| Patent Number |
Title Of Patent |
Date Issued |
| 4281723 |
Control system for a drilling apparatus |
August 4, 1981 |
| 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 |
| 4153119 |
Directional drilling apparatus |
May 8, 1979 |
| 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 |
| 4152929 |
Roof bolt tension determination |
May 8, 1979 |
| 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 |
| 4030345 |
Borehole pressure cell |
June 21, 1977 |
| 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 f |
