| 摘要 |
<p>The casement has a frame (2) with inner and outer peripheral walls (4, 5) delimiting an inner free space (8) and a peripheral opening (11). A projecting unit (6) of a sleeper (7) penetrates between the walls that have at their respective ends a brush like joint (17) intended to contact the unit (6). An acoustic filter unit is disposed in the space (8) and comprises a veil (10) that closes the opening (11). The filter unit has another veil (12) in contact with the walls (4, 5) and the veil (10), and a third veil (13) extending the veil (12) between the walls.</p> |
