US2967701A - Method of continuous low seam short wall mining using rotary auger cutters - Google Patents

Description

Jan. 10, 1961 A. G. WILCOX METHOD OF CONTINUOUS LOW SEAM SHORT WALL MINING USING ROTARY AUGER CUTTERS Original Filed May 6, 1957 7 Sheets-Sheet 1 INVENTOR.

Arnold GJAlilcox ATTORNEYS.

Jan- 1 1 A. G. WlLCOX 2,967,701

METHOD OF CONTINUOUS LOW SEAM SHORT WALL MINING USING ROTARY AUGER CUTTERS Original Filed May 6, 1957 7 $heets-$heet 2 Q Q Q N N INVENTOR Arnold GJAZiZcox ATTORNEYS.

Jan. 10, 1961 A. G. WILCOX METHOD OF CO 2,967,701 NTINUOUS LOW SEAM SHORT WALL. MINING USING ROTARY AUGER CUTTERS Original Filed May 6, 1957 7 Sheets-Sheet 3 INVENTOR.

Arnold, G.V\ilcox W flm yfiwww ATTORNEYS,

Jan. 10, 1961 A G. WILCOX 2,967,701

METHOD OF CONTiNUOUS LOW SEAM SHORT WALL. MINING USING ROTARY AUGER CUTTERS Original Filed May 6, 1957 7 Sheets-Sheet 4 INVENTOR:

Arnold GJ vjc'lcox.

A TTORNEYS.

Jan. 10, 1961 A. G. WILCOX METHOD OF couwruuous LOW SEAM suom WALL MINING usmc ROTARY AUGER CUTTERS Original Filed May 6, 1957 7 Sheets-Sheiet s Arngld G-Wcjzx, BY MM, Y M

ATTORNEYS- VON . OriginalFiled May 6, 1957 Jan. 10, 1961 A. G. WILCOX 2,967,701

METHOD OF commuous LOW SEAM SHORT WALL MINING usmc; ROTARY AUGER CUTTERS 7 Sheets-Sheet 6 L L L INVENTOR.

I Arnold GJMilcox Y MM, 1 44,? ,1

ATTORNEYS.

Jan. 10, 1961 A. G; WILCOX METHOD OF commuous LOW SEAM SHORT WALL MINING USING ROTARY AUGER CUTTERS Original Filed May 6, 1957 '7 Sheets-Sheet 7 INVENTOR:

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, 2,967,701 V Patented Jan. 10, 1961 METHOD OF CONTINUOUS LOW SEAM SHORT EAR1ISL MINING USING ROTARY AUGER CUT- Arnold G. Wilcox, Daniels, W. Va. (Shady Springs, W. Va.)

Original application May 6, 1957, Ser. No.. 657,160. giziilzd and this application June 30, 1960, Ser. No.

1 Claim. (Cl. 262-1) This invention relates to mining methods and more particularly to mining methods of the continuous type in p which the coal or other material being mined is continu'ously conveyed away from the mine face. This application constitutes a division of my copending application,

'Serial No. 657,160, filed May 6, 1957, which in turn constitutes a continuation-in-part of my earlier application Serial No. 449,851, filed August 16, 1954, now abandoned.

While the known mining methods are suitable within mines having a relatively high mining face, more and more such mines are being worked out, and it is becoming necessary to work those mines which have a relatively low mine face, in the order of 30 to 48 inches. It is frequently the case in such mines, that the face will have a vein of impure material therein and with the presently known machines, this foreign material must be removed along with the adjacent material. Since the impure vein of material is thus mixed with the relatively pure material, the expense involved in subsequently separating the materials makes the known methods impractical for working mines of the latter type.

The present method is particularly useful in mines having a relatively low face, of the type mentioned above,

and is operable to remove the coal or other material being mined without mixing the impurities therewith. The present method operates on the short-wall principle of mining.

