| 摘要 |
PURPOSE:To obtain a flat state of a sheet filter without loosening of the sheet filter and to hide a supporting crosspiece which supports the sheet filter. CONSTITUTION:A filter part 18 comprises a combination of an outer frame 19 and a sheep filter 20. On the rearside of the filter part 18, a separate supporting frame 21 is mounted, so that the sheep filter 20 can be pressed by the supporting crosspiece 21 to protrude outer than the outer frame 19 upward the inside of a room. |
