Electromagnetically actuated central shutter for photographic cameras with shutter lamellae actuated by electromagnet armature via pull rods

摘要

The electromagnet (8) is pre-excited by permanent magnets (17) allocated to the electromagnet yoke (9), while its armature (12) can be lifted from the yoke by springs (15) and moved against a stop (16) The armature is moved, against the spring force, onto the yoke poles by an end stage located in front of the central shutter, by strong activation of the magnet coil in the action direction of the permanent magnets. A considerably weaker activation of the coil in the opposite direction, weakens the armature holding magnetic field, so that the still sticking armature can be released by the spring force.