US Patent 9797539 Pipe rehabilitation method

Segments are linked in the circumferential length to assemble a pipe unit, which is linked to another pipe unit using a link bolt to install a rehabilitating pipe inside an existing pipe. An elastically deformable clip having a cylindrical cavity with a notch is attached to the link bolt between the inner plates of the segment. The clip grips the link bolt at the cavity thereof that is enlarged due to elastic deformation. When the link bolt is moved in the direction opposite the insertion direction, the clip that grips the link bolt hits the inner plate of the segment to limit the movement of the link bolt in the opposite direction and prevent the link bolt from falling out of the segment.