US1290595A - Mining-machine. - Google Patents

Description

N. D. LEVIN.

mums MACHINE APPLICATION FILED OCT. 22.1912- RENEWED MAR. 2611911.

Patented Jan. 7,1919. 4 SHEETSSHEETI N. n. LEVIN. MINING MACHINE.

APPLICATION FILED OCT. 22, I9l2- RENEWED MAR- 26. I917.

1,290,595 Patented Jan. 7, 1919.

4 SHEETS-SHEET 2.

N. D. LEVIN.

MINING MACHINE.

APPL|CATION FILED OCT. 22, 1912. RENEWED MAR. 26,1911.

1,290,595. Patented Jan. 7,1919.

4 SHEETSSHEET 3.

fl i I N. D. LEVIN.

MINING MACHINE APPLICATION mm on. 22, I912- RENEWED MAR. 26. m1.

Patented Jan. 7,1919.

4 SHEETSSHEEI 4- vwemtoz l I 1 II h l lsl l lal LV M- m.

witmwoeo UNITED STATES PATENT OFFICE.

NILS DAVID LEVIN, OF COLUMBUS, OHIO, ASSIGNOR TO THE JEFFREY MANUFACTURING COMPANY, OF COLUMBUS, OHIO, A CORPORATION OF OHIO.

MINING-MACHINE.

Specification of Letters Patent.

Application filed October 22, 1912, Serial No. 727,230. Renewed March 26, 1917. Serial. No. 157,586.

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 State of Ohio, have invented certain new and useful Improvements in Mining-Machines, of WhlCh the following is a specification, reference being had therein to the accompanying drawlhis invention relates especially to mining machines of the front thrust or breast type and in trucks for use in combination with such machines for transporting them.

The principal object of the invention is to provide an improved arrangement of gearing and power transmitting mechanlsm for driving cutters, for feeding the cutter frame forward and backward on the bed frame, and

for driving the truck upon which the ma chine'may be placed for transportation.

In the accompanying drawings I have shown one embodiment of my invention, but it will be understood that many modifications and changes may be made without departing from the spirit of my invention as set' forth in the claims which arehereto appended. I

In the drawings,

Figure 1 is a plan view of a mining machine embodying my invention.

Fig. 2 is a side elevation.

Fig. 3 is a longitudinal sectional view of a part of the machine taken along the line 3-3 of Fig.1.

Fig. 4 is a' fragmentary view partly in section and partly in elevation ofthe riving gearing.

Fig. 5 is a detail view taken looklng upward at the clutch element at the lower end of the drive shaft. I

Fig. 6 is a detail view taken looking upward at the drive sprocket for'the cutter, chain.

Fig. 7 is a side elevation showing the mining machine in place on the truck.

Fig. 8 is a fragmentary plan view showing an automatic reversing mechanism. In this view the starting box 1s omitted for the sake of clearness.

Fig. 9 is a side elevation of the mechanism shown in Fig. 8.

Fig. 10 is a fragmentary view in section on the broken line 10-1O of Fig. 11.

Fig. 11 is a vertical section on the broken line 11 11 Fig. 10.

Referring to the drawings, 1 represents as a whole the main bed frame of the machine which may be of any usual or preferred con struction. For present purposes it will be sufficient to point out that it com )rises'floor engaging shoes 2, 2 and longitudlna-l guides or rails 3, 3, supported on the'shoes. These rails are connected at their ends bylmearis of cross embers 4 and 5.

6 is carriage slidably mounted .upon the rails, 33, 3. This carriage 6 comprises the frame of'a motor 7 and a plate or casting 8 secured to the motor frame. Secured to or formed on the frame of the motor and the casting 8 are laterally projecting lugs 9, 9, which engage the rails 3, 3, and support the carnage.

