US Patent 9751221 Lever link mechanism for a folding knife

An ambidexterous, springless folding knife mechanism allows a user to open and close the knife with the repetition of a single motion by either hand. This knife does not require any spring to open or retract the blade back into the handle. A lever link couples the knife handle and the knife blade in a hinged manner. Slight modifications of the mechanism will permit the blade to be opened to a variety of angles depending on the positioning of the mechanism during the initial design. Such modification would allows application of the mechanism to other folding hand tools. In the preferred embodiment, the open and closed position of the blade does not require the blade to travel a full 180 degrees but locks the blade in a substantially straight position for use. The mechanism allows knife operation by those with handicaps or dexterity issues.