| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a multistage pressure reducing device to steppedly reduce a pressure in a part to need a vacuum until the degree of a vacuum attains a given value. SOLUTION: A multistage pressure reducing device comprises a plurality of vacuum pumps 23; and a plurality of vacuum hoses 22; a vacuum intermittent coupling means 100 to be arranged between the vacuum pumps 23 and the vacuum hoses 22 and intermittently intercouple the vacuum pump 23 and a vacuum hose 22. The vacuum pump intermittent coupling means 100 comprises a fixed coupling member 24 in which a plurality of communication holes are formed; a rotary coupling member 25; and a rotciry coupling member drive member 26 to rotate the rotary coupling member 25 for the fixed coupling member 24. Intermittent coupling between the vacuum pump 23 and the vacuum hose 22 is is effected as a process in which after coincidence between the respective communication holes 27 of the rotary coupling member 25 and the respective coupling holes 29 of the fixed coupling member 24, offset therebetween is effected is repeated with the progress of rotation of the rotary coupling member 25.</p> |
