Abstract: Example inflatable air barriers are disclosed herein. Some example barriers disclosed herein include one or more inflatable tubes for maintaining a sealed airlock leading to an underground shelter. Such shelters provide miners with temporary refuge in the event of a mining incident involving the release of contaminated air. Some example barriers disclosed herein include one or more of the following: an inflatable tube with an air permeable section, a resiliently compressible foam body or other resilient member for supporting a deflated tube, a magnet for providing a secure seal, an inflatable tube with interchangeable end caps, elastic bands for securing the position of an inflatable tube, or an inflatable tube with one or more windows.

Abstract: Pliable-wall air ducts with internal expanding structures are disclosed. An example air duct system includes a shaft to be disposed within an air duct, to extend in a longitudinal direction, and to be in longitudinal compression. The air duct system also includes a plurality of ribs to be coupled to the shaft and to engage an inner surface of the air duct and a spring to be disposed within the air duct, the spring to be coupled to the shaft. The spring under stress being a contributing factor in both the shaft being in longitudinal compression and the air duct being in longitudinal tension.

Abstract: Pliable-wall air ducts with suspended frames are disclosed herein. An example air duct system includes an air duct having a pliable sidewall to extend in a longitudinal direction, the pliable sidewall having a total weight and a framework to be disposed within the air duct. The framework includes a shaft extending in the longitudinal direction, a rib to engage an inner surface of the air duct and a plurality of spokes connecting the rib to the shaft. The example air duct system includes one or more hangers comprising an elongate member having an upper section and a lower section. The lower section to extend through a corresponding opening defined by the pliable side wall and to be coupled to the framework. Most of the total weight of the pliable sidewall is to be carried by the framework.

Abstract: Pliable-wall air ducts with suspended frames are disclosed herein. An example air duct system includes an air duct having a pliable sidewall to extend in a longitudinal direction, the pliable sidewall having a total weight and a framework to be disposed within the air duct. The framework includes a shaft extending in the longitudinal direction, a rib to engage an inner surface of the air duct and a plurality of spokes connecting the rib to the shaft. The example air duct system includes one or more hangers comprising an elongate member having an upper section and a lower section. The lower section to extend through a corresponding opening defined by the pliable side wall and to be coupled to the framework. Most of the total weight of the pliable sidewall is to be carried by the framework.

Abstract: Example air ducts comprising pliable tubular sidewalls are provided with example internal frameworks that hold the duct in a generally expanded shape even when the duct is depressurized. The framework tensions the pliable sidewall material along the length of the ducts to keep the material taut. In some examples, the framework is restrained within the duct such that the duct's sidewall, being in tension, holds the framework in compression longitudinally. Thus, in the longitudinal direction, the duct is in tension and the framework is in compression. To prevent the framework from buckling under the compressive force, some example frameworks comprise a central longitudinal shaft with a plurality of radial spokes and rings that help hold the shaft straight. In some examples, the rings also help hold the duct radially expanded.

Abstract: Example air duct systems for supplying conditioned air to comfort zones include various example inflatable tubes with various example dampers. The dampers move noticeably slowly and/or its opening is delayed to reduce the rate at which the tube is inflated by a supply air blower. Depending on the particular example, the damper can be either at the inlet end of the tube or at the tube's opposite end. In some examples, the damper is controlled by an actuator that is powered by air or driven by an electric motor.

Abstract: In some example pliable air duct systems, inflatable ducts of various diameters and lengths are created by selectively assembling pre-existing stock pieces in different combinations. In some examples, the stock pieces include disconnectable longitudinal joints and disconnectable circumferential joints, wherein the longitudinal joints enable interconnecting multiple stock pieces to achieve a desired tube diameter, and the circumferential joints allow connecting multiple tube segments end-to-end to produce an air duct assembly of a desired length. To control the volume and/or the direction of air discharged from the duct, the duct assembly, in some examples, includes an adjustable register comprising a movable pliable sheet that overlies a discharge opening in a pliable sidewall of the duct. In some examples, the inflatable duct includes one or more cutout patterns on the duct's sidewall to provide guidance in creating a sidewall discharge opening of a proper size and location.

Abstract: In some example pliable air duct systems, inflatable ducts of various diameters and lengths are created by selectively assembling pre-existing stock pieces in different combinations. In some examples, the stock pieces include disconnectable longitudinal joints and disconnectable circumferential joints, wherein the longitudinal joints enable interconnecting multiple stock pieces to achieve a desired tube diameter, and the circumferential joints allow connecting multiple tube segments end-to-end to produce an air duct assembly of a desired length. To control the volume and/or the direction of air discharged from the duct, the duct assembly, in some examples, includes an adjustable register comprising a movable pliable sheet that overlies a discharge opening in a pliable sidewall of the duct. In some examples, the inflatable duct includes one or more cutout patterns on the duct's sidewall to provide guidance in creating a sidewall discharge opening of a proper size and location.