| 摘要 |
A device and method for positively controlling and rotating an item through a predetermined angle in a plane as said item is moved longitudinally in the plane. Different lateral portions of the item are moved at different speeds in the longitudinal direction to effect the rotation. Preferably a pair of cone shaped segmented rollers are utilized which have a nip formed between high sections of the rollers, coplanar with the plane of rotation. Alternatively a pair of spaced segmented rollers having different linear surface speeds can be used to move the spaced lateral portions of the item at the different linear speeds. Positive control of the item is provided by opposed rotating members such as opposed belt conveyors or opposed sets of rollers and a mechanism is provided to selectively engage or release the opposed rotating members as required by the rotation of the item.
|
