| 摘要 |
<p>The invention is concerned with overhead line installations of the type used to supply electric power to rail vehicles including trams and trains. The line 28 is suspended through hangers 30 each of which is carried by a support structure, which may comprise an upright mast 14 and a laterally projecting bracket arm 16. An upper fixed part of each hanger is coupled to the support structure. A lower free end is coupled to the line 28. The relative positions of the fixed parts of the hangers are such that the hangers are offset from the line 28 and are therefore inclined to the vertical. On straight sections of track the offset is achieved by arranging the fixed parts of the hangers in an alternating pattern first to one side of the line and then to the other. On curves the fixed parts are typically placed to the outside of the curve, the result is that the line is laterally stabilised without need of any additional restraint upon the free part of the hanger. Also disclosed is a device for tensioning the line which applies a force to the line along a transverse direction. In this way a great deal of mechanical advantage can be created, a large line tension being achieved from a relatively small tensioning force.</p> |
