Abstract: In a bulk tape eraser, the outer edge of one outer limb of an E shaped electromagnet on which the energizing coil is mounted is chamfered inwardly to form said outer limb with a narrow free end adjacent its inner edge which directs substantially the whole of the magnetic flux to the central limb of the magnet.

Abstract: A method of oriented feeding of nonmagnetic current-conducting components is proposed, wherein an alternating magnetic field is set up, whose induction vector is normal to the desired direction of feeding. Components are introduced into this field, one by one, and at least one closed current-conducting loop is secured in the magnetic field so that its plane is normal to the induction vector of the field and offset with respect to the geometrical center of the component introduced into the field in the direction of feeding. Oriented feeding is effected under the action of electrodynamic forces induced in the alternating magnetic field as a result of the interaction of the overlapping current circuits induced by the magnetic field in the components and in the current-conducting closed loop. The device for carrying out the proposed method comprises a source of an alternating magnetic field and a sectional plate arranged in the working area of this field, each plate section including an electric coil.

Abstract: A process and apparatus for producing magnetic discs in which the preferred direction of orientation of the anisotropic magnetic particles, contained in an organic binder system, is tangential to the circumference of the disc. Orientation is effected, prior to solidification of the magnetic layer, by the action of a magnetic field which is formed in the plane of symmetry between at least two pairs of magnetic poles, the poles of each pair being of the same polarity and opposite each other. One pair of poles flares out in cross section toward the plane of symmetry between the pairs of poles, whereas the other pair or pairs of poles of opposite polarity, when viewed in cross section, taper toward the said plane of symmetry to a point, the distance between the poles of such pair(s) being greater than that between the flared poles, and the plane of symmetry of the pairs of poles being in the plane of the disc.

Abstract: A magnetizing device for a permanent magnet motor used for driving an electric vehicle in which a magnetizing coil is wound around the permanent magnet of the permanent magnet motor, and means are provided for detecting a specific step such as manipulation of the key switch in the electric vehicle in a series of predetermined steps required for the operation of the electric vehicle. In response to the detection of such specific manipulation, magnetizing current is supplied to the magnetizing coil from the battery of the electric vehicle so that the permanent magnet can be automatically magnetized.

Abstract: A degausser has a housing having two housing sections of generally tubular configurations. A support element is accommodated in the interior of the housing, and has a tubular portion and a generally flat portion. A core of an electromagnet is accommodated in the tubular portion of the support element, and a coil of the electromagnet surrounds a part of the tubular portion in the housing. The flat portion is formed with resiliently yieldable projections which engage associated recesses at the housing sections with snap action so as to connect the housing sections to the support element. Electric leads pass through an opening of one of the sections, are received in slots of the flat portion in a labyrinthine manner, and connected to a switch supported on the support element and having an actuating element passing through a slot in the housing to the exterior of the latter. The housing and the support element are of synthetic plastic material.

Abstract: Apparatus for magnetizing selected areas of data storage plates, sheets or discs of the type wherein the stored data is represented by the location and arrangement of these magnetized areas, consists of a series of pole pieces which can be shifted into contact with the selected areas and simultaneously excited by a magnetic field. The process is also claimed.

Abstract: A thermomagnetic switch is mountable on a chamber wall to extend into a liquid filled chamber. A reed switch in the switch is controlled by the strength of a magnetic field produced by a cylindrical magnet surrounding the reed switch. The magnetic flux passing through the reed switch is varied by a ferromagnetic cylindrical element having a magnetic permeability varying with temperature that shunts magnetic flux at a level varying with temperature. A ferrous slug or shaft adjacent to the reed switch is movable to shunt a selectable portion of the magnetic flux and permit a fine temperature adjustment. A method of adjusting the operating temperature of switch reduces the magnetic strength of the magnet in the switch in small increments while the switch is exposed to a selected temperature until the switch operates to establish its operating temperature.

Abstract: A device for manufacturing magnetic recording media in which the magnetic particles in the recording layer are oriented in a preferred direction, the fluid coating applied to the base being subjected to the action of a magnetic field produced in the air gaps between the spaced apart poles of two magnetic circuits, one on each side of the coated face, arranged symmetrically with respect to the plane of the coated base, the edges of the poles adjacent to the coated base terminating in screening elements shaped in such a way that the distance between the surfaces of the screening elements facing the coated base and the coated base itself increases as the screening elements extend away from the edges of the poles. A high degree of magnetic anisotropy in the recording layer can also be obtained when the magnetic circuits are at a relatively large distance from the still fluid magnetic coating.

Abstract: A process and apparatus for the manufacture of magnetic discs in which the preferred direction of particle orientation is parallel to the plane of the disc and tangential to its circumference. The base discs coated with the still fluid magnetic dispersion, are introduced into a zone of magnetic flux bounded by conductors, the conducting boundary being so arranged that the current flow on one side of the base disc runs radially outwards and on the other side runs radially inwards.

Abstract: A permanent magnet holding system, e.g. adapted to handle ferromagnetic material, of which the cancellation of the magnetic holding force is effected with a minimum expenditure of energy, and wherein the external magnetism may reliably be cancelled out, comprises two or more permanent magnets fitted with polepieces so disposed that the external holding force can be controllably varied to total disappearance by a polarity reversal of permanent magnets by means of an electromagnetic coil; wherein the permanent magnet or magnets which the coil is intended to repolarize is/are made of a low coercivity permanent magnet material, and the other permanent magnet(s) is/are made of a relatively high coercivity material.

Abstract: The permanent magnet of a magnetic structure is formed of isotropic magnetic material, and is magnetized along the path that the flux follows during use of the magnetic structure to increase the efficiency of the magnetic structure in use. The magnetic structure, which may be the annular magnetic structure of an electrodynamic loudspeaker, includes a cylindrical permanent magnet and an annular cup-like return path element connected to the magnet at one end thereof and forming an air gap with the magnet at the opposite end. Apparatus is provided for magnetizing the permanent magnet having an annular portion which may extend into the air gap of the speaker magnetic structure, to provide curved magnetic lines in the permanent magnet in substantially the path of the operating flux to the air gap.

Abstract: The flyweights of a governor of the general kind having magnetised flyweights and a field coil for modifying the bias of the flyweights, are magnetised by applying a voltage pulse to the coil when the governor is stationary.

Abstract: An apparatus for the treatment of water which includes an elongated magnet having a multiplicity of longitudinally spaced poles enclosed in an inner casing of non-magnetic material, the latter being received within an outer casing of magnetic material and in radially spaced-apart relationship thereto. The apparatus is further provided with novel porting and the magnet, non-magnetic casing and outer casing are dimensioned and proportioned to provide improved fluid flow thereabout.