Short-wall mining procedures are well known and, heretofore, have been performed first by undercutting the mine face, as by an undercutting machine or the like, blasting down the overhang and then loading the coal thus loosened, as by continuous loaders or the like. Continuous mining machines are also well known. However, they have heretofore operated on the long-wall principle of mining. This principle is applicable mainly in relatively large veins and requires the cutting of parallel corridors transverse to the mining face which extends therebetween. Such mining faces may be of the order of 300 to 500 feet and the continuous miner for cutting such faces merely cuts a thickness therefrom proceeding from one corridor to another.

Accordingly, it is an object of the present invention to provide a continuous mining method which is operable on the short-wall mining principle to remove material from relatively thin veins in the mining face.

Another object of the present invention is the provision of a continuous mining method wherein coal or other material is cut from a mine face both longitudinally and transversely thereof.

'These and other objects of the present invention will ing detailed description and appended claim.

. The invention may best be understood with reference v to the accompanying drawings wherein an illustrative embodiment-of a machine capable of carrying out the invention is shown.

In the drawings: r a I Figure 1 isa plan view of a mining machine constructed in accordance with the principles of the present invention showing the same in digging relation to a mine face;

Figure 2 is a schematic, front elevational view of the mining machine showing the manner in which the cutters are raised and lowered;

Figure 3 is a side elevational view of the mining machine;

Figure 4 is a front elevational view showing one of the cutters in raised position;

Figure 5 is a partial top plan view illustrating the details of the motion transmitting means;

Figure 6 is a cross-sectional view taken along lines V 6-6 of Figure 5;

Figures 7 and 8 are schematic views showing various stages in the operation of the machine;

- Figure 9 is a fragmentary top plan view, partly in sec tion, illustrating the manner in which the angers are along the line 11-11 of Figure 10 Figure 12-is a fragmentary side elevational view, with parts broken away, of a modified form of a continuous mining machine embodying the principles of the present invention;

Figure 13 is a top plan view :of the endless track layin frame;

Figure 14 is a fragmentary top plan view of the machine;

Figure 15 is a fragmentary side elevational view of the machine shown in Figure 12 in operative position;

Figure 16 is an enlarged horizontal sectional view of the motion transmitting mechanism of the machine shown in Figure 12;

Figure 17 is a fragmentary detailed view, partly broken away, illustrating certain parts of the mechanism shown in Figure 16; and

Figure 18 is a cross-sectional view taken along theline 18-18 of Figure 16.

Referring now more particularly to the drawings, there is shown in Figures 3 and 4 a mining, machine, generally indicated at 10, constructed in accordance with the principles of the present invention which is adapted for use in mining coal and other materials. The machine 10, includes in general, a frame 12 for supporting the same for movement along a mine floor, a vertically adjustable driven cutting means 14, for digging the coal or other materials from the mine face, a power plant 16 for propeland independently controlled in the conventional manner (not shown). Suitable cables 22 are carried by the winches 20 and through pulleys 24, the cables may be operated by the winches to propelthe machine along the As was stated above, the mechanism for propelling the machine may be conventional and the details of construction thereof form. no part of the present invention ,It is also to vbe understood that other means i I of propelling the machine may be employed. 0

The supporting frame. 12 ofthe mining machine prefer- .jably comprises an elongated, heir-shaped, longitudinally ,extending. frame,26, which supports the power-plant 16 in vertically spaced relation to the mine floor. The boy;-

like frame 26 is constructed to receive a portion of the conveyor means 19 'as'will" be hereinafter described.

