Stencil printing drum structure

摘要

Strap-like step portions each having a smaller external diameter than the external diameter of an ink supply roller are provided at opposite ends of the ink supply roller provided in a drum. Guide surfaces of ink dams urged by springs are brought into contact with the strap-like step portions respectively. Inclined surfaces of the ink dams are brought into contact with the strap-like step portions and side end surfaces of the strap-like step portions respectively. Ink leaked onto the strap-like step portions is led to the inclined surfaces in conjunction with the rotation of the ink supply roller and returned to the inner side of the ink supply roller. Ink is prevented from being leaked out of the ink supply range of the ink supply roller, so that a printing apparatus and sheets of printing paper are not stained with ink. The state of contact between the ink dams and the ink supply roller is kept stable. If the elastic force of the springs is changed, the state of contact can be changed.