Folding gear comprising a cylinder with adjustable circumference

A folding apparatus comprising:

• a cylinder;
• a cylinder gear wheel;
• means supporting said cylinder for rotation about a cylinder axis of rotation in a frame;
• a cylinder shell surface including at least one hoop extending in a circumferential direction of said cylinder shell surface, said at least one hoop being supported for displacement with respect to said cylinder shell surface;
• an adjusting gear assembly for displacement of said at least one hoop, said adjusting gear assembly including first and second stages, each of said first and second stages having a flexible toothed sleeve, said first and second flexible toothed sleeves of said first and second stages of said adjusting gear assembly being connected to each other;
• a flexible toothed sleeve support shaft having an elliptical section, said elliptical section being adapted to deform said first and second flexible toothed sleeves of said first and second stages of said adjusting gear assembly;
• a drive mechanism for said flexible toothed sleeve support shaft;
• a first internally geared wheel in said first stage, said first internally geared wheel having internal teeth meshing with said first flexible toothed sleeve and having external teeth engaging said cylinder gear wheel;
• and
• a second internally geared wheel in said second stage, said second internally geared wheel having internal teeth meshing with said second flexible toothed sleeve and having external teeth connected to said at least one hoop.