US2030064A

US2030064A - Mining apparatus

Info

Publication number: US2030064A
Application number: US649347A
Authority: US
Inventors: Morris P Holmes
Original assignee: Sullivan Machinery Co
Current assignee: Sullivan Machinery Co
Priority date: 1932-12-29
Filing date: 1932-12-29
Publication date: 1936-02-11
Anticipated expiration: 1953-02-11

Description

Feb. 1 1, 1936; p HOLMES MINING APPARATUS Filed Dec. 29, 1932 6 Sheets-Sheet l arty F831. 11, 1936. M, p HOLMES MINING APPARATUS Fiied Dec. 29, 1932 6 Sheets-Sheet 2 m Q3 m3 Feb. 11, 1936. M O 2,030,064

MINING APPARATUS Filed Dec. 29, 1932 6 Sheets-Sheet 3 6 fi WW. azzg Feb. 11, 1936; M p HOLMES 2,030,064

MINING APPARATUS Filed Dec. 29, 1952 6 Sheets-Sheet -5 Patented Feb. 11, 1936 UNITED STATES PATENT ()FFlQE MINING APPARATUS Massachusetts Application December 29, 1932, Serial No. 649,347

81 Claims.

This invention relates to mining apparatus, and more particularly to improvements in coal mining apparatus of the wheel mounted, track supported and guided, bottom cutting type.

An object of this invention is to provide an improved coal mining apparatus. Another object is to provide an improved coal mining apparatus of the wheel mounted, track supported and guided, bottom cutting type. A further object is to provide, in a mining apparatus of the above character, improved adjustable kerf cutting mechanism whereby a kerf may be cut at the level of the inine bottom outside and below the level of the mine trackway and in advance of the trackway, in an improved manner. Yet another object is to provide an improved coal mining apparatus having improved kerf cutter driving and adjusting means. Still another object of this invention is to provide, in a mining apparatus of the above character. an improved tiltable supporting structure for the kerf cutting mechanism whereby the kerf cutter may be adjusted to cut on a rolling or uneven bottom or a pitching coal seam. Still another object of this invention is to provide an improved mining apparatus of the Wheel mounted, track supported and guided, bottom cutting type particularly adapted for use in mines having relatively low head room, the improved apparatus having an extremely low compact arrangement of parts whereby the vertical dimensions thereof are reduced to a minimum. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawings there is shown for purposes of illustration, one form which the invention may assume in practice.

In these drawings,-

Fig. 1 is a plan view of the illustrative embodiment of the improved mining apparatus.

Fig. 2 is a side elevational view of the mining apparatus shown in Fig. 1.

Fig. 3 is an enlarged central, longitudinally extending, vertical sectional view taken substantially on line 3-3 of Fig. 1.

Fig. 4 is a horizontal sectional view taken substantially on line 4 l of Fig. 3.

Fig. 5 is a longitudinally extending vertical sectional view taken substantially on line 5-5 of Fig. 4.

Fig. 6 is a detail sectional view taken on line 66 of Fig. 3.

Fig. 7 is a detail sectional View taken on line l-{l of Fig. 3, Y 1

Fig. 8 is a detail sectional view taken on line B8 of Fig. '7.

Fig. 9 is an enlarged horizontal sectional view taken substantially on line 9-5! of Fig. 2.

Fig. 10 is a detail sectional view taken substantially on line lEJ-Ifi of Figs. 1 and 9.

Fig. 11 is an enlarged plan view of the cutter head shown in Fig. 1, with parts shown in horizontal section to illustrate structural details.

Fig. 12 is a longitudinally extending vertical sectional View taken substantially on line 12-42 of Fig. 11.

Fig. 13 is a detail sectional view taken on line l3|3 of Fig. 12.

Fig. 14 is a detail view of the control rod shown in Fig. 13.

Fig. 15 is a detail sectional viewtaken on line |5-l5 of Fig. 14.

Fig. 16 is a detail sectional view taken on line l6|6 of Fig. 13.

Fig. 17 is a transverse vertical sectional view taken on line I'|l1 of Figs. 1 and 3.

Fig. 18 is a detail sectional View taken on line [8-48 of Fig. 17.

Fig. 19 is a detail sectional view taken on line l9-|9 of Fig. 18.

Fig. 20 is a detail sectional view taken on line 2020 of Fig. 19.

Fig. 21 is a horizontal sectional view taken substantially on line 2l-2I of Fig. 3, with parts 3 omitted to facilitate illustration.

Fig. 22 is a detail sectional view taken on line 2222 of Fig. 21.

In this illustrative embodiment of the invention there is shown a coal mining apparatus of the wheel mounted, track supported and guided, bottom cutting type, generally comprising a selfpropelled base I having mounted thereon improved adjustable kerf cutting mechanism, generally designated 2. The base I is herein in the form of a wheeled truck comprising a low compact truck frame 3 adjustably mounted, in an improved manner as hereinafter described, on truck Wheels l adapted to run along a usual mine trackway 5 laid on the mine bottom. Mounted on this truck frame 3 for horizontal swinging movement relative thereto about a vertical axis at 6 is an arm structure I overhanging the forward end of the truck and in turn having pivotally mounted thereon at 8 for horizontal swinging movement relative thereto, the improved kerf cutting mechanism 2. Carried on the rear end of the truck frame is a motor 9 having its power shaft l0 op eratively connected to the mechanisms for driving the cutting mechanism, for swinging the arm structure and the cutting mechanism about their respective pivots, for adjusting the elevation of and tilting the cutting mechanism and for driving the truck wheels to propel the apparatus, as hereinafter described.

Now referring to the improved kerf cutting mechanism 2, and more particularly to the improved cutter driving means, it will be noted that connected to and driven by the motor power shaft H3 is an alined shaft ll suitably journaled at its forward end within a bearing [2 suitably supported within a frame l3 herein formed integral with the truck frame and which constitutes the main frame of the cutting mechanism. Keyed to the forward end of the shaft l i is a bevel pinion M (see Figs. 3 and 4), nd this pinion meshes with a large bevel gear 55 keyed to a vertical shaft [6 suitably journaled within the main frame I3 and arranged with its axis coincident with the arm structure pivot. Integral with the gear I is a bevel gear I! meshing with a bevel gear 18 keyed to the rear end of a horizontal shaft l9 herein arranged with its axis extending radially with respect to the pivotal axis of the arm structure l and suitably journaled within the arm structure, as shown in Fig. 3. Alined with the shaft l9 and connectible thereto in driving relation therewith, is a shaft 28 likewise suitably journaled within the arm structure i and having keyed thereto at its forward end, as shown in Fig. 12, a bevel pinion 2!. As shown, the bevel pinion 2i meshes with a large bevel gear 22 keyed at 23 to atubular drive shaft 24 suitably journaled within the cutter head frame 25 of the cutting mechanism and herein arranged with its axis alined with the pivotal axis 8 of the kerf cutting mechanism. Keyed at 26 to the reduced hub portion 2! of the tubular shaft 24 is a vertical shaft 28 herein formed with longitudinal splineways 29 throughout a substantial portion of its length and splined at 30 to the upper end of, and having telescopically arranged therein, a tubular shaft element 35, which has herein formed integral therewith a chain sprocket 32 which engages and drives a. usual endless cutter chain 33 mounted for orbital movement about the margin of a usual elongated plane cutter bar 34. The clutch for connecting the alined shafts i9 and 29 in driving relation, and which herein constitutes the cutter chain clutch, comprises a shiftablo clutch member 35 having internal teeth interlocked with clutch teeth 36 formed on the rear end of the shaft 2% and engageable with similar clutch teeth 3? formed on the forward end of the shaft [9. This clutch member isshiftable into its connected or released positions by means of a slidable clutch operating member 38 guided within a longitudinal slot formed within the frame id of the arm structure I. Pivotally connected at M to the member 38 is an operating handle d2 having formed thereon a pin as engageable with either of two apertures 66 formed in the arm frame 40. This pin and these apertures form a lock for holding the clutch member 35 in either of its two positions. It will thus be evident that the cutter chain 33 may be operatively connected in driving relation with the motor 9 or may remain idle, at will.

