Abstract: A universal duct elbow as for the vent system of a clothes dryer, formed of a body and a pair of swivel sleeves rotational on the body. The body has an outer 180.degree. portion of a configuration like that of a quarter toroid, and an inner 180.degree. portion like a square type elbow. The center line radius is less than about 0.6 of the duct diameter, enabling a duct assembly using the elbow to fit into a space only slightly larger than the duct diameter. The body is formed of an L-shaped plate having flow openings in the two legs of the L, plus two joined mirror image, arcuate elements. At these sleeves are radially extending flanges of the legs of the L to enable attachment to a wall.

Abstract: A dryer duct assembly employs two universal elbow components and at least one flexible component. The flexible component has ends capable of connecting to another flexible component or to a universal component without the use of other devices such as hose clamps to secure connection. Each elbow has ends capable of attaching either to the wall opening or the dryer, in addition to attaching to the flexible component in the same manner as the flexible components may attach to each other. The elbow has an outer portion resembling the outer portion of a quarter-toroid, and a square type inner portion. The outer portion is made of a pair of mirror image hemi portions connected at adjacent flanges. The inner portion has an L-shaped plate with flow-through orifices in each leg of the L.

Abstract: A flexible duct assembly having a thin peripheral wall formed with helical, i.e., sprial, ribs and adjacent grooves or valleys, the apex of each rib and valley advancing helically with axial extension of the duct, and a rotary joint on at least one end of the duct to relieve the torque otherwise resulting from the helical advancement.

Abstract: Disclosed is a metal dryer exhaust duct assembly using a pair of flexible corrugated metal ducts capable of linear extension and capable of reorientation of the duct ends, a pair of elbow connectors, one for attachment to a dryer exhaust outlet and the other for attachment to a wall inlet. Each duct has a swivel connection to its respective elbow connector, using a sleeve which interfits with the elbow connector by a peripheral projection and recess arrangement. Each duct can also be interfit with another such duct. The two ducts can be attached respectively to an dryer and a wall spaced from each other, and are vertically self supporting, whereby when the dryer is moved adjacent the wall, a person can readily telescopically interconnect the ends of the ducts over the top of the dryer. One or more pieces of the duct may be used to span the distance between the dryer and the wall outlet.