apparatus for aligning large planar workpieces on a feed table wherein a plurality of pivoted arms are provided which are biased to a raised pivotal position to engage the edge of a workpiece , with the arms being urged to a lowered pivotal position by the weight of a workpiece resting thereon so that lateral movement of a plurality of the arms which may be arranged in rows will enable one of the arms of a row to engage the edge of a workpiece while in its raised pivotal position thereby to effect positioning or alignment of the workpiece .