US1575431A - Coal-mining machine - Google Patents

Description

March 2 1926.

N. D. LEVIN COAL MINING MACHINE Original Filed Sept- 1918 6 Sheets-Sheetl INVENTOR.

:QTNESSES: l/y MZUC ATTORNEY.

March 2 1926.

N. D. LEVIN COAL MINING MACHINE Original fii 11, 1918 6 Sheets-Sheet 2 INVENTOR.

lllllllllll I l 11 L WITNESSES ATTORNEY.

March 2 1926.

N. D. LEVIN COAL MINING MACHINE Original Filed p 1918 6 Sheets-Sheet 4 l l 1 1 I A llhlfyllv MAM" INVENTOR.

ATTORNEY.

WITNESSES N. D. LEVIN 1918 6 Sheets-Sheet 5 MR x O E m m .0 /m M m (M 4 Y H B J a 2 7 March 2 1926,

GOAL MINING MACHINE Original Filed Sept.

WITNESSES: f WW 6 flwg $0M.

March 2 1926.

N. D. LEVIN COAL MINING MACHINE] 6 Sheets-Sheet 6 Original Filed Sept. 11, 1918 INVENTOR.

VWITNESSES: y BY I ATTORNEY.

Patented Filer. 2, i926.

UNITED STATEfi ATENT OFFICE.

Nil-S D. LEVIN, QF CGLUMBUS, OER), AElElIQi-NUR TO THE JEFFREY MANUFACTURING COMPANY, OF COLUMBUS, CHIC CORPORATION OF OHIO.

COAL-MINING MACHINE.

Application filed September 11, 1918, Serial No. 253,632. Renewed July 31, 1925.

To all whom it may concern:

Be it known that I, NILS D. LEVIN, a citizen of the United States, residing at Columbus, in the county of Franklin and 5 State of Ohio, have invented certain new and useful Improvements in Coal-Mining Machines, of which the following is a speci lication, reference being had therein to the accompanying drawing. w

The present invention relates to certain new and useful improvements in coal ininmachines, and particularly to that class of machines whereby coal is dislodged from its native bed, transported rearwardly of the machine and loaded intoconvenicntly placed cars for removal from the mine.

The especial object of this invention is to provide in a machine of the class described, improved devices by which'tragments of al are broken down from the mass of the vein and transported rcarwardly of the machine.

The devices by'which I attain this object are fully set forth in the following; specification reference being had to the accom 'ianying drawings of which Fig.5 1 and 2 constitute a plan view of the gn'clierred embodiment of my invention.

F 33 and 4t constitute a side elevation of the machine illustrated in Figs. 1 and 2.

Fig. 5 is a section along the line 55 of Fig. 3.

liig. 6 is a section along Fig. l.

T i T is a section along the line 1?} 1 and 2.

in. 8 a detail of the sl'ieaves.

l 9 is a section along the line 9-9 of Fig. 2.

.10 is a section along the line 1()-10 of Fig. 2.

11 is a section along the line 11.11 of Fig. 1.

Like numerals refer to similar parts in the several figures. I

Speaking broadly this machine comprises a bottom pan adapted to rest upon and slide in any direction over the floor of the mine and to be anchored in fixed relation to the coal face during the operation of the machine. Upon this bottom pan is mounted a the line 6-6 ot' teed rope guide turn table adapted to rotation ineither di reotion, and constituting the main frame upon whichthe operative parts of the machine are mounted. These operative parts consist of a cutting mechanism adapted to form a kert above, behind and below a section of the coal vein, breaking down and gathering devices by which fragments oi? coal are broken off from the partially severedsection and transferred to the loading devices by which these broken oil fragments are deposited in conveniently placed cars for transportation from the mine, and power devices by which the several elements ol' the machine are actuated.

