Automatic web rewinder for tensioned web

Abstract

In web rewinding apparatus for producing hard-wound individual rolls, a knife for cutting through the web is carried for substantially radial extension and retraction by a cutoff roll which cooperates with a bed roll around which the web has substantial wrap. When extended, the knife enters a longitudinal slot in the bed roll, in which there is a row of fixed pins. A web impalement pusher bar, extended from the cutoff roll along with the knife, impales the web onto the pins. Transfer pads carried by the bed roll extend, to detach the web from the pins and clamp it against a new core. Cores onto which web is wound are supported by six mandrels spaced circumferentially around a turret that carries them, in turn, to each of six fixed stations. Coaxial with each mandrel on the turret is a rotatable driver and a normally disengaged clutch which, when engaged, transmits rotation of its driver to its mandrel. Alternate drivers around the turret are driven from one motor, the remaining drivers by a second motor. Each clutch is engaged as its mandrel moves into an acceleration station. Shortly before a mandrel moves out of the acceleration station to a winding station it is brought up to web speed; and while it is at the winding station its motor applies a constant torque on it to maintain tension on the web. A driven rider roll augments web tension. Turret indexing is controlled by a pulse generator and a resettable counter that is adjustable to adjust length of web wound onto an individual roll.