| 摘要 |
PURPOSE:To enhance the conveying efficiency of a valve structure by evacuating a space surrounded by upper and lower valve bodies in vacuum when the bodies are hermetically sealed to a seat plate and enabling to introduce atmospheric air to the space, thereby shortening the time required to evacuate the space. CONSTITUTION:A lower article vestivule 27 communicates with a vacuum side and an upper article vestivule 28 communicates with an atmosphere side. A lower assembly 14 is disposed at the lowered position. An article is placed on an article support 19. The assembly 14 is raised, a lower valve body 17 is hermetically engaged with a seat plate 4, and the upper surface of the support 19 is let to slightly upper position from a through hole 5. Atmospheric air is led through an exhaust passage 13 to a space of the hole 5 hermetically enclosed by the plate 4, and the upper and lower valve bodies 8 and 17. The valve body 8 is raised and is upwardly isolated from the plate 4. The article is carried out from the support 19 to the atmosphere. |