In the drawings the numeral. 1 indicates as an entirety, the bottom pan which is adapted to rest directly upon the floor of the mine. This pan consists of a rectangular steel plate 2 the edges of which are turned'upward, as indicatedat 3, to facilitate its sliding'in any direction over the floor of the mine. The plate 2 is stillened by longitudinally extending steel bars 4. and by an annular angle bar 5 all of which are electrically welded to the upper surface of the plate. At its forward end the plate 2 is semicircular in form and the annular stillening angle bar 5 is positioned ads jacent to and concentric with this and ot the plate. Concentric with. the annular angle bar 5 is a pivot bearing casting 6 which engages a downwardly projecting pivot post 7 of the main frame casting 8 to prevent its lateral displacement relative to the pan. Attached to the plate 2, in a concentric circle out-side of the stiffening angle bar 5, is a plurality of bearing brackets S) in which are mounted. the antitriction bearing rollers 10. The main frame casting S is supported directly upon these rollers 10 and constitutes a turn table, adapted to rotation in either direction, upon which the operative parts of the machine are mounted.

Attached. to themain frame 8 is an electric motor 12', arranged to actuate the machine, and l have indicated at 13 a control ling mechanism, having an operating handle ll convenient to the hand of the operator, by which the operation of the motor may be controlled. The motor 12 is connected with the controller 13, and also with any convenient source of electric power, by suitable electric conductors which are not shown in the drawings as they form. no part of an c o es in enti n and are e l o:

derstood by persons skilled in the art. For purposes of illustration I have shown an electric motor, but it is to be borne in mind that any type of motor may be employed which is suitable to the conditions under which the machine operates.

Formed on the frame of the motor 12 are journal bearings 15 in which are rotatably mounted the trunnions 16 and 17 of the cradle casting 18 upon which is carried the cutting mechanism and the gathering mechanism of the machine, as will hereinafter appear. Journaled in a bearing formed in the trunnion 17 and in a second bearing 19 supported on a pedestal of the main frame 8, is a transverse power shaft 20 from which the several elements of the machine are ac tuated and which is itself driven from the motor 12 through the spur gear 21 and the armature pinion 22. I

The cutting mechanism comprises a vertically disposed loop shaped cutter frame 23 upon which travels an endless cutter chain 2-; having renewable cutter bits 25 adapted to cut a kerf in the'coal body above, behind, and below sections of the coal vein to entirely sever them from the mass of the vein. The cutter chain 2st is of a type well known in the mining machine art, consisting of alternate strap and block links, and is engaged by a sprocket wheel 26, mounted upon the power shaft 20. Upon the hub of the sprocket wheel 26 are formed clutch teeth 2'? adapted to engage with similar teeth of the clutch member 28 splined to the shaft in a manner common to such clutches.

The cutter frame is formed of a steel bar 31, of rectangular cross section, to the sides of which are attached the plates 32 the projecting edges of which form the guide ways in which the chain 24 travels. The rectangular bar 31 is bent to form a loop and is secured at both ends to the vertical plate 38 which is attached to a flange of the cradle casting 18. In order to facilitate handling the machine in the mine, the vertical width of the cutter frame 23 is made less than the total height of the coal vein which is to be removed, and this cutter frame is adapted to rotary movement about the trunnions 16 and 17 and is so formed that when in its lower position of adjustment the lower side 3% of the loop will be parallel with the general direction of the coal seam at the line of the mine floor, to remove the lower portion of the coal vein, and when in its el vated position the upper side 35 of the loop will be parallel with the general direction of the coal seam at the line of the roof of the mine to remove the upper portion of the vein. When the mining machine is placed adjacent the coal face, and the turn table 8 is rotated in a direction to cause the cutter bits 25 toengage-the coal face, there will be formed a loop shaped kerf extending above, behind and below a section of coal, entirely severing said section from the body of the vein. After the upper portion of the coal has been removed the cutter frame may be rotated upon the trunnions 16 and 17 to its lower position of vertical adjustment, as indicated by the dotted lines in Fig. l, and a second cut made to remove the remainder of the vein. '1 he vertical movement of the cutter bar may be accomplished in any preferred manner. In the drawings 1 have illustrated a hydraulic jack 36 connected to the main frame casting 8 at 37 and to tire cradle cast-ing 18 at 38 A pump 39 actuated by an eccentric 10 attached to the power shaft 20 supplies the pressure to actuatethe jack. As these devices form no part in the present invention further description of them is not thought to be required at this time.

