GB484169A - Improvements in or relating to printing presses - Google Patents

Abstract

484,169. Printing - machines. JOHNSON, F. R., and PFLANZE, C. F. Oct. 30, 1936, No. 29576. [Class 100 (ii)] Printing - surfaces.- Printing - plates are secured in presses by the use of suction applied through a vacuum chamber situated in the bed or cylinder of the press. The printing - plate shown in Fig. 3 is provided with a continuous marginal flange 16 for contact throughout with the cylinder, and with a tongue 17 at one side to be located in a longitudinal guide groove 18, Fig. 1, in the cylinder. The under surface of the plate, or the corresponding area of the cylinder, is formed with numerous grooves 15 or cavities for distribution of suction over the entire area of the plate. The cylinder B is hollow and provided with groups of apertures 13 for securing the printing-plates P, and is mounted on a hollow shaft 1 perforated at 8 and connected at one end through a stuffing- box 11 to a suction pipe 10. A slow-drying adhesive may be used to secure the plate in the press, the suction being employed only to hold the plate while the adhesive is drying. Impression adjustments.-After the plate has been located on the cylinder, longitudinal and circumferential registration are effected by adjusting the cylinder. The shaft 1<1>, Fig. 4, carries a two piece collar 8<1> between which is a member 11<1> attached at the upper part by a threaded bolt 12<1> to the fixed bearing 2<1>, and provided at the lower part with a guide post 15<1>. For the circumferential adjustment, the gear wheel 16<1> is in two parts 17<1>, 181 connected together by bolts 20<1> attached to the inner portion 18<1> and passing through curved slots in the outer portion 17 <1>, and relative rotation of these parts can be effected by means of a nut 24<1> on the outer part and connections 23<1>, 221 to the inner part.