GB235269A - Improvements appertaining to gripper mechanism for rotary printing machines - Google Patents

Abstract

235,269. Waite, F., and Waite & Saville, Ltd. March 4, 1924. Gripper mechanism.-The impression cylinder of a printing-machine is fitted with grippers 2 geared to an oscillating sector 8 for opening and closing the grippers, and the sector 8 is operated by a bowl 8<a> running in a fixed cam groove 7<a> so arranged that the grippers are positively moved by the cam to the open position and also to a position near the gripping position, the final movement to effect the gripping of the sheet being effected under spring action. The sector 8 is pivoted to a spring-pressed rod 23, guided by a bracket 25, and the rod 23 tends constantly to keep the grippers closed. The shaft 2<a> of the grippers is acted on by a spring-pressed pivoted rod 24, which, when the grippers 2 are open, tends to keep them open, but reinforces the spring action of the rod 23 when the grippers are closed by the cam 7<a>. The cam surface 7<a> is designed to be as close as possible to the path in which the pivotal centre of the grippers travels. When it is desired to retain the sheet on the impression cylinder for more than one revolution, the operating-cam for the bowl 8<a> is formed with raised flanges 7, 7<b>, Fig. 8, between which is a space 7<a> in which the bowl' 8a passes when the grippers are to be opened. A pivoted member 7f is fitted with flanges c, c<1> for controlling the bowl 8<a>, and when the grippers are to remain closed for more than a revolution the member 7f is set by the cam 13 and lever connections shown in Fig. 3 to the position shown in Fig. 8 to permit the bowl 8<a> to move though an opening c<2> on to the outside of the flange 7b, and thus to cause the grippers to remain closed. The pivoted member 7f is then returned to the position shown in Fig,. 3, and on the next rotation the bowl 8<a> is guided by the flange c<1> into the inside of the flange 7b to allow the grippers to open. In the modification shown in Fig. 3, the gear sector 8 is controlled by an extension spring 21 secured to the impression cylinder.