| 摘要 |
PURPOSE:To economize the air consumption quantity by forming a number of air discharge ports on the outer peripheral surface of a turning bar which changes the laying direction of a web and installing an opening/closing valve which is opened in laying the web and closed when the web is not present, in a printing machine, etc. CONSTITUTION:As for a turning bar 4 which direction-changes a web such as paper in laid state, a number of air discharge ports 5 are formed on the outer peripheral surface, and a back side is cut in the range between the min. and max. width S and L onto which the web is laid, and an opening/closing valve 6 is installed at each discharge port 5 in the range D, and an air feeding passage is formed by the covering with a back cover 7. Said opening/closing valve 6 is prepared from a band-shaped elastic body, and fixed by a screw 8. When the discharge port 5 is covered by the web, and the pressure difference is small, the discharge port 5 is opened, and when the discharge port is not covered, and the pressure difference is large, said discharge port 5 is closed. Therefore, the friction between the web and the turning bar is reduced drastically, and the need of cutting off the discharge port outside the web width in the manual change of the web width is avoided, and the labor can be reduced, and the capacity of an air feeding source can be reduced. |