The motion transmittingmechanism 18 is preferably carried by a sub-frame 28 mounted on the frame 26 for longitudinal sliding movement. AsshowninFigure 6, the sub-frame 28 may include opposite depending'flanges 30 whichembrace suitable frame rails 32 rigidly secured to the box-like frame 26. A pair :of plates 34 are removably mounted on the free ends of the flanges 30 so as to maintain the sub-frame on the main frame against all but longitudinal sliding movement. Carried on the sub-frame 28 is an abutting pair of transmission housings 36 and 38 which are rigidly secured thereto for longitudinal sliding movement therewith. The housing 36 is adapted to carry a suitable means 40 for transmitting the rotary motion of .the .power plantto the cutting means 14 so as to selectively reciprocate the latter longitudinally. While the means 40 may takemany forms, a preferred embodiment isshown in detailin Figures and 6. As shown, a mainshaft 42 is drivingly connected with the power plant 16, through a suitable clutch mechanism 44, and hasits .rear end splined, -as at 46, so that it may reciprocate axially therein. Rigidly mounted on the main shaft 42, within the housing 36, is a bevel gear 48 which meshes with a cooperating bevel gear 50 mounted on an-upright stub shaft 52 suitably journalled within the housing 36. Thelower portion of the bevel gear 50 is provided with suitable clutch teeth 54 and cooperating teeth 56 are provided on a clutch member 58 carried by the shaft 52. A suitable actuating means, such as linkage60, isprovided for moving the teeth of the clutch member 58 into and out of cooperating engagement'with the teethcf .the bevel. gear 50. It will be seen that when the teeth 54 and 56 are .in engagement, the stub shaft 52 willbe rotated through the bevelgears 48 and 50 by the main shaft 42. Rigidly mounted on the lower end of the stubshaft 52. is a cam 62 engaged within a plate 64 rigidly secured with:the main frame. The plate 64 includes an opening 66 constituting a cam follower which is engaged by the cam 62.

It will be seen that when the stub shaft 52 isrotated that the cam 62 and follower 66 will cause the transmission housings 36 and 38 to longitudinally reciprocate with respect to the main frame and power plant.

The main shaft 42 extends forwardly within the'transmission housing 38 and suitable gear trains '68 areconnected therewith to drive a pair of auxiliary shafts 70, suitably journalled within the housings 36 and 38.

The cutting means 14 preferably includes a pairof oppositely pitched rotary augers 72 and 74, each of which is mounted for independent vertical movement. 'To this end, a housing 76 is connected between thetransmission housing 38 and each of the augers 72 and 74. Each of the housings 76 may include a rearward cylindrical tube 78 which is journalled inthe housing 38 concentric with the shaft 70 to embrace the latter. Extending substantially perpendicular from the cylindrical tube 78 is a rigid hollow member 80 through the outer end of which the associated auger may be journalled.

In order to transmit the rotary motionof each shaft 70 to the respective auger, a sprocket wheel'82 is provided on the forward end of each shaft 70 and a cooperating sprocket wheel 84 is mounted on a reduced rearward end 86 of the auger. A suitablesprocket chain 88 may be entrained around the sprocket wheels 82 and '84 so as to connect the same in driving relation. It is to be understood that the gear train 68 mounted within the housing 38 is arranged to reduce the speed betweenithe auger shafts 86 and the mainshaft '82'a'ndto rotate the oppositely pitched augers in opposite directions.

Suitable means, such as hydraulic rams '90-'are preferably provided between the sub-frame 28 and='each 'of the housing members 80 so as to move'the augers into different positions ofverticaPadjuStment. Any suitable-means,

6 actuation under the control of the operator.

While the augers 72 and 74 are preferably oppositely pitched, except for this differencetheaugers are identical and a description of one will suffice for both. Thus,each of the augers includes a main shaft 94 having a pair of co-extensive. helical blades 96 displaced 180 from each other, and having their. inner edges rigidly secured to the shaft 94. The outer edge of each of the helical blades -96-is spaced from the axis of rotation.ofthe-auger a constant distancethroughout its extent and its'forward edge is inclined forwardly toward the shaft. Mounted on the forward end'of the shaft infacing relation to the inclined forward edges of the helical blade 96 is a tooth holding member 98 which has its forward edge likewise inclinedand its rearward edge rigidly secured,.as by weld- ,ing or the like, to the forward edge of the. helical blades.