The cutter bar 3 is mounted on the cutter head frame 25 for swinging movement therewith about the bar pivot axis 3, and is adjustable into differ-- ent elevated positions relative to the cutter head, as will now be described. The cutter head 25 s rotatively mounted within bearing sleeves d5 encircling the head and supported by a rigid anable hanger mounting 68.

nular frame 46 rigidly secured to the forward end of the arm frame 48 and constituting the outer overhanging extremity of the arm structure '5. Formed integral with the cutter head frame 25 are laterally projecting guides 4i, ii received in

vertical guideways

48, 48 formed on an arcuate frame portion 49 integral with the cutter bar hanger 50. This bar hanger is provided with a bearing portion 51 carrying bearing sleeves 5.2 interposed between flanges on the shaft 3! and within which the lower end of the latter is ion.- naled, as shown in Fig. 12. These guideways 53 are provided with adjustable bearing plates secured by screws 5% to the guide portions: 55 of the hanger frame 49, as shown in Fig. 11. It will thus be seen that the cutter bar 34 is swingable with the cutter head frame 25 relative to the an nular frame 46 of the arm structure '1, and that the cutter bar may be adjusted into different elevated positions relative to the cutter head frame by adjustment thereof along the vertical guides 41, 41.

The mechanism for adjusting the cutter bar vertically along the guideways 417, ll relative to the cutter head frame 25 herein comprises a spur gear 57 rotatably mounted on the tubular shaft 24 and connectible in driving relation with the shaft 24 by a multiple disc clutch 58 of a usual design. Herein arranged parallel with the shaft 24, and. likewise suitably journaled within the cutter head frame 25, is a tubular shaft 59 having formed integral therewith at its lower end a nut 6|] having internal threads meshing with the external threads of a vertical screw 5|. The screw 6| is herein non-rotatable and is pivotally connected at 62 at its lower end to a transverse pin 63 supported at is ends within spaced depending webs 64 integral with the bar hanger support 50. Formed integral with the shaft 59 is a spur gear 65 meshing with a spur gear 65 journaled on a Vertical shaft 61 carried by a swing- I'his hanger mounting is provided with an arcuate guiding portion 69 rotatably mounted within an arcuate bearing portion I0 herein formed integral with the cutter head frame 25, the hanger being mounted to swing horizontally about the axis of the tubular shaft 59. As shown in Fig. 13, the spur gear 6'5 meshes with a spur gear H journaled on a vertical shaft 12 arranged parallel with the shaft 6? i and likewise mounted within the swingable hanger mounting 68. When the hanger mounting 68 is in the position as shown in Fig. 13 the spur gears 66, H are both out of mesh with the teeth of the. spur gear Bl, but when the hanger mounting is swung in one direction, the

teeth of the gear 66 are brought into mesh with the gear 51, while when the hanger mounting is swung in the opposite direction, the gear ll is brought into mesh with the gear 5?. It will thus be evident that, depending upon the position of the swingable mounting 53, the gear 65, and consequently the nut 60, may be rotated in one direction or the other, thereby to efiect adjustment of the cutter bar upwardly or downwardly relative to the cutter head.

The means for applying the clutch 58 and for swinging the mounting 68 for the reversing gears will now be described. As shown in Fig. 11, journaled within the cutter head frame 25 is a 1ongitudinally extending shaft '35 having pivotally mounted thereon at 76 an operating lever H. The inner end of the shaft is transversely slotted at l8, 18 to receive arms F9, 19 integral with a rotatable operating member 8!] herein arranged surrounding the hub portion 21 of the shaft 24 and supported for rotative movement on the upper operating plate SI of the clutch 58. Also formed integral with the member 80 is a tooth-like projection 82 fitted within a notch 83 formed on a projection 84 integral with the swingable reverse gear mounting 68. It will thus be seen that when the shaft is moved axially in one direction or the other, the operating member 80 is rotated, thereby shifting the reverse gear mounting 98 in one direction or the other to bring either the gear 65 or the gear 'II in mesh with the drive gear 51. Upon rotative movement of the shaft 15, the sides of the flattened portions 18 act as cams to effect swinging of the operating member 89 downwardly about its fulcrum 85, thereby to apply the disc clutch 58. Means is provided for preventing application of the clutch 58 prior to meshing engagement of one or the other of the gears 86, II with the gear 51, and comprises

arcuate grooves

86 and 81 formed on the shaft 15 and connected by a longitudinal groove 88. Cooperating with these grooves is a pin 89 secured to the cutter head frame. When the shaft 15 is in the position shown in Fig. 13, rotative movement thereof is prevented by the pin 89 engaging the sides of the longitudinal slot 88. When the shaft 15 is slid either inwardly or outwardly to bring either the gear 55 or the gear II in meshing engagement with the drive gear 51, the pin is brought into registry with one or the other of the

arcuate grooves

88, 81, thereby permitting rotation of the shaft 15 to effect application of the disc clutch 58.

Now referring to the improved mechanism for swinging the arm and cutter bar about their respective pivots, it will be observed that secured to the vertical shaft I8 above the bevel gear I1 is a worm 99 meshing with and driving in opposite directions worm wheels 9! and 92. These worm wheels are rotatably mounted on parallel shafts 93 and 94, respectively, arranged at opposite sides of the shaft IE, on longitudinally extending axes and spaced equidistantly from the axis of the shaft I8. These worm wheels are connectible to the shafts 93 and 94, respectively, by multiple disc clutches 95 and 96. The shafts 93 and 94 are suitably journaied within the'arm frame 49 and are connectible by sliding clutches 91 and 98, respectively, to alined screw shafts 99 and I99. Threadedly engaging the screws 99 and I99 are trunnion nuts I0! and I82, respectively, mounted within longitudinal guideways I93 formed in the arm frame and pivotally connected at I94 and I 95, respectively, to pairs of link members I96 and I91. The link members I08 are pivotally connected at I 08 to lateral ears I89 formed integral with the rotatable cutter head frame 25, while the link members I91 are pivot ally connected at I II! to a lug I I I formed integral with a frame member II2 secured by screws II3 to the main frame I3. Keyed to the shafts 93 and 94, respectively, are spur gears I I4 and I I5 meshing with an idler gear H5 suitably rotatably mounted on the rearward portion of the shaft I9. The arm frame 40 is provided with a circular guide flange II'I mounted within an arcuate guideway II 8 formed by the frames l3 and H2, and is supported for rotative movement by a bearing sleeve I I9. The arm structure 1 is guided during its swinging movement relative to the truck frame, by an arcuate guide I29 integral with the front portion of the truck frame and engaging an arcuate guideway I2! formed on the frame of the arm structure. It will thus be seen that when one or the other of the

clutches

95, 95 is applied and the clutch 91 connected, the screw shaft 99 may be rotated in one direction or the other, thereby to swing the cutter bar 34 in either direction about its pivot through the trunnion nut and link connection I91, I86. It will also be seen that when one or the other of the clutches 95, 96 is applied and the clutch 98 is connected, the screw shaft I09 may be rotated in one direction or the other, thereby to elfect swinging of the arm structure 1 in either direction through the sliding trunnion nut and link connection I02, I91.

The operating means for the clutch members 91, 98 comprises, as shown in Fig. 10, shipper yokes E25, I engageable with grooves formed on the members 91 and 98. These clutch members are mounted on a transverse operating rod I21 slidably and rotatably mounted within the arm frame 49. Pivotally connected to the opposite ends of the shaft I21 are operating levers I28. The shipper yoke I25 is provided with an arcuate slot I29 and a communicating longitudinal slot I 38, while the shipper yoke I28 is provided with similar slots I3I and I32. Projecting within these slots in the shipper yokes I25, I28, respectively, and secured to the shaft I21, are pins I33 and I34. When the pins are in the position shown in Fig. 10, that is, when the shaft I21 is slid outwardly to the left, the shipper yoke I25 is connected to the shaft I21 by the pin I33 received in the longitudinal slot I39, while the shipper yoke I28 is disconnected from the shaft I21 by the arcuate slot I3I. When the rod 21 is slid into its opposite position, the shipper yoke I28 is connected to the shaft, while the shipper yoke I25 is disconnected therefrom. When the shaft I21 is in the central position, both pins are engaged within the longitudinal slots, thereby connecting both shipper yokes to the operat: ing shaft. It will thus be seen that the clutches 91, 98 may be independently or simultaneously connected.

