Abstract: A method for renewing an existing pipeline comprises the steps of advancing a shield tunnelling machine from one end of an existing pipe defining the existing pipeline to the other end thereof, excavating at least the existing pipe by the machine and disposing a new pipe in an excavated spot while the machine is advanced, whereby the existing pipeline is renewed by breaking the existing pipe embedded in the ground while laying the new pipe therein. An existing pipeline renewing apparatus embodying the method described above comprises a shield tunnelling machine for excavating an existing pipe embedded in the ground so as to define an existing pipeline and a means for disposing a new pipe in a spot excavated by the machine. Accordingly, since the new pipe is disposed while excavating the existing pipe by the shield tunnelling machine, it is not necessary to excavate the spot, in which the existing pipe to be renewed is laid, by an open cut method.

Abstract: A device for transmitting a thrust from one of a pair of adjacent pipes so as to propel the other comprises a pair of annular members adapted to be slidable relatively to each other along their spherical surfaces.

Abstract: A shield tunneling machine comprises a shield body, a rotor disposed in a front portion of the shield body, support is provided behind the rotor in the shield body and for supporting the rotor to be eccentrically movable around the center axis of the shield body, drive motor for moving the rotor eccentrically and a seal disposed between the support and the rotor. The seal is provided with an annular recess provided around the center axis in a portion where one of the supports and the rotor faces the other and opened to the other of the supports and the rotor, a ring disposed in the recess to be movable in the direction of the center axis and having a generally constant outer diameter and a spring for pressing the ring toward the other of the supports and the rotor. The diameter D.sub.1 of the ring, the maximum diameter D.sub.2 of the contact portion between the ring and the other of the supports and the rotor and the eccentrically e of the eccentric movement have the following relationship; D.sub.1 .ltoreq.D.

Abstract: A method for renewing an existing pipeline comprises the steps of advancing a shield tunnelling machine from one end of an existing pipe defining the existing pipeline to the other end thereof, excavating at least the existing pipe by the machine and disposing a new pipe in an excavated spot while the machine is advanced, whereby the existing pipeline is renewed by breaking the existing pipe embedded in the ground while laying the new pipe therein. An existing pipeline renewing apparatus embodying the method described above comprises a shield tunnelling machine for excavating an existing pipe embedded in the ground so as to define an existing pipeline and a means for disposing a new pipe in a spot excavated by the machine. Accordingly, since the new pipe is disposed while excavating the existing pipe by the shield tunnelling machine, it is not necessary to excavate the spot, in which the existing pipe to be renewed is laid, by an open cut method.

Abstract: An apparatus for building a new pipeline while breaking a plurality of existing pipelines extending parallel to each other, comprises: a shield tunnelling machine for performing the excavating operation while breaking opposed portions of a plurality of existing pipelines; and a basic thrust mechanism for thrusting a new pipe into a space obtained through excavation by the machine while advancing the machine; wherein the shield tunnelling machine includes a shield body, a cutter assembly disposed in front of the shield body to be rotatable about the axis parallel to the axis of the body and dimensioned for breaking opposed portions of the existing pipelines while the body is advanced and a pair of stabilizers positioned on the outer periphery of the body so as to project respectively from a pair of opposite outer peripheral portions of the body and dimensioned to be slidably engaged with the remaining portion of the existing pipelines opposed to each other when the body is advanced.

Abstract: A method for excavating a hole and an apparatus therefore are suitable for the operation of excavating a hole used for laying a lateral sewer or mounting pipe, which extends from a main sewer pipe toward the ground surface, on the main sewer pipe. The method comprises the step of rotating a rod about its axis in a space provided in the ground while advancing the rod in the direction of penetrating a wall member defining the space, and the step of utilizing the advanced rod as a guide while excavating a hole in the ground from the tip end of the rod toward the space. The apparatus embodying the method described above comprises a rod propelling machine disposed in a space provided in the ground for rotating a rod about its axis while advancing the rod and a excavating machine utilizing the advanced rod as a guide while excavating a hole in the ground from the tip end of the rod toward the space.

Abstract: An apparatus for propelling a plurality of pipes arranged in series comprises basic thrusting means for generating a thrust to be applied to the pipes and intermediate thrusting means for receiving the thrust from the basic thrusting means and applying the received thrust to one of the pipes. The intermediate thrusting means includes a press head provided with a portion displaceable to a position where the portion is capable of abutting against the rear end face of one of the pipes when the intermediate thrusting means is advanced while displaceable to another position where the portion does not interfere with the advance of the following pipes when the intermediate thrusting means is removed and an intermediate body extending rearward from the press head such as to receive the thrust from the basic thrusting means and apply the received thrust to the press head.

Abstract: A pipe propelling device comprises two sets of jack assemblies spaced from each other and arranged in the direction of propelling the pipe in a vertical shaft having a reacting shaft wall so that small diameter pipes such as water supply and drainage pipes, gas pipes and cable lying pipes can be propelled from the interior to the exterior of the vertical shaft by the extension of two sets of the jack assemblies. To reduce the dimension of the vertical shaft to propel the pipe, eliminate the interposition of a strut in propelling the pipe and secure an operative space in the vertical shaft, the jack assemblies comprise a plurality of first stage jacks connected to the reacting shaft wall and at least one second stage jack, a cylinder of the second stage jack being connected to cylinders of the first stage jacks.

