US Patent 7905377 Flywheel driven nailer with safety mechanism

A device for impacting a fastener in one embodiment includes a drive mechanism, a flywheel pivotable between a first flywheel position whereat the flywheel is not in contact with the drive mechanism and a second flywheel position whereat the flywheel contacts the drive mechanism, a motor operably connected to the flywheel, a trigger movable between a first trigger position and a second trigger position, and a WCE assembly movable between a first WCE position and a second WCE position, the WCE assembly configured such that (i) when the trigger is in the first trigger position and the WCE assembly is in the first WCE position, the WCE assembly mechanically engages the trigger to preclude movement of the trigger out of the first position, and (ii) when the WCE assembly is in the second WCE assembly position, the WCE assembly does not mechanically engage the trigger.