US Patent 7987601 Folding tool

The folding tool has one side-plate (1a) and the other side-plate (1b). A part of the rear side of the other side-plate (1b) or an arm-like plate (2) attached as a separate body is used as an inwardly pressing member, and a projection (3) is provided at the head of the arm-like plate (2). The base end of the body (5) having at its end a rear recess (6) is foldably pivotally attached by means of a support shaft (4) to the base ends of both the one side-plate and the other side-plate. The projection (3) and the recess (6) of the body (5) are engaged with and locked to each other.