| 摘要 |
A folding apparatus for separating a web into individual signatures and producing two folds in each signature, comprises an upper cylinder, a lower cylinder and an intermediate cylinder. Each of the cylinders is rotated about an axis, the axes of the upper and intermediate cylinders being parallel and spaced apart to define a given plane and the axis of the lower cylinder being parallel to the axes of the first and intermediate cylinders and offset from the plane thereof. The upper and lower cylinders rotate in the same direction and the intermediate cylinder in the opposite direction. First and second folding assemblies produce two folds in each signature. The first folding assembly includes cooperating portions carried on the upper cylinder and on the intermediate cylinder. The second folding assembly includes cooperating portions carried on the lower cylinder and on the intermediate cylinder. A cutting assembly separates the web to produce the individual signatures. Each of the folding assemblies includes a tucker blade having an axis, and a tucker blade mounting and control structure for mounting the tucker blade to one of the cylinders for compound pivotal motion comprising a motion which causes substantial alignment of the tucker blade axis with a given radius of the adjacent cylinder through a predetermined portion of cylinder rotation so as to urge the signature into a folded condition while substantially preventing wiping engagement between the tucker blade and the signature. |
