Abstract: A method for manufacturing a metal graphite brush comprises steps of preparing natural graphite powders of 60-70 wt %, electrolytic copper powders of 30-40 wt %, molybdenum disulfide and lead of 2.5 wt % and the mixed resin of novolak phenol resin and furfural resin powders of 1-15 wt % which are adhesives, wet-mixing graphite powders with adhesives, pulverizing mixed powders to diameters of less than 200 .mu.m, press-molding all the powders under a pressure of 2-3 ton/cm.sup.2 and heating at a temperature 700.degree. C., and attaching a lead wire thereto, simultaneously, wherein the average particle distribution of the powders is 27 .mu.m. The compound ratio of graphite powders: copper powders: molybdenum disulfide: lead is 62.5 wt %: 35 wt %: 1.5 wt %: 1.0 wt %, the adhesives comprising the mixed resin of novolak phenol resin and furfural resin by 50:50 is added by a weight ratio of 7.5 wt % to the graphite powders.

Abstract: An improved electric motor has a stator, and a hysteresis cylindrical ring formed of magnetic metallic material disposed within the stator cylindrical core with an annular air space between the hysteresis cylindrical ring and the stator core, and a rotor cylindrical sleeve formed of non-magnetic material relatively rotatably mounted within the hysteresis cylindrical ring on a suitable shaft. The improvement includes several interrelated elements. Firstly, the hysteresis cylindrical ring has four longitudinal, generally-rectangular slots spaced 90.degree. apart, and extending from an inner surface of the hysteresis cylindrical ring. Secondly, a permanent magnet is provided only in each of the slots. Thirdly, the rotor cylindrical sleeve has 4 longitudinally-extending, non-magnetically-retentive projections thereon, the projections being spaced 90.degree. apart. The rotor cylindrical sleeve thereby provides longitudinally-extending, annular air duct in each of the 4 sections.

Abstract: A dual output magnetic sensor employing a magnet having first and second poles and a pair of magnetic sensors one of which is located close to a first of the poles and the other of which is located a spaced distance from the second of the poles to form a gap and wherein first and second magnetic field shunting members are operable to move to positions away from and close to the sensors, one of the members passing adjacent to but outside of the first magnetic sensor and the second of the members passing through the gap.

Abstract: A synchronous A.C. electrical motor comprising (A) a stator having a body of slotted, soft ferromagnetic, low eddy current loss material, the slots having A.C. power windings to produce a rotating magnetic field, an excitation coil energizable with single phase A.C. located in two adjacent slots with a pole piece between them, and feedback windings located in slots such that when A.C. potential therefrom is conveyed to the excitation coil the excitation A.C.

Abstract: A hysteresis synchronous motor in which a rotor includes arcuate permanent magnets mounted adjacent to the hysteresis ring material. Permanent magnetic poles are induced in the ring material by the rotating electromagnetic stator field. After start-up, the rotor remains synchronized with the rotating field due to the mutual attraction of opposite magnetic poles.