| 摘要 |
<p>The shuttering consists of a bottom plate (10), two sides, (13) which can be lowered and raised, on the plate, and which converge at the top to form a trapezoid angle. At lease one tubular core forms a hollow duct (6, 7) which can be moved horizontally by more than the length of the ceiling girder, and crosswise to the direction in which the shuttering sides are moved. Several griders can be produced simultaneously by placing a shuttering box (16) between adjacent girders. The lengthwise sides (17, 18) mould the lengthwise sides (5) of the girders. The shuttering sides (13) and box (16) have a bead-shaped core (19, 20) to form ducts (8, 9) on the lengthwise sides (4, 5) of the ceiling girder (1).</p> |
