GB1217424A - Improvements in or relating to web feeding mechanisms - Google Patents

Abstract

1,217,424. Feeding webs. VICTORYKIDDER Ltd. 9 Oct., 1969 [14 Oct., 1968], No. 48511/68. Heading B8R. A web feeding mechanism comprises an aircushion table 4 which supports a web reel 3 on its side, the passage of air from a pressure supply 11 to the table 4 being controlled by a valve 12 responsive to the position of a dancer roller 13 around which the web 2 passes on its way to a processing machine 1, air-loaded turner bars (14, Fig. 6, not shown) being provided to turn the plane of the web from the vertical, as it leaves the reel 3, to the horizontal. Should the tension in the web become too low the supply of air to the table is reduced so that the reel tends to fall back on the table thereby increasing the friction between the two, the rate of unwind of the reel thus being automatically reduced; conversely the friction between the reel and the table is reduced by an increase in the air supply when the web tension becomes too high, and thus the web tension tends to remain constant during the unwinding process. The air cushion may be provided by supplying air under pressure to a plurality of spring loaded valves in the table 4 (Figs. 4 and 5, not shown), or to an annular groove formed in the table surface (Figs. 13 and 14, not shown); alternatively, air may be supplied through a spindle 5 to the space between the reel and the table (Fig. 15, not shown). If a plurality of webs are to be fed to a processing machine the reels may be supported on separate tables arranged one above another (Figs. 7 and 8, not shown), or side-by-side (Figs. 9 and 10, not shown), the reels being loaded on to the tables by aircushion conveyers. The spindles 5 may be pneumatically actuated to locate the reel on the table (Figs. 2 and 12, not shown) if the mechanism is used for winding rather than unwinding.