German Patent Disclosure Document DE-OS 27 41 596 describes a printing machine system, particularly for newspaper printing, in which the paper web is passed through a printing unit in essentially vertical direction. The path of the substrate web can be changed, so that regions of the machine which, in operation, are covered by the substrate web, can be made accessible, for example for maintenance work on the elements of the printing machine. The paper web is guided over a pair of deflection rollers, independently of the position of a working platform and the operating state of the machine, by being looped in an essentially S-shaped path about the deflection rollers which are positioned beneath a vertically movable working platform. The working platform can even be moved during operation of the printing machine without changing the length of the substrate path within a height difference which is determined by the upper edge of an intermediate platform bottom through which the substrate is carried to the first deflection roller and an additional further deflection roller, located in advance of the printing unit and fixed in position. The paper web is passed from the fixed further deflection roller to the second deflection roller on the work platform. When the work platform is raised, the lower printing cylinders are accessible to operators and mechanics for cleaning, maintenance and the like. When the platform is lowered, operators and mechanics can step on the platform and have access to the upper components, cylinders and rollers of the printing machine.
Rotary printing machine systems having a plurality of printing units or printing stations which are constructed in row arrangement, through which the web passes in essentially horizontal direction, cannot use the system described in the above referenced Disclosure Document 27 41 596, since the height difference of the printing machine elements, which are a condition for maintenance and moving of the platform without changing the web length no longer is available. If an S-shaped loop in the web path about deflection rollers is arranged in sequential, row-type printing stations of a composite printing machine, interference with the printed subject matter would result since ink printed on a substrate would not have time to dry and, thus, smearing of the freshly printed subject matter on the substrate would result.