US2131178A

US2131178A - Mining machine transmission mechanism

Info

Publication number: US2131178A
Application number: US71653A
Authority: US
Inventors: Joseph F Joy; Leon E Simmons
Original assignee: Sullivan Machinery Co
Current assignee: Sullivan Machinery Co
Priority date: 1936-03-30
Filing date: 1936-03-30
Publication date: 1938-09-27
Anticipated expiration: 1955-09-27

Description

Sept. 27, 1938.

J. F. JOY Er AL MINING MACHINE TRANSMISSION MECHANISM Filed March 30, 1936 l0 Sheets-Sheet 1 @mmwf MS w DU QQ Sept. 27, 1938.

Filed March 30, 1936 -J. F. JOY EF AL MINING MACHINE TRANSMISSION MECHANISM 10 Sheets-Sheet 2 Y 129.3. 3 i 424% 4019 J9 35 Z0 Je Z5 I I 4 4' )I Q) A J y i6 i 1I 18 JJ )d g ||l| :u @n D 5 J 31g@ (W l' 35 dlnIH 7 33 Z Q Zi IM im, 1li 'h'" 1^/ 0 zi "l Z5 11 30 N V//l 5 29 X02 4" l 100 150153160157 M WM5 9738 92 59 1 'r I T v I M 155 i ifi H l"165 J J 163 I 16 10 e 119 5l 16 5111 1 if r Z2/venan.- U75 [JbJep/ffg.

- Z y Leon/Eidnmon/S.

Sept. 27, 1938. J. F. JOY ET AL .2,131,178

MINING' MACHINE TRANSMISSION MECHANISM Filed March 30, 1936 l0 Sheets-Sheet 3 131 3- @y KN 1% Awww.

Leon/E. dlzmon'.

sept. 2v, 193s. J. F; JOY ET AL 2,131,178

MINING MACHINE TRANSMISSION MECHANISM Filed Marchiso, 1936 1o sheets-sheet 4 i iii@ 515891! 929 vz/ f www Aw: I' Mum cf'lozjzzecy. I

J. F. JOY vET AL Sept. 27, 1938.

MINING MACHINE TRANSMISSION MECHANISM Filed March 30, 1936 lO` Sheets-Sheet 5 J. F. JOY ET AL MINING MACHINE TRANSMISSION MEGHANISM Sept. 27, 1938.

Filed March 30, 1936 l0 Sheets-Sheet 6 fare @E6/Tag'. leon/Edy' y Sept. 27, 1938.. .1.F. .JOY ET AL 2,131,178

MNING MACHINE TRANSMISSION MECHANISM Filed March 30, 1936 10 Sheets-Sheet 7 [607i- Jim mozza.

Sept. 27, 1938. J.' F. JOY ET A1.

MINING MACHINE TRANSMISSION MEcHANIsM y. no.

www ANN, @N

Filed MaIOh 30, 1936 Sept. 27, 1938. I

J, F. JOY ET AL 10 Shee'cs-Shee'i'l 9 Filed March 50, 1936 y ym m wf W @N I ma@ m M EN J@ Sept. 27, J, F, JOY ET AL MINING MACHINE TRANSMISSION MECHANISM Filed March 30, 1956 l0 Sheets-Sheet l0 @gli Patented Sept. 27, 1938 MINING MACHINE 'TRANSMISSION M ECHANISM Joseph F. Joy and Leon E. Simmons, Claremont,

N. H., assignors to Sullivan Machinery Company, a corporation of Massachusetts A Application March 30, 1936, Serial No. 71,653

9 Claims.

. This invention relates to mining machines, and more particularly, but not exclusively, to improvements in coal mining machines of the exibly fed, room and pillar, floor cutter type.

An object of the present invention is to provide an improved coal vmining machine of the flexibly fed, room and pillar, floor cutter type having improved flexible feeding means whereby the machine may be fed and guided in an improved manner. Another object is to provide an improved flexible feeding means for a coal mining machine wherein relatively rotatable feeding and controlling members respectively cooperating With flexible feeding and controlling elements are employed for feeding and guiding the machine, such means embodying improved transmission means whereby the feeding and controlling members may be driven in an improved manner. A further object is to provide an improved plural speed trans- 20 mission means whereby the feeding and controlling members may be driven at either high or low speeds under frictional control at either speed. A still further object isto provide an improved plural speed transmission means embodying separate high and low speed gear trains individual to the drive for each member whereby the feeding and controlling `members may be independently driven in an improved manner. Still another object is to provide a novel compact arrangement of the feeding and controlling members on the machine and an improved arrangement of the gearing of the transmission means whereby an extremely compact feeding mechanism is ob.- tained. 'Other objects and advantages of the invention will, however, hereinafter more fully appear.`

In the accompanying drawings there are shown for purposes of illustration two forms which the invention may assume in practice.