10 represents as a Whole the cutter frame. This frame is triangular in outline and comprises the forward head 11 and the side rails 12, 12. There is also a central guide bar 12 which is secured at its forward end to the central part of the head 11 and comprises channel bars 12", 12 placed face to face. The cutter frame is slidably supported at the forward end of the bed frame by means'of a suitable bearing formed in a standard 2". which is secured to the cross bar 5 and carries at its lower 'end the shoe 2?. At the rear end of the cutter frame the bar 12 and the rails 12, 12, are secured to a block 13 which is slotted to receive bolts 13, 13, extending through holes in the casting 8 (see Figs. 3,

. 10 and 11). By means ofa screw 13 threaded in the block 13 and engaging the casting 8, the cutter frame may be adjusted with respect to the carriage. After the adjustment the frame can be locked in adjusted position by means of the bolts 13?, 13. The head 11 and the rails 12, 12, are provided with slots or guides in which the cutter chain 14 can.

move. At the ends of the head 11 are sprocket wheels 15, 15, over which the cutter meshes with a large drive gear 19 which is keyed to a vertical drive shaft 20 in a manner to permit the shaft to move vertically. Acasing 21 incloses the gears, this casing being supported at its rear end on the motor frame and at its forward end on vertical pins or studs 21*.

I will be described below. Preferably. this drive element is a hollow shaft or rotatable sleeve having a central aperture througl. which the shaft 20 extends. The hub 25 of the gear wheel 19 is journaled in the central aperture ofthe sleeve by means of the bearing bushing 26, and the lower parts of the shaft are journaled in this aperture by means of the bearing bushings 27, 27. Formed on the sleeve 24 at the upper end thereof is ahorizontal flange or disk 28. At the outer edge of this disk 28 there is provided a spur gear 29 which is preferably formed as a separate ring secured to the disk.

Positioned below the disk 28 and secured to the frame of the motor 7 is a supporting plate or bracket 30. This plate 30 is provided with a central aperture in which by means of a bearing bushing 31 there is journaled a hub 32 which is a part of the sleeve 24. By means of this bearing at 31 the upper end of the shaft and the associated parts .are supported.

Secured to the plate 30 and positioned directly beneath the gear ring 29 is a gear ring 32. The rings 29 and 32 are of the same size but are provided with different numbers of teeth. For example, it may be considered that the ring 29 has ninety. teeth and the ring 32 ninety-one teeth; 33 is a bearing pin secured at its upper end to the web of the gear 19 and supported at-its lower end by means of a stirrup 34 also secured to the web of the gear. Rotatably mounted upon the pin 33 is a pinion 35 of 'sufiicient width to engage the teeth on the ring 29 and also those on the ring 32. It will be observed that on account of the difference in the numbers of teeth on the gears 29 and 32 the movable gear 29 will, for every revolution of the gear wheel 19, be moved with respect to the fixed gear 32 through a distance equal to that represented by the extra teeth on the fixed gear. If the gears are provided with ninety and ninety-one teeth, respectively, the gear 29 will be moved through the distance represented by one tooth or one-ninetieth of a revolution for each complete re\' olution of the gear 19, and will be moved in the opposite direction.

The sleeve 24 has secured to it near its upper end a hub 36. Keyed to the sleeve 24 near its lower end is a hub 37. A collar 38 threaded on the sleeve engages the lower side of the hub 37 and the integral hub 32 engages tl e upper side of the hub 36. The two hubs are in this way held against being moved away from each pther. The hub 37 is journaled in a bearing aperture of the plate 8 of the carriage by means of a sleeve39. By

means of this hearing at 39 the lower ends of the sleeve 24 and' of the shaft 20 are held in posltion.

' Formed integrally with the hub 36 is an outward projecting circular flange 40 which is provided at its outer edge with a downward projecting annular collar 41. Surrounding this collar 41 is a winding drum 42. Extending from the lower edge of the drumv 42 is an inward projecting plate or web 43, the inner edge of which rests upon a ball bearing 44. This ball bearing is supported upon the hub 45 of a gear wheel 46. This hub 45 has threadedengagement with the sleeve 24. In the recess formed between the flange 40 and the Web 43 are mounted the disks of a1 friction clutch 47. These disks are connected alternately with the web 43 and the flange 41 in the manner which is Well known. It will be clear that by means of the gear wheel 46 the hub 45 can be t irned and raised or lowered because of its threaded engagement with the sleeve 24. As the hub 45 is raised the web 43 and the drum 42 are raised and the friction disks ef'the clutch 47 are forced into engagement with each other. When the hub 45 is lowered the pressure between the disks of the clutch is relieved.

