| 摘要 |
A suction device used for picking up sheets, for example in a paper printing machine, has a valve which automatically closes, cutting off the suction device from a suction manifold, when the mouth of the device is not covered by a sheet, thereby preventing unnecessary loss of suction in the manifold, which usually serves a number of suction devices. The valve is closed by the air which flows through the device when its mouth is uncovered. |
