| 摘要 |
<p>Both panels and uprights may be made of steel, glass fibre or other material. The prop rests against the upright which in turn supports the plates. The upright can be moved in a lengthwise direction in relation to one of the panels by means of a dovetailed connection with a projection on one panel, which projects beyond it and is inserted into the upright. The other panel has a reinforced end which fits into a groove in the first panel, and also has a projection fitting into a groove on the upright, when the first panel and upright are joined. The shoring plates may be single or double height.</p> |