.hub 36, and the sleeve 24.

48is a second drum of considerably less diameter than the drum 42. This drum 48 is journaled on the sleeve 24 at 49. The drum 48 is positioned directly beneath the hub 45 and a ball bearing 50 is interposed between the hub and the drum. Between the flange 48 on the drum 48 and a flange 51 on the hub 37 before referred to there are located the disks of a friction clutch 52. These disks are alternately connected with the flange of thedrum and with the flange of the hub in the well known manner. When the hub 45 is turned in one direction by means of the gear wheel 46, the disks of the wheel 46 and the same central hub 15 controls the two clutches 17 and 52. When the gear wheel is turned in one direction theclutch 17 is engaged and the clutch 52 is re-:-

leased. When the gear wheel is turned in the other direction the clutch 52 isengaged and the clutch 4:7 is released. The two clutches cannot both be engaged at the same time.

J ournaled on the shaft 20 at the lower end thereof is the sprocket wheel 16 before referred to, over which the cutter chain 11 passes. T his sprocket wheel 16 is provided at its lower edge with clutch teeth 53.. The lower end of the shaft 20'is provided with a clutch element 54 having radially extending teeth adapted to lie between and engage the teeth 53 when the shaft 20 is in its uppermost position. The teeth 51 can be disengaged from the teeth 53 by turning the nut 22 by means of a suitable wrench andthus lowering the -shaft'20. By lowering the shaft further the clutch element 51 can, when the machine is on a suitable truck, be brought into engagement with a clutch element on the truck. A projection on the carriage supports the sprocket. wheel 16 when the shaftis lowered.

56 is a feed rope connected to be wound upon the smaller drum 48. The feed rope extends forward and is connected with the forward end of the main frame. Preferably this connection with the main frame is by means of a rotatable sheave or pulley 57 secured to the cross-piece 5, but it will be understood that if desired the rope may be connected directly with the cross-piece. lVhen a pulley is used the end of the rope is carried around the pulley and backward to a point of attachment at 58 on the carriage.

Connected to the other drum 12 to be wound thereon is a retracting rope 59. This rope is carried from the drum backward to a point of attachment at the rear end of the bed frame. an idlersheave 60 on the carriage and the idler 61 on the bed frame. From the sheave 61 the ropepasses to a hook 62 which is pivoted at 63 to the cross-piece l of the bed frame. A lug or pin 61 supports the hook .62 against movement in one direction and the parts are so arranged that the line of tension from the rope is such as to force the hook against the pin. It will be clear, however, that if the hook is moved to bring the line of tension at the other side of the pivot .63 the, tension will swing the hook into such a position that the rope will be disengaged. The reason for this construction will be referred to later.

For rotating the gear 16 and the hub 15 I provide a pinion 65 which meshes with the gear. This pinion is secured to a shaft 66 .rotatably mounted in suitable bearings on power is Preferably the rope engages to cut a kerf in a coal face, the machine is moved into proper position and secured in place by means of jacks such as those indi-' cated at 68 and 69. By means of the starting box '7 the motor is setin operation and transmitted from the motor through the gearing and the shaft 20 to the sprocket wheel 16 and the cutter chain 11.. The operator by turning the wheel 67 in the proper direction can engage the clutch 52 and connect the drum 18 with the drive sleeve '24. The feed rope 56 will then be slowly wound upon the drum and the carriage and cutter frame will be moved forward, the cutters cutting their way into the coal. During the forward movement of the carriage and cutter frame. the rope 59 will be unwound from the druni-PZ.

