Patent GB-184176-A (GB)
Title: Improvements in or relating to printing presses
IPC: B41F33/12
Filed: 1922-07-27
Abstract: 184,176. American Type Founders Co., (Assignees of Kelly, W. M.). Aug. 6, 1921, [Convention date]. Stopping and tripping arrangements.-A printing - machine is fitted with means for controlling the sheetfeed mechanism, the stopping of the press, and the throwing on and off of the impression, and the controlling mechanism is arranged so that the machine can be converted from one dealing with a sheet at every rotation to one dealing with sheets at alternate or periodic rotations, so that double rolling occurs. The machine is fitted with a detector which, if a sheet is not fed or if a crumpled sheet is fed, acts to cut off the feed and throw-off the impression, and also to stop the press. When the machine prints alternate sheets, a detector acts to cut off the feed and trip the impression for each alternate rotation of the machine. As shown in Fig. 2, the sheets are fed from a pile 10 by a mouth-piece 14 in communication with a suction pipe 15 and by a pair of rotating wheels 12 with suction nozzles 13. As the nozzles 13 pass the mouth-piece, the front edge of the sheet is drawn up, and the feeding and forwarding of the sheet takes place by the progressive suction action on narrow portions of the sheet extending from the front to the rear edge of the same. The suction in pipe 15 is relieved at the desired time by a cam-operated valve 16, and this valve may be opened by means controlled by detectors when it is desired to stop the feed. The sheets pass over a feed board 19 to a cylinder 11, and pass under a detector 20 which is swung to the left by the sheet about its pivot 21, and permits a shoulder 22 on a lever 24 to move with the lever in a clockwise direction under the action of a spring 23. This movement is permitted by a cam 28 engaged by a roller 27 on a lever 26 connected by a link 25 to lever 24. A pin 30 on lever 26 thereby controls a dog 31 on an oscillating lever 35, and the dog 31 is moved clear of a rod 34. If, however, no sheet is present, the lever 24 is not moved, and in consequence the dog 31 comes into contact with rod 34 and this is depressed and actuates the three following trip mechanisms. (1) A lever 39 on the rod 34 actuates a link 40, and arm 41 on a shaft 42 controlling the impression. (2) A pawl 43 on rod 34 actuates the plunger 44 of a switch 45 to stop the press. (3) A pawl 46 acts on a lever 49 connected by a slotted link 50 to an arm 51 which opens the valve 16 to cut out the suction feed. To cause the machine to operate on sheets for alternate revolutions only, a dog 56 on a rod 54 mounted alongside of rod 34 is turned to the position shown in Fig. 4, and it is then moved by the dog 31 to depress the rod 54, and this by a lever 60 trips the pawl 43 out of the path of the plunger 44 of the switch. The lever 48 is now actuated by hand to prevent the feed of one sheet, and the absence of this sheet on the feed board will cause the next sheet but one to be automatically prevented from being fed, and the machine will continue to feed alternate sheets only. A crumpled-sheet-detector 69 is actuated by a crumpled sheet to cause a latch 71 to restrain the lever 24 from its normal movements, and this actuates the trips in the manner described in connection with detector 20.