In a great many veins of coal the natural 'cleavagescause the severed blocks to break off into smaller fragments of suitable size to be conveniently transported from the mine, while in other veins the coal has a tendency to hang and special devices must be provided to insure its breaking down. In the present machine I have provided combined breaking and loading mechanism adapted to insure the breaking down of the coal and to receive the fragments as they are broken down and remove them rearwardly of the machine.

The loading mechanism comprises a receiving conveyer having a forward por tion extending parallel with and in the same horizontal plane as the lower side of the cutter frame, in position to receive the coal as itis severed from the body of the vein. and a. rearward portion inclined upwardly to discharge said severed material into a loading convcyer by which it is delivered to cars conveniently placed upon the mine track at the rear of the machine.

The receiving conveyor is of a well known type having an endless chain 41 adapted to travel in the guide ways and 4:3 and having late-rally extending flights lei adapted to engage the coalto move it along a suitable trough 15. The guide ways i). and 43 are formed of longitudinally extending angle bars 16 and ll which are held in spaced relation by suitable cross members to constitute a supporting frame work for the conveyer. At the rearward end of the conveyer the angle bars 46 and a7 are attached to a yokecasting 4-8 in which are formed journal bearings 19 and 50 which support the vertical shaft 51. To the shaft 51 is attached a sprocket wheel which engages the conveyer chain 41 to drive it. Formed on the lateral extension 58 of the yoke casting 18 are journal bearings 54 and 55 which engage the outer surface of the hubs 56 of the bracket castings 57 to form a hinge support upon which the conveyor frame may be rotatably adjusted. Formed in the hubs 58 of the bracket castings 57 are journal hearings in which is mounted a horizontal shaft 58 having a bevel pinion 59 which engages with the bevel gear 60 attached to the vertical shaft 51. An outboard bearing 61 formed on the yoke casting d8 affords additional support to the shaft 58 and insures the proper meshing of the gears. Rotatably mounted upon the shaft 58 is a sprocket wheel 62 which is in alignment with the sprocket wheel upon the power shaft 20. The sprocket wheels 62 and 63 are connected together by a suitable driving chain 64. The sprocket wheel is adapted to be connected with the shaft 58 through a multiple disk'friction clutch 65 arranged to be controlled by the hand wheel 66 which is within convenient reach of the hand of the operator. By the arrangement of parts just described the conveyer may be operatively connected with the motor 12. The bracket castings 57 being secured to the frame of the motor 12 affords support for the conveyor from the main frame casting 8.

To the angle bars 46 of the guide ways 42 is attached a plate 67 which forms the bottom of the conveyor trough 45 and suitably supported side plates 68 confine the material in the trough; To the angles at? of the guide ways 4:3 is attached a plate 69 which affords a slide way for the support of the conveyer flights at of the return strand of the conveyor and longitudinal angle bars 70 are suitably disposed to protect these flights from accidental contact with the person of the operator. At their forward ends the guide ways as and 43 are connected by a horizontal hinge 71 with extension guide ways 72 and 73. At their forward. end these extension guide ways 72 and 73 are attached to a foot casting 74ihaving a semicircular guide surface 7 5 around which the conveyor chain l1 slides. Provision is made for the adjustment of the tension of the conveyor chain all by the longitudinal movement of the foot casting- H relative to the extension guide ways 72 and 73 by means of the adjustin screw 76 in the manner common to CODJGYGI practice. To the extension guide ways 72 and 73 is attached a plate 77 extending laterally and forwardly to afl'or a sliding suppport for the conveyer flights ad. The plate 77 is extended laterally towards the cutter bar 23 and constitutes the apron upon which the coal is received as it is dislodged from the body of the vein. Along the advancing edge of the apron 77 are dow'i'iwardly projecting lugs 78 which engage the flange 79 of the cutter arm to support the apron and mainhis it spans-e mecca with the cutter bar. Along the edge of the apron T7, res mote from the cutter bar, is attached a channel bar 80 which serves to stiffen the apron and to support the protecting plate 51 by which the conveyer flights are guarded from accidental'contact with the person of the operator. Asthe center of vertical rotation of the conveyor is considerably removed from the center of vertical rotation of the cuttter bar there will result, when the parts are vertically adjusted, a variation of role tion between the receiving apron 7 and the lower side 3& of the cutter arm. This variation of relation is provided for by the sliding contact of the lugs 78 upon the flange 79 and by the flexibility of the conveyer frame at the hinge 71.. A bracket 82 extending forwardly from the cradle casting 18 engages the hinge 71 to support the forward part of the conveyer frame and by means of this support the conveyor and the receiving apron are elevated and depressed with the cutter arm by the actuation of the hydraulic jack 86.

