Patent ID: 7156615

Claim:
A fan shroud structure constructed and arranged to carry a fan, the fan shroud structure comprising: a body having a periphery, a main portion, and an annular rim defining a generally central opening, the opening being sized to accommodate blades of a fan, fan mounting structure coupled with the body and disposed generally adjacent to the central opening, the fan mounting structure being constructed and arranged to support a motor of a fan, wherein the body includes a plurality of surface features constructed and arranged to affect resonance of the shroud structure, each feature extending from the annular rim to the periphery of the body, with the surface features completely surrounding the annular rim, and wherein each feature has a first surface that extends above the main portion at a front end of the body and an opposing second surface that extends below the main portion at a back end of the body, whereby each first and second surface is discontinuous with respect to the main portion of the body.