| 摘要 |
<p>Control unit (1) for an electric switch, comprising a yoke (3) of magnetic material, an armature (4), a coil (9), a permanent magnet (13) and spring means (10). The yoke (3) consists of a base part (5) and two legs (6,7) which extend at a distance from each other and in the same direction from the base part (5), and at right angles thereto. The armature (4) is made of magnetic material, bridges the free ends of the yoke legs (6,7) and is movably supported. The permanent magnet (13) is fitted in such a way that the magnetic lines of flux run through the armature (4) and the yoke (3). The coil (9) is fitted on the yoke (3). At one side the spring means (10) act upon an armature part (11) extending beyond a yoke leg face which faces away from the other yoke leg, the armature (4) assuming a first position under the influence of the magnetic field of the permanent magnet (13), against the spring force of the spring means (10), and being able to assume a second position under the influence of the magnetic field created by an electric current which flows through the coil (9) and exceeds a preset limit value. At the other side the spring means (10) act upon a yoke projection (12) extending beyond the abovementioned yoke leg face at a distance from the projecting armature part (11). The armature (4) and yoke (3) are made of flat magnetic material. <IMAGE></p> |
