Assembly of straight duct and transitions

Abstract

A method for formation of duct from preformed pieces. A number of ductwork pieces are formed out of sheet material, the pieces having edge configurations adapted to interlock with each other to form a seam of a completed duct. The individual pieces are fed into an edge interlocking machine and are acted upon by the machine to form a duct having a predetermined length. The machine includes a stationary frame member, guide rails elongated in the direction of ductwork movement through the machine, rollers associated with at least some of the guide rails for effecting interlocking of the edge configurations of the duct work pieces to form duct seams, and structure for mounting the guide rails to the frame member. The guide rails are relatively movable with respect to the frame member and to each other to form ducts of different sizes and so that transition ducts can be formed as well as straight duct. The machine may be made portable and the ductwork pieces transported to job site in a low volume configuration and assembled by the portable machine at the job site.

Dependencies are inferred from the claim text.