In these drawings- Fig. 1 is a plan View of a coal mining machine embodying one illustrative form of the improved feeding means.

Fig. 2 is a side elevational View of the mining machine shown in Fig. l.

Fig. 3 is an enlarged view in longitudinal vertical section taken substantially on line 3-3 of Fig. 1.

Fig. 4 is an enlarged View in longitudinal vertical section taken substantially on line 4--4 of Fig. 1.

Fig. 5 is a horizontal sectional View, with parts shown in plan, taken Asubstantially on line 5-5 of Figs. 2 and 4.

Fig. 6 is a cross sectional view taken substantially on line 6 5 of Fig. 4.

Fig. 7 is a detail vertical sectional view taken substantially on line 'l-'I of Fig. 6.

Fig. 8 is a cross sectional view taken substantially on line 8--8 of Fig. 5.

Fig. 9 is a-detail vertical sectional view taken on line 9-9 of Fig. 8. Y

Fig. V10 is an enlarged detail vertical sectional view taken substantially on line IU-Ill of Fig. 1. Fig. 11 is a plan view of a coal miningimachine embodyinga modified form of the invention.

Fig. 12 is a side elevational view of the mining machine shown infFi'g. l1.

Fig. 13 is an enlarged horizontal sectional View, with parts shown in plan, taken substantially online |3-I3 of Figs. 12 and 14.

Fig. 14 is a view in longitudinal vertical section taken substantially on line I4--I4 of Figs. 11 and 13.

Fig. 15 is a detail vertical sectional view taken on line l5,-I5 of Fig. 13.

Fig. 16 is a cross sectional View taken substantially on line Iii- I6 of Figs. 11 and 13.

Fig, 1,7 is a View in longitudinal vertical section taken substantially on line I'I-I'I of Figs. 13 and 16. I n

Fig. 18 isacross sectional view taken substantially on line I8-I8 of Fig. 13.

In both embodiments of the invention the improved feeding mechanism is shown incorporated in a coal mining machine'of the ileXibly fed, room and pillar, floor cutter type, although it will kloe evident that various features of the inventionl may be embodied in coal mining machines of various other types.

In the illustrative embodiment .of the invention shown in Figs. 1 to 10, inclusive, the improved feeding mechanism is shown embodied in a coal miningmachine of the room and pillar lowvein type comprising a low compactmachine frame I having a smooth bottom surface 2 and adapted to rest upon and slide in any direction over the mine floor, the machine frame being composed of a pluralityV of frameY sections united `together' to form a compact .rigid unit including a motor frame section 3, a front cutter frame section 4 and a rear feed frame section 5. The motorr frame section is supported on a bottom skid plate 6 and the motor section arranged intermediate thecutter frame and feed'frame sections, thereby to provide an extremelylow, compact construction. Supported on'and projecting forwardly from the cutter frame section ,Ijis an elon'gated'horizontal plane cutter bar 1 having mounted Onits margin for circulation thereabout an endless cutter. chain 8,the cutter bar supported by a hanger frame 9 formed with a circulariiange I0 rigidly secured, as by bolts Il, to a Kflange I2`integral with the cutter frame. Formed onthe lower surface` of the hanger frame9 is a narrow skid plate or shoe I3 having a smooth bottom surface I4 slidably engageableV with the mine floor. The motor frame section 3 contains a motor` I5, herein preferably of the reversible electric type, having its power shaft I6 horiz'ontally'disposed and extendshaft I9 is journaled at its upper end Within a ball` bearing supported within a detachable cover plate 28 of the cutter frame and atl its Vlower end within a ball bearing seated within the recessed lower face of the bevel gear |8 and supported on a stub shaft 2| fixed at 22 within the cutterframe. Keyed to the shaft I9 above the bevel gear. |8l is a spur gear 23 meshing with a large spur gear 24 journaled for rotation about a vertical axis are ranged in advance of the shaft I9. 'I'he hub 25 of the gear 24 is journaled on ball bearings' supported by a vertical shaft 26.v The shaft v261s journaled at its upper end within a ball bearing supported within the cover plate 2U and near its lower end Within a roller bearing supported within a cylindrical bearing support 21 formed integral with the lower portion of the cutter frame. As illustrated, the cutter bar hanger 9 has a cylindrical bearing support 28 surrounding and supported on the cylindrical bearing support 21. Keyed to the lower end of the shaft 26 is a chain sprocket 29 arranged in a transverse chamber 30 extending across the lower portion of :the cutter frame, and engaging and driving the endless cutter chain 8. Formed on the hub of the gear 24 are clutch teeth 3| connectible by a sliding clutch 32 to clutch teeth 33 formed on a clutch member 34 keyed to the shaft 26. Engaging the slidable clutch member 32 is a shipper yoke 35 mounted on a transverse shaft 36. Fixed to the shaft 36 are levers 31 pivotally connected at 38 to links 39, the latter in turn pivotally connected at 40 to levers 4| fixed to a transverse operating shaft 42. Fixed to the outer end of this operating shaft is a lever 43 engaging a reciprocable operating -rod 44 i extending longitudinally of and guided within the '1* machine frame.

