GB753746A - Improvements in or relating to flat-bed cylinder printing presses - Google Patents

Abstract

753,746. Cylinder printing-machines. SOC. NEBIOLO. March 18, 1954 [March 25, 1953], No. 7976/54. Class 100 (2). The cylinder 2 of a stop-cylinder press has a circumference substantially greater than the stroke of the flat bed 4, and between the end of the operative part of one impression stroke and the beginning of the operative part of the succeeding impression stroke the cylinder is driven by a drive which produces the rest period and transmits to the cylinder the angular movement necessary to bring it into position for re-engagement by the bed for direct drive. In the machine shown the bed is reciprocated by a crank 9, a connecting rod 8, and a toothed wheel 6 located between a fixed rack 7 and a rack 5 on the bed. At the end of impression a rack 11 driving the cylinder 2 anti-clockwise reaches the end of a toothed sector 12 and the cylinder drive is continued by a cam-actuated toothed sector 15 which engages a sector 13 fixed to the cylinder shaft, the motion imparted being a deceleration to stop at the position shown, and later an acceleration to the correct speed for reengagement of the rack 11 and sector 12; the stop point may be after, and the re-start point before, the respective reversal points of the bed 4. The cam mechanism shown (which may be replaced by cams acting directly on the sector 15) consists of complementary cams 20, 21 fixed to the driving shaft 10 one at each side of a free guide block 19 on which slides a slotted follower link 17 having rollers 22, 23 which engage the respective cams. The sectors 13, 15 may be elliptical, parabolic, &c., to supplement the cams 20,-21 in obtaining the required motion.