Patent ID: 6105621
Filing Date: 2000-08-22
Classification: F16L,F24F

Abstract:
A duct for conducting pressurized air in a heating or cooling or ventilating system comprising an elongated resilient wire disposed in a coil consisting of a plurality of substantially identical turns, an elongated air impermeable flexible tube, said tube having an axial channel of uniform cross section extending along the axis of elongation of the tube, the circumference of the tube at the channel being approximately equal to the length of each turn of the wire coil, the wire coil being disposed coaxially of the flexible tube and the tube being attached to the coil, characterized by the improved construction wherein each turn of the wire coil consists of two elongated side portions and two end portions connected in a series, the side portions being substantially longer than the end portions and confronting each other, the side portions having opposite ends, one end of one side portion being connected to one end of the other side portion by one end portion, and the other end of the one side portion being connected to the one end of the other end portion, each of the end portions having a permanent set in the form of a U-shaped bend, and the side portions of each turn of the wire coil confronting the side portions of adjacent turns of the wire coil.