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 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.