US Patent 6848183 Thumb lock for a butterfly knife

A locking mechanism is coupled to a distal end of the butterfly knife for securing the butterfly knife in an open position and in a closed position. The locking mechanism has a movable magnetic component coupled to a distal end of the first handle component. The magnetic component is magnetically coupled to a metallic surface of the second handle component to lock the butterfly knife. At least one spring device is movably coupled to the magnetic component. The spring device is used for moving the magnetic component in a downward manner to free the magnetic component from the metallic surface of the second handle component to unlock the butterfly knife.