| 摘要 |
A gripper opening/closing apparatus in a sheet-fed rotary printing press, the apparatus having a broadside printing cam and a perfecting cam which are commonly brought into contact with cam followers, and which are adjacent to each other to be coaxial with an impression cylinder, and the apparatus being arranged such that, in a broadside printing mode, grippers of the impression cylinder are opened/closed by the broadside printing cam to cause reversing grippers of a reversing cylinder to grip a leading end of a printed sheet gripped by the grippers of the impression cylinder, and that, in a perfecting mode, the grippers of the impression cylinder is opened/closed by the perfecting cam and the broadside printing cam to cause the reversing grippers of the reversing cylinder to grip a trailing end of the printed sheet gripped by the grippers of the impression cylinder, wherein a central angle of the impression cylinder which is formed between a sheet gripping position where the grippers of the impression cylinder grip the sheet from a preceding stage and a transfer position where the sheet is transferred from the grippers of the impression cylinder to the reversing grippers of the reversing cylinder is set to be smaller than a remaining central angle of the impression cylinder, and wherein shapes of the broadside printing cam and the perfecting cam are determined in such a manner that, in the broadside printing mode, the perfecting cam is located in a portion of the impression cylinder which corresponds to the remaining central angle so as to set the perfecting cam away from a sheet release position of the broadside printing cam and to set the perfecting cam in an inactive state, and that, in the perfecting mode, the perfecting cam is located to be continuous with the sheet release position of the broadside printing cam.
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