Abstract: An improved deflecting device is provided for a drilling apparatus having a rotatable drill shaft extending from a power source through said deflection device to a drill bit. The deflection device includes an outer housing affixed to the power source and extending axially therefrom. An inner ring is disposed within the housing and encompasses a portion of the drill shaft. An intermediate ring is disposed between the outer housing and the inner ring and has an inner configuration such that the inner ring is immovable relative to the intermediate ring in a first direction, and is prevented from rotating relative to said intermediate ring about an axis parallel to a second direction perpendicular to said first direction, and such that said inner ring is movable relative to the intermediate ring in said second direction.

Abstract: A device for facilitating directional drilling of small diameter holes radially of a mine long hole comprising a segmented sleeve for movement through a guide channel in a main drill unit. A small bit is driven by a flexible shaft which passes through the segmented sleeve. The segmented sleeve remains partially in the guide channel and extends partially out of the guide channel in a straight line from the guide channel. The segments are joined in a manner permitting a 90.degree. turn in the guide channel but allowing no curvature in the portion of the segmented sleeve extending from the guide channel.

Abstract: Apparatus and method for determining the tensile load on a mine roof bolt, which is indicative of the support provided by the bolt. The device comprises a hammer for striking a roof bolt to produce a sound pulse, a microphone for picking up the sound pulse, and a sound comparator having a recorded sound or sounds whereby an operator can match the induced sound pulse with a recorded sound pulse to provide an indication of the tensile load on the roof bolt. The comparator may include a range of sounds, or may incorporate a variable speed function whereby the pitch of the recorded sound may be varied until the induced sound is matched. Comparison of the induced sound with the recorded sound provides an indication of the tensile load on the roof bolt.

Abstract: A device and method for determining strength properties of a subterranean formation. The device is insertable into a borehole formed in the formation, and includes a pair of inflatable semi-cylindrical members mounted on a shaft. The inflatable members when pressurized exert radial force in all directions except along the plane between the members, with the result that a higher parting force is exerted on the formation perpendicular to the plane between the members than across any other plane through the axis of the device.