| 摘要 |
PURPOSE:To easily remove extra-banking concrete by a method in which an inlet opening of the bottom of a bucket body is opened or closed by a bottom cover attached to the end of a rotary shaft interlocked with a drive shaft and the bottom cover is positioned by stopper. CONSTITUTION:Before an extra-banking concrete C hardens, when a bucket body 1 is penetrated slowly into the concrete C under a condition that the inlet opening 2a of the bucket body 1 is opened, concrete C containing slime, etc., is put into the bucket 1. When a kelly bar 8 is turned, the bottom cover 9 is turned in the direction of arrow through a rotary shaft 5. Whereupon, the cover plate 9a contacts with the stopper plate 4a, the cover plate 9b contacts with the stopper plate 4b, and the cover plate 9c contacts with the stopper plate 4c. The opening 2a is closed. The bucket body 1 is lifted up, the kelly bar 8 is turned in the opposite direction, and the opening 2a is opened to discharge the concrete C. |
