Patent ID: 7905445

Claim:
An unwinding device for wound rolls, comprising: a bearing element; a first support element and a second support element mounted on the bearing element, the first and second support elements adapted to rotatably hold the wound roll on opposed sides, wherein the first support element and the second support element are movable along the bearing element with respect to one another; and a drive mechanism adapted to move the first support element and the second support element along the bearing element, the drive mechanism comprising: a single one of a chain or toothed belt movable along the bearing element; and a first engagement member disposed on the first support element, wherein the first engagement member is adapted to releasably lock the first support element to the chain or toothed belt, and is rotatable about an axis crosswise to a direction of movement of the chain or toothed belt; the first engagement member engages the chain or toothed belt such that, upon rotation of the first engagement member, the first engagement member moves along the chain or toothed belt, thereby producing a relative movement of the first support element with respect to the chain or toothed belt; and the first support element is locked to the chain or toothed belt when the first engagement member is locked still, wherein the drive mechanism comprises a drive disposed on the bearing element that is adapted to move the chain or toothed belt along the bearing element, and drives for each of the first and second support elements that are adapted to rotate a respective engagement member, wherein each of the drives for the first and second support elements comprise a brake adapted to hold the respective engagement member at a standstill.