Abstract: A shield-type tunneling machine comprises a shield body having a front portion converging gradually rearward, a crankshaft journalled rotatably by a diaphragm provided in the shield body, a drive mechanism connected to an end of the crankshaft and a conical or frustoconical rotary head supported rotatably by the other end and disposed in the front portion of the shield body to be turned eccentrically, a gear mechanism for forcibly rotate the rotary head and a means for discharging debris from a front area of the diaphragm to a rear area. The tunneling machine, when thrusted in the ground by a jack, receives earth and sand into the front portion of the shield body and compresses them between the rotary head and the shield body to send them to the rear. The machine can be used for a pipe jacking as well as the tunneling in the soft ground.

Abstract: An earth auger is provided which can be compacted, lightened and adjusted with respect to feed speed according to geology. The earth auger has a screw having a spiral blade provided with notches arranged axially linearly. A first rotary member and a second rotary member arranged coaxially in a case for the screw and surrounding partially the screw are disposed rotatably about the axis. The first rotary member has a key engaging the notches of the screw, and the second rotary member has a thread groove meshing with the blade of the screw. The first and the second rotary members are rotated respectively in any one of forward and backward directions through a drive mechanism. The screw is rotated by at least one of rotational operations of the first and the second rotary members to advance or retreat relative to the case for excavating.

Abstract: A pipe propelling device comprises two sets of jack assemblies spaced from each other and arranged in the direction of propelling the pipe in a vertical shaft having a reacting shaft wall so that the small diameter pipe such as water supply and drainage pipes, gas pipes and cable laying pipes can be propelled from the interior to the exterior of the vertical shaft by the extension of two sets of the jack assemblies. To reduce the dimension of the vertical shaft due to propel the pipe, eliminate the interposition of a strut in propelling the pipe and secure an operative space in the vertical shaft, the jack assemblies comprise a plurality of first stage jacks connected to the reacting shaft wall and at least one second stage jack, a cylinder of the second stage jack being connected to cylinders of the first stage jacks.

Abstract: A shield tunneling machine comprises a tubular shield body, a partition wall provided in the shield body, a rotary shaft supported rotatably by the partition wall and extending longitudinally of the shield body, a cutter head disposed on the front end of the rotary shaft and a mechanism for rotating the cutter head through the rotary shaft. The cutter head comprises a first cutter provided with a plurality of cutter bits and a second cutter provided with a plurality of roller bits. The machine also comprises a mechanism for moving straight forward and backward one of the first and second cutters relative to the other. The machine locates the first cutter more forward than the second cutter for excavating the face of stratum having a soft layer like clay layer with the first cutter and the second cutter more forward than the first cutter for excavating the face of the stratum having a hard layer like bedrock layer with the second cutter.

Abstract: Method for thrusting a shield for use in tunneling includes the steps of causing a rotary head, provided at the front portion of a shield body, an eccentric motion so that earth, soil or sand covering the front of the shield is pressed away radially of the shield, and exerting a thrust on the shield body during the eccentric motion of said rotary head. Apparatus for carrying out the method includes a driven crank shaft or a driven eccentric straight shaft, a conical or frustoconical rotary head supported rotatably by the crank or eccentric straight shaft, conveyor for discharging mined material backwardly, and hydraulic jacks for imparting a thrust to the shield body.

Abstract: A method for excavating a tunnel wherein the muck from the tunnel face is admitted into the shield; the muck is pressed by a pressure of a predetermined level higher than an active earth pressure in the face and lower than a passive earth pressure as the shield body is moved forward, thereby establishing the balance between the earth pressure in the face ground and the muck pressure; and a liquid of a level balancing the underground water pressure is used to resist the underground water, thereby preventing movement of the underground water, whereby the face is maintained stable; and when the muck pressure is raised over the predetermined level, the muck is discharged out of the shield.

Abstract: In a shield-type tunneling machine, a pair of comb-type bit-plates are pivotally supported on a peripheral wall of each cutter slit provided in a cutter disc. In order to adjust a degree of opening of each slit as well as a cutting angle of the bits with respect to the facing, the bit plates are pivotally moved to an open position or a close position for opening or closing each slit, in association with the reciprocating motion of a slide shaft disposed in a hollow drive shaft which rotates the cutter disc.

Abstract: A pipe jacking apparatus comprises a shield type tunneling machine equipped with direction adjusting jacks, a tubular body joined to the rear of the shield type tunneling machine, and a thrust jack provided within a thrust pit and thrusting forward a pipe member placed between the shield tunneling machine and the thrust jack, in cooperation with the shield type tunneling machine. The aforesaid tubular body includes a panel therein having output gages for the aforesaid jacks and a mark representing the center of the tubular body, and a TV camera for taking a picture of the panel. This TV camera is connected to a TV receiver provided in a remote control unit. In the aforesaid pit, there is provided an optical unit having a line of collimation directed to a predetermined direction to thrust a pipe, or a light source for light beams.