Abstract: In order to improve a gripper opening/closing mechanism of a sheet transfer cylinder in a sheet-fed printing machine in the prior art, the gripper opening/closing mechanism of the sheet transfer cylinder in the sheet-fed printing machine comprises: a plurality of grippers; a gripper shaft whereupon the plurality of grippers are disposed over specific intervals; and a cam mechanism provided at each of two ends of the gripper shaft, which cause the gripper shaft to move when the sheet transfer cylinder has rotated to a first specific position so that the grippers and the external circumferential side surface of the sheet transfer cylinder come in contact with each other and causes the gripper shaft to move in the opposite direction when the sheet transfer cylinder has rotated to a second specific position so that the grippers and the external circumferential side surface of the sheet transfer cylinder depart from each other.

Abstract: A perfecting sheet rotary offfset press has a top surface printing unit and a back surface printing unit each formed of an impression cylinder, and a blanket cylinder, a plate cylinder, and an inking mechanism which are disposed above or below the impression cylinder, respectively. The top and back surface printing units are connected through the impression cylinders constituting the respective printing units. A sheet is sequentially transferred by the respective impression cylinders of the top and back surface printing units, and printing is performed on the top and back surfaces of the sheet as it passes through the printing units. Thus, this perfecting sheet rotary offset press can print at high speeds and presents few printing faults, and its dimension can be made smaller.

Abstract: A plate adjusting mechanism for a leaf-type printing machine is provided to shift a plate wrapped around a plate roller. The top side plate clamp is pivoted about a fulcrum located at one end, and an actuator is mounted on the end of the plate roller. The actuator is arranged to move the top side plate clamp and thereby pivot the same.

Abstract: A plate clamping apparatus for a leaf-type printing machine which enables substantially automatic plate clamping and stretching operations. Top and bottom side plate clamps are respectively provided with upper and lower teeth for clamping and releasing the top and bottom side end of a plate by rotating top and bottom side cam shafts. A plate stretcher moves the bottom side plate clamp in a stretching direction or a releasing direction of the plate by rotating a plate stretching cam. Top and bottom side cam followers are respectively coupled by a joint to transmit rotation to the top and bottom cam shafts. A motive force transmitting mechanism is attached to a rotating shaft of the plate roller. A groove cam puts the top and bottom side cam followers into a predetermined action for rotating the top and bottom side cam shafts.

Abstract: A dampening water feed roller, characterized by a process of manufacturing which comprises forming a flame sprayed layer of a ceramic material composed of Al.sub.2 O.sub.3, TiO.sub.2, or a mixture of Al.sub.2 O.sub.3 and TiO.sub.2 on the peripheral surface of a metallic roller, subjecting the flame sprayed ceramic layer to a pore-occluding treatment with a hydrophilic SiO.sub.2 type inorganic pore-occluding agent, and grinding the treated layer to surface roughness of not more than 1.6 S. The roller permits supply of the dampening water without using the additives such as isopropyl alcohol in the dampening water.

Abstract: A varnish scraper is fitted to a varnish applicator roller to scrape off extra varnish which has remained after the varnish has been supplied to a blanket drum. The scraped extra varnish is circulated to a varnish vessel for re-using.

Abstract: The present invention relates to an apparatus for matching register marks and punching U-holes for a press plate which is capable of executing regular print by single register mark matching, and is composed of a press plate loading table for loading a press plate material, a pin hole positioning mechanism for supporting the lower edge of said press plate material, a press plate material centering mechanism for centering said press plate material in the horizontal direction, a register mark location reading device for reading register marks on said press plate material, a press plate material horizontal and vertical feed mechanism for adjusting said press plate material in the horizontal and vertical directions, a press plate locking device for vacuum contacting and releasing said press plate material, an automatic U-hole punching mechanism for punching a pair or two pairs of U-holes of predetermined pitches on said plate material, and an operation device for controlling the operation of each mechanism.