Abstract: A manually operated cutting tool has a pair of handles, a stationary cutting plate to which one handle is attached pivotally and the other one rigidly, and a rotary knife also pivotally attached to the cutting plate. A force-and-motion transmission mechanism between the movable handle, which is mounted with the aid of a pivot pin, and the rotary knife, is defined by an excenter drive comprising a cylindrical block affixed to the movable handle excentrically relative to the pivot pin, and a driving pawl having a circular opening for accommodating said block and a toothing for engagement with a circular row of teeth provided on the outer edge of the rotary knife. The rotary knife has at its inner edge a curvilinear cutting edge which, being generally concave, may have two convex projections, a first one adjacent the end opposite the location of the pivotal attachment, and the other projection, less sharp than the first one, between the first one and the end adjacent the pivotal attachment.