Improved variable speed mechanism is provided for controlling the disc clutches 95, 96 so that the arm and bar swinging screws may be operated at a wide range of speeds between zero and a predetermined maximum. This improved clutch controlling means comprises an operating shaft I35 having pivotally connected thereto an operating lever I38, as shown in Figs. 3 and 9. This shaft I35 is threaded at I31 with right and left hand threads, and is threadedly engaged with a split sleeve forming separately adjustable nut elements I38 and I39. Engaging collared portions of these nut elements are levers I40 and I4 I As the connections between these pivoted levers I49, MI and the operating elements I42 for each of the disc clutches 95, 98 are identical, the detailed description of the operating means for the clutch 95 will suffice for both. Rotatable with the gear 9| is a sleeve I43 (see Fig. 21) having formed on its rearward face a cam surface I44 with which engages a sliding member I45 pivotally connected at I48 to the lever I48. Fulcrumed at I41 against the forward face of the bearing sleeve I49 for the rearward end of the shaft 93 is a lever I49, and this lever is engageable with the rear face of the outer race of a ball thrust bearing I59 through which pressure is transmitted to the clutch operating member I42 to effect application of the clutch 85. The inner end of the lever I49 is pivotally connected at I5I to the eye of a bolt member I52. This bolt is slidably guided within a sleeve I52 on which isslidably mounted a trunnion l53 pivotally connected at I54 to the-lever I40. Encircling the bolt I52 between the bolt head I55 and a washer I56 abutting the rear end of the-sleeve 552*, is a coiled spring I51 which normally urges the bolt eye in engagement with the front end of the sleeve. The .bolt I52 is threaded within its eye and is adjustable relative thereto to vary the compression of the spring I51 as desired. The sliding or lost-motion connection between the trunnion I53 and the sleeve l52 permits adjustment of the lever I40, upon adjustment of the nut I38, without affecting the position of the lever I49, the trunnion sliding on the sleeve during such adjustment. When the operator rotates the shaft I35 in the proper direction, the control mechanism forthe clutch 96 is operated to release its respective clutch, while the control mechanism for the clutch 95 is operated to apply its respective clutch. It will thus be seen that as the cam I44 rotates with the worm wheel 9I, the cam acts on the inner end of the slide I 45, moving the latter rearwardly and thereby swinging the lever I49 and, through the bolt connection, swinging the lever I49 forwardly against the thrust bearing I59 to effect application of the clutch 95. By adjustment of the screw E31, the lever i 19 may be swung either forwardly or rearwardly to vary the position of its pivoting point; and as a result, as the cam I44 rotates, the lever I49 is variably swung, thereby varying the intervals of application of the disc clutch 95. By adjustment of the lever i 39 into a position wherein the slide member I 45 is held continuously against the surface of the cam, the disc clutch 95 is constantly applied. In other words, movement of the slide member I45 to the left in Fig. 21 will impart a load to the shipper member I42 which will be determined by the extent of movement of the bolt I52 and the degree of compression of the spring I51. More specifically, rotation of the screw I31 in a direction to effect axial movement of the half nut toward the left in Fig. 21, moves the fulcrum of the lever I40 toward the left, and thereby moves the member I45 into engagement with the cam i4 2; and upon rotation of the cam the lever I40 is swung, thereby moving the bolt I52 to the left to swing the lever I49 to the right, and thereby load the clutch 95. When the half nut is moved to the left so far that the trunnion I53 continuously abuts the washer I56 encircling the bolt I52, continuous application of the clutch 95 will be effected and the spring I51 will compress during each rotation of the cam an amount substantially equal to the full throw of the cam; but since the load of the spring is desirably above the minimum necessary to effect power trans mission through the clutch discs, there will be no release even when the slide I45 is in engagement with the lowermost point in the cam. However, by moving the nut graduated amounts toward the right in Fig. 21, the period of drive during each rotation of the cam will be progressively reduced until the clutch is entirely released and drive is discontinued. It will thus be seen that drive of the screws 99 and I through the disc clutches may be effected at any desired speed from its maximum speed down to zero, by proper adjustment of the parts. Overloading will be prevented by the presence of the springs I51.

The improved mechanism for effecting truck wheel drive to propel the apparatus along the mine trackway both during cutting and transport, herein comprises a worm I60 (see Fig. 3) formed integral with the shaft I6 below the bevel gear I and meshing with and driving in opposite directions worm wheels I6I and I62. These worm wheels are journaled on parallel longitudinally extending shafts I63, I64, respectively, arranged at the opposite sides of the shaft I6 and in the same longitudinally extending vertical planes as the screw shafts 99 and I00. These worm wheels are connected to the shafts by multiple disc clutches I65, I66, respectively. Keyed to the rear ends of the shafts I63, I64, respectively, are spur gears I61 and I 68 meshing with a spur gear I69 journaled on a tubular shaft I10. The shaft I surrounds the shaft II heretofore described and is clutched at its rearward end at I1I to a worm I12 suitably journaled within a gear and axle housing I13. The worm I12 meshes, as shown in Fig. 17, with a worm wheel I14 connectible by a multiple disc clutch I to a transverse shaft I16 suitably journaled within the gear housing I13. The operating means for the clutch I15 com prises a pressure plate I18 with which engages a ball thrust bearing I19. Engageable with the outer race of the ball thrust bearing is a shipper yoke I80 fixed to an operating shaft I8I suitably journaled within the gear housing I13. Fixed to the shaft I8I is a suitable operating lever I82 (see Fig. 3). Keyed to the shaft I16 and driven thereby is a chain sprocket I83 connected by a chain 84 to a chain sprocket I85 keyed to the rear axle I86 to which the rear truck wheels 4 are secured. Fixed to the opposite ends of the axle I86 are chain sprockets I81, I81 connected by endless chains I88, I88 to chain sprockets I89, I69 secured to the front truck wheels 4, as shown in Fig. 4. Splined to the sleeve I10 is a jaw clutch member I90 having clutch teeth I9I connectible to clutch teeth I92 formed on the gear I69. The clutch member I90 is also provided with clutch teeth I93 connectible to clutch teeth I94 formed on the bevel pinion I4. The clutch member I90 is operated by a shipper yoke I95 fixed to a transverse operating shaft I96 having a suitable operating handle I91. The disc clutches I65, I66 are each provided with a variable speed control mechanism, respectively generally designated I98, I99, whereby the disc clutches may be either constantly or intermittently and variably applied to effect variable speed drive of the shafts I63, I64, and this control mechanism is identical to that above described in connection with the arm and bar swinging screw shafts 99, I00. Therefore, further detailed description of the same is deemed unnecessary. However, in this instance the operating mechanism for the mechanisms I98, I99 includes a toothed wheel 209 keyed to the screw operating shaft, and pivotally mounted on the screw operating shaft is a lever I carrying a dog 202. This dog is slidably guided at 203 within the lever and is normally held in its released position by a coiled spring 204. Formed at the outer extremity of the lever is a. socket 295 for receiving a spherical member 206 formed on an operating rod 201. This operating rod is provided with a suitable handle 208 conveniently located at the side of the truck frame. The spherical member 206 is provided with a cam surface 209 so that when the rod 201 is rotated, the dog 202 is slid downwardly into engagement with the teeth of the member 200. The operator then grasps the handle 208 and pulls the rod 201 outwardly to effect swinging of the lever to thereby rotate the screw operating rod of the control mechanism. The dog 202 may be released by rotating the spherical'member 206 to bring the cam surface 269 into a position to permit release of the dog. It will thus be seen that the truck wheels may be driven at a high transport speed directly through the shaft II, bevel pinion I4, clutch I99, sleeve I16 and the worm gearing I12, I14, and at a. relatively w cutting speed through the worm gearing I60, I6I, I62, parallel shafts I63, Hi l, spur gears I61, I68 meshing with spur gear I69, and in either of opposite directions under the control of the disc clutches I65, I66. The low cutting speed may be varied by regulating the control mechanisms I68, I99 for the disc clutches I65,I66.

As above mentioned, the truck frame is mounted for tilting movement; and to afford-such tiltin movement, the gear housing I13 is provided with bearing portions 2I5, 2I6 mounted within bearing sleeves 2I1 carried within bearing supports 2I8, 259 formed, respectively, on the truck frame and the main frame I3, as shown in Fig. 4. This bearing mounting on the gear housing I13 permits rocking movement of the truck frame about a longitudinal axis, i. e. the axis of the shaft II. The axle housing mounting for the truck frame is also provided with

journals

226, 226 within which the rear axle is rotatably mounted, and these journals form a pivotal mounting for the truck frame to enable tilting of the truck frame about a transverse axis, i. e. the axis of the rear axle I86. The improved mechanism for effecting such tilting movement of the truck frame to vary the angle in altitude of the cutting mechanism, herein comprises shafts 22 I, 2 22 aligned with the shafts I63, I64, respectively, as shown in Fig. 4 and connectible to the latter shafts by sliding toothed

clutch members

223 and 226, respectively. These clutch members are each operated by a shipper yoke 225 secured to a transverse shaft 226 having a suitable-operating lever 221. These shafts 22 I, 222 are suitably journaled within the main frame I3 and have formed thereon screw shafts 228 and 229, and. these screw shafts are each connected, as shown in Fig. 5, to a nut 230. Pivotally connected at 23I to each nut is a link 232, in turn pivotally connected at 233 to an arm 234. These arms are keyed at 235 to

alined shafts

236, 231, respectively, suitably journaled within the truck frame, as shown in Fig. 4 Formed integral with the arms 234 are arms 258 carrying the axles 239, 229, respectively, on which the front truck wheels are journaled. It will thus be seen that when the

clutches

223, 224 are connected, the screw shafts 223, 229 may be rotated to effect swinging of the arms, thereby tilting the truck frame upwardly about the axis of the rear truck wheel axle. By releasing one or the other of the

clutches

223, 224, one of the arms may be swung while the other is stationary, thereby effecting tilting of the truck fra-me'within its journal 2I5, 2I1 about a longitudinal axis. It is accordingly evident that by suitable adjustment of the arms carrying the front truck wheels, the truck frame may be tilted relative to the horizontal, and as a result the angle in altitude of the cutter bar may be varied relative to the horizontal, it being possible to tilt the cutter bar about transverse and longitudinal axes. The drive chains I88, I88 for the front truck wheels are maintained under tension by spring pressed guide plates or shoes 2 -15, 246 slidably engaging the upper and lower runs of the chains and maintained under tension by coiled springs 241, the spring pressed

plates

255, 246 maintaining the chains at all times under tension during adjustment of the front tilting arms for the truck frame.

