| 摘要 |
Groups of corrugations 3 are formed in a strip 2 of cardboard, Fig. 1 (not shown), by a machine comprising a toothed roller which pushes the strip between pairs of rods to form the peaks of the corrugations. The rods of each pair are urged together to compress the corrugations so formed. Between the groups of corrugations flat portions 4 in the strip are provided for by flat sections on the roller where the teeth are omitted. A distance member, replacing the rods in that area of the machine, may be formed by rods lying side by side. Alternatively, the corrugations may be formed by plungers which press the strip between pairs of stationary rods. The rods then move past the plungers to compress the corrugations. The flat portions in the strip are provided by the plungers remaining inoperative between successive movements of the rods. The strip forms part of a box blank (see Division B8) when it is glued to a further strip 1 of cardboard, Fig. 2, (not shown). |
