Patent ID: 7722449
Filing Date: 2010-05-25
Classification: F24F

Abstract:
1. A security grill comprising: a. a first face comprising an air outlet, wherein said outlet faces the inside of a room; b. a second face comprising an air inlet, wherein said inlet faces the inside of a duct; c. zigzag channels defined by slats, each channel having at least three consecutive segments oriented in alternating directions, extending from a point adjacent the first face toward the second face, wherein each segment is free of hooks and protrusions, and each segment of each channel has a cross-sectional width, and wherein for each channel the cross-sectional width of the first segment adjacent the first face is less than the cross-sectional width of all successive segments extending toward the second face, and wherein each angle formed by each segment of the zigzag channels relative to the next segment is between 84 degrees and 100 degrees, and wherein the vertex of each angle is rounded, and wherein the cross-sectional width of each slat is substantially the same throughout, and wherein the angle formed by the first segment of the zigzag channel is less than the angle formed by all of the successive segments of the zigzag channel.