Ryobi Limited

Masamichi Sasaki

Kiyomi Utsumi

Yoshinori Honkawa

Masazumi Hidera

Yoshitsugu Miyaguchi

Minoru Tokinaga

A sheet aligning device includes first and second aligning plates disposed on opposite lateral sides of the feeder board, the first and second aligning plates being capable of being reciprocatingly moved in a direction orthogonal to a sheet conveying direction and each having a sheet abutting surface parallel to the sheet conveying direction, an input member for inputting a sheet width, and a controller for controlling the first and second aligning plates so that the first aligning plate is moved, based on the inputted sheet width, to allow the sheet abutting surface thereof to be brought into abutment with a first lateral side of each sheet, thereby laterally aligning the sheet, and the second aligning plate is moved, based on the inputted sheet width, to allow a second lateral side of each sheet close to the second aligning plate to pass through a sheet-lateral-side passing zone on the second aligning plate. The sheet-lateral-side passing zone is located closer to the axis or centerline of the sheet than the sheet abutting surface is and has a flat surface throughout the sheet conveying direction.

Sheet aligning device of a printing press and method of controlling the same

There is provided a sheet-fed printing press that is capable of rapidly performing printing preparatory work for more secured double sheet detection. A double-sheet-detector control part judges whether an ultrasonic double sheet detector outputs double sheet detected signal during test printing or during feeding a first printing sheet of successively fed printing sheets in large quantity or successive printing. Where double sheet detected signal was output, it is judged that the detection made by the ultrasonic double sheet detector is erroneous so that the double-sheet-detector control part switches to a photoelectric double sheet detector to be employed as a double sheet detector for use in large quantity or successive printing. On the other hand, where no double sheet detected signal was output, it is judged that the detection made by the ultrasonic double sheet detector is correct so that the double-sheet-detector control part keeps the ultrasonic double sheet detector in operation to employ the same as a double sheet detector for use in large quantity or successive printing.

Sheet-fed printing press

There is provided a double-sided printing press that includes a sheet-turning-over mechanism for turning sheets upside down at a sheet-turning-timing according to a set length of sheets, which has been previously set for the sheet-turning-over mechanism; and a sheet-length-detection means for detecting the length of sheets, which are fed to the sheet-turning-over mechanism; wherein where the length of sheets, which are fed to the sheet-turning-over mechanism and detected by the sheet-length-detection means, is deferent from the set length of sheets as a result of comparison therebetween, the sheets are stopped from being transferred to the sheet-turning-over mechanism.

Double-sided printing press

There is provided a printing press with a sheet-turning-over-mechanism for turning over a printing sheet, enabling the printing press to be selectively operable in a one-sided printing mode and a double-sided printing mode. The printing press includes a controller which, when any failure stops any one of steps of a mode switching operation for switching the printing press from the one-sided printing mode to the double-sided printing mode or vice versa, stores the information representative of a state of the mode switching operation at the moment of the stop due to the failure, and when a normal operable state is restored from the failure, resumes the mode switching operation from a step of the mode switching operation indicated by the operational state stored therein.

Printing press with a sheet-turning-over-mechanism

There is provided a sheet feeder for a sheet-fed press which allows an optimum separation state of printing sheets 27 to be established readily and certainly. Air is jetted out from an injection nozzle 6 toward the upper part of a bundle 2 of printing sheets to thereby float up printing sheets 27. A top printing sheet 27 thus floated is absorbed by an absorption foot 8 and conveyed to a printing process. The number of floating printing sheets 27 is detected using photoelectric sensors 21 and 22, and in order to establish the optimum separation state, is adjusted by varying the injection air quantity from the injection nozzle 6 or by moving the paper pressure bar 4 in directions of arrows 93 and 94. Further, by equalizing outputs G1 and G2 from detection areas M1 and M2, it is possible to place the top printing sheet 27 in parallel with the absorption surface 8Q of the absorption foot 8 and realize secure absorption. A fuzzy inference system may be used for adjustment.

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Fuchu, Japan

Masamichi Sasaki