Magnetic latching relay

A magnetic latching apparatus having a permanent magnet, electro-magnet including magnetic core and coil, and bi-stable magnetic armature having a spring biased unlatched position and a permanent magnet flux biased latched position, said coil adapted for bi-directional energization to selectively establish one of said latched and unlatched positions of the armature, the apparatus comprising, in combination:

• said permanent magnet having a first magnetization axis and a pair of opposite pole faces aligned therewith;
• back iron comprising a first high permeance flux path which is substantially parallel to said magnetization axis;
• said electro-magnet having a second magnetization axis substantially parallel with said first magnetization axis, the core having a pair of axially opposite ends and comprising a second high permeance flux path which is substantially parallel to said first and second magnetization axes;
• said permanent magnet, back iron and core being arranged such that the permanent magnet is intermediate the back iron and ferromagnetic core;
• a high permeance member extending substantially perpendicular to said first and second magnetic axes from said back iron across one of said pair of axially opposite pole faces of said permanent magnet and one of said pair of axially opposite ends of said core, said member being in substantial contact with said back iron, permanent magnet and core;
• and,
• said armature pivotally coupled to said back iron and extending substantially perpendicular therefrom with respect to said first and second magnetic axes across the other of said pair of axially opposite pole faces of said permanent magnet and the other of said pair of axially opposite ends of said core, said armature being in spaced adjacency relative to the core when in the spring biased unlatched position, and in substantial contact with the core when in the permanent magnet flux biased latched position.