The tooth holding member 98. includes a plurality of spaced'socketelements 100 within whichare removably carried .a plurality'of cutting teeth 102. -As.shown in Figure 4, suitable pins 104. may be employed to removably secure the teeth 102 within socket members 100.

Spaced along the outer edge of the helical blades 96 area plurality of additionaltooth holding elements 106 which carry additional teeth 108. The teeth 108 preferablyextend .substantially radially outwardly from the shaft 94 and are likewise removably mounted withinthc iholders .106.

. The conveyor means 19 of the mining machine preferably includes a pair of laterally extending. mold boards .110 which rotatably carry a pair of oppositelypitched 3 screw conveyors 112. Mounted within the box-like main frame 26 and extending from the conveyor 112 tothc -rear of the machine is a suitable endless conveyor 112 which is adapted to carrythe coal moved inwardly .by the screw conveyors 112 rearwardly through the .box-likc frame-26 to the rear of the machine where other'means may be-provided to carry the material removed out of themine. The conveyors 112 and 114 may 'be driven :by suitable connections withthe power plant 16or by separate motor means not shown.

Referring now more particularly to Figures 1,7 and 8, the operation of the machine will now be. described. In order to sump the machine into longitudinal cutting relation with the mine face, the winch and cablezmecha nisms 20and 22 are actuated in the conventional manner by' the operator. 'To.this end, a jack 116 may' be wedged between the mine floor and ceiling,:asshown.in: Figure l. i and the cable connected thereto. Thewinch 20 may. then be actuated I by the operator so as to wind .thezca'blc thereon. In this manner, the machine is advanced. longitudinally into the mine face. 'During this sumping operation,the clutch linkage 60.is actuated to disengagethc clutchiteeth 54 and 56. so that'the cutting augers will not be reciprocated longitudinally. Howeven'the main drive clutch is actuated so astotransrnit Ltherotary motion ofithe power plantto the cutting augerssxthrough the main shaft 42, gear trains 68', shaft 70 and sprocket and chain 82, 84 and 88. As. the operator actuates the winches to advancethe machine,rthe teeth 102' will dig into the mine face during their rotary motion and loosen thecoal so that the same will be carried rearwardly by the helical blades 96, from where the coal will beconveyed laterally by the screw conveyors 102/toward the endless conveyor 114 which, in turn, will. pick up the removed coal and convey it to the rearrofthe machine.

As stated above, the machine of the present invention is particularly adapted to remove material from a relatively'lowmine face which may include a vein'. of impure material. The 'operationof the present machinc whereby a mine face of this type may be dug swithout mixing the impurities with the pure materiat is as follows.

Before the sumping operation as described above, the augers are selectively advanced vertically by means of hydraulic rams 90 so that the uppermost portion thereof will engage the bottom of the vein of impure material. The sumping operation of the machine is then carried out as set forth above until the machine assumes the position shown in the right hand portion of Figure 7. The cables 22 are then attached so that actuation of the winches will move the machine laterally across the mine face as shown in Figure 1. The clutch linkage 16 is then actuated by the operator to bring the clutch teeth 54 and 56 into engagement so that the augers will be longitudinally reciprocated through the main shaft 42, bevel gears 48 and 50, shaft 52, cam 62 and plate cam followers 64 and 66. In this regard, it is to be understood that since the plate 64 is rigid with the power plant and main frame, the sub-frame 28 and all of the structural elements carried thereby, including housings 36, 38, and 76, will be caused to longitudinally reciprocate. The operator may then actuate the winches 20 to cause the machine to move across the mine face and during this movement the combined rotary and reciprocating motion of the cutter will cause the teeth 108 and 102' to loosen the coal which will then be conveyed rearwardly by the helical blades '96 from where it is conveyed to the rear of the machine by the screw conveyor 112 and endless conveyor 114. This movement of the machine is shown in the left hand portion of Figure 7 and illustrates how the pure vein of coal or other material disposed below the impure vein is removed without mixing the impurities therewith. 1

