Abstract: A tube conveyor, in particular a tube conveyor in which an endlessly revolving conveying belt is guided at least partly in the interior of carrier rolls (5) which are attached in a ring-shaped manner and whose axes extend substantially transversally to the direction of conveyance, and is substantially shaped into a tube, with the return of the conveying belt (3) being performed outside of the loaded strand shaped into a tube. In order to provide a tube conveyor which does not require any additional external supporting rolls for the return of the unloaded strand and thus both simplifies the installation of such a tube conveyor and reduces its noise production during operation, the return of the unloaded strand (9) of the conveying belt (3) is performed while resting on the upper carrier rolls (5) which are arranged in a ring-shaped manner.

Abstract: A boring spindle unit with automatic tool liftoff, especially for the finish boring of a workpiece with an oxide-ceramic boring tool carried by the spindle shaft. The spindle shaft is journaled in at least two main bearings and at least a further bearing is disposed proximal to the main bearing at the tool end of the shaft. During the spindle retraction movement, the additional bearing takes up the journaling of the shaft and has an axis which is offset by a distance from the axis of the main bearings and in a direction opposite that from which the tool projects from the shaft so that the tool does not groove the workpiece during the retraction operation. While the main bearings are effected, the auxiliary bearing receives the shaft with radial play and, while the auxiliary bearing is effective, at least the main bearing proximal to the tool end receives the shaft with radial play.