Feed Box

a mechanism of a metal-cutting machine; used for changing the feed. It consists of interchangeable gear drives in a housing. The kinematic features of the feed box make possible exact matching of the movement of the tool feed during the shaping of the workpiece (cutting threads and teeth) with other movements of the tool relative to the workpiece. For example, in a screw-cutting lathe it is necessary to move the cutting tool along the workpiece in one of its revolutions by an amount equal to the spacing of the thread being cut. The feed box is equipped with a tumbler gear attached to the shaft and a series of gears mounted on another shaft to change the gear ratio. Such a feed box usually also has a drive for adjusting thread types and multiplier drives for expanding the range of control of the feed.