In practice it is commonly preferable to remove the upper portion of the vein first and afterwards to lower the cutting mocha nism and remove the remainder of the vein. hen the cutter arm is in its elevated position its lower side Set will be inclined upwardly resulting in the formation of a come cal surface in the lower kerf. I have, therefore, curved the plate 77 upwardly along transverse lines, as indicated in'l ig. 10, so that it shall conform approximately to this conical surface of the coal thereby avoiding the cramping of the parts and the undesirable friction of the conveyor structure upon the coal.

During the operation of the machine, the cutter arm 28 is rotated about the center 7 of the turn table the cutter bits 30 form a kerf in the coal body above, behind and below a crescent shaped section of coal to completely severit from the body of the vein. At the thinner parts of this section, near the crevices of the coal cause it to break down IOU ends ol the crescent, the natural cleavage in fragments of convenient size to be removed by the conveyor. At its middle however, this section is of such thickness that the natural cleavages cannot be depended upon to break down the coal and I have provided auiitiliary devices associated with the loading conveyor to insure the breaking down of the coal thereby guarding against the partly severed section overhanging to such an ex tent that its rearward end will abut against the frame work of the conveyer producing undesirable strains both in i the conveyor struct-ure and in the feeding mechanism. Formed upon the conveyer r'lin hts 4e are up wardly projecting sockets 83 in which are mounted cutter bits 84; similar to those used --en the cutter chain thecenveyer fli hts 1% travel, around the foot casting 74: these upon the mine tracks in the rear of the machine. At its forward end the conveyer is attached to and supported by a steel plate 88 having a hub casting 89 secured to its center. Through the hub casting 89 extends a pivot pin about which the conveyer is re tatable. The pivot pin 90 has a broad head 91 which engages the upper surface of the hub casting 89 and at its lower end it is provided with a suitable nut 92 to resist. the upward thrust upon the pin. 7 Upon the ease extension 85 is mounted a plurality of rollers 98 upon which the plate 88 hears as a fulcrum to support the overhanging weight of the conveyer. The conveyer 80 is provided with an auxiliary motor 9% by which it is actuated independently of the motor 12. The conveyer 86 comprises .a trough 95 along which the material is propelled by a plurality of cross bars 96 extending between two parallel endless chains 97 which areadapted to travel in guide ways at the sides of the conveyor trough in a man ner well known in conveyer practice, but as the details of this conveyor form no part of the present invention further description is not thought to be required at this time.

