| 摘要 |
The lower part of the pipe is pressed to form two tracks bent longitudinally, and to enclose the ends formed with bends of a flat iron or round stirrup (1) inserted into the pipe. After the pipe has been driven into the ground to the required depth, taking the stirrup with it under the force of strokes imparted by an iron bar inserted into the pipe, the stirrup arms (2) are rounded outwards below the pipe so as to form an anchor. In preparing the pipe, it is first cut to length, and the stirrup with bent lower ends isinserted into the lower part of the pipe with its ends at the pipe end. The lower part of the pipe, by pressing, is formed into tracks which enclose the stirrup ends sufficiently tightly so that a sliding ability exists by adjustment of the press striker mechanism. |
