GB632264A - A new or improved electric motor - Google Patents

Abstract

632,264. Electric clocks. HORSTMANN CLIFFORD MAGNETICS, Ltd., HORSTMANN, F. O., and CLIFFORD, C. F. Aug. 26, 1947, Nos. 23550 and 27144. [Class 139] [Also in Group XXXV] The movement of a clock is driven by an electric motor which, if desired in association with a spring drive, may serve to maintain synchronism of a rotary member e.g. in a clock and which comprises an oscillating member such as a reed or pendulum magnetically coupled to a rotary member and one of these members has a wavy magnetic track adapted to guide and be guided by the other member during relative movement. As shown in Fig. 1 an iron yoke 4 attached to a magnet core 5 has an A.C. magnetising coil 6 and an air gap between pole pieces 7. A reed 8 carries a magnet 9 the upper portion of which lies in the air gap so that these parts vibrate at the frequency of the A.C. A tuning collar 10 mounted on magnet 9 may adjust the resonant frequency. The magnet 9 has two pole pieces 12 lying close to the periphery of a rotor 13 carrying a wavy magnetic path 14. The distance between pole pieces 12 is equal to a whole multiple of the pitch of the wave 14. A hand operated starting device 15, 16, 17, 18 is provided. When the rotor 13 is set in motion the pole pieces 12 follow the track 14 driving it synchronously with the A.C. supply with sufficient torque to drive the gear train of a clock. To obtain a small energy consumption the coil 6 may be connected in series with a condenser or the winding on coil 6 may consist of two insulated metal foil strips the opposite ends of which form the terminals. The device may be driven electrostatically (Fig. 9 not shown). In a D.C. arrangement the reed operates a trembler contact in the coil circuit. To avoid reduction of the magnetic coupling with increasing amplitude of oscillation the crests of the track waves may be laterally extended as shown in Fig. 6. Fig. 7 shows a plastic disc with magnetic pins 23 and a vibrating reed carrying a magnet. The edge of the rotor projects into the gap between the poles of this magnet. Each magnet pole carries a wavy magnetic track with extensions as described. Two or more oscillating members may cooperate in the drive. Fig. 10 shows a shading coil 32 causing a phase displacement of one of two drives which are correspondingly phase-displaced with regard to the wave track. Three phase displaced oscillating members may be driven by the phases of a 3-phase supply. Specification 596,216 is referred to in the first Provisional Specification.