| Patent Number |
Title Of Patent |
Date Issued |
| 4087131 |
Drag bit excavation |
May 2, 1978 |
| A drag bit excavating device comprising a core extending along an axis; a bit carrier supported on the core; cutter bits supported by the carrier along a three dimensional spiral having constant pitch and increasing radius along at least a portion of the axis, the carrier being relieved |
| 4084854 |
Drag bit excavation |
April 18, 1978 |
| In a drag bit excavating device having a plurality of cutting elements, each element comprising a core extending along an axis; a bit carrier supported on the core; cutter bits supported by the carrier along a three dimensional spiral having constant pitch and increasing radius along at |
| 4031974 |
Boring apparatus capable of boring straight holes |
June 28, 1977 |
| A rock boring assembly for producing a straight hole for use in a drill string above a pilot boring bit of predetermined diameter smaller than the desired final hole size. The boring assembly comprises a small conical boring bit and a larger conical boring bit, the conical boring bits |
| 4020910 |
Sealing between relatively rotating members in boring apparatus |
May 3, 1977 |
| A boring apparatus having a working member mounted for rotation on a lubricated bearing about a shaft member, the apparatus being of the type in which substantial radial and axial relative motion between said members occurs in response to radial and axial loading conditions encountered b |
| 3977481 |
Boring apparatus |
August 31, 1976 |
| Boring apparatus having a plurality of hole-enlarging assemblies comprising shaft-mounted working members. In a convergent arrangement of the axes of the working members the assemblies are completed by insertion of the elongated shafts via a hollow space in the bottom connector, through |
| 3975056 |
Longwall canted drum mining machine |
August 17, 1976 |
| A side excavating machine comprising a rotatably driven cylindrical drum adapted to advance generally endwise along a pre-existing working face, but angled so that trailing portions of the drum project beneath the plane of the pre-existing face. The drum has a distribution of rock cuttin |
| 3957305 |
In situ values extraction |
May 18, 1976 |
| The invention is directed to a method of in situ extraction of a constituent of a rock formation, e.g., copper deposits or particular petroleum deposits as found in oil shale, and to a method of preparing the rock formation for in situ extraction of the rock constituent. Various embo |
| 3945447 |
Boring apparatus |
March 23, 1976 |
| In boring apparatus of the type having cutters mounted for rotation about respective cutter axes in a frame which is in turn rotatable about a frame axis, each cutter having a body carrying teeth which in operation sweep a surface which is oblique to the axis of advance of the apparatus, |
