Abstract

In order to overcome the unexpected dynamic lifting action of an easily installed rotary cutter tool in a food processor as the lower blade revolves at relatively high velocity through food material, such as shelled nuts in making nut butter, a downward inclination in a forward direction is provided in at least the lower blade, near its outer tip. If desired, such an inclination may be incorporated into both blades of the cutter tool. This downward inclination of the blade surface to provide a negative angle of attack (-A) relative to the direction of rotation may be accomplished in a preferred embodiment by twisting the outer blade portion into a negative angle of attack relative to the remainder of the blade or by mounting the whole blade onto the hub at a negative angle of attack. Thus, as the lower blade moves at relatively high velocity through food material, there is a continuous impact of the food material against the downwardly inclined blade surface at least near the tip region producing a downward component of thrust for holding the tool hub down firmly seated in its proper relationship upon the rotating drive shaft.