| 摘要 |
PURPOSE:To obtain excellent effects of completing an evacuating operation in a short time, attaining a high degree of vacuum, preventing an excessive load from being exerted on a vacuum pump or the like, by a construction wherein air can be extracted from a container without passing through a check valve. CONSTITUTION:An air-extracting pipe 13 is connected to the vacuum pump, and a change-over valve 6 is set into a position for shutting off an intermediate part of a passage in a cylindrical body 9 by operating a change-over handle 25. In this condition, when the vacuum pump is driven to extract air from the interior of the container 23, air is sucked out through a pipe 5 provided with a fitting seat for the check valve, a connecting pipe part 14, the change-over valve 6 and the pipe 13. In this case, the air flow does not collide against the check valve 4 inserted into a guide cylinder 22, the entire part of the foreign matter such as dusts and metallic powders discharged from the container 23 together with the air flow is sucked by the vacuum pump. |
