| 摘要 |
1,145,253. Electric timepieces. KIENZLE UHRENFABRIKEN G.m.b.H. March 18, 1966 [March 26, 1965], No. 12007/66. Heading G3T. [Also in Division H2] An electromagnetic mechanical oscillator for a timepiece comprises a rotor having rotatable masses 1, 4 connected by a resilient member 3, the mass 1 having a number of magnetic poles of alternate polarity and a stator 2 which encircles the mass 1 and has a limb on which a drive coil 6 and a pick-up coil 7 are mounted. When the rotor is given an initial rotation, pulses induced in the pick-up coil are amplified by a transistor circuit 8 and fed to the drive coil to produce driving pulses for maintaining the rotation of the rotor. Superposed on its rotational motion is a torsional oscillation of the rotor so that when the frequency of the applied driving pulses equals the natural torsional oscillation frequency, the rotor speed stabilizes at the rotational speed corresponding to this frequency. As shown the member 3 comprises a torsion shaft but a hair spring or arrangements of leaf-springs may be used. An output drive pinion 5 is provided. In order to ensure that the rotor has a preferred direction of rotation, a toothed disc of soft iron, which may be the mass 4, is mounted on the rotor and co-operates with a fixed multi-polar permanent magnet, the teeth of the disc being slightly offset with respect to the poles of the magnet. |