After the pure coal has been removed and collected as described above, the operator may then selectively raise the augers by actuation of the associated hydraulic ram 90. It is to be noted that during this raising motion the anger is both rotated and reciprocated. When the upper level of the augers has been adjusted to the height of the upper level of the vein of impurities, the operator may then actuate the winches 20 to propel the machine across the mine face to thereby remove the vein of impure material and convey the same rearwardly where it may be separately collected. By adjusting the vertical height of the augers still higher, the relatively pure vein of material above the vein of impurities may then be removed by a similar procedure, as shown in Figure 8.

It will be understood that where it is desired to dig out a seam of a height higher than the vertical height of the augers themselves, one of the augers may be raised relatively to the other so that during the movement of the machine across the mine face, the augers will remove a seam of a height equal to the upper level of the raised auger. At the lateral ends of the seam, the adjacent auger may be either raised or lowered in operation to complete the seam.

The above description exemplifies how the principles of the present invention may be embodied in a conventional cable and winch operated mining machine. vThe invention may also be readily embodied in the form of a mobile continuous miner of the type, propelled by a track laying frame.

Referring now more particularly to Figures 12-18, the continuous mining machine of the self-propelled type includes a track laying frame assembly, generally indicated at 120, a conveyor assembly, generally indicated at 122, mounted on the track laying frame 120 and extending forwardly and rearwardly thereof. The forward end of the conveyor assembly 122, which is swingable in a horizontal plane about a vertical axis, as will be hereinafter more fully described, has a power transmission assembly, generally indicated at 124 mounted thereon for vertical translational movement and a rotary auger cutter, generally indicated at 126, is drivingly connected with the power transmission assembly 124. Preferably, the rotary auger cutter 126 is identical in construction to the cutter 74 previouslyv described so that a detailed description of the same is not believed to be necessai'y.

As best shown in Figures 12 and 13, the track laying frame assembly includes a main frame 128 having a pair of endless track laying units 130, of conventional construction, rigidly carried on .opposite sides thereof. Each track laying unit 130 is driven by any suitable means, such as hydraulic motors 132 or the like, schematically illustrated in Figure 13. The central portionof the frame is preferably provided with a motor 134 which drives a hydraulic pump 136 for operating the motors 132.

As best shown in Figures 12 and 14, the conveyor assembly 122 comprises a forward boom section 138 and a rearward boom section 140. The boom section 138 includes a vertical shaft 142 rotatably mounted within a bearing 1'44 rigidly carried by the frame 128 of the track laying frame assembly 120 in the central forward-portion thereof. The upper end of the shaft 142 is rigidly connected with a horizontally disposed circular plate 146 having a forwardly and downwardly extending projecting portion 148. The track laying frame assembly 120 in the central portion of the frame 128 is provided with a plate 150, which is arranged to engage the circular plate 146 at its forward edge and has its rearward edge arranged to engage the forward edge of a circular plate 152 of the rear conveyor section .v Extending rigidly downwardly from the plate 152 is a shaft 154, which is journaled within a bearing 156 carried by the track laying assembly frame 128 in the central rearward portion thereof. Plate 152 also includes a projecting portion 157 extending rearwardly therefrom.

The forward section 138 includes side rails 158 rigidly secured to the projecting portion 148 and extending up.- wardly therefrom. An intermediate plate 160, identical in plan to the plate 146 and projecting portion 148, is rigidly secured between the side rails in vertically spaced relation to the plate 146. The plate on the frame 128 includes side plate 162 having an intermediate plate 164, identical in plan to the plate 150, rigidly secured therebetween in alignment with the rearward edge of the plate 160. In a like manner, the rear section 140* includes side rails 166 rigidly secured to the plate 152 and extending upwardly therefrom and an intermediate plate 168 is secured between the side rails 166 in spaced relation to the plate 152 and extends forwardly in. abutting engagement with the rear edge of the plate 164 on the frame 128.