Pivotally mounted at 45 on the side of the feed frame 5 at the rear end of the machine is an operating lever 46 engaging the slidable operating rod 44. It will thus be seen that the cutter chain clutch operating lever is conveniently located at the rear end of the machine frame,and when the clutch 32 is connected to the clutch teeth 3|, the cutter chain may be driven from the motor through the bevelA gearing |'I, |8,.spur gearing 23, 24, shaft 26 and chain sprocket 29.v

Now referring to the improved flexible. feeding means, it willA be noted that arranged in coaxial relation on the opposite sides of the feed frame 5 are feeding and ,controlling

members

50 and 5|, herein in the form of cable winding or. haulage drums respectively having wound thereupon feed-` ing and controlling

cables

52 and 53. The opposite sides of the feed frame Vsection are recessed at 54 and the feeding and controlling drums 50 and 5I are arranged within these-recesses so that the lateral limits of the machine aremaintained extreinelyV compact. As illustrated, the operating lever 46..for the cutter` chain control clutch is located in one of these recesses 54 in advance of the winding drum 5| in the `manner shown in Figs. 1 and 2. Arranged at the rear end of the feed frame are horizontal guide sheaves 55 and 56, while pivotally mounted about axes coincidentl with the guidesheave axes are swinging brackets 51A respectively supporting jhorizcntal guide sheaves 58and 59. Mounted at the advancing side of the machine frame' on the cutter frame section 4 is a front guide sheave 68.

vImproved mounting structure is provided for the guide sheave 60, whereby the latter may be transposably supported at either side of the cutter frame section, herein comprising a hanger 6I pivotally` supported for vertical swinging movement on a horizontal bolt 62 supported within spaced perforated lugs 63, 63 integral with a bracketv 64. 'I'he'opposite sides of the cutter `frame are provided with sets of upper and lower

perforated lugs

65 and 66, and the bracket 64 is provided with spaced perforated lugs 61 adapted to be inserted between the sets of upper and

lower lugs

65, 66 and held in position thereon by means of holding pins 68, 68. It will be evident that when the pins 68, 68 are released, the sheave hanger bracket 64 may be readily detached from one side of` the cutter frame and re-attached'to the'oppcsite side of the cutter frame, as indicated constructively in dot and dash lines in Fig. 1.

It is accordingly evident that the feeding and controlling

cables

52, 53 may be extended in opposite directions from the bottoms of the feeding and controllingdrums 50 and 5| in various directions aboutthe guide sheaves 55, 56, 58, 59 and 68 in the manner Well understood by those skilled in the art.

