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US 12,492,654 B2Granted
Sound absorbing element with low profile micro-louver slits and muffler assembly using the same
AssigneeACS Industries, Inc.
InventorsChristof Bock, Henry C. Howell, III, Stacey L. Smith
Life of this patent
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Abstract
A novel sound absorbing sheet material with a unique combination of micro-louver slit parameters and patterns provides superior noise attenuation and a reduced perforation area (less than 3.5%) to better protect fiberglass insulation when used in a muffler assembly. A muffler assembly is disclosed incorporating the novel sound absorbing sheet as the inner exhaust conduit.
Claims22
A sound absorbing element comprising:
- a metal sheet having a thickness (t) greater than or equal to 0.2 mm and less than or equal to 0.4 mm,
- said metal sheet having a plurality of louvered slits formed in a predetermined longitudinally extending pattern,
- wherein each of said plurality of louvered slits has a width (w) greater than or equal to 1 mm and less than or equal to 3 mm, a louver height (h) greater than or equal to 0.35 mm and less than or equal to 0.45 mm, and a slit height (x) greater than or equal to 0.03 mm and less than or equal to 0.120 mm,
- wherein the metal sheet has a perforation ratio (P) greater than or equal to 1% and less than or equal to 3.5%,
- wherein said metal sheet comprises a tube having an inner conduit through which an airflow passes from a first end to a second end;
- and
- at least one layer of fiber insulation extending around said outside of said sheet metal tube,
- said slit height and width, said louver height and said perforation ratio being configured to allow acoustic waves through the louvered slits for sound attenuation yet also retain fibers from said fiber insulation from entering the airflow within the inner conduit.
5 more elements
A muffler assembly comprising:
- a sound attenuating inner tube;
- an outer concentric housing tube;
- opposing end caps configured to capture the inner and outer tubes in concentric relation and form input and output ends for exhaust gases;
- and
- at least one layer of fiber insulation disposed between the inner tube and the outer tube,
- wherein the sound attenuating inner tube comprises,
- a metal sheet having a thickness (t) greater than or equal to 0.2 mm and less than or equal to 0.4 mm,
- said metal sheet having a plurality of louvered slits formed in a predetermined longitudinally extending pattern,
- wherein each of said plurality of louvered slits has a width (w) greater than or equal to 1 mm and less than or equal to 3 mm, a louver height (h) greater than or equal to 0.35 mm and less than or equal to 0.45 mm, and a slit height (x) greater than or equal to 0.03 mm and less than or equal to 0.120 mm,
- wherein the metal sheet has a perforation ratio (P) greater than or equal to 1% and less than or equal to 3.5%,
- said slit height and width, said louver height and said perforation ratio being configured to allow acoustic waves through the louvered slits for sound attenuation yet also retain fibers from said fiber insulation from entering the airflow within the inner conduit.
8 more elements
Dependencies are inferred from the claim text.