Electromagnetic drive

An electromagnetic drive for an electrical switch with a movable switching contact, the electromagnetic drive comprising:

• a movable armature to be connected to the movable switching contact of the switch and disposed to implement a lifting movement along a predetermined pushing direction and to assume a closed position, said movable armature having a first armature-side stop face and a second armature-side stop face;
• a yoke having a first magnetically conductive yoke part and a second magnetically conductive yoke part;
• said armature, in the closed position, closing a magnetic circuit of the drive at said first armature-side stop face with said first magnetically conductive yoke part and at said second armature-side stop face with said second magnetically conductive yoke part;
• at least one permanent magnet for producing a magnetic field for the magnetic circuit and for generating a holding force for holding said armature in the closed position;
• and
• a coil disposed to generate a magnetic flux brought about by a current flow through said coil, the magnetic flux being directed in the same direction as or in opposition to the magnetic flux of said permanent magnet in the magnetic circuit;
• wherein, after an installation of the electromagnetic drive, a readjustment state is provided by virtue of a self-adjustment of a position of said first and second yoke parts relative to one another due to a magnetic force of the permanent magnet;
• and
• wherein said first and second yoke parts are mountable into a fixed, installed state in which an alignment and relative position of said first and second yoke parts is fixed independently of a further positioning of said armature.

A method for installing an electromagnetic drive for an electrical switch, the method comprising:

• pre-installing the electromagnetic drive and subsequently closing a magnetic circuit with an armature by moving the armature into a closed position thereof;
• causing the drive to assume a readjustment state wherein a self-adjustment of a position of yoke parts of a yoke of the electromagnetic drive relative to one another occurs due to a magnetic force of a permanent magnet;
• and
• following a self-adjustment of the yoke parts, fixing the yoke parts in position in a fixedly installed state in which an alignment of the yoke parts remains fixed independently of a further positioning of the armature.