| 摘要 |
PURPOSE:To catch quickly dust existing in a vessel and keep clean the interior of the vessel by installing a dust box to a dust catching device and providing a free rolling filter which is located at the edge of the opening, stands in a laser medium gas flow, rolls back by the halt of the flow, and clogs the opening. CONSTITUTION:During the shutdown of laser medium gas, the center of gravity of a cover 17, a wind receiving plate 16, and a filter 15 is located at a position marked with a sign 21. Therefore, the wind receiving plate 16 stands substantially in the vertical direction while the filter 15 rolls back in the upperstream direction and clogs an opening section 13 and stands still under a contact state with an impact absorbing rubber 19 on the upper side. When the circulation of laser gas medium 6 starts, the wind receiving plate 16 receives wind and pushed to the left side or the downstream side so that it may rotate, centering on a rotation axis 14. Then, the cover 17 comes into contact with shock absorbing rubber 19 on the lower side and clogs a dust collection box 12 so that dust may not be scattered in a vessel 4. While the gas 6 keeps its circulation, the filter 15 catches dust in the vessel 4 when the gas 6 passes through. |
