Sound attenuation apparatus

Abstract

A stacked cavity structure for arrangement on a mounting surface of a duct includes a support spine configured to be arranged on the mounting surface and extending into the duct with a longitudinal axis defining a longitudinal orientation. The stacked cavity structure includes a plurality of arms extending from the support spine and at least partially forming a plurality of overlapping cavities relative to the longitudinal orientation. Each of the plurality of arms includes at least a proximal first arm segment and a distal first arm segment.

What is claimed is: 
     
         1 . A stacked cavity structure for arrangement on a mounting surface of a duct, comprising:
 a support spine configured to be arranged on the mounting surface and extending into the duct with a longitudinal axis defining a longitudinal orientation; and   a plurality of arms extending from the support spine and at least partially forming a plurality of overlapping cavities relative to the longitudinal orientation, wherein each of the plurality of arms includes at least a proximal first arm segment and a distal first arm segment.   
     
     
         2 . The stacked cavity structure of  claim 1 , wherein at least one of the plurality of arms includes at least one intermediate first arm segment in between the proximal first arm segment and the distal first arm segment. 
     
     
         3 . The stacked cavity structure of  claim 1 , wherein the plurality of overlapping cavities includes at least three overlapping cavities. 
     
     
         4 . The stacked cavity structure of  claim 1 ,
 wherein the plurality of arms and the plurality of cavities extend about the support spine with a hexagonal cross-sectional shape, and   wherein the stacked cavity structure further comprises a first side wall that surrounds the plurality of arms and the plurality of overlapping cavities.   
     
     
         5 . The stacked cavity structure of  claim 4 , further comprising a passage extending along the longitudinal orientation and positioned between the first side wall and the plurality of arms, wherein each of the plurality of overlapping cavities includes a cavity inlet fluidly coupled to the passage. 
     
     
         6 . The stacked cavity structure of  claim 1 ,
 wherein the plurality of arms is a first plurality of arms and the plurality of overlapping cavities is a first plurality of overlapping cavities, and   wherein the stacked cavity structure further comprises a second plurality of arms extending from the first side wall and at least partially forming a second plurality of overlapping cavities relative to the longitudinal orientation, wherein each of the second plurality of arms includes a proximal second arm segment and a distal second arm segment, wherein each of the second plurality of cavities has a second cavity inlet fluidly coupled to the passage on an opposite side relative to the first plurality of overlapping cavities.   
     
     
         7 . A stacked cavity structure for arrangement on a mounting surface of a duct, comprising:
 a support spine configured to be arranged on the mounting surface and extending into the duct with a longitudinal axis defining a longitudinal orientation; and   a plurality of arms extending from the support spine and at least partially forming a plurality of overlapping cavities relative to the longitudinal orientation, each of the plurality of arms includes at least a proximal first arm segment and a distal first arm segment, and the proximal first arm segment extends from the support spine at an angle.   
     
     
         8 . The stacked cavity structure of  claim 7 , wherein at least one of the plurality of arms includes at least one intermediate first arm segment in between the proximal first arm segment and the distal first arm segment. 
     
     
         9 . The stacked cavity structure of  claim 7 , wherein the plurality of overlapping cavities includes at least three overlapping cavities. 
     
     
         10 . The stacked cavity structure of  claim 7 ,
 wherein the plurality of arms and the plurality of cavities extend about the support spine with a hexagonal cross-sectional shape, and   wherein the stacked cavity structure further comprises a first side wall that surrounds the plurality of arms and the plurality of overlapping cavities.   
     
     
         11 . The stacked cavity structure of  claim 10 , further comprising a passage extending along the longitudinal orientation and positioned between the first side wall and the plurality of arms, wherein each of the plurality of overlapping cavities includes a cavity inlet fluidly coupled to the passage. 
     
     
         12 . The stacked cavity structure of  claim 7 ,
 wherein the plurality of arms is a first plurality of arms and the plurality of overlapping cavities is a first plurality of overlapping cavities, and   wherein the stacked cavity structure further comprises a second plurality of arms extending from the first side wall and at least partially forming a second plurality of overlapping cavities relative to the longitudinal orientation, wherein each of the second plurality of arms includes a proximal second arm segment and a distal second arm segment, wherein each of the second plurality of cavities has a second cavity inlet fluidly coupled to the passage on an opposite side relative to the first plurality of overlapping cavities.   
     
     
         13 . The stacked cavity structure of  claim 7 , wherein the first distal arm segment extends from the first proximal arm segment at a second angle. 
     
     
         14 . The stacked cavity structure of  claim 7 , wherein the first distal arm segment includes a tapered end.