Kubota Corporation

Masao Nakagawa

Shigeaki Okuyama

Siro Sugiyama

Katsuhiko Mukuno

Teruo Kabeuchi

Kazunori Tsujimoto

Masaya Hattori

Yukishige Yamada

Takashi Togawa

A propelling apparatus includes a plurality of propellant cylinders series-connected to each other to be propelled by receiving a pushing force from behind, joints for series-connecting the propellant cylinders, a propellant head connected to a forward-most end of the propellant cylinders to be pressed into the earth, a leader member constituting a leading end of the propellant head, the leader member being rotatable about an axis of the propellant head by receiving a driving force from a driving device. An inclined pressure-receiving face is formed at a forward portion of the leader member for receiving an earth pressure in association with the underground propelling movement of the propellant head and steering the propellant head toward the direction of application of the earth pressure to the pressure-receiving face. The joint includes a flexible joint which is pivotally flexible about a transverse axis extending normal to an axis of the propellant cylinder.

Propelling apparatus for underground propelling construction work

An underground propelling method uses a propellant apparatus including a propellant head having a pressure receiving face portion inclined relative to an axis of the head and a plurality of propellant cylinders flexibly and pivotally connected in series to a rear end of the propellant head. The propellant apparatus is propelled under the ground by applying a thrust to the propellant apparatus from behind. Each propellant cylinder of the apparatus is pivotal about a single pivot axis thereof alone. The apparatus is propelled with the pressure receiving face portion thereof being oriented along a pivotal direction of the propellant cylinder about the pivot axis.

Underground propelling method

A structure for a running system, in a work vehicle, has right and left running wheels, hydraulic cylinders extensible and retractable in opposition to each other in response to axle-tilting displacement of the wheels as they rise and lower in turn in opposition to each other, a conduit connecting the cylinders with each other with an on-off valve interposed therein to be arbitrarily maneuverable thus to enable the lock up of both cylinders, and, a supply conduit made connectable to the cylinder-connecting conduit. There are provided valves in order to permit oil to be supplied only when inner pressure within this cylinder-connecting conduit has dropped to show negative pressure below a preset threshold.

Structure of a running system in a work vehicle

A working vehicle having a pair of opposite wheels movable up and down with each other in opposed relation under hydraulic pressure, and brakes for braking the vehicle during running and also for parking the vehicle. The circuit for the hydraulic pressure is provided with a stop valve which is coupled to the system for operating the brakes by a mechanism for holding the stop valve opened while the vehicle is not braked and also when the vehicle is braked for a speed reduction during running and for holding the stop valve closed while the vehicle is braked for parking.

Growing community of inventors

Amagasaki, Japan

Masao Nakagawa