US Patent 6997365 Contact trip assembly for fastening tool

A fastening tool including a housing, a magazine connected to the housing for storing a fastener, a driving mechanism disposed within the housing for driving the fastener into a workpiece, a trigger assembly pivotally attached to the housing for activating the driving mechanism, the trigger assembly comprising a main trigger, pivotally attached to the housing and a supplemental trigger pivotally attached to the main trigger; and a contact trip assembly comprising an upper contact trip contacting the supplemental trigger, a lower contact trip connected to the upper contact trip, wherein the upper and lower contact trips have teeth that mesh together for locking the upper and lower contact trips.