| 摘要 |
<p>A canvas tent is designed to cover swimming baths, tennis courts, greenhouses or other wide areas. It can be stretched and riged, and fully dismantled. It is used with an easily handled, demountable support frame, comprising metal uprights inserted in cement base blocks on both sides of the area, wit with a similar number of support cables (12). Each of these bears a number of running rollers, with a pulley (21) support on the cable. The sheet is made up from a number of lengths (11) fitted with metal bars (26), and connectors (27) for joining these to the rollers. Traction cables (25) slide freely in holes in the roller casings, held and deflected by pulleys above the uprights so as to form a closed ring, and running to and from a winch on a upright. Two rollers are arranged so that operation of the winch in one direction or the other effects sheet bracing along the support cables.</p> |