The feeding mechanism, by which the main frame casting 8 is rotated to cause the .cutter bits 25 to engage the coal, consists of a winding drum 98 upon which is windable a. feed rope 99 having a suitable terminal 100 adapted to engage with an abutment 101 attached to the bottom pan 1. Sheaves 102, 103 and 10% are provided to guide the rope A sheave 1105 is mounted in a castor support 106 having trunnions 107 jour. naled in bearings of the main frame in such manner that the rope 99 may be led off from the druni in any desired direction. As shown in Fig. (5 the winding drur mounted upon a vertical shaft 108 journaled in a suitable bearing 109 of the main frame casting. Contained within the body of the drum 98 is a multiple disl: friction clutch 110 of well known construction adapted to be cont-rolled by the hand wheel 111 to connect said drum with the vertical shaft 108. Attached to the lower end of the vertical shaft 108 is a worm gear wheel 112 in en gagement with the worm 113. The worm 113 is mounted upon a transverse shaft 114 j rnals; in suitable b ri gs 11. and 1.1

as shown in Fig. 5. Fixed to the shaft 11 is a ratchet wheel 117 engaged by a pawl 118 carried by the ratchet lever 119 which is oscillatable about the shaft 11%. The spring 118 insures the engagement of the pawl 118 with the rachet whcelll'? in the manner well understood by those well skilled in the art. The rachet lever 119 is connected by an eccentric rod 120 v with the eccentric 121 attached to the power shaft 20. By the rotation of the eccentric 121 the rachet lever 119 is caused to oscillate, thereby rotating the rachet wheel 117 with a step by step movement, and, through the worm gears 112 and 113, to drive the winding drum 98. A second pawl 122 supported upon the gear case housing 123, engages the rachet wheel, to prevent the rotation of the shaft 114 in a dircctionto unwind the rope. metallic shield 12d adapted to engage the pawl 1181s supported concentrically with the rachet wheel by an arm 125 pivotally mounted upon the shaft 114; at either side of the rachet wheel 117. On the arm 125 is formed an extension arm 126 connected by a link 127 with the bell crank 128 attached to the shaft 129 journaled in suitable bearings of the main frame of the machine. The shaft 129 is provided with controlling handles 130, withinconvenient reach of the hands of the operator, by:tl1e manipulation of which the shield 1241 may be moved rota tively of the rachet wheel to engage the pawl 118 during a greater or less portion of its oscillation, thereby controlling the rateot rotationof the rachet wheel 117 and the consequent rate of winding of the feed rope 98. Attached to the-base plate 1 are hinges 131 to which are secured laterally extending arms formed of the angle bars 132 which are adapted to be engaged by suitable anchor jacks to prevent movement of the base plate 1 during the operation of the machine, but as these devices form no part in the present invention further description of them. is not thought to be required at this time.

hen mining by the room and pillar system, at the beginning of each cycle of operation, the machine is placed at a suitable distance from the working face with the cutter arm extending to the right hand side at right angles to the longitudinal lines of the machine. T he cutter arm is then elevated to theline of the roof, the feed rope 99 passed around the guide sheaves 1.02.

103 and 10st from rightto left and attached to the abutment 101 of the bottom pan. After starting the cutting mechanism the feeding devices are actuated to wind the rope causing the turn table to rotate in. the anti clockwise direction. The cutter bits 25 will then engage the coal to form a hertabove, behind and below a section of the vein to sever a crescent shaped section from the body f; th we As the i Mm A curved advances fragments of coal will drop by their own weight upon the apron 77 and be gathered by the conveyor fiightskt't to be moved rearwardly of the machine. If owing either to the thickness of the section or the hardness of the coal such fragments should fail to drop by their own weight the cutter bits 8 attached to the conveyor flights is will engage the partly severed coal section, pry off fragments therefrom and insure breaking up of the coal into fragments of suitable size for loading. After the upper section has been completely removed the cutter arm will be returned to the right hand side of the machine, lowered to the line of the floor and the operation as above described repeated.

l l hat I claim is p 1. In a machine of the class described, the combination of a forwardly extending upwardly inclined cutting mechanism adapted to rotation about a vertical axis to form a' kerf in the mine wall, conveying mechanism adapted to follow said cutting mechanism to remove material dislodged from said mine wall said conveying, mechanism including a pan curved along trans verse lines to conform approximately. to the conical surfaces generated by the rotation of said inclined; cutting mechanism.

