Duct jointing system

Abstract

A duct jointing system is provided which includes a plurality of elongate frame members, each being a single piece of sheet metal folded to define a particular section. The section includes an open channel to receive an edge portion of the sheet metal duct, the channel having a base, a first web extending generally perpendicularly to said channel from a location adjacent the base, an outer portion at the end of the first web remote from the channel, the outer portion extending in the same general direction as the channel, and a second web extending obliquely toward the channel from a location adjacent the remote end of the first web. The single piece of sheet metal has an expanded portion constituting substantially the whole of the second web. A plurality of corner pieces are provided, each having two ends angled to each other, each end being insertable endwise into one end of one of the elongate frame members, and means are provided for securing together adjacent frame members on opposing duct ends.

Dependencies are inferred from the claim text.