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AssigneeBridgestone Tire Company Limited
InventorsMasayasu Matsumoto, Kazuyoshi Iida, Yoshikazu Kondo, Keiichiro Mizuno, Sadao Nomoto, Noriaki Murayama, Kei Watanabe, Tomonori Katayama
Estimating the term…
A device for controlling a propagation direction of noise, which is preferably associated with a sound insulating wall to significantly improve its sound reducing effect of alleviating noise emitted from a noise source such as a railroad, highway and the like on which an electric car and automobiles run. The device comprises a hollow structural body composed of a plurality of elongated vertical hollow passages arranged at right angles to a substrate and spaced apart from each other by means of partition walls. The upper noise inlet side surface of the hollow passages face a propagation direction of noise emitted from the noise source and serve to refract and lag in phase the noise passed therethrough, thereby producing a sound reducing region located intermediate between a direct sound propagation and the refracted sound propagation. In one embodiment, a pair of hollow structural bodies are arranged in opposition to each other to form an arch type device. In another embodiment, the hollow structural body may be provided at its noise inlet or outlet side surface with an extension of the hollow passages.
A device for controlling a propagation direction of noise, comprising a hollow structural body composed of a plurality of elongated hollow passages, said hollow passages being arranged at right angles to a substrate and having upper and lower ends open to the atmosphere, two adjacent hollow passages being different in length and at least one part of said hollow passages being separated from the substrate, the other part being located substantially on the substrate, and said hollow structural body being provided at its lower portion with a space freely communicating with the outside of said hollow structural body, whereby a part of noise emitted and propagated from a noise source is refracted and lags in phase when passed through said hollow passages and the refracted sound is interfered with a direct sound propagation passing over the upper edge of the hollow passages to produce a sound reducing region intermediate between the direct sound propagation and the refraction sound propagation.
Dependencies are inferred from the claim text.