Abstract: Apparatus for enlarging or removing irregularities in an underground duct comprises first and second expandable segmented nose and intermediate shell portions (10,20) each comprising a respective set of shell parts (14,18) arranged around a longitudinal axis (16). The shell parts (14) of the nose portion (10) are pivotally connected to a nose cone (12) and to the front ends of the shell parts (18), while the shell parts (18) are pivotally connected at their rear ends to a rear pivot assembly (22). Expansion of the duct is achieved by repeatedly driving the joints between the shell parts (14) of the nose portion (10) and the shell parts (18) of the intermediate portion (20) outwards so as to force the wall of the duct outwards, returning the shell parts (14,18) to a contracted configuration, and moving the apparatus forward in the duct.

Abstract: A device for removing irregularities in or enlarging a buried duct comprises a cylindrical housing corresponding approximately in diameter to the required diameter of the duct, an expandable shell comprising a plurality of tapered leaf members pivotally attached at their rear ends to the front of the housing, and remotely controllable drive means for moving the leaf members between contracted and expanded configurations. In operation, the apparatus is drawn through the duct with the leaf members in a contracted configuration in which they enter a portion of the duct of a diameter less than the required diameter. The drive means is operated to force the leaf members outwardly against the sides of the duct to expand the duct. The leaf members are then retracted and the apparatus is drawn forward. The apparatus is particularly intended for preparing damaged sewers prior to fitting an inner, lining pipe.

Abstract: A device for removing irregularities in or enlarging a buried duct comprises a cylindrical housing corresponding approximately in diameter to the required diameter of the duct, an expandable sheet comprising a plurality of tapered leaf members pivotally attached at their rear ends to the front of the housing, and remotely controllable drive means for moving the leaf members between contracted and expanded configurations. In operation, the apparatus is drawn through the duct with the leaf members in a contracted configuration in which they enter a portion of the duct of a diameter less than the required diameter. The drive means is operated to force the leaf members outwardly against the sides of the duct to expand the duct. The leaf members are then retracted and the apparatus is drawn forward. The apparatus is particularly intended for preparing damaged sewers prior to fitting an inner, lining pipe.

Abstract: A remotely controllable travelling robot for operation inside a pipe or bore-hole has a tool mounting assembly (22) which is rotatable in support structure (14, 16) about a longitudinal axis. The support structure (14, 16) is mounted on a pair of skids (10, 12) by means of a hydraulically driven elevator mechanism including rams (32) mounted on the skids 10, 12 which lift the support structure (14, 16) to a required height so as to place the longitudinal axis approximately in coincidence with the axis of the pipe or bore-hole. A tool mounting head (80) forming part of the tool mounting assembly (22) is itself hydraulically powered for tilting about a transverse axis and for moving transversely relative to the longitudinal axis along a transverse bar (88) fixed in a tool mounting assembly casing 60.

Abstract: A device for removing irregularities in or enlarging a buried duct comprises a cylindrical housing (10) corresponding approximately in diameter to the required diameter of the duct, a plurality of tapered leaf members (14) pivotally attached at their rear ends to the front of the housing, and a conical wedge (18) driven by an axial hydraulic ram (12) mounted inside the housing (10). In operation, the apparatus is drawn through the duct with the leaf members (14) in a retracted position in which they form a tapered nose portion, until an irregularity in the duct causes resistance to forward movement. The ram (12) is operated to force the leaf members outwardly against the wall of the duct to remove the irregularity. The leaf members (14) are then retracted as the apparatus is drawn forward to the next obstruction. The apparatus is particularly intended for preparing damaged sewers prior to fitting an inner, lining pipe.

Abstract: A device for removing irregularities in or enlarging a buried duct comprises a cylindrical housing (10) corresponding approximately in diameter to the required diameter of the duct, a plurality of tapered leaf members (14) pivotally attached at their rear ends to the front of the housing, and a conical wedge (18) driven by an axial hydraulic ram (12) mounted inside the housing (10). In operation, the apparatus is drawn through the duct with the leaf members (14) in a retracted position in which they form a tapered nose portion, until an irregularity in the duct causes resistance to forward movement. The ram (12) is operated to force the leaf members outwardly against the wall of the duct to remove the irregularity. The leaf members (14) are then retracted as the apparatus is drawn forward to the next obstruction. The apparatus is particularly intended for preparing damaged sewers prior to fitting an inner, lining pipe.