Abstract: Apparatus having two stepping motors mounted in two mutually perpendicular planes and connected by means of bellows clutches to a top and a bottom lead screw, onto which there are screwed-on cut nuts. The top lead screw is seated on both side in a cradle which determines the working length of the screw A, while the cut nut of the same screw is fastened to a body lying with its legs on a base and carries a mechanism for vertical lifting of the working table. The bottom lead screw is seated in a carrier. Means on the left connect the left end of the cradle to the left side of the carrier, while means on the right connect the right end of the cradle to the right side of the carrier.