The improved transmission means between the motor vand the feeding and controlling drums herein comprises a spur pinion 18 formed on the rearward extremity of the motor power shaft I6 and meshing, as shown most clearly in Fig. 6, with spur gears 1| and 12 arranged on parallel horizontal axesv extending longitudinallyk of the machine and spaced equi-distantly from a' central longitudinally extending vertical Vplane Vincluding the motor power shaft axis, the motor pinion driving the spur gears 1I, 12 in the same `rection. YEach of the spur gears 1| and 12- is formed integral with a shaft 13 journaled in ball bearingsl suitably supported within the feed frame (see Fig. 5) and these spur gears are connectible bymultiple disc'clutches 14 toV coaxial shafts 'I5 and 16. Formed on the supporting shaft 'I3 for the spur gear A12 is a spur gear 11 meshing with a large spur gear 18 keyed to a horizontal shaft 19, herein arrangedl parallel with the shaft 16 beneath the latter (see Fig. 7). 'I'he shaft 19`is journaled within ball bearings suitably supported within the feed frame, and formed integrally with the shaft is a spur gear 8|) meshing with a spur gear 8| coaxial with the spur gear 12. Meshing with and driven by the spur gear 8| isan intermediate spur gear 82 meshing with a spur gear 83 arranged coaxially with the spur gear 1 I. :'I'he spur gears 1| and 12 constitute the high speed terminal gears of the high speed gear trains, while the spur gears 8| and 83 constitute the low speed terminal gears of the low speed gear trains. The gears 8| and 83 are connectible by multipledisc clutches -84 to the shafts 'I5 and 16 respectively. The slow speed'terminal `gears 8|, 83 have their hubs journaled on ball bearings supported by the

shafts

15 and 16, while the rear ends of these shafts are journaled in ball bearings supported within the hubs of the fast speed terminal gears 1| and 12 in the manner shown in Fig. 5.

Now referring to the operating means for the

multiple disc clutches

14, 14 and 84, 84 for'the high and low speed terminal gears, it will be noted that supported on each of the

shafts

15, 16 intermediate the inner

clutch elements

85 and 86 of the disc clutches are sleeves 81 having slidably mounted thereon clutch applying

rings

88 and 89. Surrounding these sleeves and arranged intermediate'the clutch applying rings is a ball thrust bearing 98 having engaging its outer race a clutch shifter ring 9|. Engaging these clutch shifter rings are

clutch shippers

92 and 93 respectively pivotally mounted at 94 within the feed frame and each having a projection 95 extending within slots 98 arranged in

parallel operating rods

91 and 98 respectively. Pivotally mounted at 99 on the top surface. of the feed frame are levers and I0| having' arms |02 projecting within slots formed in the

rods

91 and 98, respectively. It will thus be seen that Vwhen the levers |00, 0| are swung about their pivots the operating

rods

91 and 98 are moved axially to swing the shipper yokes 92, 93 about their'pivots, thereby to move the clutch shipper rings 9| axially relative to the sleeves 81 surrounding the shafts to move either the clutch applying ring 88 or.89 into a position to apply either the high speed clutch 14 or the low speed clutch 84. In Fig. 1 the lever |00 is shown in low speed clutch applying position. Pivotally mounted on horizontal pivot pins |03 supported in upstanding lugs |04 formed on the upper surface of the feed frame are brackets having projecting arms carrying adjusting screws |06 engageable with prof jecting arms |01 formed on the levers |00 and 0 When the lever |00 is in its low speed clutch applying position as shown in Fig. l, the bracket |05 may be swung about its pivot pin to bring the adjusting screw |06 into engagement with the projecting arm |01, thereby tol lock the lever |00 in such position. By adjusting the screw |06 any desired clutch loading pressure may be attained. When the levers |90, |0| are swung into their high speed clutch loading position, the brackets |05 are swung up out of the way.

Again referring to the improved transmission means, it will be noted that xed to the parallel

longitudinal shafts

15 and 16 are worms H0 and respectively, these worms having teeth of the same pitch but of opposite inclination and meshing with the teeth of worm wheels H2 and H3 at the tops of the latter. Since the worms H0, I rotate in the same direction, the worm wheels H2, H3, due to the opposite inclination of the worm teeth, are driven in relatively opposite directions. As shown most clearly in Fig. 8, the worm wheels are connectible by multiple disc clutches H4 to coaxial shafts H5 and H6. The hubs H1 and H8 of each worm wheel are journaled within ball bearings supported within the feed frame, and the shafts H5, H6 journaled within bearing sleeves H9 and |20 supported within the worm wheel hubs H1. Fixed to each of the shafts is a spur gear I2| meshing with the teeth of an internal gear |22 formed on the flanges of the cable Winding drums 50 and 5|. As shown in Fig. 8, each of the cable winding drums is journaled on a bearing sleeve |23 supported o-n an eccentric sleeve |24 in turn rotatably mounted on a cylindrical bearing projection |25 formed integral with a bracket |26 attached to the feed frame and forming a part of the latter. A washer |21 secured, as by screws |28, to the cylindrical bearing projection |25 engages the outer surface of the eccentric sleeve |24 to maintain the latter on the bearing projection, and the eccentric sleeve is provided with a flange |29 for retaining the bearing sleeve |23 and the drum in position on the eccentric sleeve.

