Patent ID: 8366417

Claim:
A fan housing comprising: a frame; the frame comprising: a main part; an opening on an outlet side of the frame; at least two supporting parts provided around the opening, the main part and the supporting parts being undetachable as a single unit; wherein the supporting parts extend from the main part to the outlet side of the frame in an axial direction; at least two fixing parts disposed on the supporting parts; at least two grooves defined on the supporting parts; at least one uncovered installation hole defined on the supporting parts and preserved for an external device to engage with on the outlet side of the frame; at least one anti-backflow sheet pivotally installed on the at least two fixing parts directly for covering the opening; and at least two protrusions disposed on the at least one anti-backflow sheet, wherein the at least two protrusions move within the at least two grooves, and the length of the at least two grooves restricts the maximum stroke of the at least one anti-backflow sheet such that the at least one anti-backflow sheet does not obstruct the at least one uncovered installation hole.