When the operator desires to stop the advance of the carriage on the bed he turns the wheel 67 in a counterclockwise direction and correspondingly rotates the-wheel 4,6. and the latter is, by the threads on the hollow shaft or sleeve, caused to move away from the feed drum, and this releases the clutch at 52, thus stopping the forward feed of the carriage and of the cutter frame. In order to cause the carriage receding devices to operate he continues the movement, bodily, of the wheel 4:6,and its hub 45, until the thread causes the parts of the clutch at- 17 to close, whereupon the rope 59 is tendrawn backward, the movement being subject to control by the clutch operating devices 67 and 65.- This backward movement at once releases the wheel 67 from the rack 70 and rotation, of the wheel is again possible. It will be noted that the, two drums 48 and 12 are driven at the same speeds and it will also be noted that on account of the larger diameter of the drum 42 the backward movement will be much faster than the forward movement.

The backward movement of thecarriage and cutter frame may be stopped manually by the operator or by automatic means such as will be described. In order to prevent injury to the machine in case the backward movement is not stopped in the normal man- .ner, I provide the hook 62. which has beeii mal rotation of the wheel. In order that this movement ma be effected automatically, I prefer to provide as shown in Figs. 8 and 9 a rack bar 71 which is slidable longitudinally in bearings 71, 71, on the main frame. At the forward end of the rack bar 71 there is pivotally connected a rack 71". This rack bar 71 is connected with a lever 72 which is pivoted at 73 to the cross piece 4 of the main frame. The lever 72 has a forward extending end 74 adapted to be engaged by the frame of the motor 7 when the carriage ap proaches its rearmost position. As the pivot 73 is near the end 74 of the lever, the engagement of the motor frame with this end 74 causes the other end to be moved forward at a relatively high speed, carrying with it the rack 71. As the rack moves forward it engages the wheel 67 and rotates it in the counterclockwise direction at a speed greater than normal, thus causing a corresponding movement of the gear wheel'46 and the hub 45 ahead of the sleeve 24. This movement of the hub 45 ahead of the sleeve 24 causes it to be lowered, the clutch 47 being thus released. I

The rack 71 is adjustably supported preferably by means of an eccentric 71. By turning this eccentric the operator can release the rack and permit it to be lowered out of engagement with the wheel 67. The wheel 67 is thus freed and can be turned by the operator to again connect the lower clutch 52 for feeding the carriage and cutter frame forward. It will be understood, of course, that before the carriage is again fed forward, the machine will have been moved and secured in a new position.

In addition to the sheave 61 there is .provided on the main frame a sheave 75 over which the rope 59 can be guided when detached from the hook 62. The end of the rope can be attached at a fixed point and by winding the rope on the drum the machine can be moved about the mine room or onto a truck.

As is well understood, the sprocket wheel which drives the cutter chain, in machines of the sort to which my invention relates, necessarily is mounted to rotate on an upright axis. In my improved machine the armature shaft of the motor, the rotary devices by which the carriage is fed forward and re tracted, and the various transmission gears between the motor shaft and the sprocket wheel and the said rotary devices, respectively, are all mounted to rotate about upright axes so that I am able to employ spur gears only and to secure an exceedingly compact arrangement of the parts. Furthermore, by arrangin the motor low down between the side ra1 s of the bed frame and grouping the operating parts in front of the motor, the over-all height of the machine is kept relatively small. It is to be noted also that the attainment both of general compactness and of a small over-all height is facilitated by the arrangement of the driving pinion at the upper end of the motor shaft.

In order that my improved machine may be readily transported from place to place about a mine, I preferably provide in combination with it a truck such as is shown in Fig. 8. As to the details of this truck therev may be variations but the construction which I deem most advantageous is shown in the drawings.

The frame of the truck comprises side rails 78 which are connected by a number of cross bars. The truck frame carries front and rear axles 83, 84 to which are connected pairs of track wheels 85 and 86, respectively. The front wheels 85 are connected, as by chain 86 to the rear axle 84. The wheels 85 are not connected directly to the axle 83 but are mounted on the outer end of crank arms 88. These arms are keyed to the ends of the axle 83. This construction provides in effect an axle bent at its two ends, and the wheels 85 arexthus'mounted eccentrically with respect to the central part of the axle.

