| 摘要 |
PURPOSE:To decrease the quantity of influent gas during carrying-out or carrying- in of a hoop, by installing covers over whole rolls arranged at the hoop-inlet of a vacuum chamber so that the gaps made along the shape of the rolls may be minimized. CONSTITUTION:Along the plural rolls 2 arranged at the entrance of a vacuum chamber where a hoop 1 is plated are fitted a hoop surface cover 3a, a roll surface cover 3b, and a roll side cover 3c. These divided covers are assembled each other with O-rings and packings to form gaps of several millimeter between the covers and the rolls or the hoop. When the hoop 1 passes around the rolls 2 then into the vacuum chamber, hoop end gaps A, and the gaps B formed along the hoop surface and the roll surfaces show a minimum passage length of about (semi-roll circle)X2, and the gaps C between the cover and the roll sides a minimum passage length of about roll diameter X 2, so that the resistances of the passages to the air flow are increased, hence gas is hardly flows in the vacuum chamber. |
