Patent ID: 6262648
Filing Date: 2001-07-17
Classification: H01F,H01H

Abstract:
Electromagnetic actuator for moving a contact (2) into a switched-on or switched-off state, comprising a contact-actuating rod (1), which is displaceable in the longitudinal direction between a first position, corresponding to the switched-off state, and a second position, corresponding to the switched-on state, a core (4), which is made of magnetizable material and is attached to the contact-actuating rod (1), a switch-on coil (5), which interacts with the core (4), a pole piece (6), which is made of magnetizable material and of which that face which is directed towards the core (4), in the first position of the contact-actuating rod (1), is arranged at an air-gap distance (d.sub.1) from that surface of the core (4) which runs perpendicular to the direction of displacement and, in the second position, bears as closely as possible against the said core surface, a yoke (10), which is made of magnetizable material, for closing the magnetic flux circuit of the switch-on coil through the pole piece (6) and the core (4), a permanent magnet device (8) for maintaining the contact-actuating rod (1) in the second position and a spring (3) which preloads the contact-actuating rod, in its second position, towards the first position, characterized in that a switch-off coil (14) is present, which, for the purpose of moving the contact-actuating rod (1) from the second position to the first position, is excited in order to eliminate the magnetic field of the permanent magnet device at least temporarily, and in that the magnetic flux circuit of the permanent magnet device (8) is at least partially separate from that of the switch-on coil (5) such that the magnetic flux circuit of the permanent magnet device does not extend through an internal space of the switch-on coil.