| 摘要 |
PURPOSE:To simply attach a second filter to a first filter by superposing the second filter on the first filter to thrust the pins of the first filter in the second filter to attach the second filter to the first filter. CONSTITUTION:When a second filter 12 is superposed on a first filter 10 as shown by a two-dot chain line, the pins 17 of the first filter are thrust in a paper filter part 22 having a honeycomb shape to attach the second filter 12 to the first filter 10. Since the filter part 22 of the second filter 12 is made of paper and has the honeycomb shape whose grid parts have flexibility, the filter part 22 can follow the positions of the pins 17 and the pins 17 are surely thrust in the grid parts. Therefore, the second filter 12 is fixed by the friction force of the grid parts of the paper honeycomb-shaped filter part 22 and the pins 17. The pins 17 of the first filter 10 can be provided not only to the central part 15b of a frame 15 but also to the outer peripheral part 15a thereof. |