and since the latter is interlockedat |33 t'o theY cylindrical projection .|25 the eccentric sleeve is at that time rigidly locked by the lever |30 to the cylindrical projection |25. Spring clips |34 engageable with the lever are provi-ded for frictionally maintaining the lever within the slot. When the lever |30 is swung outwardly from the slot the eccentric sleeve may be rotated relative to the cylindrical projection |25 to move the internal gear'l22 out of mesh with the teeth of the spur gear |2| and at that time the cable winding drum may rotate freely on its bearing sleeve |23. The drum may be locked in its freed position by again swinging the lever 30 within the slot in the member |21, thereby to again lock the eccentric sleeve to the cylindrical projection |25. Means is also .provided for braking rotation of the cable winding drums so that when the latter arereleased from their drives, undue spinning of the drums is prevented, and these spinning brakes each comprise a braking plunger |36 frictionally engaging the inner surface |31 of the drum and mounted in a sleeve |38 guided in a horizontal borev |39 formed in the bracket |26. Engaging a flange |40 on the sleeve and encircling the sleeve is a coil spring |4| for constantly urging the sleeve and plunger |36 toward braking position.

Now `referring to the operating means for the disc clutches H4, it will'be observed that slidably mounted on the hubs H8 on each of the worm wheels is a clutch yapplying ring V| 45 engaged by an operating ring |46. Engaging these operating rings are shipper yokes |41 and |48 pivotally mounted on vertical shafts |49 (see Fig. 5). Fixed to the shafts |49 are levers |50 and |5| each having a bifurcated end |52 engaging'the flattened sides of nuts |53 and |54'threadedly engaging operating screws |55 and |56 respectively (see also Fig. 4). The operating screws are journaled within ball bearings supported within the feed frame and are held in proper'spaced relation by a spacing washer |51 fixed to a shaft |58 extending centrally within bores formed axially through the screw shafts. Formed on the screw shafts are gears |60 and |6| with which a spur gearl |62 is selectively engageable. The gear |62 is keyed to a recip-rocable operating shaft |63 guided within bearing bushings |64 supported within the feed-frame. Keyed to the outer end of the shaft |63 is an operating handle |65. It will thus be seen that the shaft |63 may be slid axially to bring the teeth of the gear |62 intoengagement with the teeth of either of the gears |60 and 6|, and upon rotation of the gear |62 one of the adjusting screws is rotated to move its cooperating nut axially relative thereto, thereby to swing oneor the other of the levers |50, |5| and the cooperating shipperyoke about their pivot to apply one or the other of the disc clutches. It isjaccordingly evident that the cable winding drums may be -driven in winding direction at either high or low speeds, one of the cable winding drums rotating inthe directionV ting mechanism are driven .from the rear end of a forwardly located motor arranged vabove the Cil c-utter bar. The mining machine comprises a motor frame section |10, a feed and cutter frame section |1| and a bed frame section |12, the frame sections |18 and |1| being supported on the bed frame section with the motor frame section located at the forward end of the machine. As shown in Fig. 16, the bed frame |12 is in the form of a skidplate |13 having upturned sides |14, |14 secured, as by screws, to longitudinal flanges depending from the bottom surfaces of the frame sections |10, |1|, and this bed frame provides a chamber |15 Yextending longitudinally throughout the length of the machine frame beneath the frame sections |19, |1|. Secured `within the machine frame and projecting within the chamber in the lower bed frame i12 is an elongated horizontal plane cutter bar |16 having mounted on its margin for circulation thereabout anendless cutter chain |11, the cutter barV projecting from the chamber |15 forwardly from the forward end of the machine frame in the manner shown in Figs. 11 and 12.

