GB960903A - Printing machines - Google Patents

Abstract

960,903. Printing machines. ADDRESSOGRAPH-MULTIGRAPH CORPORATION. Feb. 6, 1961 [Feb. 10, 1960], No. 4387/61. Heading B6C. In a hand-operated printing machine a platen carriage carrying a platen roller is movable over a bed on which is arranged in superimposed relationship an upwardly disposed printing plate, inking means and the matter to be printed. The bed comprises a top plate 26, Fig. 3, integral with depending side portions 28, Fig. 1, and end lugs 31, Fig. 7, the latter adjustably mounting end caps 40, Figs. 1 and 3, which serve both as a supporting structure for the machine and as a support for a central rail 42 upon which runs rollers 105 of a guide 110, Fig. 15, forming part of the platen carriage. The carriage also incorporates a saddle-shaped member 120, 121 which mounts, through adjustable eccentric bearings, rollers 135 for engagement with the lower surfaces 28F of the bed side portions 28. The platen roller is mounted in the carriage on eccentrically arranged bushings 147 and 148, Figs. 10 and 12, such that on the return stroke, i.e. to the left as viewed in Fig. 1, the roller is out of contact with the matter-sheets, cards &c.-that has just been printed. The lifting and lowering of the roller relative to the bed is effected by a toothed gear segment 150 fixed to the bushing 148 which engages teeth 153T and 154T, Fig. 7, formed in plastic mouldings secured to the plate 26 in the path of the gear segment 150. In the " before " printing position of Fig. 1 the roller is raised, but on moving the carriage the teeth 153T engage the gear 150 such that the eccentric bushings are rotated to lower the roller for the printing operation. As the end of the printing stroke the teeth 154T engages the gear 150 to raise the roller and this position is maintained throughout the return or non-printing stroke. In the modified machine shown in Fig. 16, the cards or sheets to be printed thereby are of short dimension which enables the removal thereof after a stroke of the platen carriage irrespective of the end of the machine where the carriage happens to be. The platen roller need not therefore be shifted during the course of a reciprocal movement of the carriage and to this end gear 190 and associated teeth 154T, 153T and the various eccentrics are omitted. During the printing operation in both embodiments ink is exuded if the platen roller is impregnated, or " carbon " is offset image-wise if carbon sheets are used in conjunction with a dry platen. Specifications 951,249 and 960,904 are referred to.