| 摘要 |
An apparatus is provided for handling a web of material fed from a roll. When the roll is larger than a selected amount, a roll contacting belt contacts the outer surface of the roll to aid in rotating the roll. The roll contacting belt is speed-responsive to a tension sensing means. Once the roll decreases to the selected amount, the roll contacting belt is disengaged from the roll and a core brake controls the speed of the roll. This arrangement reduces web upsets caused by out of round new large rolls and eliminates telescoping due to the action of the belt against small diameter rolls. In the illustrative form of the invention, the apparatus provides a continuous supply of web material by handling a first roll from which web material is being fed through an infeed roller and a nip roller, and a second roll from which web material is fed after the web material of the first roll has expired. The speed of the first roll is controlled by the core brake and when the web from the first roll has almost expired, the roll contacting belt contacts the outer surface of the second roll to aid in its rotation. A web tension sensing means controls the speed of the infeed roller, which speed is transmitted to the roll contacting belt so that the speed of the web at the infeed roller and the speed of the roll contacting belt are matched. The web from the first roll is adhesively connected to the web from the second roll and then severed, while both webs are at the same speed. A system is disclosed for anticipating the inherent dealy time between the actuating signal for the severing operation and the actual severing of the web.
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