GB317526A - Improvements in or relating to tripping mechanism of rotary printing machines - Google Patents

Abstract

317,526. Linotype & Machinery, Ltd., and Dowson, R. May 18, 1928. Tripping-arrangements.-A multicolour rotary printing-machine in which the work is fed in succession through printing couples such as offset cylinders 2, 2<a>, and impression cylinders 3, 3<a>, is fitted with trip mechanism which trips each couple successively after it has printed the sheet last fed. The tripping-devices are constructed so that either of the couples may be tripped independently of the other, and sheetfeed tripping-devices also are employed which may be operated to prevent feed if the first printing-couple is tripped, or the sheet-feed tripping-devices may be prevented from being actuated if it is desired to print a sheet by the second couple only. The offset cylinders 2, 2<a> are operated by similar trip mechanism comprising eccentrics 10, 10<a>, connected by adjustable links to lever arms 9, 9<a> on trip-shafts 7, 7<a>, which are rotated, when desired, by oscillating pawls 12, 12<a>, 13, 13<a>, connected by curved links and controlled by levers 19, 19<a>, the lever 19 being actuated by yielding lever-and-link mechanism 23, 22, 21, 20 from a pedal 8. The lever 19<a> is operated from the trip shaft 7 owing to a yielding lever-and-link connection 30, 21<a>, 22a, 23<a>, and the levers 19, 19<a> so control the pawls that on depression of pedal 8 the cylinder 2 is tripped by the engagement of pawl 12 with an abutment on a sector 6 rocked by a cam on impression cylinder 3, the cylinder 2 being tripped after an impression is completed. The succeeding cylinder 2<a> is tripped when a further impression has been produced on the same sheet. The sheet-feed tripping-devices are of the kind set forth in Specification 288,405 and comprise a stop-shaft 25 which is connected by a link 27 and lever 28 to the pedal trip, so that when this is operated, the oscillating gripper feed is also tripped. A lay shaft which interposes a stop in the path of the sheet to be feed is also operatively connected to lever 9 so that the stop is raised when cylinder 2 is tripped. The connections between the cylinder and feed trips can be adjusted so as to permit the cylinder 2 to be tripped without actuating the feed trips, so that a sheet can pass from cylinder 3 to 3<a> and be printed only by the second couple. The lever 19<a> can be held permanently by a pin 48 in positions corresponding to the tripped and untripped positions of the couple 2a, 3<a>, so that it is possible to print in single colour from either couple as well as in multicolour. The eccentrics 10, 10<a> are connected to ink-tripping devices to prevent double inking of the plates when the printing-couples are tripped.