Abstract: The invention relates to a sheet feeder for the individual feeding of sheets to a sheet treating machine. A first sheet pile is carried by a main pile table, and sheets from this sheet pile can be fed by a sheet separating device, optionally via a first feed table, to the sheet treating machine. A further sheet pile is carried by an auxiliary pile table. Sheets can be fed by a second sheet separating device from this further sheet pile to the sheet treating machine, again optionally via a second feed table. Using this arrangement, in place of the sheets from the first pile table, sheets from the auxiliary pile table can be fed to the sheet treating machine without interruption, as the sheet feed from the two piles is carried out in the same rhythm. Preferably a control circuit is used to meter out a selected number of prerun sheets from the auxiliary pile table followed without interruption by another selected number of continuous running sheets.

Abstract: A warning system for a printing press to warn the operator upon the exceeding, or departure from, a desired set of running conditions which includes a plurality of remote condition transducers which, in the simplest form of the invention, are in the form of switches. Coupled to the transducers are respective signal generators each of which generates an acoustic signal which has a distinctive quality as compared to all of the other acoustic signals. A loudspeaker common to all of the signal generators is audible at the control station. The distinctiveness of the signal serves to promptly inform the operator which of the running conditions has been exceeded so that corrective action may be taken. In a second embodiment of the invention the transducers produce output control signals which vary in magnitude with the condition, and the corresponding acoustic signal generator produces a signal having a distinctive first quality when the control signal exceeds a threshold level.

Abstract: A mechanism for sorting sheets from a printing press to assure proper color density and to assist in making corrective adjustment which includes a main conveyor for normally conducting sheets to a main delivery pile and having a transfer station. An auxiliary conveyor extends from the transfer station to an auxiliary delivery pile. A scanning device is arranged upstream of the main conveyor for responding to the color density of the printed image on a passing sheet. A comparator produces a control signal when the color density is above or below tolerance, signifying a sub-quality sheet. Mechanism at the transfer station is triggered by the control signal so that the sub-quality sheet is diverted to the auxiliary conveyor for depositing on the auxiliary pile. The mechanism not only accomplishes sorting but the fact of diversion and the observed rate of diversion provides constant instruction to the pressman as to the necessity for, and the degree of, a corrective change in ink feed rate.