Snap action relay with close operate and release voltages

Claim 1

A RELAY CIRCUIT RESPONSIVE TO A VARIABLE VOLTAGE COMPRISING A VOLTAGE DIVIDER TO WHICH SAID VARIABLE VOLTAGE MAY BE APPLIED, A RELAY HAVING FIRST AND SECOND WINDINGS AND A PLURALITY OF CONTACTS, SAID FIRST WINDING BEING RESPONSIVELY COUPLED ACROSS AT LEAST PART OF SAID VOLTAGE DIVIDER, SAID FIRST WINDING BEING EFFECTIVE TO OPERATE SAID RELAY IN RESPONSE TO AN INCREASE IN SAID VARIABLE VOLTAGE ABOVE A FIRST LEVEL, MEANS RESPONSIVE TO THE OPERATION OF SAID RELAY FOR REDUCING THE EFFECTIVENESS OF SAID FIRST WINDING TO PERMIT RELEASE OF SAID RELAY IN RESPONSE TO A DECREASE OF SAID VARIABLE VOLTAGE BELOW A SECOND LEVEL THAT IS CLOSER TO SAID FIRST LEVEL THAN IN THE ABSENCE OF SAID REDUCING MEANS, MEANS FOR CONNECTING SAID SECOND WINDING ACROSS A FIRST PORTION OF SAID VOLTAGE DIVIDER IN A POLARITY TO OPPOSE SAID FIRST WINDING WHEN SAID RELAY IS RELEASED, AND A NORMALLY OPEN CONTACT OF SAID RELAY EFFECTIVE TO CONNECT SAID SECOND WINDING ACROSS A SECOND ADJACENT PORTION OF SAID VOLTAGE DIVIDER IN A POLARITY TO SAID RELAY, SAID NOR- L INTERMEDIATELY DURING OPERATION OF SAID RELAY, SAID NORMALLY OPEN CONTACT BEING OPPOSED INTERMEDIATELY DURING RELEASE OF SAID RELAY.