Patent ID: 6865973

Claim:
A method of feeding a workpiece comprising the steps of: (a) conveying an elongate workpiece in a direction perpendicular to a lengthwise direction of the workpiece by a workpiece conveying unit so as to convey the workpiece toward a workpiece feeding unit having a workpiece conveying passage therein; (b) detecting by a side-surface detection means a side surface of the workpiece being conveyed toward the workpiece conveying passage by the workpiece conveying unit; (c) determining a diameter of the workpiece and an offset distance between the workpiece conveying passage and a position where the side surface detection means is disposed, and calculating a distance between the workpiece conveying passage and a position where a center of the workpiece is located when the side surface of the workpiece is detected by the side-surface detection means, in accordance with the diameter of the workpiece and the an offset distance between the workpiece conveying passage and a position where the side-surface detection means is disposed; (d) further conveying the workpiece toward the workpiece conveying passage in accordance with the distance calculated in step (c), until the center of the workpiece is vertically aligned with the workpiece conveying passage; (e) causing relative vertical movement between the workpiece feeding unit and the workpiece conveying unit so as to convey the workpiece placed on the workpiece conveying unit onto the workpiece conveying passage of said workpiece feeding unit; and (f) feeding the workpiece in the lengthwise direction to a cutting machine by the workpiece feeding unit, wherein the offset distance between the workpiece conveying passage and the side surface detection means is zero.