Abstract: There is described a sheet inspection system for a sheet-fed recto-verso printing press of the type comprising two printing cylinders (10, 20) for carrying out simultaneous recto-verso printing of the sheets, said sheet inspection system comprising at least a first inspection device (100) for taking an image of a first side of the printed sheets. The first inspection device (100) comprises a first line image sensor (110) for performing line-scanning image acquisition of the first side of the printed sheets, and the first inspection device (100) is disposed in such a way that the first line image sensor visually acquires an image of a printed sheet while the said printed sheet is still adhering onto the surface of a first one (10) of the two printing cylinders (10, 20) of the printing press and immediately before the said printed sheet is transferred to a chain gripper system (5) of the printing press. Also described is a printing press equipped with the inspection system.

Abstract: There is described a sheet inspection system for a sheet-fed recto-verso printing press of the type comprising two printing cylinders (10, 20) for carrying out simultaneous recto-verso printing of the sheets, said sheet inspection system comprising at least one inspection device (200; 300; 400) for taking an image of one side of the printed sheets. The sheet inspection system comprises first and second transfer cylinders (60, 65) interposed between a first (10) of the two printing cylinders (10, 20) and a chain gripper system (5) of the printing press, printed sheets being transferred successively from the first printing cylinder (10) to the first transfer cylinder (60), to the second transfer cylinder (65), and to the chain gripper system (5).

Abstract: The present invention relates to a device for placing and removing a doctor blade in a printing screen cylinder mounted on a printing machine having a support mounted on the frame of the machine in the continuation of the cylinder, and a track mounted on the support and designed to allow a slider to move parallel only to the axis of the cylinder between a first limit position situated outside of the cylinder and a second limit position situated inside the cylinder facing the working position of the doctor blade.

Abstract: The invention relates to a placement and removal device of a doctor blade in a screen printing impression cylinder mounted on a printing machine. The device comprises a support fixed to the frame of the machine in the extension of the cylinder on which a slide is mounted in a manner that enables it to pivot about an axis parallel to the axis of said cylinder. The slide is provided for enabling a slider to be displaced only parallel to said axis. The slider is equipped with rapid assembling and disassembling means that interact with mating means on the doctor blade for permitting the doctor blade to be rapidly fixed to or removed from the slider. The slider is designed for enabling it, in a first limit position situated on the outside of the cylinder, to rise in order to remove the doctor blade and, in a second limit position inside the cylinder, to be placed in front of the working position of the doctor blade.