| 摘要 |
PURPOSE:To prevent the distortion of reinforced concrete by mounting rotatably on the end of a boom an L-shaped pipe end member having a resistant valve at the outlet, by maintaining the outlet section of the pipe end horizontally and by constituting the pipe end so that it may rotate around the center of a rising axis. CONSTITUTION:A resistant valve 18 provided at the tip of a sliding sleeve 16 is positioned so as to meet the section of concrete placing by controlling hydraulic cylinders 6 and 8 and a motor 13 while keeping the rising part of boom 9 in vertical attitude. Then, the sliding sleeve 16 can be maintained horizontally. When concrete is transmitted under pressure by a pump 2, the concrete remains at the pipe end 14. If a pressure higher than the specified is applied to the rotating plate of a resistant valve 17, the valve 17 is opened to discharge the concrete. The sliding sleeve 16 at the pipe end 14 is horizontally rotated by operating the motor 13 so that the discharge direction and placing location of concrete may be altered. With this construction, the distortion of reinforced concrete can be prevented when the position of concrete placing is changed. |
