier of electrographic copiers is provided by single piece integrally formed permanent magnet bodies extending from end to end of the tubular carrier, the latter comprising a thin layer of ferromagnetic material to reduce the effect on inhomogeneities which may exist in the magnet bodies.

Abstract: A mold for producing anisotropic permanent magnets consists of a cavity defined by a thin-walled tubular lining element closely surrounded by an electrical field coil, reinforced by a metal ring enclosing the field coil so that a magnetic field of a given strength can be generated in the cavity with less power than in the case of the conventional field coil normally positioned at a relatively greater distance from the interior of the cavity. The lining element can be composed of a non-metallic material such as a ceramic, or sintered Al.sub.2 O.sub.3.

Abstract: The magnet carrier assembly of an electrographic copying device is fabricated from a number of separate parts instead of being machined from a single block of metal. The assembly can consist of a tubular body which supports the magnets either on the outside, or inside, peripheral surface. The tubular body can be formed by extrusion integrally with a radial spider connected to a hub which supports the body. In another form the carrier can be built up by combining specially profiled sheet metal strips with other axially extending elements with which they are joined in a tongue-in-groove arrangement.

Abstract: A process for preparing anisotropic permanent magnets from crude solidified cast bars of magnet material consists in etching the surface thereof to determine the crystalline structure of the several zones of the bar before subdividing it.

Abstract: This invention makes it possible to use mechanically hard magnetic materials in the formation of one, or both, of the annular press rams used in closing the mold because at least one of the rams is not permitted to enter the mold a distance sufficient to short circuit the magnetic flux flowing radially between the center ram and the outer wall of the mold.