Abstract: A caterpillar take-off device for hauling off extrusion products, in particular plastic tubes, includes at least two caterpillar tracks arranged symmetrically in relation to a length axis of the caterpillar take-off device, at least during take-off process by changing the distance from the caterpillar tracks to the length axis. In the event of a change in cross-section of the extrusion product, the change is measured and the distance of the caterpillar tracks from the length axis is automatically adjusted such that the symmetry axis of the extrusion product coincides with the longitudinal axis of the caterpillar take-off unit.

Abstract: For the production of a hollow cylindrical body, for example a tube or a container, first a bottom channel (1) is wound spirally onto a mandrel. A top channel (2) is wound on to the bottom channel (1) offset by half the channel width. The top and bottom channel (1, 2) both have an approximately E-shaped cross section with two outside flanges (3, 4) and two middle flanges (5, 6). The distance between the two middle flanges (5, 6) correspond to the combined thicknesses of the two outside flanges (3, 4). The confronting surfaces (7, 8) of the two outside flanges (3, 4) and of the two middle flanges (5, 6) are provided with a sawtooth cross-sectional shape, so that an inseparable, interlocking connection results between the bottom channel (1) and the top channel (2). The bottom channel (1) and top channel (2) can consist of different plastic materials.