1. Technical Field
The present invention relates generally to augering systems which remove coal from seams within a hill by boring long horizontally extending holes into the coal seam using an auger comprising a rotary cutting head and a string of auger flights to convey the cut coal from the coal seam, and more particularly to auger flight supports for reducing boring friction to extend the distance the auger system can bore into the hill.
2. Background Information
Augering machines powered by internal combustion engines have been used for mining coal from hills containing a coal seam for many years. These augering machines utilize an auger having a cutting head which is advanced horizontally into the coal seam. The auger is usually made up of a series of sections or auger flights having a helically wound flighting, which removably couple together end-to-end to convey the cut coal from the cutting head to a point of discharge outside the hill. The auger flights are rotationally and axially coupled by having a socket at one end and a mating shank on the opposite end. The shank of one auger flight fits into the socket of the next auger flight. A slidable latch pin extends transversely through a hole in the auger flight and into a hole in the shank of the auger flight to be coupled thereto. A release lever permits uncoupling of the auger flights such as when the cutting head is being withdrawn from the bored hole at the completion of the boring. As the string of auger flights is withdrawn, the auger flights are sequentially removed from the auger string by uncoupling and lifting the rearmost auger flight from the auger machine. Pairs of side-by-side cutting heads and augers have been used recently to form a pair of parallel holes in the coal seam to remove a larger volume of coal at once. Each auger is powered by an auger machine which applies axial as well as rotational forces to the augers to force the augers and the cutting heads into the coal seam and to rotate the cutting heads breaking away the material which the augers then convey out of the hole.
There is considerable friction developed between the flighting of the auger flights and the bored holes which requires considerable power from the augering machine, and which reduces the power available to the cutting heads and to convey the cut coal. Attempts have been made to reduce such frictional power losses in auger systems. For example, in U.S. Pat. No. 3,036,821 issued to H. D. Letts is disclosed a spider device where bearings are attached between each of the linearly extending augers, and a plurality of legs are attached to the bearings to form a xe2x80x9cspiderxe2x80x9d. The spider somewhat supports the flighting on the bottom of the bored hole so that the flighting does not rub the ground as hard when rotating, thus reducing the power requirements of the auger machine. In U.S. Pat. No. 5,685,382 issued to Deeter is disclosed a similar auger support having a plurality of radially extending support legs affixed a bearing housing surrounding a bearing. The drive shank of an auger flight is rotatably supported by the bearing at one end of an auger flight, independently of the support provided by the auger flighting, to reduce wear and tear of the flighting and to reduce frictional drag of the auger flights. Finally, in U.S. Pat. No. Re 24,503 to C. E. Compton, which was originally U.S. Pat. No. 2,751,203 is disclosed a spider-type support system for an auger mining system. All of these devices, however, fail to solve a number of problems associated therewith.
There is thus, a continuing need for a support device which overcomes a number of problems associated with the prior art.
One of the advantages of the present invention is that it provides reduced frictional losses between the flighting and the bottom of the bored holes resulting in less power required to bore a given length hole.
A further advantage of the present invention is that it permits longer holes to be bored using the same augering machine due to the reduced friction.
A still further advantage of the present invention is that it is used for dual auger boring.
These and other advantages of the present invention may be realized by reference to the remaining portions of the specification, claims, and abstract.
The present invention relates to an auger flight support for unitizing and supporting pairs of auger flights by connecting together respective first ends of each pair of parallel tubular auger flights. The auger flights each include a respective helical flighting affixed exteriorly therearound having a respective outer diameter, and include respective second ends having a drive socket. The unitized auger flights are adapted for use with an augering apparatus of the type used for rotating and advancing a pair of side-by-side cutting heads of a drilling section. The drilling section is driven horizontally into the side of a hill with the cutting heads driven rotationally through the drive sockets by the augering apparatus. The unitized auger flights are inserted between the drilling section and the augering apparatus in a rotationally coupled end-to-end manner as drilling progresses. The auger flight support includes a pair of support posts, each having a tubular bearing housing and a radially dependent support leg. A pair of drive shafts each includes a first end adapted to closely fit within and be affixable to the first end portion of a respective flight auger, a second end portion of mating configuration to the drive sockets, and a middle bearing portion which fits within said bearing housing. At least one bearing is disposed within each of the bearing housings between the respective bearing housing and the bearing portion of the respective drive shaft which bearing rotationally supports and longitudinally retains the respective drive shaft to the respective support post. A tie bar is adapted to rigidly interconnect the support posts at such a spacing that the respective of the outer boring diameters of the flightings which are closely adjacent one another. The support legs extend generally downwardly and coplanar so as to provide support for the auger flights.
The above description sets forth, rather broadly, the more important features of the present invention so that the detailed description of the preferred embodiment that follows may be better understood and contributions of the present invention to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and will form the subject matter of claims. In this respect, before explaining at least one preferred embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and to the arrangement of the components set forth in the following description or as illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.