Power is supplied to the 'motor 9 through a power conductor cable 250 wound upon a cable reel 25I mounted at one side of the truck frame, as shown in Fig. 1. This cable reel is driven to effect winding or unwinding of the power conductor cable as the apparatus moves along the trackway by a pulley 252 keyed to the shaft I16 (see Fig. 17). This pulley is connected by a belt 253 to a pulley 254 keyed to the cable reel driving shaft 255. A suitable adjustable pulley 256 engages the upper run of the belt 253 to vary the tension of the belt. Formed internally within the pulley I52 is a braking surface 251 with which a brake band 258 cooperates. This brake band, as shown in Fig. 18, is formed in segments, and these segments are pivotally connected at 259 to adjusting screws 260 connected to abutments 26I formed on the gear housing I13. Secured to the ends of the brake segments are operating

elements

262, 262 cooperating to form a conical surface 263 with which a conical operating member 264 cooperates. When the operating member 264 is moved inwardly, the operating

elements

262, 262 are separated, thereby forcing the brake segments into braking contact with the brake surface 251. The operating mem. her 264 is actuated by a screw shaft 265 threadedly connected within a trunnion nut 266 carried by the gear housing I13. This shaft is provided with a suitable operating handle 261. The operating lever I82 for the disc clutch I of the truck wheel driving mechanism is so arranged that when the truck wheel brake is applied, the disc clutch is always released, and vice versa. As shown in Fig. 19, the clutch operating lever I82 is arranged directly in the path of movement of the operating shaft 265 for the brake, so that when the brake is applied, as in the manner shown, the lever I82 is released. When the screw shaft 265 is moved inwardly to effect release of the brake operating element 26 the clutch operating lever I82 is engaged by the shaft and swung outwardly toeifect application of the clutch.

The operation of the improved mining apparatus'is as follows: The apparatus is propelled along the mine trackway at a high transport speed through the high speed drive mechanism including drive shaft II, bevel pinion I4, clutch I99, worm gearing I12, I14 and the chain and sprocket connections connected to the truck wheels. The direction of high speed truck wheel drive may be reversed by reversing the motor 9. When the working face is reached, the clutch 98 is connected, and upon application of the disc clutch 96 the screw I08 is rotated, thereby effecting swinging of the arm structure 1 horizontally relative to the truck frame, through the trunnion nut and link connection, from the central position shown in Fig. l to a position wherein the bar pivot axis 8 lies outside the trackway. As the arm structure is swung laterally, the clutch 91 may be connected to effect drive of the screw 99, thereby to effect swinging of the cutter bar about its pivot through the trunnion nut and link connection in the opposite direction until the parts assume an angularly related position with the tip end of the cutter bar at the right hand rib of the entry. The bar and arm swinging clutches 91, 98 are then disconnected. The bar elevating nut 66 is then operated by bringing the proper gears 66, H in mesh with the spur gear 51, thereby lowering the cutter bar to a position at the level of the mine bottom outside and below the level of the trackway. The clutch I96 is then shifted to connect the spur .;advance of the trackway.

gear 169 to the sleeve Hi and upon'application of the slow speed truck drive controlling clutch i6 5 and application of the friction clutch H5, the truck wheels are driven to propelthe apparatus forwardly along the mine trackway at a low speed to sump the cutter bar beneath the coal. After the completion of the sumping cut, the

brake

251, 258 is applied, thereby holding the truck wheels stationary, and the arm and bar swinging screws 99, I60 are then operated to swing the arm and cutter bar in opposite directions about their respective pivots until they assume a straight line position, the bar swinging screw thereafter being disconnected from the motor and the cutter bar swung about the axis 5 of the arm to effect its swinging cut across the coal face in advance of the trackway. When the tip end of the cutter bar reaches the left hand rib, the cutter bar is swung in the opposite di- ,rection until the parts assume an angularly related position, the arm and bar swinging mechanisms thereafter being disconnected from their drives. The apparatus is then propelled rearwardly along the mine trackway to effect with- ;drawal of the cutter bar from beneath the coal.

It will be evident that the arm i and cutter bar 34 may be independently or simultaneously swung about their respective pivots at variable cutting speeds under the control of the variable ,i peed control mechanism for the disc clutches e5, 96 and that the apparatus may be propelled at a predetermined high transport speed. If it is desired to tilt the cutter bar to vary its angle in altitude during the horizontal cutting operation, this may be accomplished by operating the

clutches

223, 224 controlling the tilting screws 228, 229, it being possible to tilt the cutter bar about longitudinal and transverse axes. The cutter bar may be adjusted to cut at different levels simply by operating the elevating screw and nut mechanism 66, E! to raise or lower the cutter bar.

As a result of this invention, it will be noted that an improved wheel mounted, track supported and guided, bottom cutting type mining apparatus is provided, having improved adjustable cutting mechanism whereby a horizontal kerf may be cut at the level of the mine bottom outside and below the level of the mine trackway and in It will further be noted that by the provision of the improved bar adjusting and swinging mechanism, it is possible to swing and adjust the bar in an improved manner. It will still further be noted that by the provision ,;of the improved tilting mechanism for the cutter bar, the cutter bar may be adjusted to out on uneven or rolling bottom or a pitching coal seam. These and other uses and advantages of the improved mining apparatus will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may as sume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a. mining apparatus, a support, a cutter frame mounted on said support for rotation relative thereto about a vertical axis with the bottom of said frame projecting below the bottom of said vsupport and said frame having depending vertical guides extending downwardly from'the -up er portion of said support a substantial distance below the bottom of said support, a cutter support mounted on said cutter frame for rotation therewith and adjustable vertically along said guides, a kerf cutter carried by said cutter support, and driving means for said kerf cutter including a cutter driving element arranged with its axis coincident with the axis of rotation of said cutter frame.

2. In a mining apparatus, a support, a cutte frame mounted on said support for rotation relative thereto about a vertical axis with the bottom of said frame projecting below the bottom of said support and said frame having depending vertical guides extending dowardly from the upper portion of said support a substantial distance below the bottom of said support, a cutter support mounted on said cutter frame in planes below the bottom of said first support for rotation therewith and adjustabie vertically along said guides, a kerf cutter carried by said cutter support and swingable horizontally with said cutter support and frame relative to said first support, and driving means for said kerf cutter including a cutter driving element arranged with its axis coincident with the axis of rotation of said cutter frame.

3. In a mining apparatus, a wheeled truck frame having front and rear truck wheels, an arm pivotally mounted on said truck frame for horizontal swinging movement relative thereto about a vertical axis located between the front and rear truck wheel axes, a kerf cutter pivotally mounted on the outer extremity of said arm, and

motor operated devices between the truck frame and the front truck wheels and separately or simultaneously adjustable to effect tilting of said truck frame about longitudinal and transverse axes.

4. In a mining apparatus, a wheeled truck rame having front and rear truck wheels, kerf cutting mechanism thereon, motor operated devices between the front truck wheels and said truck frame and independently or simultaneously 1 independently swinging said arm and kerf cutter about their respective axes including rectilinearly guided, movable-power swinging devices,-. one for effecting arm swing and the other for-effecting cutter swing and each including a power :element movable rectilinearly of its guiding means dur ing the swinging operation.

6. In a mining apparatus, a portable base, an arm mounted on and overlying said base and at its outer extremity overhanging said base, a kerf cutter pivotally mounted on said overhanging extremity of said arm, motor operated swinging devices carried by said arm for independently swinging said arm and kerf cutter about their respective axes and including rectilinearly guided, movable power swinging devices, one for effecting arm swing and the other for effecting cutter swing and each including a power element movable rectilinearly of its guiding means during the swinging operation, and a motor carried by said base and relative to which said arm is swingable for operating said power swinging devices.

