| 摘要 |
<p>PURPOSE:To prevent the generation of air flow around a vacuum paper-conveying device by providing valves in air-intake holes of the paper-conveying device and opening the air-intake holes automatically only at the time of paper conveyance. CONSTITUTION:In a vacuum paper-conveying device such as an electric photo- duplicating machine and the like, air-intake holes 2 of a vacuum box 1 are shaped into concaves 16 of a larger area in the surface than the sectional area of a throat part 15, while at the bottoms of each concave 16, a valve 17 is fixed to close the hole of the throat part 15 by the difference of inner pressures bebetwen the concave 16 and the throat 15 and be opened by a spring force only when there is no essential difference of pressures. This construction permits to prevent the generation of air flow essentially around the paper-conveying device and prolong the life of an air filter provided at an exhaust port greatly.</p> |