It will be observed that this cranked axte construction makes it possible for the for ward end of the truck to be raised and low ered by rotating the axle. When the forward end of the truck is in its lower position the mining machine can be readily moved onto or off from it, and when the forward end of the truck is in its upper position the truck is adapted in be moved along the track. In moving the. machine onto the truck the rope 59 is passed to the rear between the sheaves 61 and 75, and is secured at a suitable point to the rear end of the truck. The operator by engaging the clutch 47 'can cause the cable to be wound and the machine to be moved bodily along the truck. To each of the crank arms 88 is secured an upstanding horn 89 in position to be engaged by a pin or roller 90 on the frame of the mining machine. \Vhen the pins 90 are forced into engagement with the horns 89 by the continued movement of the mining machine, the axle 83 is rotated and the truck is raised to horizontal position.

When the mining machine is in proper position upon the truck the clutch element 54 is in mating -position over a clutch element at the lower end of the main power shaft 20 91 which is mounted on the truck frame for from the mining machine motor to the truck.

At the rear end of. the truck a, vertical shaft 94 is provided. This shaft carries a sprocket wheel in horizontal alinement with the sprocket wheel 92'and overxthese two sprocket wheels there'passes a drive chain 95. The vertical shaft 94: is'connected by suitable gearing (not shown) with a transverse shaft 99.- At one end of the shaft 99 is a sprocket wheel 101 which is in longitudinal alinement with a similar sprocket wheel 102 on the axle 84. A chain 103 passes over these two sprocket wheels and serves to transmit power from the shaft 99,

It will be clear that by means of the devices which have been described,

to the axles.

power can be transmitted from the mining machine motor to the truck Wheels.

. On the rear end of the truck ismounted an electric cable reel v104 but said reel and the mechanism for driving and controlling it need not be described herein.

In the present application I make no claim to the construction of the truck per 86 or to the combinationof the electric cable reel mechanism with the truck, or to the cable reel mechanism per-8e, as these sub jects-matter are claimed, respectively, in my co-pending applications for mining machines and trucks, Serial No. 557 ,432, filed .April'25, 1910, for mining machines and trucks, Serial No. 579,798, filed August 31, 1910, and for cable winding mechanisms, Serial No. 664,037, filed December 5, 1911.

I heretoforereferred to the present machine as being one of the front thrust or breast class; that is to say, a machine having an elongated bed adapted to be made temporarily stationary, and also having a longitudinally reciprocating carriage below the top of the bed together with a cutting a paratus, which is thrust into and drawn directly backward from the kerf under the coal by longitudinal movements of the car riage between the side bars of the bed. Machines of this class should be as narrow as possible under all. circumstances. Consequently, the cubic space required by a large motor has necessitated the extending of the motor upward or forward on longitudinal lines, both of which are objectionable.

, I introduce a large and powerful motor,

utilizing the space at the rear of the other parts and disposing it so that its lower end is in a plane just above the floor from which it extends upward between the side rails of the bed. It is secured to the extreme rear end of the carriage and has its upper end' brought to a low plane, permitting the. height of the machine to be reduced. I shorten the reciprocating structure by placing all of the rotating driving and transmitting parts on a single axis, placing the shaft which supports and carries them directly in front-of the motor.

