Electromagnetic contactor with reduced noise magnetic armature

Abstract

An electromagnetic contactor is taught having an E-shaped movable magnetic armature and a complementary E-shaped permanent magnet. The outboard legs of the E-shaped members abut at closure. Each of the central legs of the complementary magnetic members have significant magnetic material removed from the face thereof leaving complementary abutting nipples or protrusions which mate or make with each other as the outer legs make or mate with each other. The total reluctance of the magnetic system when in the abutted state is significantly lower than if the air-gap material had not been removed. This allows the kickout spring to operate effectively to separate the magnets at an appropriate time. The lower the magnetic reluctance the higher the residual magnetism and the more difficult it is for the kickout spring to separate the magnetic members and thus the contacts of the contactor during an opening operation. The central nipple portions or protrusions abut against each other to prevent longitudinal movement of one magnetic central leg member relative to the other. This reduces wear and noise. This is particularly important when the magnets are maintained in the closed state by the utilization of an assisting HOLD pulse which is continuously supplied to the electromagnet.