7. In a mining apparatus, a portable base, an arm swingably mounted on and overlying said base and at its forward extremity overhanging said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm, motor operated screw and nut devices for independently swinging said arm and kerf cutter about their respective pivots, and a motor for actuating both of said devices.

8. In a mining apparatus, a portable base, an

arm swingably mounted on and overlying said base and at its forward extremity overhanging said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm, motor operated screw and nut devices carried by said arm for independently swinging said arm and kerf cutter about their respective pivots, and a motor for actuating both of said devices.

9. In a mining apparatus, a portable base, an arm swingably mounted on and overlying said base and at its forward extremity overhanging said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm, motor operated screw and nut devices for independently swinging said arm and kerf cutter about their respective pivots, and a motor on said base and relative to which said arm is swingable for actuating said screw and nut devices.

10. In a mining apparatus, a portable base, an arm swingably mounted on and overlying said base and at its forward extremity overhanging said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm, motor operated screw and nut devices carried by said arm for independently swinging said arm and kerf cutter about their respective pivots, and a motor on said base and relative to" which said arm is swingable for actuating said screw andnut devices.

11. In a mining apparatus, a portable base, but a single arm mounted on and overlying said base and at its outer extremity overhanging said base, said arm mounted for but confined to horizontal swinging movement relative to said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm and having a support, said arm constituting the sole supporting connection between said base and said kerf cutter support, a motor on said base and relative to which said arm is swingable, and means driven by said motor and including arm and kerf cutter swinging devices mounted on said arm for independently swinging said arm and kerf cutter about their respective pivots.

12. In a mining apparatus, a portable base, but a single arm mounted on and overlying said base and at its outer extremity overhanging said base, said arm mounted for but confined to horizontal swinging movement relative to said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm and adjustable relative to said arm into different elevated positions, said kerf cutter having a support and said arm constituting the sole supporting connection between said base and said cutter support, a motor on said base and relative to which said arm is swingable, means driven by said motor for independently swinging said arm and kerf cutter about their respective pivots, and means driven by said motor for adjusting said kerf cutter into aforesaid elevated positions relative to said arm;

13. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame, and motor operated screw and nut devices for independently swinging said frame and kerf cutter about their respective pivots and common motor operated driving means for said devices.

14. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame, and motor operated screw and nut devices carried by said frame for independently swinging said frame and kerf cutter about their respective pivots and common motor operated driving means for said devices.

15. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame, motor operated screw and nut devices for independently swinging said rrame and kerf cutter about their respective pivots, and a motor on said support and relative to which said frame is swingable for actuating said screw and nut devices.

16. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame, motor operated screw and nut devices carried by said frame for independently swinging said frame and kerf cutter about their respective pivots, and a motor on said support and relative to which said frame is swingable for actuating said screw and nut devices.

1'7. In a mining apparatus, a portable base, a single rigid horizontal arm swingably mounted on and overlying said base and at its outer extremity overhanging said base, said arm confined to horizontal swinging movement relative to said base, a horizontal kerf cutter pivotally mounted on the overhanging extremity of said arm and having a support, said arm constituting the sole supporting connection between said base and said cutter support, a motor on said base and relative to which said arm is swingable for independently swinging said arm and kerf cutter about their respective pivots, and means driven by said motor for tilting said base relative to the horizontal to vary the plane of swinging movement of said arm.

18. In a mining apparatus, a portable base, a single rigid horizontal arm swingably mounted on and overlying said base and at its outer extremity overhanging said base, said arm confined to horizontal swinging movement relative to said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm and adjustable relative to said arm into different elevated positions, said kerf cutter having a support and said arm constituting the sole supporting connection between said base and said cutter support, a motor on said base and relative to which said arm is swingable for independently swinging said arm and kerf cutter about their respective pivots and for adjusting said kerf cutter into aforesaid elevated positions relative to said arm, and means driven by said motor for tilting said'base with respect to the horizontal to vary the plane of swinging movement of said arm.

19. In a mining apparatus, a portable base, a single rigid horizontal arm swingably mounted on and overlying said base and at its outer extremity overhanging said base, said arm confined to horizontal swinging movement relative to said base, a horizontal kerf cutter pivotally mounted on the overhanging extremity of said arm and having a support, said arm constituting the sole supporting connection between said base and said cutter support, a motor on said base and relative to which said arm is swingable for independently swinging said arm and kerf cutter about their respective pivots, and devices driven by said motor for actuating said kerf cutter and for tilting said base with respect to the horizontal to vary the plane of swinging movement of said arm.

20. In a mining apparatus, a portable base, a single rigid horizontal arm swingably mounted on and overlying said base and at its outer extremity overhanging said base, said arm confined to horizontal swinging movement relative to said base, a kerf cutter pivotally mounted on the overhanging extremity of said arm and adjustable relative to said arm into different elevated positions, said kerf cutter having a support and said arm constituting the sole supporting connection between said base and said cutter support, a motor on said base and relative to which said arm is swingable for independently swinging said arm and kerf cutter about their respective pivots and for adjusting said kerf cutter into aforesaid elevated positions relative to said arm, and devices driven by said motor for actuating said kerf cutter and for tilting said base with respect to the horizontal to vary the plane of swinging movement of said arm.

21. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto, the forward extremity of said arm structure overhanging the forward end of said base, a cutter frame pivotally mounted on the outer overhanging extremity of said arm structure for rotation about an axis parallel with the arm structure axis and having depending vertical guides extending downwardly in advance of said base, a cutter support mounted on said guides for vertical adjustment therealong and swingable with said cutter frame relative to said arm structure, and a kerf cutter carried by said cutter support, said cutter frame and cutter support being swingable relative to said arm to swing said kerf cutter about the axis of said cutter frame.

22. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto, the forward extremity of said arm structure overhanging the forward end of said base, a cutter frame pivotally mounted on the outer overhanging extremity of said arm structure for rotation about an axis parallel with the arm structure axis and having depending vertical guides extending downwardly in advance of said base, a cutter support mounted on said guides for vertical adjustment therealong and swingable with said cutter frame relative to said arm structure, a kerf cutter carried by said cutter support, said cutter frame and cutter support being swingable relative to said arm to swing said kerf cutter about the axis of said cutter frame, and a motor carried by said base and relative to which said arm structure is swingable for actuating said kerf cutter, for rotating said cutter frame relative to said arm structure and for adjusting said cutter support vertically along said guides.

23. In a mining apparatus, a frame, a swingable arm structure overlying said frame and having at its outer extremity an annular frame portion, a cutter frame rotatably mounted on said arm structure and having top and bottom bearing elements journaled on said annular frame portion, a cutter support carried by said cutter frame beneath the latter, and a kerf cutter carried by said cutter support, said cutter frame and cutter support being swingable about the cutter frame axis to swing said kerf cutter about the cutter frame axis.

24. In a mining apparatus, a swingable arm structure having at its outer extremity an annular portion, a cutter frame rotatably mounted on said arm structure and having top and bottom portions j ournaled on said annular portion, said outter frame having depending vertical guides, a cutter support adjustable vertically along said guides relative to said cutter frame, and a kerf cutter carried by said cutter support, said kerf cutter being swingable with said cutter frame and cutter support about the cutter frame axis and adjustable along said guides into difierent elevated positions.

25. In a mining apparatus, a swingable arm structure having at its outer extremity an annular frame portion, a cutter frame rotatably mounted on said arm structure and having top and bottom bearing elements journaled on said annular frame portion, a cutter support carried by said cutter frame, a kerf cutter carried by said cutter support, said cutter frame and cutter support being swingable about the cutter frame axis to swing said kerf cutter about the cutter frame axis, motor operated means for actuating said kerf cutter including a motor driven shaft. journaled on said arm structure, a shaft journaled on said cutter frame and arranged with its axis coincident with the cutter frame axis, gearing connecting said shafts in driving relation and housed Within said cutter frame and driving connections between the last mentioned shaft and the kerf cutter, and means driven by said gearing for swinging said cutter frame, cutter support and kerf cutter about the cutter frame axis.

26. In a mining apparatus, a swingable arm structure having at its outer extremity an annular portion, a cutter frame rotatably mounted on said arm structure and having top and bottom portions journaled on said annular portion, said cutter frame having depending vertical guides, a cutter support adjustable vertically along said guides relative to said cutter frame, a kerf cutter carried by said cutter support, said kerf cutter being swingable with said cutter frame and cutter support about the cutter frame axis and adjustable along said guides into different elevated positions, and motor operated devices for actuating said kerf cutter including a motor driven shaft journaled on said arm structure, a telescopic torque shaft journaled on said cutter frame and cutter support and arranged with its axis coinci-' dent with the cutter frame axis, gearing connecting said shafts in driving relation and arranged within said cutter frame, and driving connections between said torque shaft and the kerf cutter.

