Kajima Corporation

Yoichi Kume

Hiroshi Yoshida

Taro Ikeda

Kenji Nishi

Teruo Yahiro

Takahisa Isobe

Hidenobu Hamano

Method and apparatus for crushing the earth under the ground by boring a hole; inserting a drill head having radially directed water jet thereon down the hole to the desired stratum; rotatingly moving the drill head upwardly while jetting water radially to form a cylindrical crushed area; lowering the drill head to the original depth; extending a water jet extender arm radially to a projecting position; again rotatingly moving the drill head upwardly while jetting water from the nozzles on the radial outward portions of the extender arm to radially enlarge the cylindrical crushed area, the rotation of the extender arm also stirring the already crushed area; returning the extender arm to an original waiting position; and lifting the drill head out of the hole.

Growing community of inventors

Tokyo, Japan

Yoichi Kume