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US 4,533,015 AGranted
Sound arresting device
OwnerHisao Kojimainventor
Life of this patent
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OwnerHisao Kojimainventor
Estimating the term…
An element of a sound arresting device has a cylinder and a blade integrally formed in the cylinder and helically twisted along the longitudinal direction of the cylinder. A plurality of elements are coupled to each other along their longitudinal direction and are fitted in a pipe. The ends of the two adjacent blades are perpendicular to each other. The pipe is covered with a sound insulating material. The elements and the pipe are made of a porous metal material, a porous plastic material or a porous ceramic material. When the sound arresting device is used as an automobile muffler, acoustic waves propagating in the gas are repeatedly mixed, interfere with each other and are absorbed by the apertures and the sound insulating material, thereby decreasing noise from the engine. Dust in the exhaust gas is captured by the apertures of the elements and the pipe, and is removed from the exhaust gas.
A sound arresting device comprising a plurality of longitudinally coupled elements, each of the elements including a cylinder having an axis extending in a longitudinal direction and coupled to an adjacent cylinder of another element spaced therefrom along said longitudinal direction, and a blade formed in said cylinder so as to be integral therewith, each said blade being helically twisted along said longitudinal direction of said cylinder and being arranged such that each end of each said blade crosses an adjacent end of an adjacent blade, so that an inner portion of said cylinder is divided into plurality of channels through each of which a gas flows.
Dependencies are inferred from the claim text.