Abstract: A drill bit for use in combination with a through-the-steel drill stem, the drill bit including an elongated body portion having a bore through which cuttings may be removed, a web extending transversely across the bore for receiving a drill tip, and drill ports leading from the drill tip to the bore and from the periphery of the body portion to the bore, the drill ports comprising opposed axially extending openings contoured as a hemisphere to define opposed axially extending faces of the web and opening to the bore from the drill tip and extending axially along the body portion and opening from the periphery thereof to the bore below the web. The drill bit may be provided with a sleeve to delimit the drill ports.

Abstract: A drill bit for use in combination with a through-the-steel drill stem, the drill bit including an elongated body portion having a bore through which cuttings may be removed through the drill stem, a web for receiving a drill tip, and a sleeve attached about the body portion thereof, the web thereof having axially extending faces coutoured from the periphery of the body portion toward the axis thereof, and the sleeve extending from the body portion and in spaced apart axial relation to the contoured faces of the web in a manner to define drill cut receiving ports opening upwardly to the drill tip and downwardly to the bore of the body portion. The drill bit may be provided with a male keeper or retainer to mate with a complementary female receptor of the drill stem for interconnection of the drill bit to the drill stem.

Abstract: Disclosed herein is a new method and improved apparatus for digging and mining earth formations, especially coal formations. A mining or excavating machine having a movable frame with a drive means mounted on the frame is provided with a rotatable structural member and a rotatable cutter support having cutter bits mounted thereon. The structural member is rotatably mounted on the frame and connected to the drive means so as to be driven in one direction of rotation about a longitudinal axis of the structural member. The rotatable cutter support assembly with the cutter bits mounted thereon is rotatably mounted on the structural member and is freely rotatable about its longitudinal axis. The mining machine is then positioned so that the cutter bits will reduce the mineral formation by driving the structural member in one direction of rotation about its longitudinal axis.

Abstract: A tool for being inserted in a hole, especially a hole in an earth formation, and adapted for being rotated in the hole. A cutting element moveably mounted on the tool is provided for cutting a groove in the hole and, if the tool is moved axially in the hole while rotating, a helical groove will result. The cutting element is retractable to permit removal of the tool from the hole. The hole with the groove formed therein is adapted for receiving a roof bolt or the like which is cemented in place and the aforementioned groove improves the strength with which the bolt is held in the hole.