Patent ID: 7992904

Claim:
A circular cross-sectional sheet metal duct comprising: (a) a tube; (b) a female end on an end of the tube; (c) a male end on an opposite end of the tube extending essentially in the same direction as the tube and the male end having a smaller outer diameter than an inner diameter of the female end of the duct so that the male end can be inserted into a female end on another piece of circular cross-sectional sheet metal duct and when inserted the male end retains the same geometry with the tube as it had prior to being inserted; (d) a longitudinal snap locking mechanism through the length of the circular cross-sectional sheet metal duct that allows the duct to be opened and closed along a longitudinal seam; (e) an uncured gasket applied to the sheet metal during the forming of the sheet metal to form the male end and the female end such that the gasket when cured adheres to the duct and has minimal surface tack and is proximate to one of the ends so that when the circular cross-section sheet metal duct is joined to another piece of circular cross-sectional sheet metal duct a sealed joint is created between inner and outer circular surfaces of the two ducts.