GB1162708A - Rotary Machines - Google Patents

Abstract

1,162,708. Rotary printing machines. HARRIS-INTERTYPE CORP. 11 Oct., 1966 [20 Oct., 1965 (2)], No. 45399/66. Heading B6C. Rotary machines having co-operating cylinders with gaps in their peripheries are provided with means adjacent to a gap of at least one of the cylinders for causing the pressure between the cylinders to change over an appreciable angular movement of the cylinder, when the gap is in the vicinity of the point of contact of the cylinders. In particular, the invention applies to the blanket cylinder of a rotary press where means for attaching a blanket is provided in a gap in the surface of the cylinder, but it is also applicable for plate and impression cylinders where means are provided for attaching printing plates and sheets of paper in respective gaps in the surfaces of the cylinders (Fig. 1, not shown). Fig. 2 illustrates a blanket cylinder 11 with a gap in its surface and means for fixing the blanket to the cylinder. The leading and trailing sides 75, 70 of the gap are provided with undercuts 27, 32 which extend in the direction of the circumference of the cylinder undercutting the periphery and hence forming resilient cantilevered projections 29, 33, the deflection being limited by stops 34, held in position by screws 35. The undercut may be filled with a resilient material which deforms but limits movement of the cantilevered projection (Fig. 3, not shown). Alternatively an alloy steel insert is positioned adjacent the gap (Fig. 4), an undercut 50 being formed in the insert and a wedge block 51 being supported on an inclined surface 50a; the block 51 can be moved up and down the inclined surface by rotation of adjusting screws 55, thus moving the top of the wedge block 51a towards and away from the cantilever projection 53. A third embodiment involves a cut-out portion adjacent the gap, the cut-out being completely filled by a resiliently deflectable wedge (Fig. 5, not shown). Blanket gripping device (Fig. 2).-The ends of the blanket carry bars 60a and 60b which cooperate with clamps 18a, 18b in a dovetail fashion. Clamp member 18a contains a rotatable shaft 64 which is turned counterclockwise to tighten the blanket about the cylinder. Clamp member 18b includes a fixed support 66 and a movable support 67 which slides on support 66 by means of adjustment screws 71 abutting rod 72 which in turn abuts the side of the gap. On tightening the screw, the blanket is tensioned, preventing angular misalignment on the cylinder.