27. Ina mining apparatus, a swingable arm structure having at its outer extremity an annular portion, a cutter frame rotatably mounted on said arm structure and having top and bottom portions journaled on said annular portion, said cutter frame having depending vertical guides, a cutter support adjustable vertically along said guides relative to said cutter frame, a kerf cutter carried by said cutter support, said kerf cutter being swingable with said cutter frame and cutter support about the cutter frame axis and adjustable along said guides into different elevated positions, motor operated devices for actuating said kerf cutter including a motor driven shaft journaled on said arm structure, a telescopic torque shaft journaled on said cutter frame and cutter support and arranged with its axis coincident with the cutter frame axis, gearing connecting said shafts in driving relation and arranged within said cutter frame, driving connections between said torque shaft and the kerf cutter, and means for adjusting said cutter support vertically along said guides including adjusting devices driven by said gearing.

28. In a mining apparatus, a swingable arm structure, a cutter frame pivotally mounted on said arm structure for rotation about an axis parallel with the arm structure axis, a cutter support carried by said cutter frame and rotatable with said cutter frame about the cutter frame axis, a kerf cutter carried by said cutter support, motor operated means for actuating the kerf cutter including a motor driven shaft journaled on the arm structure, a shaft journaled on the cutter frame and arranged with its axis coincident with the cutter frame axis, gearing connecting said shafts in driving relation and arranged within the cutter frame and driving connections between said last mentioned shaft and the kerf cutter, and means driven by said gearing for swinging said cutter frame, cutter support and kerf cutter about the cutter frame axis.

29. In a mining apparatus, a swingable arm structure, a cutter frame rotatably mounted on said arm structure about an axis parallel with the arm structure axis, said cutter frame having vertical guides, a cutter support mounted on said cutter frame for adjustment vertically along said guides, a kerf cutter carried by said cutter support, said cutter frame and cutter support being rotatable about the cutter frame axis to swing the kerf cutter about the cutter frame axis, and motor operated devices for actuating the kerf cutter including a motor driven shaft journaled on the arm structure, a telescopic torque shaft journaled on the cutter frame and cutter support and arranged with its axis coincident with the cutter frame axis, gearing connecting said shafts in driving relation and arranged within said cutter frame, and driving connections between said torque shaft and the kerf cutter.

30. In a mining apparatus, a swingable arm structure, a cutter frame rotatably mounted on said arm structure about an axis parallel with the arm structure axis, said cutter frame having vertical guides, a cutter support mounted on said cutter frame for adjustment vertically along said guides, a kerf cutter carried by said cutter support, said cutter frame and cutter support being rotatable about the cutter frame axis to swing the kerf cutter about the cutter frame axis, motor operated devices for actuating the kerf cutter including a motor driven shaft journaled on the arm structure, a telescopic torque shaft journaled on the cutter frame and cutter support and arranged with its axis coincident with the cutter frame axis, gearing connecting said shafts in driving relation and arranged within said cutter frame, driving connections between said torque shaft and the kerf cutter, and means for adjusting said cutter support vertically along said guides including adjusting devices driven by said earing.

31. In a mining apparatus, a swingable arm structure, a cutter frame rotatably mounted on said arm structure about an axis parallel with the arm structure axis, said cutter frame having vertical guides, a cutter support mounted on said cutter frame for adjustment vertically along said guides, a kerf cutter carried by said cutter support, said cutter frame and cutter support being rotatable about the cutter frame axis to swing the kerf cutter about the cutter frame axis, motor operated devices for actuating the kerf cutter including a motor driven shaft journaled on the arm structure, a telescopic torque shaft journaled on the cutter frame and cutter support and arranged with its axis coincident with the cutter frame axis, gearing connecting said shafts in driving relation and arranged within said cutter frame, driving connections between said torque shaft and the kerf cutter, and means for adjusting said cutter support vertically along said guides including adjusting devices driven by said gearing, said adjusting devices including a vertical screw connected at its lower end to the cutter support, and a cooperating rotatable nut journaled on said cutter frame.

32. In a mining apparatus, a swingable arm structure, a cutter frame rotatably mounted on said arm structure about an axis parallel with the arm structure axis, said cutter frame having vertical guides, a cutter support mounted on said cutter frame for adjustment vertically along said guides, a kerf cutter carried by said cutter support, said cutter frame and cutter support being rotatable about the cutter frame axis to swing the kerf cutter about the cutter frame axis, motor operated devices for actuating the kerf cutter including a motor driven shaft journaled on the arm structure, a telescopic torque shaft journaled on the cutter frame and cutter support and arranged with its axis coincident with the cutter frame axis, gearing connecting said shafts in driving relation and arranged within said cutter frame, driving connections between said torque shaft and the kerf cutter, and means for adjusting said cutter support vertically along said guides including adjusting devices driven by said gearing, said adjusting devices including a vertical screw connected at its lower end to the cutter support, a cooperating rotatable nut journaled on said cutter frame, and gearing connecting said nut in driving relation with said first mentioned gearing including a gear element formed on the nut, a gear element coaxial with the torque shaft, and gearing meshing with said two last mentioned gear elements.

33. In a mining apparatus, a cutter frame having vertical guides, a cutter support mounted on said guides for adjustment vertically therealong, a kerf cutter carried by said cutter support, motor operated means for actuating the kerf cutter including a rotatable driving member journaled in said cutter frame, a telescopic torque shaft journaled in said cutter frame and cutter support, said torque shaft arranged coaxially with and driven by said driving member, and a driving connection between said torque shaft and said kerf cutter, and means for adjusting said cutter support along said guides relative to said cutter frame including adjusting devices separate and distinct from said torque shaft and having driving means driven by said driving member, said driving means for said adjusting means including a driving member coaxial with and rotatable relative to said first mentioned driving member, a driving connection between said last mentioned driving member and. said adjusting devices, and a clutch for connecting said second mentioned driving member to said first mentioned driving member for rotation with the latter.

34. In a mining apparatus, a cutter frame having vertical guides, a cutter support mounted on said guides for adjustment vertically therealong, a kerf cutter carried by said cutter support, mo-

tor operated means for actuating the kerf cutter including a rotatable driving member journaled in said cutter frame, a telescopic torque shaft journaled in said cutter frame and cutter support, said torque shaft arranged coaxially with and driven by said driving member, and a driving connection between said torque shaft and "said kerf cutter, and means for adjusting said cutter support along said guides relative to said cutter frame including adjusting devices separate and distinct from said torque shaft and having driving means driven by said driving member, said adjusting devices including a vertical screw connected at its lower end to the cutter support.

and a cooperating rotatable nut journaled in said cutter frame, said driving means for adjusting means including a driving member coaxial with and rotatable relative to said first mentioned driving member, a driving connection tween said last mentioned driving member and said adjusting devices, and a clutch for connecw ing said second mentioned driving member to said first mentioned driving member for rotation with the latter.

35. In a mining apparatus, a cutter frame haw ing vertical guides, a cutter support mounted on said guides for adjustment vertically therealong, a kerf cutter carried by said cutter suppoi motor operated devices for actuating the kerf cut ter including a telescopic torque shaft journaled in said cutter frame and said cutter support, a gear coaxial with said torque shaft for driving the latter, and driving connections between said torque shaft and the kerf cutter, and means for adjusting the cutter support along said guides relative to said cutter frame including adjusting devices driven by said gear, said adjusting devices including a vertical screw connec'ed at its lower end to the cutter support, and a cooperating rotatable nut journaled in said cutter frame and gearing driven by said gear for rotating said nut including a gear coaxial with the torque shaft, a gear formed on said rotatable nut, and gearing meshing with said gears.

36. In a mining apparatus, a cutter frame having vertical guides, a cutter support mounted on said guides for adjustment verticaily therealong, a kerf cutter carried by said cutter support, motor operated devices for actuating the kerf cutter including a motor driven shaft journaled in said cutter frame, a telescopic torque shaft journal-ed in said cutter frame and said cutter support, gearing connecting said shafts in driving relation and driving connections between said torque shaft and the kerf cutter, and means for adjusting said cutter support along said guides relative to said cutter frame including adjusting devices driven by said gearing, the driving connections between said gearing and said adjusting devices including reversing means whereby while said gearing operates continuously in the same direction the adjusting devices may be operated in either of opposite directions.

37. In a mining apparatus, a support, a swingable frame mounted on said support, a cutter frame pivotally mounted on said frame to about an axis parallel with the swingable frame axis, and motor operated devices for swinging said frames about their respective axes includ ing parallel screws journaled on said swingable frame, means for rotating said screws, nuts cooperating with said screws respectively and guided by said swingable frame, and links pivotally connected to said nuts respectively and respectively to said cutter frame and support.

