| 摘要 |
<p>The three-legged chair is used to locate an electric junction box or similar in an in situ concrete member, fixes the position of the box while concrete is poured, and adjusts to suit boxes of different lateral dimensions. The legs may be of straight bar with an assymetric 'S' formation in the region of the upper quarter point, locate box flanges, and are stabilized by a radial brace. The brace may have three inclined arms radiating from a hub the arms terminating in forks which grip the tripod legs. Fixing to a shutter may be by nail through the hub, all feet being set in plastic cups or similar. When the chair is assembled the legs may converge towards the top, and may reduce in the box support zones to avoid thermal bridging.</p> |
