US Patent 7856856 Independently interactive interconnected lock

An independently interactive interconnected lock includes an interconnecting mechanism that retracts a latchbolt and a deadbolt when an inner handle is moved between an up position, an intermediate position and a down position. The deadbolt is retracted by a deadbolt lock mechanism as the inner handle moves from the up position to the intermediate position. The latchbolt is retracted by a latchbolt lock mechanism as the inner handle continues to move from the intermediate position to the down position. When the inner handle is moved to the up position, both the latchbolt and deadbolt are extended and the deadbolt lock mechanism is disconnected from the latchbolt lock mechanism such that manipulation of the latchbolt lock mechanism to retract the latchbolt does not retract the deadbolt. The inner handle operates with low handle torque because the deadbolt and the latchbolt are not retracted simultaneously.