Folding apparatus and method

An apparatus for folding sheets or sheet stacks, comprising at least two folding/transport rollers, a transport device and a knife, the transport device defining a transport plane E for sheets or sheet stacks fed in a transport direction R, the knife being movable substantially perpendicularly to and through the transport plane E, the folding/transport rollers being arranged above the transport plane E, oppositely on both sides of the knife, an axis of rotation A of the folding/transport rollers extending substantially perpendicularly to the transport plane E, and the at least two folding/transport rollers each having, at their end facing toward the transport plane E, a rounded portion, such that a narrowing gap S is formed between the at least two folding/transport rollers, into said gap the sheets or sheet stacks can be introduced by means of the knife so as to be folded there and at the same time conveyed away in the transport direction R and wherein the knife is configured to carry out a horizontal movement during the folding process,

• the apparatus further comprising at least two drive rollers configured to rotate about an axis of rotation extending substantially perpendicular to the axis of rotation A of the folding/transport rollers and substantially perpendicular to the transport plane E,
• wherein the knife is hingedly coupled to the at least two drive rollers such that rotation of the driver rollers moves the knife through a circular path, and a component of the circular path includes the horizontal movement during the folding process.