NowA referring to the improved feeding mechanism for the machine, it will be noted that meshing with the spur gear |8| are spur gears |91 and |98 arranged on parallel axes arranged parallel with and spaced equidistantly from the shaft |82 at the opposite sides of the machine frame. The spur gears |91, |98 are connectible by multiple disc clutches, similar to the'clutches of the form of the invention above described, to shafts |99 and 200 respectively, the shafts arranged coaxially with the spur gears and suitably journaled within the frame section |1|. Rotatable with and driven by the spur gear 98 is a spur gear 20| meshing with a spur gear 202 keyedto a shaft 203 herein arranged parallel with and above the shaft 200 and likewise suitably -journaled within the frame section |1|. Fixed to the shaft 203 is a spur gear 204 meshing with a spur gear 205 herein arranged coaxially with the spur gear |98. The gear4 205 meshes with a spur gear 206 herein arranged coaxially with the spur gear |8| and, as shown in Fig. 14, journaled on ball bearings sup-ported by the shaft |82. The gear 206 meshes with a spur gear 291 arranged coaxially with the spur gear |91. The spur gears 91, |98 constitute the high speed terminal Y driving elements of the high speed transmissions, while the spur gears 205, 201 constitute the low speed driving elements of the low speed transmissions, and the gears 205 and 291 are connectible by multiple disc clutches similar to those disclosed in the form of the invention above described, to the coaxial shafts 200 and |99 respectively. Fixed to the shafts |99 and 200 are worms 288 similar to the Aworms and of the form of the invention above described, herein meshing with the bottoms of and driving in relatively opposite

directions worm wheels

209 and 2|0respectively (see Fig. 13). These worm wheels are connectible by multiple disc clutches 2|| and 2|2 respectively to coaxial shafts 2|3 and 2|4 herein arranged with their axes horizontally disposed and extending transversely of the machine. Fixed to these shafts are spur pinions 2|5 engaging the internal gears on'the Vdrums likewise in the manner above described and as is clearly disclosed in Fig. 8. The operating means for the high and low speed disc clutches are the same as those disclosed in Fig. 6, while the operating means for the disc clutches 2H and V2|2 each comprise a shipper yoke 2id engaging a clutch applying ring 2|1 slidably guided on and surrounding the hub 2|8 of the worm wheel. The shipper yoke has a lever 2|9 having a bifurcated end 220A'engaging a nut 22| inturn threadedly engaging an adjusting screw 222. 'I'his adjusting screw is suitably journaled within the rear wall of the frame section |1| and has an operating handle 223. Otherwise this form of the invention is generally similar to the embodiment disclosed in Figs. 1 to 10, inclusive.

The general mode of operation of both forms of the improved mining machine will be clearly apparent from the description given. The feeding and controlling cables areV extended from the feeding and controlling drums around certain of the guide sheaves and are connected at their free ends to suitable anchorjacks located at the rib and face, and as the cables are wound in by the drums, the cutter bar is sumped beneath the coal, the controlling drum guiding the machine during the sumping operation. Upon completion of the vsumping cut, the feed cable is detached from the anchor jack at the face and extended from the front guide sheave laterally from the advancing side of the machine to an anchor jack located at the left hand rib. The machine is then fed by the feed drum transversely across the coal face, while the controlling drum controls the angular position of the machine with respect to the face. During the transverse cutting operation the controlling cable guides the machine, it being understood that at that time the controlling drum`is disconnected from its drive and merely pays out the cable as the ma chine is fed laterally under the control of its friction clutch, the latter at that timev acting as a brake against the then stationary worm wheel or so-called dead gear. The controlling drum may, of course, be connected to its drive to wind in the cable if it is desired to swing the machine to vary the angular position of the cutter bar with respect to the coal face, for instance, when it is necessary to cut around obstructions encountered by the cutter bar. Upon completion of the transverse cutting operation the machine is angled, and by suitable rearrangement of the anchor jacks and cables the machine is moved rearwardly to withdraw the cutter bar from beneath the coal. The machine may be fed rapidly over the mine floor by winding in the cables at a relatively high machine-moving speed, and in both embodiments of the invention-the machine may be mounted on a transport truck during transport of the machine from one working place to another, and the truck wheels of the truck may be driven from the mining machine motor through the truck driving means on the machine. The machine may be operated to cut from left to right simply by reversing the cutter bits in the cutter chain, rearranging the feed cables on the drums and reversing the motor. Other uses and advantages of the improved mining machine will be clearly apparent to those skilled in the art.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be further modified and embodied in'various other forms without departing from its spirit or the scope of the appended claims.