38. In a mining apparatus, a support, a swingable frame adjustably mounted thereon, a cutter frame rotatably mounted on said swingable frame, and means for swinging said frames about their respective axes including parallel guideways formed on said swingable frame, elements reciprocable in said guidesways, means for reciprocating said elements, and links pivotally connected to said reciprocable elements respectively and respectively connected to said cutter frame and support.

39. In a mining apparatus, a wheel supported truck frame adapted to run along a mine trackway and having front and rear truck wheels, horizontal kerf cutting mechanism carried by said truck frame, and means for tilting said truck frame about transverse and longitudinal axes relative to a horizontal plane including the truck wheel axes including an axle mounting for the rear truck wheels and with which said truck frame has pivotal connection about a longitudinal axis, separate axle mountings for the front truck wheels, arms pivotally connected to said front axle mountings and swingably mounted on the truck frame about axes 'oifset from the truck wheel axes, and separate adjusting means for independently swinging saidarms.

40. In a mining apparatus, a wheel supported truck frame adapted to run along a mine track- Way and having front and rear truck wheels, horizontal kerf cutting mechanism carried by said truck frame, and means for tilting said truck frame about transverse and longitudinal axes relative to ahorizontal plane including the truck wheel axes including an axle mounting for the rear truck wheels and with which said truck frame has pivotal connection about a longitudinal axis, separate axle mountings for the front truck wheels, arms pivotally connected to said front axle mountings and swingably mounted on the truck frame about axes offset from the truck wheel axes, and separate adjusting means for independently swinging said arms including adjusting devices having relatively reciprocable adjusting elements carried by said truck frame, one adjusting device for actuating each arm.

41. In "a mining apparatus, a wheel supported truck frame adapted to run along a mine trackway and having front and rear truck wheels, horizontal kerf-cutting-mechanism carried by said truck frame, and means for tilting said truck frame about transverse and longitudinal axes relative to a horizontal plane including the truck wheel axes including an axle mounting for the rear truck wheels and with which said truck frame has pivotal connection about a longitudinal-axis, separate axle mountings for the front truck wheels, arms pivotally connected to said front axle mountings and swingably mounted on the truck frameabout axes offset from the truck Wheel axes, and separate adjusting means for independently swinging said arms including adjusting devices carried by said truck frame, one for actuating each arm, said devices each including a re'ctilinearly movable adjusting element and a cooperating element, an arm swingable with said truck wheel axle mounting arm, and a link connecting said last mentioned arm and said rectilinearly movable element.

42. In a mining apparatus, a wheel supported truck frame adapted to run along a mine trackway and having front and rear truck wheels, horizontal kerf cutting mechanism carried by said truck frame, and means for tilting said truck frame about transverse and longitudinal axes relative to a horizontal plane including the truck wheel axes including an axle mounting for the rear truck wheels and with which said truck frame has pivotal connection about a longitudinal axis, separate axle mountings for the front truck wheels, said front axle mountings each having independent adjustable mountings on the truck frame, and independent adjusting means for adjusting said front axle mountings.

43. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto: about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm structure and adjustable relative thereto, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and. driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis and gearing connecting said shafting and said last mentioned shaft in driving relation, and means driven by said last mentioned gearing for adjusting said kerf cutter relative to said arm structure and including a shaft parallel with said last mentioned shaft.

44. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base toswing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on and adjustable relative to the outer extremity of said arm structure, and motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft 'journaled on said I base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said base, and means driven by said last mentioned gearing for adjusting said kerf cutter relative to said arm structure.

45. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm structure, and motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged wiih its axis coincident with the arm structure pivot axis, gearing conn cting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said base and for swinging said kerf cutter relative to said arm structure, and means driven by said last mentioned gearing for adjusting said kerf cutter relative to said arm structure.

46(In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer exterrnity of said arm structure, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, and means driven by saidsecond mentioned shaft for tilting said base relative to the horizontal.

4'7. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm structure, motor v operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said base, and means driven by said second mentioned shaft for tilting said base relative to the horizontal.

48. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf'cutter pivotally mounted on the outer extremity of said arm structure, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journale-d on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said base and for swinging said kerf cutter relative to said arm structure, and means driven by said second mentioned shaft for tilting said base relative to the horizontal.

49. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm structure, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said last mentioned gearing for adjusting said kerf cutter relative to said arm structure and including a shaft parallel with said last mentioned shaft, and means driven by said first mentioned shaft for propelling said base.

50. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on and adjustable relative to the outer extremity of said arm structure, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearng connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said base, means driven by said last mentioned gearing for adjusting said kerf cutter relative to said arm structure, and means driven by said first mentioned shaft for propelling said base.

51. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on and adjustable relative to the outer extremity of said arm structure, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said and for swinging said kerf cutter relative to said arm structure, means driven by said last mentioned gearing for adjusting said kerf cutter relative to said arm structure, and means driven by said first mentioned shaft for propelling said base.

52. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm structure, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for tilting said base relative to the horizontal, and means driven by said first mentioned shaft for propelling said base.

53. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm structure, motor operated kerf cutter actuating means including a motor driven shaft journaled on said base, a

shaft journaled on said base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said shafts in driving relation, shafting journaled on said arm structure and driven by said gearing, a shaft arranged with its axis coincident with the kerf cutter pivot axis, and gearing connecting said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said base, means driven by said second mentioned shaft for tilting said base relative to the horizontal, and means driven by said first mentioned shaft for propelling said base.

54. In a mining apparatus, a portable base, an arm structure pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm structure, motor operat'ed kerf cutter actuating means including a motor driven shaft journaled on said base, a shaft journaled on base and arm structure and arranged with its axis coincident with the arm structure pivot axis, gearing connecting said said shafting and said last mentioned shaft in driving relation, means driven by said second mentioned shaft for swinging said arm structure relative to said base and for swinging said kerf cutter relative to said arm structure, means driven by said second mentioned haft for tilting said base relative to the horizontal, and means driven by said first mentioned shaft for propelling said base.

55. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame, and motor operated devices for independently swinging said frame and kerf cutter about their respective pivots comprising separate adjusting devices each including relatively rotatable and axially movable meill chanically interlocking adjusting elements, said elements being self -locking for holding the frame and kerf cutter in adjusted position.

56. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame, and motor operated devices carried by said frame for independently swinging said frame and kerf cutter about their respective pivots comprising separate adjusting devices each including relatively rotatable and axially movable mechanically interlocking adjusting elements, said elements being self-locking for holding the frame and kerf cutter in adjusted position.

57. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame about an axis parallel with the frame pivot axis, and motor operated devices for independently swinging said frame and kerf cutter about their respective pivots comprising separate adjusting devices each including cooperating motor actuated adjusting elements having relative axial movement.

58. In a mining apparatus, a support, a frame swingably mounted thereon, a kerf cutter pivotally mounted on said frame, and motor operated devices carried by said frame for independently swinging said frame and kerf cutter about their respective pivots comprising separate adjusting devices each including cooperating motor actuated adjusting elements having relative axial movement.

59. In a mining apparatus, a portable base comprising a low compact base frame, but a single rigid horizontal arm swingably arranged in relatively low planes closely adjacent the top of said base frame and confined to horizontal swinging movement relative to the base frame, said arm overlying said base frame and at its forward extremity overhanging the forward end of the base frame, vertical depending guides carried at the outer overhanging extremity of said arm and extending downwardly below the top surface of said arm in advance of said base, a cutter support ad justable vertically along said guides, said arm constituting the sole supporting connection between said cutter support and base, a kerf cutter carried by said cutter support, and a motor carried on said base frame at the rear of said arm and in planes below the top surface of said arm and relative to which said arm is swingable for actuating said kerf cutter and for adjusting said kerf cutter support along said guides.

60. In a mining apparatus, a portable base, a horizontally swingable arm pivotally mounted on and overlying said base and at its forward extremity overhanging said base, a cutter frame mounted on the forward overhanging extremity of said arm for rotation relative thereto about an axis parallel with the arm pivot axis, said cutter frame having depending vertical guides, a cutter support mounted on said cutter frame for rotative movement therewith relative to said arm and for vertical adjustment relative to said cutter frame along said guides, a kerf cutter carried by said cutter support, mechanism for swinging said arm while said cutter frame remains stationary as regards rotative movement about its axis relative to said arm, and mechanism for rotating said cutter frame relative to said arm while the latter remains stationary as regards swinging movement about its pivotal axis relative to said base, said mechanisms being operative to swing simultaneously said arm and cutter frame about their respective pivotal axes.

