| 摘要 |
<p>A tube serves in particular as core tube for winding up web shaped material. In order to achieve a stable and cheap tube the tube consists of a piece of material (2) bent into tubular shape. On the piece of material rows of hollow projections (3) are arranged. When the piece of material has been bent into the tubular shape, the projections (3) face with their tops (7) inwardly and the latter comprise abutment surfaces or edges (12, 13) facing each other. The projections (3) arranged along the edges of the piece of material (2) extending in the longitudinal direction of the tube (1) are shaped for mutual engagement. An object to be used for forming such tube has the shape necessary for this purpose and several such objects may be stacked into a compact stack for shipment and storing. Tubes having different diameters may be produced by means of objects of the same size.</p> |