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

ll. In a mining machine transmission mechamsm, in combination, relatively rotatable members to be driven, and motor driven means for lndependently rotating said members at either high or low speeds including a separate vplural speed transmission mechanism for each member through which it, but not the other member, is driven, each transmission mechanism including high` and low speed terminal gears arranged in coaxial relation, a horizontal shaft extending longitudinally of the machine, clutches for selectively connecting said terminal gears in driving relation with said shaft, said shaft extending rearwardly relative to said high and low speed gears, and self-locking worm gearing including a worm xed to the rearwardly extended portion of said shaft and a worm wheel meshing with said worm, and friction clutches for connecting said worm wheels in driving relation with said members respectively, said friction clutch for one member operative to act as a friction drag brake for variably controlling rotation of said member while the clutches of its transmission mechanism are released and while said other member is being rotated through a terminal gear of its transmission mechanism without releasing the gear-connecting clutch of the latter, said drag brake acting to brake rotation of said member whose' rotation is controlled thereby and said worm gearing associated with said member acting as a stationary reaction means for said drag brake.

2. In a mining machine transmission mechanism, in combination, relatively rotatable members to be driven, and motor driven means for independently rotating said members at either high or low speeds including a separate plural speed transmission mechanism for each member through which it, butnot the other member, is driven, each transmission mechanism including high and low speed terminal gears arranged in coaxial relation, a horizontal shaft extending longitudinally of the machine, clutches for selectively connecting saidterminal gears in driving relation with said shaft, said shaft extending rearwardly relative to said high and low speed gears, and self-locking worm gearing including a worm fixed to the rearwardly extended portion of said shaft and a worm wheel meshing with said worm and arranged on a horizontal axis, and friction clutches for connecting said worm wheels in driving relation with said members respectively, said friction clutch for one member operative to act as a friction drag brake for variably controlling rotation of said member while the' cutches of its transmission mechanism are released and while said other member is being rotated through a terminal gear of its transmission mechanism without releasing the gear-connecting clutch of the latter, said drag brake acting to brake rotation of said member whose rotation is controlled thereby and saidworm gearing associated with said member acting asa stationary reaction means for said drag brake.

3. In a mining machine transmission mechanism, in combination, relatively rotatable members to be driven, and motor driven means for independently rotating said members at either high or low speeds including a separate plural speed transmission mechanism for each member through which it, but not the other member, is driven, each transmission mechanism including high and low speed terminal gears arranged in coaxial relation, a horizontal shaft extending longitudinally of the machine, clutches for selectively connecting said terminal gears in driving relation with said shaft, saidfshaft extending rearwardly relative to said high and low speed gears, and self-locking worm gearing including a worm xed to the rearwardly extended portion of said shaft and a worm wheel meshing with said Worm and arranged on a horizontal axis extending transversely of the machine, and friction clutches for connecting said worm wheels in driving relation with said members respectively, said friction clutch for one member operative to act as a friction' drag brake for variably controlling rotation of said memberv while the clutches of its transmission mechanism are released and while said other member is being rotated through a terminal gear of its transmission mechanism Without releasing the gear-connecting clutch of the latter, said drag brake acting to brake rotation of said member whose rotation is controlled thereby and said worm gearing associated with said member acting as a stationary reaction means for said drag brake.

4. In a mining machine transmission mechanism, in combination, relatively Yrotatable members to be driven, and motor driven means for independently rotating said members at either high or lowr speeds including a separate plural speed transmission mechanismV for each member through which it, but not the other member, is driven,Y each transmission mechanism including high `and low speed terminal gears arranged in coaxial relation, a `horizontal shaftY extending longitudinally of the machine, clutches for selec-V tively connecting saidterminal gears in driving relation with said shaft, said shaft extending rearwardly relative to said high and low speed gears, and self-locking worm gearing including a worm fixed to the' rearwardly extended portion of said shaft and a worm wheel meshing with said worm and arranged on an axis parallel with the axis of the member driven thereby,-and friction 75 Cil clutches for connecting said Worm wheels in driving relation with said Vmembers respectively, said friction clutch for one member operative to act as a friction drag brake for variably controlling rotation of said member while the clutches of its transmission mechanism are released and while said other member is being rotated through a terminal gear of its transmission mechanism Without releasing the gear-connecting clutch of the latter, said drag brake acting to brake rotation of said member whose rotation is controlled thereby and said wormgearing associated with said member acting as a stationary reaction means for said drag brake.