Pivotally mounted on the forward end of the side rails 158 of the forward boom section 138, as by pivots 170, is a forward end section 172 having side rails 174 interconnected by a bottom plate 176 and an intermediate plate 178. In a like manner, the rear ends of the side rails 166 of the rear section 140 have a rearward end section 180 pivotally mounted thereto, as by pivots 182. The section 180 includes side rails 184 interconnected by bottom plate 186 and intermediate plate 188. The forward end .section 172 may be pivoted with respect to the side rails 158 by any suitable means, such as hydraulic pistonand cylinder units 190, pivotally connected between lugs 192 and 194 carried by the side rails 158 and side rails 178 respectively. In a like manner, the rearward end section 180 is pivoted with respectto the side rails 166 by hydraulic piston and cylinder units 196 pivotally connected between lugs 198 and 200 carried by the side rails 166 and 188 respectively.

Journaled on the forward end of the end section 172 is a horizontal shaft 202 having screw conveyors 204 rigidly secured to the ends thereof and arranged to move material toward the central portion thereof. Mounted on the central portion of the shaft 202 is a sprocket wheel 206 around which a conveyor chain 208 is trained. The rear end of the chain 208 is trained about a sprocket wheel 210 suitably journaled on the rear end of the section 180 and includes a plurality of longitudinally spaced flights 212, which are arranged to move with the endless chain on the upper surface of the intermediate 7 plates 178, 160, 164, 168 and 188 and the upper surface of the lower plates 176, 148, 150, 152 and 186. The endless chain carrying the conveyor'flights may be rotated by any suitable means, such as a hydraulic motor 214 operated by the pump 136 and drivingly connected with the rear sprocket wheel 210.

The forward boom section 138 is pivoted in a horizontal plane about the shaft 142 by any suitable means, such as a pair of hydraulic piston and cylinder units 216 rigidly secured to the frame 128 of the track laying assembly 120 on opposite sides thereof. The cylinder units are suitably operated from the pump 136 in cooperation with each other and each has one end of a cable 218 connected therewith. Each cable 218'extends around a pulley 219 mounted on frame 128 and has its opposite end anchored to a lug 220 rigidly secured to the lower plate 146 of the section. In a like manner, the rear section is pivoted in a horizontal plane about the vertical shaft 154 by a pair of hydraulic piston and cylinder units 222 rigidly secured to the frame 128 on opposite sides thereof adjacent the units 216. The piston of each unit is connected to the boom section, as by a cable 224 extending around a pulley 225 and anchored to a lug 226rigidly secured to the plate 152.

In order to permit the pivotal movement of each section and also to provide a continuation of the side rails of the conveyor booms, a pair of spring steel side rail elements 228 are rigidly secured to the side rails 164 of the frame 128 and have their ends extending in overlapping relation with the rear ends of side rails 158 and-forward ends of side rails 166respectively. It will also be understood that the chain 208 is laterally flexible to permit such movement.

The power transmission assembly 124 is mounted on the forward boom section 138 for vertical translational movement respective thereto by a pair of mounting arms 230 having their rear ends pivoted, as at 232, to the side rails 158 and their forward end portions pivotally connected, as at 233, to a power transmission assembly carrying frame 234. The mounting arms 230 are vertically adjusted by any suitable means, such as hydraulic piston and cylinder units 236 suitably driven by the pump 136 and interconnected between the side rails 158 and mounting arms 230 respectively. In order to maintain the frame 234 in a horizontal position in any position of vertical adjustment of the mounting arms 230, additional hydraulic piston and cylinder units 238 are connected between the forward extremity of the mounting arms 230 and the forward end of the frame 234. Mounted on the frame 234 is a source of power, preferably in the form of an electrical motor 240 or the like of conventional construction. A transmission housing 242 is carried by the frame 234 adjacentthe motor 240.

