Abstract: An improved web tension control system including a shaft and a hollow cylindrical roller mounted on the shaft for rotation about the shaft and for universal pivoting movement relative to the shaft that tends to compensate for variations in the tension of a moving web or substrate passing over the hollow cylindrical roller. The hollow cylindrical roller is mounted on the shaft by a spherical bearing assembly that permits universal pivoting movement of the hollow cylindrical roller relative to the shaft and a roller bearing assembly positioned between the outer surface of the spherical bearing assembly and the inner cylindrical surface of the hollow cylindrical roller to permit free relative rotation of the roller about the shaft. In an alternate embodiment, slots may be formed in the abutting spherical surfaces of the spherical bearing assembly, and an insertable wafer can be placed in such slots to selectively limit the pivoting movement of the hollow cylindrical roller.

Abstract: A web tensioning control device includes a cylindrical roller that automatically adjusts its orientation in order to equalize the tension across a moving web. Each end of the cylindrical roller is supported by a pneumatic spring. A conduit connects the two pneumatic springs so that pressurized air can shift between the springs in response to changes in the tension across the moving web. Thus, the cylindrical roller is allowed to pivot about an axis perpendicular to its roll axle so that the tension at each point across the moving web is substantially equal after encountering the roller.

Abstract: A web tension control system includes a stationary rod and a roller attached to the rod by a flexible coupling. A bearing is attached to the inner surface of the roller. The flexible coupling is attached, at one end, to the rod, and, at a second end to the inner portion of the bearing. The inner portion of the bearing is attached to the flexible coupling. One embodiment enables the roller to pivot about a central location where the bearing is attached to the inner surface of the roller. Another embodiment provides full pivotal freedom for the roller to angularly rotate about a central location through a limited range of angular displacement.

Abstract: A device for measuring warpage of a surface is disclosed including a rigid support plate having first and second guide tracks attached thereto. A resiliently flexible band extends between the first and second guide tracks and includes first and second guides attached at ends of the band. A dial indicator is mounted to the rigid support plate for measuring deflection of the resiliently flexible band relative to the plate, wherein the dial indicator includes a probe attached to the flexible band for detecting deflection of the band relative to the plate. The flexible band resiliently deflects to conform to a warped surface when placed thereagainst, and the first and second guides reciprocate in the guide tracks as the band deflects to allow the band to conform to the warped surface. The band is of a predetermined length such that the dial indicator indicates deflection of the flexible band as a function of the predetermined length.

Abstract: An improved corrugated board manufacturing apparatus and method including precise web moisture and temperature control is disclosed. The apparatus includes steam driven manifolds for zone drying of the web using pressurized steam to reduce moisture and equalize the moisture content across the web. Moisture sensors and temperature sensors are implemented to scan the web and provide feedback information regarding web moisture and temperature. Wrap arm position is automatically controlled to obtain ideal web temperatures for corrugated board production. Web speed and take-up ratios are monitored to determine when process parameters are out of limits which may cause waste. An improved hot plate section including variable pressure applied to the web as well as variable steam supplied to the hot plates results in a more effective process control loop in achieving and maintaining web temperature for curing the adhesive and preventing warping.