Image Number 3 for United States Patent #6644754.
A tunnel excavating machine having an excavating machine body can be moved forward by shield jacks. A rotatable cutter head is mounted in a front portion of the excavating machine body. An erector device for assembling segments in a ring form is mounted in a rear portion of the excavating machine body. A rest extends rearward from the rear portion of the excavating machine body. A shape retainer for making pressurized contact with inner peripheral surfaces of the assembled segments to retain the segments in a predetermined shape is supported on the rest so as to be movable along a fore-and-aft direction. Also, a revolving frame is located between the erector device and the shape retainer, and supported on the rest so as to be movable along the fore-and-aft direction such that the revolving frame does not interfere with the erector device and the shape retainer. A cage is supported on the revolving frame so as to be revolvable in a circumferential direction of an existing tunnel.