| 摘要 |
<p>The wall is thin and consists of flexible material such as rubber, plastics or canvas, or a combination of materials. The bottom edge touches the ground when in operation and has a rigid rim. Rigid or flexible connecting-pieces attached to the rotor hub and to the rim join the wall on. Spring devices prevent deformation to the surface of the wall, and are positioned in the bottom part, or the inside, of the wall. The wall may be reinforced by a strip running round it, or by axial strips, of reinforced plastics, etc. An adjustable regulator(s) for the wall in an axial or radial direction consists of a spring with a weight, and centrifugal force. The outer wall surface has prongs arranged in groups round it in the vicinity of which are regulators with weights in the form of a chain, wire or strip fixed between two adjacent groups of prongs.</p> |