Referring now more particularly to Figure 16, the transmission housing 242 carries a mechanism arranged to transmit the rotary motion from the motor 240 to a combined rotary and longitudinal reciprocatory motion of the'cutter. To this end, an input shaft 244 is suitably journalled within the housing, as by ball bearings 246 or-the like, in alignment with an output shaft 248 of the motor 240. The shaft 244 has its rear end exteriorly splined, as indicated at 250, to receive the interiorly splined end of a connecting element 252 rigidly secured to the output shaft 248, as by a key 254 or the like. The spline connection 250 permits longitudinal movement of the shaft 244 relative to the shaft 248, but at all times maintains the same in driving relation.

Formed on the shaft 244 between the bearings 246 is a spur gear 256, which meshes with a cooperating spur gear 258 rigidly secured, as by a key 260 or the like, to'a secondary shaft 262 journalled in the housing 242, as by ball bearings 264 or the like. Rigidly secured, as byqa key 266 or the like, to the shaft 262 adjacentthe forward end thereof is a small spur gear 268 which meshes with a larger spur gear 270 fixedly secured,; as by a key 272 or the like, to an output shaft 274 journalled in the housing 242, as by bearings 276. The rear end of the shaft of the cutter 126 is fixedly secured to the forward end of the output shaft 274, as by connecting flanges 27 8or the like. It will be seen that operation of the motor 240 will impart a rotary motion to the cutter through connecting element 252, shaft 244, gears 256 and 258, shaft 262, gears 268 and 270, shaft 274 and coupling 278.

The housing 242 is mounted on the frame 234 for horizontal reciprocating movement by any suitable means, such as transversely spaced rails 280 rigidly secured to the frame 234 and cooperating guide rails 282 rigidly secured to the housing 242. In order to effect this longitudinal reciprocation, the shaft 262 is provided with an extension 284 having a sprocket wheel 286 fixedly secured thereto, as by a key 288 or the-like. Trained about the sprocket wheel 286 and a second sprocket wheel 290 is an endless chain 292. The sprocket wheel 290 is rigidly secured to the rear end of a shaft 294, as by a key 296 or the like. The shaft 294 is suitably journalled in the housing 242, as by ball bearings 298 or the like, and has a small spur gear 300 formed on the forward end thereof, which meshes with a larger spur gear 302 rigidly secured, as by a key 304, to a parallel horizontal shaft 306 journalled in the housing, as by bearings 308 or the like.

The rear end of the shaft 306 has a bevel gear 310 fixed thereto, as by a key 312 or the like, which meshes with a cooperating bevel gear 314 rigidlysecured to the upper end of a vertical stub shaft 316 suitably journalled in the housing, as by a bearing sleeve 318 (see Figure 17).

Extending downwardly in fixed relation to the stub shaft 316 is an eccentric rotary cam element 320 seating within a cam follower 322. The cam follower is rigidly secured, as by bolts 324 or the like, to the forward end of a connecting bar 326, the rearward end of which is connected with a pin 328 rigidly carried by the frame 234. It will be understood that the mechanism within the housing 242 is thus operable to impart a longitudinal reciprocation to the cutter 126, as well as a rotary motion, as noted above. Thus, the entire housing 242, as well as the cutter 126 connected therewith, will be horizontally reciprocated on the frame 234 when the motor 240 is operated through the shaft 248, coupling 252, shaft 244, gears 256 and 258, shaft 262, sprocket wheels 286 and 290 interconnected by chain 292, shaft 294, gears 300 and 302, shaft 306, bevel gears 310 and 314, stub shaft 316, cam elements 320 and 322 and connecting bar 326.

