Nippon Telegraph and Telephone Public Corporation

Hitachi, Ltd.

Hitachi Construction Machinery Co., Ltd.

Minoru Shiozaki

Kozo Ono

Tsuyoshi Inoue

Naoki Miyanagi

Kojiro Ogata

Kiyoshi Tsuchiya

Nobuyuki Tobita

Masao Suda

Yoshiyuki Iwai

Shuichi Satoh

Osamu Ae

Manabu Nakano

A vibration generating apparatus including a support body having a first center axis, a first spherical joint element provided at a forward end of the support body and having the center of a sphere located on the first center axis, a vibrating body having a second center axis passing through the sphere center, a second spherical joint element provided on the vibrating body and concentric complementary with the first spherical joint element to cooperate therewith to allow the vibrating body to be supported on the support member for universal movement, a rotary shaft coaxially rotatably supported within the vibrating body, a pair of eccentric weights mounted on the rotary shaft with a phase deviation of 180 degrees and in a manner symmetrical with respect to the sphere center, and a drive motor connected to the rotary shaft for driving same for rotation whereby the pair of eccentric weights are rotated about the second center axis to cause the vibrating body to move in conical motion vibration such that the second center axis describes a circular cone having a vertex located at the sphere center about the first center axis.

Vibration generating apparatus

A pipe laying apparatus including an excavator propulsion unit located in a starting pit. The excavator includes an excavator body having a first axis, an excavating tool having a second axis and located at a forward end portion of the excavator body, and injection ports formed in the excavating tool for injecting a viscosity imparting liquid into soil as excavated. The excavator body has a rearward portion thereof disposed adjacent pipes to be laid each having an outer diameter smaller than the outer diameter of the excavating tool and positioned at a rearward end thereof against the propulsion means, and is operative to excavate the earth to form a hole therein while the viscosity imparting liquid is being injected through the injection ports into the soil as excavated to thereby produce a viscosity imparting liquid containing soil which is conveyed rearwardly through an outer periphery of the excavator body while being filled in an annular clearance defined between the hole formed in the earth and the pipes to be laid, so that the pipes can be successively laid as the excavator body and the pipes are propelled forwardly by the propulsion unit.

Pipe laying apparatus

Growing community of inventors

Ibaraki, Japan

Minoru Shiozaki