Combination mechanical and electrical interlock mechanism

In an interlock mechanism for a pair of circuit controllers each having normally open contact assemblies concurrently operable with a respective circuit controller, said mechanism responsive to movement of individual controller elements movable in the same direction, said mechanism comprising a stationary support member, first and second movable operators supported by said support members, each of said operators including means for respectively engaging one of said individual controller elements, each of said operators including a blocking formation, said operators being independently movable from a first position to a second position, said operators positioned so that predetermined movement of either operator partway from its first position toward its second position places the blocking formation of this operator in the path of movement of the blocking formation of the other of said operators so that the latter is prevented from moving to its second position;

• the combination therewith of first and second electrical interlock contact assemblies, each electrical contact assembly respectively including a first and a second pair of stationary contacts and a first and second movable bridging contact, said bridging contacts each respectively operated by the said first and second operators from a first normally closed contact position to a second contact open position concurrently with contact closure of the auxiliary contact assembly of a respective one of said pair of circuit controllers, and biasing means urging each of the movable contacts of said interlock contact assemblies towards contact closed position.