| 摘要 |
PURPOSE:To make vibro-isolating structure for a vacuum unit so simple and compact in size, by installing two relatively slidable frames inside a bellows being connected in an interval between a process chamber and a vacuum pump, while connecting them with a flexible member altogether. CONSTITUTION:When the inside of a vacuum exhaust pipe 27 is of the atmosphere, a flange 30 goes down by weight of a weight 36 and a cryopump 28 whereby a second frame 33 and a stopper 34 go down as well. However, when the stopper 34 comes into contact with a first frame 32, a descent of the said exhaust pipe 27 is checked and thereby full extension of a bellows 26 is prevented. On the other hand, when the inside of a vacuum chamber 11 becomes a vacuum, the exhaust pipe 27 and the second frame 33 are pushed upward. But, at this time, since a chain 35 installed in position between these frames 32 and 33 aforesaid is pulled tight, the exhaust pipe 27 moves freely with a center point of the bellows 26 as a fulcrum, while it upward motion is checked with length of the chain 35 as the limit. |