The machine disclosed in Figures 12-18 operates essentially in the same way as the machine disclosed in Figures l-ll. However, since only a single cutter is provided in the embodiment of Figures 12-18, in cutting seams which are thicker than the diameter of the cutter, two passes through the same are required. It will be understood that the cycle of operation commences with the movement of the track laying frame forwardly so as to sump the cutter substantially longitudinally into the mine face. Next, the hydraulic cylinders 216 are actuated to swing the forward boom section about the vertical shaft 142 moving the cutter transversely along thecutting face, which will be arcuate after a short period of operation. As the cutter moves transversely of the face, the coal engaged by the cutter is moved rearwardly thereby and is picked up by the screw conveyors 20-4 and, finally, conveyed to the conveyor flights 212, which serve to move the coal to the rear end of the boom section 140.

If one pass across the seam is not sufiicient to remove the coal desired, the auger is then swung back to the right side of the mining room and sumped into the bottom portion of the seam desired to be cut. The cylinders 216 are again operated to swing the boom to the left,

which removes the remainder of the seam. With the cutter shown, the direction of operation should be right to left but, of course, it will be understood that a left to right operation may be utilized by changing the direction of pitch of the cutter.

In the embodiment of Figures 12-18, cylinder units 190 are operable to efiect a tilting movement of the forward end section 172 to accommodate dilferent floor conditions as desired. Cylinder units 222 are operable to effect a swinging of the rear boom section 140 to accommodate difierent discharge positions for the coal delivered by the conveyor. Cylinder units 196 are perable to adjust the vertical position of the rear end of the conveyor.

It can thus be seen that there has been provided a continuous mining machine having cutter means which is both rotated and reciprocated longitudinally so as to render the same operable both longitudinally and transversely to the coal face. The mining machine includes an improved auger construction which provides an optimum digging eificiency in both directions and which is constructed so as to be economical to manufacture and simple to maintain in working order. The machine fur ther provides improved means for vertically adjusting the operating height of the cutting means so that seams of varying heights may be cut and so that different horizontal veins in the mine face may be cut separately.

It is also to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same and that various changes may be made without departing from the spirit of the invention or the scope of the appended claim.

I claim:

A process of continuous short wall coal mining in a coal seam having a height less than of the order of 48 inches by the use of a continuous mining machine including a pair of parallel oppositely pitched rotary auger cutters each having a diameter dimension less than the height of the seam being mined but a combined diameter dimension greater than the height of the seam being mined which comprises the steps of: sumping said pair of parallel auger cutters longitudinally into a face of such a seam of coal while oppositely rotating said auger cut- 'ters in directions so as to simultaneously convey the coal engaged by said auger cutters outwardly of the seam face to thereby longitudinally progressively inwardly form in such seam an opening in the shape of a pair of side-byside cylinders; moving said auger cutters in a direction transverse to the rotational axes thereof into engagement with the coal in said seam between the face thereof and the inner end of said opening while oppositely rotating said auger cutters in directions so as to simultaneously convey the coal engaged by said auger cutters outwardly of the seam face until a room section is formed having a substantailly horizontally extending roof defined by said upper strata, a substantially horizontally extending floor substantially defined by said lower strata, sides spaced horizontally apart a distance substantially greater than the largest horizontal transverse dimension of said opening, and an end defining a new seam face spaced a substam tial horizontal distance from said first mentioned seam face, the opposite sides of said room section being formed by substantially vertical transverse movement of opposite auger cutters, the portion of said room section extending from a position adjacent one side thereof to a position adjacent the other side thereof being formed by simultaneous horizontal transverse movement of said parallel auger cutters in one direction only with the lower periphery of one auger cutter forming said floor and the upper periphery of the other auger cutter forming said roof; and continuously gathering and conveying away from the first mentioned seam face the coal conveyed outwardly thereof during the sumping and transverse movements of said auger cutters.

References Cited in the file of this patent UNITEDSTATES PATENTS 1,032,902 Hess Aug. 8, 1911 1,143,599 Hess June 15, 1915 2,853,923 OBrien Apr. 12, 1932 FOREIGN PATENTS 516,636 Belgium Jan. 15, 1953

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