| 摘要 |
<p>1467248 Electric timepieces HORSTMANN CLIFFORD MAGNETICS Ltd 12 July 1974 [30 July 1973 31 Aug 1973] 36232/73 Heading G3T An electric motor, e.g. for driving a timepiece, comprises an oscillatory element 1 which drives a rotor 2 via a magnetic coupling and which is driven by impressed electric signals having a frequency of which is less than the natural frequency of the element by f/2Q where Q is the Q-factor of the element. Self-starting and continuous rotation of the rotor are said to be thereby ensured. As shown the element 1 carries a magnet 4 one pole of which drives the rotor while the other pole co-operates with a coil 5. The signals to the coil may be derived from the A.C. mains or from a quartz crystal oscillator via a frequency divider, Fig. 4 (not shown) Various forms of magnet 4 and rotor are envisaged, and the element 1 may oscillate parallel to the rotor shaft (3), Fig. 3 (not shown). This shaft carries a loose stabilizer disc 3'. The coil 5 may co-operate with an intermediate portion of the element (1), Fig. 2 (not shown), or the latter may be a Piezo-electric multimorph bender.</p> |