61. In a mining apparatus, a portable base, a horizontally swingable arm pivotally mounted on and overlying said base and at its forward extremity overhanging said base, a cutter frame mounted on the forward overhanging extremity of said arm for rotation relative thereto about an axis parallel with the arm pivot axis, said cutter frame having depending vertical guides, a cutter support mounted on said cutter frame for rotative movement therewith relative to said arm and for vertical adjustment relative to said cutter frame along said guides, a kerf cutter carried by said cutter support and swingable horizontally with said cutter frame and support about the cutter frame axis relative to said arm, mechanism for swinging said arm while said cutter frame remains stationary as regards rotative movement about its axis relative to said arm, and

mechanism for rotating said cutter frame relative to said arm while the latter remains stationary as regards swinging movement about its pivotal axis relative to said base, said mechanisms being operative to swing simultaneously said arm and cutter frame about their respective pivotal axes.

62. In a mining apparatus, a swingable frame, a cutter frame mounted on said frame for rotation relative thereto about a vertical axis and having depending vertical guides extending downwardly from the upper portion of said first frame, a cutter support mounted on said cutter frame for rotation therewith relative to said first frame and adjustable vertically relative to said cutter frame along said guides, a kerf cutter carried by said cutter support, mechanism for rotating said cutter frame relative to said first frame while the latter remains stationary, mechanism for swinging said first mentioned frame about its pivot while said cutter frame remains stationary as regards rotation relative to said swingable frame, said mechanisms being simultaneously operable to effect simultaneous rotation of said cutter frame and swinging of said swingable frame, and mechanism for adjusting said cutter support vertically along said guides and for actuating said kerf cutter.

63. In a mining apparatus, a swingable frame, a cutter frame mounted on said frame for rotation relative thereto about a vertical axis and having depending vertical guides extending downwardly from the upper portion of said first frame, a cutter support mounted on said cutter frame for rotation therewith relative to said first frame and adjustable vertically relative to said cutter frame along said guides, a kerf cutter carried by said cutter support and swingable horizontally with said cutter support and cutter frame relative to said first frame, mechanism for rotating said cutter frame relative to said first frame while the latter remains stationary, mechanism for swinging said first mentioned frame about its pivot while said cutter frame remains stationary as regards rotation relative to said swingable frame, said mechanisms being simultaneously operable to effect simultaneous rotation of said cutter frame and swinging of said swingable frame, and mechanism for adjusting said cutter support vertically along said guides and for actuating said kerf cutter.

64. In a mining apparatus, a portable base,

a horizontally swingable arm pivotally mounted on and overlying said base and at its forward extremity overhanging said base, a cutter frame mounted on the forward overhanging extremity of said arm for rotation relative thereto: about an axis parallel with the arm pivot axis and having depending vertical guides, a cutter support mounted on said cutter frame for vertical adjustment along said guides, a kerf cutter carried by said cutter support and having orbitally movable cutting means, the pivotal axis of said cutter frame lying within the orbit of said cutting means, and a motor on said base and relative to which said arm is swingable for actuating said kerf cutter, for swinging said arm, for rotating said cutter frame and for adjusting said cutter support along said guides.

65. In a mining apparatus, a portable base, a horizontally swingable arm pivotally mounted on and overlying said base and at its forward extremity overhanging said base, a cutter frame mounted on the forward overhanging extremity of said arm for rotation relative thereto about an axis parallel with the arm pivot axis and having depending vertical guides, a cutter support mounted on said cutter frame for vertical adjustment along said guides, a kerf cutter carried by said cutter support and having orbitally movable cutting means, the pivotal axis of said cutter frame lying within the orbit of said cutting means, said kerf cutter swingable horizontally with said cutter support and cutter frame about the axis of the latter relative tosaid arm, and a motor on said base and relative to which said arm is swingable for actuating said kerf cutter, for

and for adjusting said cutter support along its guides.

66. In a mining apparatus, a frame, a cutter frame mounted on said frame for rotation relative thereto about a vertical axis and having depending vertical guides extending downwardly from the upper portion of, said first frame, a cutter support mounted on said cutter frame in planes below the bottom of said first frame for rotation with said cutter frame and adjustable vertically relative to said cutter frame along said guides, and a kerf cutter carried by said cutter support and swingable horizontally with said support and cutter frame relative to said first frame, said kerf cutter having orbitally movable cutting means and the pivotal axis of said outter frame lying within the orbit of said cutting means.

67. In a mining apparatus a wheeled truck frame, kerf cutting mechanism on said truck frame, and motor operated devices between the truck frame and the front truck wheels and separately or simultaneously adjustable to effect tilting of said truck frame about longitudinal and transverse axes to vary the angular cutting position of said kerf cutting mechanism, said adjusting devices for each front truck wheel including a rectilinearly guided, movable element, a connection between said movable element and the truck wheels, and power operated means for moving said element rectilinearly of its guiding means.

68. In a mining apparatus, a portable base, an arm pivotally swingably mounted on and overlying said base and at its forward extremity overhanging said base, a kerf cutter pivotally mounted on the forward overhanging extremity of said arm, motor operated means for independently swinging said arm and kerf cutter about their respective pivots including separate means individual to said arm and kerf cutter and each including a rectilinearly guided, movable element, a connection between said movable element and the element swung thereby and power operated means for moving said element rectilinearly of its guiding means, and a motor on said base and relative to which said arm is swingable for operating said elements.

69. In a mining apparatus, a portable base, an arm pivotally swingably mounted on and overlying said base and at its forward extremity overhanging said base, a kerf cutter pivotally mounted on the forward overhanging extremity of said arm, motor operated means carried by said arm for independently swinging said arm and kerf cutter about their respective pivots and including for said arm and kerf cutter separate adjusting means including for each a rectilinearly guided, movable power swinging device carried by said arm, and a motor on said base relative to which said arm is swingable for operating said power swinging devices.

70. In a mining apparatus, a portable base, an arm pivotally mounted on said base to swing horizontally relative thereto about a vertical axis, a kerf cutter pivotally mounted on the outer extremity of said arm to swing relative thereto about a parallel axis, said kerf cutter being adjustable vertically into different elevated positions with respect to said arm and said arm being tiltable with respect to the horizontal, rectilinearly guided, movable power devices for tilting said arm, rectilinearly guided, movable power devices for swinging said arm and kerf cutter swinging said arm, for rotating said cutter framev about their respective pivots, a rectilinearly movable power device for adjusting said kerf cutter into different elevated positions with respect to said arm, and a motor on said base and relative to which said arm is swingable for operating said power devices.

'71. In a mining apparatus, a frame, a kerf cutter pivotally mounted on said frame, and mechanism for swinging said kerf cutter about its pivot including a screw, a nut threadedly connected to said screw to travel therealong, a link pivotally connecting said nut to said kerf cutter, and motor operated devices for rotating said screw through a wide range of speeds including a driving element coaxial with said screw, a clutch for connecting said driving element in driving relation with said screw, and means actuated by said driving element for automatically intermittently applying and releasing said clutch at varying intervals.

'72. In a mining apparatus, a portable base, an arm pivotally mounted on said base to swing horizontally relative thereto, a kerf cutter pivotally mounted on the outer extremity of said arm, and motor operated means for swinging said arm about its pivot through a wide range of speeds including a friction clutch and means for automatically intermittently applying and releasing said clutch, and means for swinging said kerf cutter about its pivot through a wide range of 7 speeds including a friction clutch and means for automatically intermittently applying and releasing said clutch, said arm and kerf cutter swinging means including driving elements coaxial with said clutches respectively and by which said clutch applying and releasing means are respectively actuated.

73. In a mining apparatus, a portable base of relatively low overall height, a'horizontal kerf cutter, means for swingably supporting said kerf cutter on said base comprising but a single rigid horizontal arm mounted on and disposed in horizontal planes closely adjacent the top of said base in overlying relation with respect to the latter, said rigid arm at its forward extremity overhanging the forward end of said base and swingable horizontally relative to said base about a vertical axis, said horizontal kerf cutter pivotally mounted on the forward overhanging extremity of said rigid arm, a motor on said base at the rear of said arm and relative to which said arm is swingable for independently swinging said arm and kerf cutter about their respective pivots, said motor disposed within the vertical limits of the apparatus below the top surface of said arm, and means driven by said motor for tilting said base with respect to the horizontal to change the plane of swinging movement of said arm.

74. In a mining apparatus, a portable base of relatively low overall height, a horizontal kerf cutter, means for swingably supporting said kerf cutter on said base comprising but a single rigid horizontal arm mounted on and disposed in horizontal planes closely adjacent the top of said base in overlying relation with respect to the latter, said rigid arm at its forward extremity overhanging the front end of said base and swingable horizontally relative to said base about a vertical axis, said kerf cutter being pivotally mounted on the forward overhanging extremity of said arm and adjustable relative to said arm into different elevated positions between the lower surface of said arm and the mine fioor, a motor on said base at the rear of said arm and relative to which said arm is swingable for independently