What I claim is 1. In a breast mining machine of the class described, the combination with the bed, the longitudinally reciprocable carriage on the-bed, and the horizontally arranged chain cutter onthe carriage, of the electric motor movable with the carriageand secured thereto at its extreme rear end, and positioned to extend from a horizontal plane 1 near the floor upward on lines between the slde rails of the bed, and having a vertical \armature shaft, the vertical power transmitting shaft geared directly to the armature shaft and connected: directly to the cutter chain,the carriage moving mechanism and the rotary transmitting devices on said shaft for actuating the carriage moving mechanism. 4

2. In a breast mining machine of the-class described, the combination with the bed, the longitudinally reciprocable carriage on the bed, and the horizontally arranged chain cutter on the carriage, of the electric motor movable with and secured to the carriage at the extreme rear end, and positioned to.

extend from a horizontal plane :near the floor upward on lines between the side rails of the. bed, and having a vertical armature shaft, carriage advancing means, means for receding the carriage, and a. single power transmitting shaft arranged vertically, and

geared directly to the armature'shaft at its upper end, and connected at its lower end directly to the chain cutter, and two rotating elements both on the axis of said shaft, one connected to and actuating the carriageadvancin'gmechanism, and the other connected to and actuating the carriage receding meche v 'anism, and both adapted to be s'eparablyl connected to said shaft.

3. In a mining machine, the combination of a bed frame, a carriage and horizontally arranged cutter-frame longitudinally movable on the bed frame, a cutter chain supported on and guided by the cutter frame,

a. sprocket wheel rotating about a vertical axis and engagin the cutter chain to drive it, a motor on t e carriage with its drive shaft arranged vertically and connected with the sprocket wheel, two rotatable drums mountedon-the carriage for rotation about the same vertical axis, p'ower connections between the motor and the respective drums whereby one or the other can be rotated, a feed rope engaging one drum and connected with the forward end of the bed frame to move the carriage and cutter frame forward as the said drum is rotated, and a retracting rope engaging the other drum and connected with the rear end ofthe bed frame to move the carriage and cutter frame backward as the said drum is rotated.

4. In a mining machine, .the combination of a relatively stationary bed frame, a carriage movable longitudinally of the bed frame, cutting mechanism comprising a cutter chain carried by the carriage and adapted to form a horizontal kerf in the base of the coal vein, a vertically disposed driving element mounted upon the carriage, means to rotate said driving element, a sprocket wheel mounted upon said driving element and engaging the cutter chain to drive it, two winding drums rotatably mounted upon the driving element, clutches arranged to connect the winding drums with the driving element, a flexible draft member windable upon one of said drums and arranged to advance the carriage and cutting mechanism relative to the bed frame when said drum is rotated, and a second flexible draft member connected to the other drum and arranged to retract said carriage and cutting mechanism when said second drum is rotated.

5. In a mining machine, the combination of a relatively stationa bed frame, a carriage movable longitudinally of the bed frame, cutting mechanism comprising a cutter chain carried by the carriage and adapted to form a horizontal kerf in theb'ase of the coal vein, a vertically disposed driving element mounted upon the carriage, means to rotate said driving element, a sprocket wheel mounted upon said driving element and engaging the cutter chain to drive it, two winding drums rotatably mounted upon the driving element, clutches arranged to connect the winding drums with the driving element, controlling devices arranged to cause the engagement of either one of said clutches to drive its respective winding drum, a flexible draft member windable upon one of said drums and arranged to advance the carriage and cutting mechanism relative to the bed frame when said drum is rotated, and a second flexible draft memberconnected to the other drum and arranged to retract said carriage and cutting mechanism when said second drum is rotated.

6. In a mining machine, the combination element mounted upon the carriage, means to rotate said driving element, a sprocket wheel mounted upon said driving element and engaging the cutter chain to drive it, two winding drums rotatably mounted upon the driving element, clutches arranged to connect the winding drums with the driving element, controlling devices arranged to cause the engagement of either one of said clutches to drive its respective winding drum and to prevent simultaneous engagement of the other clutch, a flexible draft member windable upon one of said drums and arranged to advance the carriage and cutting mechanism relative to the bed frame when said drum is rotated, and a second flexible draft member connected to the other drum and arranged to retract said carriage and cutting mechanism when said second drum is rotated.

