A mole launcher which has a hydraulically powered, double-acting piston and cylinder unit to push or pull a slider. The slider carries a drill head connected to a drill string. The other end of the drill string carries a mole to bore an underground passage. By releasably locking the slider to the front of the launcher, the cylinder can be moved between a first position in which it projects beyond the chassis of the launcher, and a second position in which it is placed only within the length of the chassis. Thus, the mole launcher is considerably shorter in its transportation state than in its operating state.
An underground directional boring machine includes a frame and a drive mechanism slidably mounted on the frame. A drill string is coupled to the drive mechanism for rotation and longitudinal advancement and retraction. A drive assembly moves the drive mechanism along the frame. The drive assembly includes two hydraulic cylinders coupled to the drive mechanism and extending in opposite directions. Free ends of the hydraulic cylinders are releasably secured to the frame at any one of a plurality of positions along the length of the frame. Selective pressurization of the cylinders results in sequential movement of the drive mechanism along the frame by alternative extension and retraction of the cylinders.
In apparatus for producing and expanding earth boreholes and for destroying and replacing underground pipelines or for driving in pipes, a feed drive and a rotary drive having a plug-in coupling comprising a chuck and a locking portion at the end of a string is located in a frame. The string comprises a plurality of sections or lengths having an internal screw thread at one end and an external screw thread on the locking portion at the other end, which at the same time is provided with a key face to hold fast said string section while it is screwed together with the next following string section.
A horizontal directional drilling machine for generating a bore with a drill string. The machine includes a frame defining a thrust axis. A rotational drive head for rotating the drill string is mounted on the frame. A thrust mechanism is provided for moving the rotational drive head in a first direction along the thrust axis to push the drill string into the ground, and a second direction along the thrust axis to pull the drill string from the ground. The horizontal directional drilling machine also includes an anchoring arrangement connected to the frame. In one embodiment, the anchoring arrangement includes a stake-down unit that is pivotally movable about a pivot axis that is generally transversely oriented relative to the thrust axis. The stake-down unit includes a power auger, and a stake-down actuator for moving the power auger toward and away from the ground. The anchoring arrangement also includes a tilt actuator for pivoting the stake-down unit about the pivot axis. In another embodiment, the anchoring arrangement can include a stake-down unit as described above that is laterally adjustable relative to the thrust axis.