5. In a mining machine transmission mechanism, in combination, relatively rotatable members to be driven, and motor driven means for independently rotating said members at either high or low speeds including a separate plural speed transmission mechanism for each member, each transmission mechanism including high and low speed gear trains and clutches for rendering said gear trains alternately eiectiva and driving connections between said transmission mechanisms and said members respectively each including a self-locking worm gearing, said worm gearings arranged at the same side of said gear trains, and a friction clutch for connecting said worm gearing in driving relation with one of said members, said friction clutch for'v one member operative to act as a friction drag brake for variably controlling rotation of said member while the clutches of its transmission mechanism are released and While said other member is being rotated through a gear train of its transmission mechanism without releasing the gear train controlling clutch, said drag brake acting to brake rotation of said member whose rotation is controlled thereby and said worm gearing associated with said member acting as a stationary reaction means for said dragbrake.

6. In a mining. machine transmission mechanism, in combination, relatively rotatable members to be driven, and operating and controlling means for said members for elfecting rotation of the latter in one direction comprising transmission mechanisms including self-locking Worm gearings individual to each of said members, each transmission mechanism including high and low speed terminal gears arranged in coaxial relation, a horizontal shaft extending longitudinally of the machine, and clutches for selectively connecting said terminal gears in driving relation with said shaft, said shafts extending rearwardly relative to said high and low speed terminal gears and said self-locking worm gearings including worms fixed to the rearwardly extended portions of said shafts respectively, and friction devices for Connecting said members for drive by their respective worm gearings when the latter'are driven through either terminal gears and for brakingly connecting said members to said worm gearings when the latter are not driven and said terminal gear controlling clutches are released, to provide a controlled reverse rotation of said members.

7. In a mining machine transmission mechanism, in combination, relatively rotatable members to be driven, and operating and controlling means for said members for effecting rotation of the latter in one direction including a transmission mechanism for each member through which it, but not the other member, is driven, one transmission mechanism including an element driven through the other transmission mechanism, said transmission mechanisms each including high and low speed terminal gears arranged in coaxial relation, a horizontal shaft extending longitudinally of the machine, and clutches for selectively connecting said terminal gears in driving relation with said shaft, said shafts extending rearwardly relative to said high and low speed gears, selflocking worm gearings individual to each of said members including worms fixed to the rearwardly extended portions of said shafts respectively, and friction devices for connecting said members for drive by their respective Worm gearings when the latter are driven by either of said terminal y elements and for brakingly connecting said members to said worm gearings when the latter are not driven and said transmission clutches are released to provide a controlled reverse rotation of said members.

8. In a mining machine transmission mechanism, in combination, relatively rotatable members to be driven, and motor driven means for independently rotating said members at either high or low speeds including a separate plural speed transmission mechanism for each member, each transmission mechanism including high and low speed terminal gears arranged in coaxial relation, a coaxial driven element, and clutches for selectively connecting said terminal gears in driving relation with said driven element to effect drive of the latter, a driving gear meshing with said high speed terminal gears of both transmission mechanisms, a gear coaxial with one transmission mechanism and driven by the high speed terminal gear thereof, gearing driven by said last recited gear and including a gear meshing with the low speed terminal gear of one transmission mechanism, and a gear meshing With the low speed terminal gears of both transmission mechanisms for connecting said low speed terminal gears in driving relation.

9. In a mining machine transmission mechanism, in combination, relatively rotatable members to be driven, and motor driven means for independently rotating said members at either high or low speeds including a separate plural speed transmission mechanism for each member, each transmission mechanism including high and low speed terminal gears arranged in coaxial relation, a coaxial driven element, and clutches for selectively connecting said terminal gears in driving relation with Ysaid driven element to eifect drive of the latter, a driving gear meshing with said high speed terminal gears of both transmission mechanisms, a gear coaxial with one transmission mechanism and driven by the high speed terminal gear thereof, gearing driven by said last recited gear and including a gear meshing with the low speed terminal gear of the transmission mechanism with which vsaid coaxial gear is coaxial, and a gear meshing with the low speed terminal gears of both transmission mechanisms for connecting said low speed terminal gears in driving relation.

JOSEPH F.V JOY. LEON E. SIMMONS.