Title:
SOUNDPROOF DEVICE
Document Type and Number:
WIPO Patent Application WO/2001/061111
Kind Code:
A1
Abstract:
A small soundproof device having a sound screening band of sound wave diffracting at the top of a soundproof wall and leaking. A phase-inverting structure (20) having a sound pressure reflectance of about -1 at the surface at frequencies in the band of noise is attached to the top of a soundproof wall (10) along the length of the soundproof wall (10). The phase-inverting structure (20) is an assembly of a multitude of sound tubes (21, 22, 23, 24, 25) having 1/4 of the wavelength of any of soundwaves of the frequencies, opening upward, and closing at their ends. The phase inverting structure (20) comprising units (29) arranged in line and coupled to one another. Each unit has a first partition (30) and second partitions (31 to 39) one end of each of which is connected to one side of the first partition (30) perpendicularly thereto. The other ends of the second partitions of one unit are connected to the other side of the first partition of another unit adjacent to the one unit. Thus the first partition and second partitions constitute the sound tubes (21 to 25).
Inventors:
FUJIWARA KYOJI (JP)
TASHIRO MOTOJI (JP)
TASHIRO MOTOJI (JP)
Application Number:
PCT/JP2000/000887
Publication Date:
August 23, 2001
Filing Date:
February 17, 2000
Export Citation:
Assignee:
TOKYO ROPE MFG CO (JP)
FUJIWARA KYOJI (JP)
TASHIRO MOTOJI (JP)
FUJIWARA KYOJI (JP)
TASHIRO MOTOJI (JP)
International Classes:
E01F8/00; (IPC1-7): E01F8/00
Foreign References:
| JPH09151424A | 1997-06-10 | |||
| JPH11256523A | 1999-09-21 | |||
| JPH09151422A | 1997-06-10 |
Attorney, Agent or Firm:
Ushiku, Kenji (Shimbashi 3-chome Minato-ku Tokyo, JP)
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