Patent ID: 8373524
Filing Date: 2013-02-12
Classification: H01H

Abstract:
1. A double-throw multi-pole power relay switch that is modified to function as a transfer switch in the automatic switching of a load from a primary power source to a secondary power source in the event that the primary source is interrupted, comprising: providing a conventional double-throw multi-pole power relay switch, said relay switch having a plurality of moveable contacts, each movable contact being mounted upon a magnetic armature and held in place by a damper spring, a coil and coil core which when the coil is energized, attracts the magnetic armature causing it to overcome the tension of an armature return spring, said damper spring having a spring force sufficient to overcome the magnetic attraction of the coil and coil core when the coil is energized so as to prevent cross connection between the primary power source and the secondary power source in the event that contacts in the power relay switch become welded.