| 摘要 |
<p>Improvement in fences and security walls for sport fields in general comprehended at least around part of the perimeter of a playing field and placed between it and the watching public, a plurality of spaced apart vertical posts (1, 2). Between each pair of said vertical posts is placed a rod (3) defining with the floor a frame, inside which is individually fixed and held a portion of metal wire net or metallic gauze (5). Over each rod (3) is placed a flat panel (6) made of transparent material and is created through the metal wire net or metallic gauze a bottom zone of air, water and/or gas free passage. The top panels create a barrier for the temporary contention of gases (as tear gas) and at the same time induce an air stream to quickly dissipate them. The same way, such plates, without impeding the view of the watchers, define an efficient barrier against things thrown from the tribune to the playing field.</p> |
