Dynamic gauging and automatic adjusting of relays

THE GAUGING AND ADJUSTMENT of the contact operate points of the Bell System´s wire spring relay^{1, 2} will be considered in this article. It is clear that if relays are to perform their function of making and breaking electric circuits rapidly, reliably, and in the proper sequence, it is necessary to specify a range or ranges within the armature´s total travel within which all the contacts must operate. Presently, the gauging is done on a purely “go, no-go” basis using thickness gauges to displace the armature to the specified limits, say 0.007 and 0.016 inch, and then ascertaining the contacts´ state. This method provides a satisfactory, but not necessarily optimum, adjustment.