Flange type duct joint assembly and seal arrangement therefor

Abstract

A joint assembly for connecting the ends of a pair of generally rectangular sheet metal duct sections includes a pair of frame members secured to each other and connected to the respective duct end sections. The frame members each include four flange portions. Each flange portion has an upstanding channel shaped leg portion and an angularly extending duct receiving leg portion. A corner piece connects adjacent flange portions and extends into the channel portions of the upstanding leg portions to form the generally rectangular frame. The end portions of the ducts are inserted into longitudinal openings of the duct receiving leg portions. A flowing type gasket material is positioned in a longitudinal pocket of each flange. The end of each duct wall partially displaces the gasket material so that the gasket material extrudes outwardly around the duct wall and between the ends of the flange portion and the corner piece. The surface of the corner piece flange portion is displaced from the front vertical wall of the upstanding channel shaped leg portion so that the edge of the duct extends beyond the flange portion and penetrates an outside gasket member positioned on the upstanding channel shaped leg portion and the corner piece. This provides an effective seal to prevent air within the duct from flowing around the end of the duct and between the outer surface of the duct and the surface of the flange portion of the corner piece.