US Patent 11052551 Folding knife

This disclosure describes systems, methods, and apparatus for a locking folding knife having a handle lock and a safety switch arranged around and rotatable around a pivot axis of the knife. In an engaged position the switch overlaps at least a portion of the handle lock and prevents it from moving into an unlocked position. A spring, such as a wire form spring, can be arranged within a pocket of the switch, and when the switch is moved between engaged and disengaged positions the spring can be compressed generating a rotational bias on the switch urging the switch toward either the engaged or disengaged position.