| 摘要 |
PURPOSE:To reduce height of ceiling walls effectively by forming the coil of a magnetic base foundation and a ring groove for accommodation of said coil in double construction concentrical with each other. CONSTITUTION:This is composed of an electromagnet foundation, which is formed by coil ring-grooves 8a, 8b as in a double construction concentrical with each other. Coils 9a, 9b fitted in these ring-grooves are supplied with current flowing opposite directions. Because formation of this double groove construction signifies dividing a single magnetic field into two, for inner and outer magnetic rings, the height of ceiling walls h2 can be reduced effectively. Practically, the area of one magnetic field is divided into M' and M'', and accordingly the flux at the inner magnetic ring can be arranged so that the wall area of ring-goove in the ring is equal to M' at the point A of the coil 8a and the area m'' to M'' at the point B of the coil 9b. Thus the height of ceiling walls can be raduced effectively. |
