Fan shroud with complementary two-sided ribbing

Abstract

A fan shroud has a panel including a first surface and a second surface substantially opposite the first surface. A first rib extends substantially perpendicularly from the first surface, and the first rib has an area of discontinuity where a height of the first rib is reduced. A second rib extends substantially perpendicularly from the second surface, and the second rib is substantially aligned with the first rib and positioned substantially opposite the area of discontinuity of the first rib.

What is claimed is: 
     
         1 . A fan shroud comprising:
 a panel including a first surface and a second surface substantially opposite the first surface;   a first rib extending substantially perpendicularly from the first surface to define a height, the first rib having an area of discontinuity where a height of the first rib is reduced; and   a second rib extending substantially perpendicularly from the second surface, the second rib being aligned with the first rib and being positioned directly across from the area of discontinuity of the first rib.   
     
     
         2 . The fan shroud of  claim 1 , wherein the panel is a plenum portion of the fan shroud. 
     
     
         3 . The fan shroud of  claim 2 , wherein the fan shroud includes a generally cylindrical barrel portion adjacent the plenum portion, and the first rib forms an integral extension from the barrel portion. 
     
     
         4 . The fan shroud of  claim 3 , wherein the first rib extends substantially radially outwardly from the barrel portion. 
     
     
         5 . The fan shroud of  claim 2 , wherein the first rib is formed on an exterior of the plenum portion, and the second rib is formed on an interior of the plenum portion. 
     
     
         6 . The fan shroud of  claim 1 , wherein the first rib includes two aligned rib portions separated by the area of discontinuity. 
     
     
         7 . The fan shroud of  claim 6 , wherein the height of the first rib is reduced to zero in the area of discontinuity. 
     
     
         8 . The fan shroud of  claim 1 , wherein the height of the first rib is reduced to zero in the area of discontinuity. 
     
     
         9 . The fan shroud of  claim 1 , wherein the combination of the first rib and the second rib span between a pair of structurally-reinforced portions of the fan shroud. 
     
     
         10 . The fan shroud of  claim 9 , wherein the pair of structurally-reinforced portions includes a generally cylindrical barrel portion and a mounting structure positioned at an outer edge portion of the panel. 
     
     
         11 . A fan shroud comprising:
 a generally cylindrical barrel portion having an opening configured to receive a fan;   a plenum portion adjacent the barrel portion and defining an exterior surface and an interior surface opposite the exterior surface;   a first rib extending substantially perpendicularly from the exterior surface and defining a path between the barrel portion and an outer edge of the plenum portion; and   a second rib extending substantially perpendicularly from the interior surface, wherein the second rib does not extend from the barrel portion to the outer edge, but extends substantially along the path defined by the first rib, substantially opposite an area of discontinuity in the first rib.   
     
     
         12 . The fan shroud of  claim 11 , wherein the first rib forms an integral extension from the barrel portion. 
     
     
         13 . The fan shroud of  claim 12 , wherein the first rib follows the path to become increasingly distant from the barrel portion. 
     
     
         14 . The fan shroud of  claim 11 , wherein the first rib includes two aligned rib portions separated by the area of discontinuity. 
     
     
         15 . The fan shroud of  claim 14 , wherein the height of the first rib is reduced to zero in the area of discontinuity so that the first rib includes a pair of facing ends. 
     
     
         16 . The fan shroud of  claim 15 , wherein the height of the first rib is reduced gradually over a smooth transition toward each of the facing ends. 
     
     
         17 . The fan shroud of  claim 16 , wherein the second rib includes a pair of opposed ends from which the height of the second rib gradually increases over a smooth transition, and wherein the smooth transitions adjacent the opposed ends of the second rib overlap with the smooth transitions adjacent the facing ends of the first rib. 
     
     
         18 . The fan shroud of  claim 11 , wherein the height of the first rib is reduced to zero in the area of discontinuity. 
     
     
         19 . The fan shroud of  claim 11 , wherein the combination of the first rib and the second rib span between the generally cylindrical barrel portion and a mounting structure positioned at the outer edge. 
     
     
         20 . A fan shroud comprising:
 a panel including a first surface and a second surface substantially opposite the first surface;   a first rib extending substantially perpendicularly from the first surface to define a height, the first rib having a portion of decreasing height corresponding to a decreased stiffening effect of the first rib; and   a second rib positioned on the second surface substantially opposite the portion of decreasing height to compensate for the decreased stiffening effect of the first rib.