Patent GB-1030269-A (GB)
Title: Impression cylinder combination for a press
IPC: B41F21/10
Filed: 1964-12-08
Abstract: 1,030,269. Printing apparatus; feeding and delivering sheets. L. MESTRE. Dec. 8, 1964 [Dec. 19, 1963], No. 49949/64. Headings B6B, B6C and B6H. Printing apparatus; gripper mechanisms.- The impression cylinder, Fig. 3, of a rotary offset printing machine comprises a head member at each end of the cylinder, each head member being provided with a bearing adapted to receive a shaft 14 on which the cylinder rotates, a plurality of spaced sheet grippers 19 supported by a pivotally mounted shaft 18, and operating means adapted to pivot the shaft 18 to open and close the grippers 19 with respect to a clamping surface 25. The said means include a pinion 28 secured to the shaft 18, a rack 29 meshing with the pinion, an operating lever 33, both the rack and the lever being mounted on a pivot 30, and an operating connection between the rack and the lever provided by a screw 35, a spring 34, and an adjustable nut 37. The lever 33 is oscillated to close the grippers by a fixed cam 46 which is engaged by a follower 39 on the lever, said cam having a high land 48 which causes the grippers to be closed, an intermediate land 49 which opens the grippers sufficiently to release the leading edge of the sheet, and a low land 50 which allows the grippers 19 to open completely. The adjustable, resilient connection 34, 35, 37 between the rack and the lever 33 prevents damage on jamming, allows the gripper pressure to be adjusted, and allows the timing of the gripper closing to be adjusted. Tripping.-The cylinder shaft 14, Fig. 5, is eccentric and is oscillated to move the cylinder away from the offset roller B if a sheet sensor 53 fails to detect a sheet on a guide plate 52. Feeding sheets.-The top sheet from a pile on a supply platform, not shown, is fed over the guide plate 52, Fig. 5, moves a sheet sensor 53, and engages stop means comprising a plurality of fingers 54. Each finger is provided at its bottom end with a groove which cooperates with a long finger 57 of a stripper mechanism. The fingers 54 are pivotally mounted on a frame and are moved into and away from a stop position by known means in a timed sequence with the rotation of the cylinder. Delivering sheets.-The leading edge of the printed sheet is raised from the cylinder when the grippers are partially opened by pairs of spaced fingers 57, 58 which are secured to a frame 59. The frame is projected to cause the fingers 57, 58 to lift the sheet when a follower 63 engages the high land of a cam 67. The raised sheet is then engaged by stripping fingers 69 which are located to come between the grippers 19 and the lifting fingers. Auxiliary sheet delivery means includes a pair of discs 77 mounted on a shaft 74 and adapted to be adjusted axially to engage sheets of different widths, and a roller 84 having a pair of spaced ridges 85 arranged to co-operate with a pair of rollers 87 carried by frame members 86. The members 77, 86 and 87 may all be adjusted axially by sliding a bracket 91 along a rod 92 and then securing them in position by screw means 93. One end 94 of each bracket is forkshaped and straddles the roller or disc 77 and the frame 86.