7. In a mining machine, the combination of a relatively stationary bed frame, a carriage movable longitudinally of said bed frame, cutting mechanism comprising a cutter chain carried by the carriage and adapted to form a horizontal kerf in the base of the coal vein, a vertically disposed driving" element mounted upon the carriage, means to rotate said driving element, a sprocket wheel mounted upon said driving element and'engaging the cutter chain .to drive it, two winding drums rotatably mounted upon the driving element, clutches arranged to connect said drums with the driving element, a controlling wheel screw threaded to the driving element and arranged to cause the engagement of one of said clutches to rotate one of said drums when said controller wheel is rotated in one direction relative to the driving element and to cause the engagement of the other clutch to rotate the other drum when said controller wheel is rotated in the other direction relative to the driving element, a flexible draft memberwindable' upon one of said drums and arranged to advance the carriage and cutting mechanism relative to the bed frame when said drum is rotated, and a second flexible draft member connected to the other drum and arranged to retract said carriage and cutting mechanism when said second drum is rotated.

8. In a mining machine, the combination of a relatively stationary bed frame, a carriage movable longitudinally of said bed frame, a cutting mechanism comprising a 5 cutter chain carried by the carnage and adapted to form a horizontal kerf in the base of the coal vein, a vertically disposed driving element mounted upon the carriage, means to rotate said driving element, a sprocket wheel mounted upon said driving element and engaging the cutter chain todrive it, two winding drums rotatably mounted upon the driving element, clutches positioned between the winding drums and arranged to connect said drums with the driving element, a controlling wheel screw threaded to the driving element and arranged to cause the engagement of one of said clutches to rotate one of said drums when said controller wheel is rotated in one direction relative to the driving element and to cause the engagement of the other clutch to rotate the other drum when said controller wheel is rotated in the other direction relative to the driving element, a flexible draft member windable upon one of said drums and arranged to advance the'carriage and cutting mechanism relative to the bed frame when said drum is rotated, and a second flexible draft member connected to the other drum and arranged to retract the carriage and cutting mechanism when said second drum is rotated.

9. In a mining machine, the combination of a bed frame, a carriage and cutter frame longitudinally movable on the bed frame, a cutter chain supported on and guided by the cutter frame, a sprocket wheel en aging the cutter chain to drive it, a clutch e ement on the sprocket wheel, a motor, a vertical drive shaft connected with the motor and mounted in axial alinement with the sprocket wheel, a clutch element at the lower end of the shaft, a manually operable device for moving the clutch element vertically to bring it into or out of engagement with the clutch element on the sprocket wheel, two rotatable drums mounted concentrically with the drive shaft, power connections between the motor and the respective drums comprisingin each case a clutch adapted to be thrown into or out of operation, a feed rope engaging one drum and connected with the forward end of the bed frame to move the carriage and cutter frame forward as the said drum is rotated, a retracting rope engaging the other drum and connected with the rear endof the bed frame to move the carriage and cutter frame backward as the said drum is rotated, a wheeled truck upon which the mining machine can be supported, and a clutch element on the truck connected with the wheels thereof, the said clutch element being in position to be engaged by the clutch element at the lower end of the drive shaft when the mining machine is in place on the truck.

10. In a mining machine, the combination of a bed frame,.a carriage and cutter frame longitudinally movable on the bed frame, a cutter chain supported on and guided by the cutter frame, a sprocket wheel engaging the cutter chain to drive it, a motor on the carriage connected with the sprocket wheel, two rotatable drums mounted on the carriage, power connections between the motor and the respective drums comprising in each case a friction clutch adapted to be thrown in or out of operation, a feed rope engaging one drum and connected with the forward end of the bed frame to move the carriage and cutter frame forward as the said drum is rotated, a retracting rone engaging the other drum, means for detachably connect ing the retract-ing rope with the rear end of the bed frame to move the carriage and cutter frame backward as the drum is rotated,

and automatically acting means for detaching the retracting rope from the bed frame when the carriage and cutter frame moves ratus on the bed frame comprising a power driven rotary drum, mounted on the carriage, a rope engaging the said drum, means NILS DAVID LEVIN.-

' Witnesses:

DUDLEY T. FIsHER, G. B. Noxms.

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