Sheet feeder and inverter apparatus for sheet-processing machines, preferably for two offset printing machines disposed in tandem

#The present invention relates to a sheet feeder and inverter apparatus for sheet-processing machines for selective operation with or without inverting the sheets, preferably for two offset printing machines disposed in tandem.

#Sheet feeder and inverter apparatus is already known in many variant forms in the prior art. As a rule, the ability to invert the sheets can be switched on and off, so that the sheets to be processed in any machines can be either processed twice on one side or successively on both sides, or in the case of printing machines can be so printed.

#A substantial disadvantage of such known feeder and inverter apparatus is that they are either structurally too complicated and hence expensive, or that they cannot operate fast enough, so that high-speed offset printing machines, for example, which are capable of processing up to 25,000 sheets per hour, cannot be run at their maximum rate.

#FIG. 1 shows the substantial elements of two offset printing machines disposed one after the other, which are connected to one another via the apparatus according to the invention for printing sheets in succession;

#FIGS. 2 and 3 show different operating states of the apparatus according to the invention, without inversion of the sheet delivered to the second printing machine and with such inversion, respectively;

#FIG. 4 shows an example of a structural embodiment of the inverter apparatus of FIGS. 1-3; and

#The two printing machines 3, 5 shown in FIG. 1 and disposed one after the other are highly modern offset printing machines with automatic plate changing apparatus.

#Each machine has a stacking table 2 for the supply of plates, a plate individualizing device 4 for taking the plates from the stacking table, and a plate transporting and guiding device 6, which guides the new plate that is to be applied onto the form cylinder 8 of the offset printing machine from the separating device through a fixative container and directs it to the form, cylinder and guides the previously used plate from the form cylinder to a repository, not shown. An inking and moistening mechanism 12 acts on the form cylinder in a known manner, inking the plates on the form cylinder in a known manner.

#The sheets that are to be printed are removed from a stacking table 16 by known means, such as a suction roller 14 that shuttles back and forth, and delivered to the counter-pressure cylinder 18, whereupon they are printed as they pass in between the counter-pressure cylinder 18 and the rubber blanket or offset cylinder 20. From there, in the case of the machine shown on the left in FIG. 1, the printed sheets are delivered to the feeder and inverter apparatus according to the invention, while in the case of the printing machine shown on the right in FIG. 1 the sheets printed twice on one side or once on both sides are set aside on a lowerable receiving table 22.