GB1137967A - Improvements in or relating to web printing machines - Google Patents

Abstract

1,137,967. Web printing machines. FRITZ BUSER A.G. 26 Aug., 1966 [16 Sept., 1965], No. 38474/66. Addition to 1,037,467. Heading B6C. A web printing machine, see Fig. 1, comprises an endless conveyer 2 trained around two rollers 3 and 4 at opposite ends of the machine, means being provided to drive the upper flight of the conveyer 2a intermittently across a printing table 1, and to drive the lower flight 2b continuously through a masking installation 5 and a glue applicator 6; the rollers move in unison towards positions 3<SP>1</SP> and 4<SP>1</SP> when the upper flight 2a is in motion and return to original positions 3 and 4 when the upper flight is stationary, i.e. during printing, at least the roller 3 being displaceable above the plane of the table 1. The upper flight 2a is driven by means similar to that described in Specification 1,037,467, that is hydraulic or magnetic tongs 10 connected to a piston 8 in a cylinder 7 containing oil under pressure; the lower flight 2b is driven by roller 34 which is connected to electric motor 36 via an infinitely variable gear. In order to keep the conveyer belt under tension throughout displacement of rollers 3 and 4, the latter are connected together by a chain 19 which passes over deflection rollers 20, 21 and 22. The web is fed on to the conveyer from the web roll 25 by means of e supply roller 26 which may be heated; the supply roller 26 bears up against a deflecting roller 24 through the thickness of the conveyer, while the speed at which the conveyer is moving governs the amount of pressure applied by the supply roller for adhesion of the web to the conveyer, the governor being a pivoted lever 29 controlled by an hydraulic piston 33 connected to a pump 30 which is in turn controlled by the roller 24. Fig. 2 illustrates the means by which the infinitely variable gear of the motor 36 is controlled by the actual motion of the rollers 3 and 4. A chain 37 is connected to the chain 19 by end-pieces 38, and passes over a wheel 39; coaxial with the first wheel 39 is a second or control wheel 43 which controls the gearing of motor 36 via chain 40. Both wheels are provided with pins and corresponding stops so that movement of chain 37 rotates wheel 39 and causes suitable movement of wheel 43 controlling the gearing of motor 36 and hence of the lower flight of the conveyer 2b (Figs. 3 to 6, not shown).