Abstract: A printing press is provided with a temperature control unit for controlling the temperature of a surface of a printing plate mounted on a plate cylinder by feeding air onto the plate cylinder. A plate-replacement space is provided in a certain region around the plate cylinder for replacement of a printing plate mounted on the plate cylinder with a new one introduced from the outside of the printing press. The temperature control unit is designed to be selectively shifted between a temperature control mode and a space opening mode, in which the temperature control mode enables air to be fed through the plate-replacement space onto the plate cylinder, and the space opening mode makes the plate-replacement space open to the outside of the printing press so that the replacement of a printing plate can be done.

Abstract: A printing press is provided with a temperature control unit for controlling the temperature of a surface of a printing plate mounted on a plate cylinder by feeding air onto the plate cylinder. A plate-replacement space is provided in a certain region around the plate cylinder for replacement of a printing plate mounted on the plate cylinder with a new one introduced from the outside of the printing press. The temperature control unit is designed to be selectively shifted between a temperature control mode and a space opening mode, in which the temperature control mode enables air to be fed through the plate-replacement space onto the plate cylinder, and the space opening mode makes the plate-replacement space open to the outside of the printing press so that the replacement of a printing plate can be done.

Abstract: A printing unit, a sheet-feeding unit, a sheet-discharging unit, an ink-feeding unit and a roller-oscillating unit of a digital printing press are adapted to receive the driving force from a common motor. An image-forming device fixedly mounted on the digital printing press is adapted to form images on printing plates mounted on the printing unit as the plate cylinder rotates upon receiving the driving force from the common motor. The transmission of the driving force to at least two of the sheet-feeding unit, the sheet-discharging unit, the ink-feeding unit and the roller-oscillating unit is shut off by means of a single clutch during the image-forming operation.

Abstract: A multiple color offset printer having a sheet feed mechanism in which a sheet feed cylinder receives a sheet in timed relation to a sheet transfer timing from the sheet feed cylinder to an impression cylinder. A blanket cylinder is divided into a plurality of uniform sized color sections around its periphery. The sheet feed cylinder has an outer peripheral length that is the same length as the peripheral length of each color section of the blanket cylinder. A sheet is transferred from the sheet feed cylinder to the impression cylinder once each time the sheet feed cylinder rotates a number of times equivalent to the number of color sections. A front lay cam rotates a single time during the same number of rotations as the number of the color sections. An abutment member moves from a projecting position in the sheet transport pathway to a retracted position separated therefrom a single time each time the front lay cam rotates a single time, so that a sheet is allowed to be supplied to the sheet feed cylinder.

Abstract: An offset printing machine including an impression cylinder, a sheet feed cylinder and a blanket cylinder. An outer peripheral surface of the blanket cylinder is divided into a plurality of color sections in a circumferential direction thereof, and an outer peripheral surface of the sheet feed cylinder has a peripheral length equal to the circumferential length of each color section. A sheet held in the sheet feed cylinder is transferred to the impression cylinder each time the sheet feed cylinder rotates a predetermined number equal to the number of the color sections. One of impression cylinder grippers and a sheet feed cylinder gripper intermittently confront with each other upon rotation of these cylinders.

Abstract: An offset printer capable of contacting a plurality of ink rollers of a predetermined ink supply unit with a predetermined plate segment on a plate cylinder, and capable of out of contacting the ink rollers from a remaining plate segment on the plate cylinder. Roller support arms each supporting each ink roller are pivotally movably supported on a frame, and each support arm is moved by each, cam members pivotally movably supported on the frame. Each cam member is in contact with a center cam provided coaxially with and rotatable together with the plate cylinder, so that the ink rollers are successively moved. An interlocking mechanism including a lever is further provided. The lever moves concurrently the cam members to concurrently move the ink rollers.

Abstract: A printing unit, a sheet-feeding unit, a sheet-discharging unit, an ink-feeding unit and a roller-oscillating unit of a digital printing press are adapted to receive the driving force from a common motor. An image-forming device fixedly mounted on the digital printing press is adapted to form images on printing plates mounted on the printing unit as the plate cylinder rotates upon receiving the driving force from the common motor. The transmission of the driving force to at least two of the sheet-feeding unit, the sheet-discharging unit, the ink-feeding unit and the roller-oscillating unit is shut off by means of a single clutch during the image-forming operation.

Abstract: An offset printer includes a drive motor, an impression cylinder gear, a paper feed cylinder, a paper feed cylinder gear, a paper discharge portion, a paper discharge gear, a blanket gear, a plate cylinder gear, an ink reciprocation roller, a mechanism for rotating the ink reciprocation roller, a mechanism for reciprocating the ink reciprocation roller, and first through fourth electromagnetic clutches. Rotation of the drive motor is transmitted to the paper feed cylinder gear and the paper discharge gear through the impression cylinder gear. The rotation force of the impression cylinder gear is also transmitted to, in the order of, the blanket cylinder gear, the plate cylinder gear, and the rotation and reciprocation mechanisms. Driving connection between the paper feed cylinder gear and the paper feed cylinder is selectively disconnected by the first clutch. Driving connection between the paper discharge gear and the paper discharge portion is selectively disconnected by the second clutch.

Abstract: An offset printing machine including an impression cylinder, a sheet feed cylinder and a blanket cylinder. An outer peripheral surface of the blanket cylinder is divided into a plurality of color sections in a circumferential direction thereof, and an outer peripheral surface of the sheet feed cylinder has a peripheral length equal to the circumferential length of each color section. A sheet held in the sheet feed cylinder is transferred to the impression cylinder each time the sheet feed cylinder rotates a predetermined number equal to the number of the color sections. One of impression cylinder grippers and a sheet feed cylinder gripper intermittently confront with each other upon rotation of these cylinders.

Abstract: A multiple color offset printer having a sheet feed mechanism in which a sheet feed cylinder receives a sheet in timed relation to a sheet transfer timing from the sheet feed cylinder to an impression cylinder. A blanket cylinder is divided into a plurality of uniform sized color sections around its periphery. The sheet feed cylinder has an outer peripheral length that is the same length as the peripheral length of each color section of the blanket cylinder. A sheet is transferred from the sheet feed cylinder to the impression cylinder once each time the sheet feed cylinder rotates a number of times equivalent to the number of color sections. A front lay cam rotates a single time during the same number of rotations as the number of the color sections. An abutment member moves from a projecting position in the sheet transport pathway to a retracted position separated therefrom a single time each time the front lay cam rotates a single time, so that a sheet is allowed to be supplied to the sheet feed cylinder.

Abstract: A number printing unit for an offset printing machine in which blocks are fixed to a numbering unit mounting holder provided rotatably on an operation side frame. Coupling retainer blocks are inserted into groups formed in the blocks. The coupling retainer blocks are mounted on the numbering unit mounting holder by screws, washers and bolts. A gear is rotatably mounted on the numbering unit mounting holder through a bearing. A coupling ring is fixed to the gear by screw. Abutment portions of the coupling retainer blocks are brought into contact with the coupling ring.