An intermediate cylinder (3b) comprising a main body (11), and a plurality of suction boxes (15a, 15b) formed in the main body (11) at positions different with respect to a rotation axis of the main body (11). The intermediate cylinder (3b) further comprises a plurality of suction bores (16) formed in the suction boxes (15a, 15b) so that they are open at an outer peripheral surface of the main body (11), an air suction source (10) for generating suction force within the suction boxes (15s, 15b), and a switching means (7) for selectively switching connections between the plurality of suction boxes (15a, 15b) and the air suction source (10).
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