2. In a machine of the class described, the combination of a base frame adapted to rotation about a vertical axis, forwardly ex tending upwardly inclined cutting mechanism mounted upon said base frame and rotatable therevith to form. a kerf injthe mine wall, conveying mechanism mounted upon said base frame and adapted to follow said cutting mechanism to remove material dislodged from said mine wall said coir veying mechanism including a pan curved along transverse lines to conform approxi mately to the conical surfaces generatedby the rotation of said inclined cutting mechanism.

3. In a machine of the class described, the combination of aforwardly extending upwardly inclined cutting mechanism adapted to rotation about a vertical axis to form a kerf in the mine wall, conveying mechanism adapted to enter said kerf to receive and remove material dislodged from said mine wall said conveyer including a pan curved along transverse lines to conform approximately to the conical surfaces generated by the rotation of said inclined cutting mechanism;

lnia machine of the class described, the combination of a base frame adapted to rotation about a vertical axis, forwardly extending upwardly inclined cutting mechanism mounted upon said'base frame and rotatable therewith to form a kerf .in the mine wall, conveying mechanism mounted upon said base humane adapted to enter saidkerf to receive and remove material dislodged from said mine wall, said conveye'r including a pan curved along trans- \y'erse'f lines to conform approximately to the conicalsurfaces generated by the rotation of said inclined cutting mechanism.

In a machine of the class described, the combination of a base frame adapted to rotation about a vertical axis, forwardly extending upwardly inclined cutting mechanism mounted upon said base frame and rotatable therewith to form a kerf inthe mine. wall, conveying mechanism mounted upon said base frame and adapted to fol low said cutting mechanism to remove material dislodged from said mine wall said conveying mechanism comprising an endless chain, flights extending laterally from said chain, and a trough along which said flights are adapted to travel to conveytheldisiodged material, said trough being curved alongt'ransverse lines to conform. approximately to the conical surfaces generated by anis'ml V a o 6. Ina machine of the classdescribed, the combinationof a base frameadapted to rotationabout a vertical axis, forwardly extending upwardly inclined cutting mecha nism mounted upon said base frame and rotatable therewith j to form a kerf a" mine wall, conveying mechanism mounted upon said base frame andadapte d to enter said keiif'to receive andremove material dislodgedfrom said mine wall said conveying mechanismcomprising an endless chain, flights extending laterally from saidchain, and a trough along which said flights are adaptezil to travel tolcon'vey dislodged mate 'ifal, ,sali-cl trough being came; along transverse lin'e to conform approximately to the conical surfaces generated by the r0 tation of said inclined cutting mechanism. V o o '7. Ina machine of the class described, the combination of a forwardly extending cutting mechanism adapted to rotation about a vertical axis to form akerf in a mine wall, conveyingmechanismadaptedto follow said cutting mechanismtoremo'vc material dislodged from said mine wall, and devices actuated by said conveying mechzinism to dislodge said material. I o 7 o r 8. In a machine of the class described, the combination of a base frame adapted to rotation about a vertical axis, forwardly extending cuttii'ig mechanism mounted upon said base frame and rotatable therewitlrto form akerf in the mine wall, conveying the rotation of said inclined cut-ting mechmechanism mounted upon said base frame and adapted to follow said cutting meclr anism to removematerial dislodged from saidmine wall, and devices actuated by said 9. In a machine of the class described, the combination with a base frame adapted to rotation about a vertical axis, forwardly extending cutting mechanism mounted up, on said base frame and rotatable therewith to form a kerf in a mine wall, conveying mechanism mounted upon said base frame and adapted to follow said cutting mechanism to remove material dislodged from said mine wall, said conveying mechanism comprisingan endless chain, flights extending laterally from said chain, a trough along which said fiights are adapted to travel to convey the dislodged material, and devices attached to said flights to engage and dislodge the material above said flights.

