| 摘要 |
<p>The purpose is to provide reliable storm and other weather protection for playing fields in sports stadia, or other large open spaces, esp. those with a grass surface. This is in the form of a protective sheeting made of translucent plastics with a skeleton framework of steel cables. Individual sheets, of various plan sizes, can be combined into a composite sheeting unit with the aid of hooks, or other linking devices, in such a way as to span open surfaces of every sort or size. The sheets may incorporate heating wires, interconnected by plugs when sheets are joined together, and then connected to a current supply. In addition, a system of perforated pipes can serve for watering the ground. Support can be provided by steel posts, with steel tension cables on rollers, the posts being concreted into position; they may be fitted with generators, to derive electric energy with wind assistance.</p> |
