GB620524A - System of setting paper positioning parts on a printing machine - Google Patents

Abstract

620,524. Printing-machines. NEWTON, E. P. (Addressograph-Multigraph Corporation). Nov. 27, 1946, No. 35201. [Class 100 (ii)] A printing-machine of the kind in which impressions are taken from a master printing- sheet secured to a drum, is constructed with scale means which enable the printed impression to be placed accurately on the printed sheet, one of the scales being on the drum and the other mounted on means which can be adjusted to control the position of the first printed impression. The invention is described in connection with a planographic offset machine as described in Specification 499,800 in which a master drum 20 coacts with an offset cylinder 30 and an impression roller 40 and cylinder 30 prints on sheets fed by a drop roller 71 to grippers 39, the printed sheets passing to a receiver with adjustable sides 91. The master sheet A is held to the drum 20 by clamps 27, 28, and the clamps used may grip the sheet A in either of three positions which are indicated by lines a, b, c, on scales E, Fig. 10, which are used in the process of adjusting the machine to position the impression correctly. The sheet A, Fig. 16, is marked with scales C<SP>2</SP>, and by means of a scale E the distance of the head K of the design from the end of the sheet is measured. The cylinders 20, 30 are connected by gears 26, 36, and gear 26 is circumferentially adjustable relatively to the cylinder 20 by loosening a bolt 29 which normally clamps the gear 26 to the cylinder. The gear 26 and a flange 25 can then be moved circumferentially to the position which ensures correct printing. The position is determined by a scale D carried by the flange 25, and a scale C secured to the drum 20, Fig. 13. A scale E, Fig. 12, is set to correspond with the required distance of the printed impression from the top of the paper, and a corresponding marking, e.g. the letter P on the scale D, is set to coincide with the numerical marking on scale C<SP>2</SP>, e.g. 7, obtained by the scale E, Fig. 10, which is set to indicate the position of the head K of the design from the top of the master sheet. The gear 26 is then fixed in position by the bolt 29. The numerical markings may be on the scale C instead of on the master sheet A, and other distinguishing marks than numerals and letters may be employed. Instead of using two scales E one scale may be used marked on one side with numerals and on the other side with letters. For laterally adjusting the sheets, the feed hopper 80 and the delivery receiver 90 may be fitted with adjustable sides 81, 91 set by means of scales F, G, Fig. 1 (not shown), which may be set by the aid of scales H on a master sheet A, Fig. 16, which are marked from the centre outwards in numerals on one side and letters on the other. The sheet H is marked at J to indicate the required position of the sheet to be printed, and by means of the readings on the scale H the sides 81, 91 are set.