GB325901A - Improvements in or relating to printing machines - Google Patents

Abstract

325,901. Timson, A. R. Dec. 7, 1928, Platen machines. - In webprinting machines comprising a flat type-bed and a movable platen, intermittently actuated web-feeding means, preferably comprising Geneva-mechanism for causing the feed movement to have a slow start and finish, is mounted on the platen, and continuously operated means is provided for drawing the web off the roll. The platen may be actuated by toggle-mechanism. and the type-bed may be hinged to afford access thereto. In the machine shown in Figs. 1 and 4, feed-rollers 29 for the web are mounted in bearings 48 on a reciprocating platen 1 arranged below a type-bed 14. The feed-rollers are geared as described below to Geneva-mechanism mounted on the framework 3 and comprising a slotted member 24, Fig. 4, driven by pins 26 on a member 25 geared to a shaft 9. A driving-shaft 12 provided with a pedal-actuated clutch is geared to the shaft 9. The feed-rollers are geared to a shaft 42 mounted in a bearing 50 on the platen and passing through a bracket 40 on the framework. A bevel-wheel 43 mounted on the bracket and splined to the shaft engages a bevel-wheel 41 which is provided with a pinion 38 engaging a pinion 35 driven by a pinion 34 on the shaft 33 of the member 24. At each actuation of the pedal, the platen is operated by means described below and a length of web is fed, the feed movement having a slow start and finish. The peripheries 28 of the members 24, 25 co-operate to hold the member 24. The pinion 35 is changed to vary the feed movement. A second set of feed-rollers 51, mounted on the platen and driven in the above-described manner, is employed for drawing the web across the platen. The web is continuously drawn off the roll 57 by rollers 55, 56, a weight 59 being placed in the loop 58 formed by the rollers. The web may be re-wound on a roll 54, or may be cut by a knife 52 and delivered to a receptacle 53, the knife being mounted on the platen and being operated on the up-stroke by an abutment. The rolls 57, 54 and rollers 55, 56 may be duplicated to deal with two webs, these .being arranged to overlap, and the lower web being printed on the margin only. The platen reciprocates in guides 2 and is connected to a toggle 5 provided with a roller 7 engaging a cam 8 on the shaft 9. The type-bed is secured to a shaft 15 mounted in brackets 16 on the framework, the arrangement enabling the type-bed to be raised to facilitate access thereto. The type-bed is secured by means of hand-nuts 18 and pivoted bolts 17, and, is connected to a counterweight 21 by a wire 20 passing over a quadrant 19 on the shaft 15.