| 摘要 |
1,207,638. Guiding webs. E.I. DU PONT DE NEMOURS & CO. 27 May, 1969 [29 May, 1968], No. 26610/69. Heading B8R. A web-aligning unit comprises two multi-roll assemblies 3, 4 mounted parallel and in tandem to provide an 8-shaped path for a moving web, each roll assembly including a plurality of rollers equally spaced about the central axis of the assembly and having one end 12 fixed and the other end, i.e. end plate 26 for assembly 3 and end plate 27 for assembly 4, movable in journals 28 or 29 about said axis so that the rollers 23 can be inclined with respect to the axis, the entrance roller 22 above being maintained in a position perpendicular to the path of the web by a ball-joint 35 which holds the end plate 26 at that point; a carrier 2 for the assemblies 3, 4 pivoted about an axis 16; an actuator 31 responsive to a web-sensing feeler detecting web misalignment (Fig. 5, not shown) for pivoting the carrier 2 in the direction of the desired correction; and a connecting rod 30 joining the end plates 26, 27 which thus rotate slightly in response to the pivotal movement of the carrier 2 so that the rollers of the assemblies 3, 4 incline simultaneously, whereby the travel of the web is corrected, the web following a true helical path through the unit. Disturbance of the cylindrical geometry of the roll assemblies caused by skewing of the rollers is controlled by flexing the rollers 23 slightly at their mid points, pairs of wheels 40 being provided for this purpose. In a modification (Figs. 6 and 7, not shown), the unit is controlled by a position sensing system, e.g. of the fluidic, optical, radiation, inductance or capacitance type, so as to cause the web to traverse slightly from side-to-side as it leaves the unit to be wound into a package, thereby to prevent uneven build-up of the package in the vicinity of gauge thickness variations. |
