Patent ID: 8127798

Claim:
An air turning vane and rail assembly for promoting laminar air flow in an angled duct work section, comprising: a. a pair of rails in parallel spaced apart relation, b. each of said rails having an elongated body part and a plurality of tabs spaced apart from each other punched from and bent to extend generally perpendicular to said body part in a height distance H, and c. a plurality of air turning vanes in parallel and spaced apart relation to each other and situated between and perpendicular to said rails in a ladder-like assembly, each of said vanes having opposite ends, with each of said ends attached to one of said tabs of said rails, d. each of said turning vanes comprising a single sheet of metal that is folded in a U-bend to form elongated generally rectangular upper and lower walls, e. each wall having a main portion extending lengthwise with near side edge marginal portions extending contiguously from said U-bend and opposite remote side edge marginal portions and having opposite end edges, f. said vane defining a lengthwise axis extending between said opposite ends, g. said upper wall in end view defining an arc of first radius of curvature, and h. said lower wall in end view defining an arc of second radius of curvature greater than said first radius of curvature, with a crescent shaped space defined between said upper and lower walls, i. said lower wall remote side marginal portion being closely adjacent, overlying and folded over as a hem onto said upper wall remote side marginal portion, j. said near side edge marginal portions of said upper and lower walls being overlying and closely adjacent, k. a plurality of crimp spots spaced apart from each other in said lengthwise direction for stabilizing said upper and lower walls in said vane configuration, each crimp spot (i) extending transversely through said remote edge marginal portions of said upper and lower walls and said folded over hem, and (ii) extending through said near edge marginal portions of said upper and lower walls, each two adjacent crimp spots being spaced apart from each other in said lengthwise direction a distance L which is less than said distance H, and l. in each of said crescent shaped spaces in ends of said vanes one of said tabs being inserted and bent to generally conform to and fit snugly.