| 摘要 |
<p>1,196,152. Printing apparatus; transfer cylinders. MILLER PRINTING MACHINERY CO. 19 July, 1967 [19`Dec., 1966]. No. 33092/67. Heading B6C. A transfer cylinder comprises gripper means for receiving the leading edge of a sheet, and sheet-engaging means for the trailing edge of the sheet, wherein mechanical means are operative to remove the sheet-engaging means towards the grippers around the periphery of the cylinder to receive a sheet and then to move the sheetengaging means away from the gripper to tension the sheet. The cylinder is especially applicable as the second transfer cylinder of the press disclosed in Specification 735,477, where the sheet-engaging means comprise at least one suction head. Fig. 2 illustrates the leading edge 30 of a sheet 32 engaged by gripper 14 while the trailing edge 36 is about to pass from the first transfer cylinder 34 over suction head 20; vacuum is applied and wrinkles 38, 40 in the sheet are removed by swivelling arm 24 in a clockwise direction to draw the sheet taut. The vacuum and the movement of the arm 24 is cam-controlled with the aid of a resilient bias, springs causing the clockwise movement of the arm 24. When it is required to release the trailing edge of the sheet for transfer to a third cylinder, air under pressure is applied through the suction head (Figs. 5-11, not shown). Alternatively, the cams can be replaced by electromagnetic actuators (Figs. 12, 13, not shown).</p> |
