A folding apparatus includes a folding blade cylinder that carries at
least one group of identical tools which are distributed homogeneously
about the periphery of the folding blade cylinder. A cam plate is traced
or followed by a control lever of each such group of tools and is usable
to control a working movement of the tool. A cover disk, consisting of a
plurality of cover cams, can be rotated. The cover cams of the cover disk
are displaceable between an inactive position, in which they enable the
control of the working movement by the cam plate, and an active position
in which they prevent such movement. Two groups of tools are used on the
folding blade cylinder and the cover cams form a first group of cams at
an angular distance of between 60.degree. or 120.degree. to each other,
and a second group of cams at an angular distance of between 90.degree.
to 180.degree. to each other.