Flange connector

Apparatus for joining adjacent sections of forced air heating ducts having generally rectangular profiles in cross-section, comprising:

• (a) a plurality of angle bar members arranged to be mounted on the apposed end edges of said adjacent ducts to be joined, each said angle bar member having first and second mutually perpendicular flange segments, said flange segments being provided with a generally semicircular, inwardly-projecting, indentation extending along the imaginary line of intersection of the planes in which said first and second flange segments lie and each said first and second flange segments having its outer longitudinal edge formed into an arcuate, inwardly-turned curve;
• (b) a plurality of molded corner pieces, each having a block portion having first and second generally planar major surfaces with an "L"-shaped recess formed in one corner of said first major surface thereof for receiving a corner edge of said forced air heating ducts and a pair of pluggable members projecting laterally outwardly from adjacent side edges of said block portion, said pluggable members being grooved for fitting within said arcuate, inwardly-turned curve of said first and second flanges and an arcuate groove formed in the second major surface of said block member, which when secured to the flanges of said angle bar members by said pair of pluggable members, forms a continuation of said generally semicircular inwardly projecting indentation.