Miniature mercury contact reed switch construction

A miniature reed switch comprising:

• an insulating support structure,
• a first conductive magnetic member providing a fixed pole supported by the insulating support structure and supporting one switch terminal and having a stepped construction provided by a magnetic conductive extension laterally offset from axial alignment with the rest of the member and extending parallel to the axial direction,
• a second conductive magnetic member providing an armature support element supported on the insulating support structure and generally aligned with but separated from the first magnetic member, providing the other switch terminal and having a stepped construction provided by a magnetic conductive extension laterally offset from axial alignment to the same side as the extension of the first conductive magnetic member,
• a magnetic armature member extending between said first and second magnetic members and of such length and position that it overlaps axial extending portions of each conductive magnetic member and fits within the step of each without touching,
• a spring support member connected between the armature support element and the armature and supporting the armature in a position spaced away from the first conductive magnetic member in the absence of a magnetic field in its unstressed condition and providing a flexible connection which permits the armature to move into improved alignment with said first and second magnetic members to a reluctance minimizing position in the presence of a magnetic field, and
• a conductive contact on the extension of the fixed first conductive magnetic member projecting toward the axis and providing an electrical circuit completing contact for the fixed pole and mechanical spacing means limiting the approach of the armature to the magnetic extension.