| 摘要 |
PURPOSE:To aim at simplifying the structure and improving reliability by way of thoroughly intercepting the flow of gas, by enabling a plate to be operated with an electromagnet inside a vacuum, while making the connection between the plate and a movable core of the electromagnet into free linkage. CONSTITUTION:A gas flow cutoff plate 7 is suspended from the lower end of a holding bar 8 attached to a movable iron core 9 of an electromagnet and said movable core 9 is housed in a guide cylinder 15 which is airtightly secured to a device body 16. Accordingly, the core 9 is isolated from the open air, staying in space interconnected to a gas passage, and an electromagnet coil 10 is provided on the outside of the cylinder 15 and operated from an outside vacuum. The plate 7 blocks up the end face of a nozzle 6 by coming down to position between nozzles 5 and 6 opposite to said plate. In addition, the lower end of the bar 8 is formed in a fork 13 and arms 14 are protruded horizontally to the left from both legs of the fork 13; the plate 7 is gently suspended from these arms through holes 14'. |
