Abstract: A two-piece planetary hub and output shaft for use in a planetary reduction gear drive assembly for a raise drill having a drive motor and a drive train path including first, second and third reduction gearing driving the planetary hub and output shaft. The hub and shaft are formed as two major pieces, an upper hub and a lower output shaft which are rigidly interconnected by three planet gear shafts each engaging a hole in said hub and a recess in said lower output shaft. Such interconnection is suitably by taper lock bushing assemblies locking the shafts to both said hub and said shaft. Transfer of torque occurs essentially through the planet shafts and the hub, and transfer of load occurs essentially through the output shaft.

Abstract: A drill pipe has a central axis and comprises a first end and a second end with a portion of the second end being substantially triangular in the lateral cross-section and having three faces. At least one concave wrench recess is located in each of the three faces of the substantially triangular portion of the second end. Each of the recesses has a surface with an axially extending center line. The center line is located a predetermined distance from the central axis, with this predetermined distance being less than the distance from the central axis of all other axial lines on the surface of the recess.Each of the recesses may be comprised of two adjoining planes having exterior surfaces, the cross-section of the two adjoining planes forming an angle of less than 180 degrees as measured between the exterior surfaces of the two adjoining planes. Alternatively, the recesses can be comprised of three adjoining planes. Finally, the recesses may be comprised of an arcuate segment.

Abstract: An inflatable gripper assembly for a rock boring or cutting machine is disclosed. The inflatable gripper assembly comprises a base member and an elastomeric sheet secured in a fluid-tight and reaction force secure manner to the base member. The elastomeric sheet expands when fluid is supplied between the base member and the elastomeric sheet to brace a rock boring or cutting machine in a tunnel. The elastomeric sheet contracts when fluid is removed from between the base member and the elastomeric sheet to allow the rock boring or cutting machine to move within the tunnel.

Abstract: A rock cutting tool with a plurality of independently rotatable cutter units and with a shaft, a sleeve located around the shaft, and at least two rotatable hubs located around the sleeve. At least one cutter unit is located on each of the two rotatable hubs for rotation about an axis of rotation with respect to a rock-face. Bearings between the sleeve and each of the hubs rotatably support the hubs. The bearings comprise at least one cylindrical roller bearing set and at least one ball bearing set for each hub. Each roller bearing set is located substantially entirely under the cutter unit of its associated hub to absorb radial loads, and each ball bearing set is located remotely from the cutter unit of its associated hub to be isolated from radial loads. The shaft has first and second key receiving openings. The key is located on the interior surface of the sleeve.