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 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: 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.