10. In a machine of the class described, the combination of a forwardly extending cutting mechanism adapted to rotation about a vertical axis to form kerfs above, behind and below a section of the mine wall, conveying mechanism adapted to follow said cutting mechanism to remove dislodged material, and devices actuated by said conveying mechanism adapted to engage the par tially severed section to dislodge'fragments therefrom.

11. In a machine of the class described, ;he combination of cutting mechanism adapted to movement relative to a mine wall to form kerfs above, behind and below a section thereof, conveying mechanism adapted to follow said cutting mechanism to remove dislodged material, and devices actuated by said conveying mechanism adapted to engage the partially severed section and dislodge fragments thereof.

12. In a machine of the class described, the combination with cutting mechanism adapted to form a kerf in the mine wall, of a conveyor adapted to follow in the path of said cutting mechanism, a system of coal engaging devices movable with said conveyor into proximity with the coal above said kerf, and means to actuate said devices to cause them to engage the coal and dislodge it onto said conveyor.

13. In a machine of the class described, the combination with cutting mechanism adapted to form a kerf in a mine wall, of a conveyor adapted to follow in the path. of said cutting mechanism, a system of teeth movable with said conveyor into proximity with the coal above said kerf, and means to impart movement to said teeth to cause them to engagethe coal above said kerf to dislodge it onto said conveyor.

, 1a. In a machine of the class described, the combination with cutting mechanism adapted to forma kerf in a mine wall, of a conveyor, adapted to follow in the path of said cutting mechanism, a system of teeth movable with said conveyor into proximity with the coal above said kerf, and means actuated by said conveyor to impart movement to said teeth to cause them to engage the coal above said kerf and dislodge it onto said conveyor.

15. In a machine of the class described, the combination with a conveyor comprising a chain and coal transporting devices attached to the said chain, of a system of spurs -movable with said conveyor into proximity with a body of coal above a previously formed kerf, and means actuated by said conveyor chain to impart movement to said spurs and cause them to engage the coal above said kerf and dislodge it onto said conveyor.

16. In a machine of the class described, the combination with a conveyor comprising a chain and coal transporting devices attached to said chain, of a system of coal engaging devices comprising sockets and cutter bit-s romovably secured in said sockets movable with said conveyor into proximity with the coal above a previously formed kerf, and means actuated by said conveyor chain to impart movement to said coal engaging devices to cause said cutter bits to engage the coal above said kerf and dislodge it onto said conveyor.

17. In a machine of the class described, the combination with an elongated conveyor having a receiving portion adjacent the mine floor, a system of coal engaging de vices movable with said conveyor into proximity with a body of coal above a previously formed kerf, and means actuated by said conveyor to impart motion to said coal engaging devices to cause them to engage the coal above said kerf and dislodge it onto said conveyor.

18. In a machine of the class described, the combination with an elongated conveyor having a receiving portion adjacent the mine floor, of a system of teeth movable with said conveyor into proximity with a body of coal above a previously formed kerf, and means to impart a cutting movement to said teeeth to cause them to engage the coal above said kerf and dislodge it'onto said conveyor.

19. In a machine of the class described, the combination with cutting mechanism adapted to form a kerf in the mine wall, a conveyor having laterally extending flights adapted to enter said kerf to receive and remove material as it is dislodged from the I it. is dislodged from the mine wall, and

spurs attached to said flights adapted to engage the material above said kerl to dislodge fragments therefrom.

21. In a machine of the class described, the combination With cutting mechanism adapted to f rm kerfs above, behind and below a section of the mine Wall, devices adapted to enter the lower kerf to receive and remove material dislodged from said mine Wall, and devices attached to said re- I moving devices adapted to engage the partly 22. In a machine of the class described, the combination with cutting mechanism adapted to form kerfs above, behind and below a section of the mine Wall, a conveyor having laterally extending flights adapted to enter the lower keri to receive and remove material as it is dislodged from the mine Wall, and spurs attached to said flights adapted to engage the partly severed section and dislodge fragments therefrom.

In testimony whereof I ailix my signature.

NILS D. LEVIN.

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