US2302034A - Coal mining machine - Google Patents

Description

Nov. 17, 1942. J. F. JOY

COAL MINING MACHINE Filed Nov. 24, 1939 2 Sheets-Sheet 1 QQQQQQ mw .uvm hm n@ N n -L www., S u m v mm ww. -mfm m lM/\M\/ /l/,ff/ 1 N* A A 1 l.: R .n 4 ,/,wmmn// z f, -,w u HV c@ @ik bb M Nov. 17, 1942. F, JOY

COAL MINING MACHINE 2 Sheets-Sheet 2 Filed Nov. 24, 1939 vmechanism were positively driven at Vthe same Patented Nov. 17, 1942 COAL MINING MACHINE Joseph F. Joy, Franklin, Pa., assignor to Sullivan Machinery Company, a corporation of Massachusetts Application November 24, 1939, Serial No. 305,863

1 Claim. (Cl. 262-28) This invention relates to mining machines, and more particularly to an improved safety mechanism for a coal mining machine of the flexibly fed, floor cutter type adapted to operate on a steeply inclined or pitching coal seam.

During cutting of coal in accordance with the longwall system, on a steeply inclined or pitching coalseam, the feed cable of the machine feeding means is usually anchored at the `top of the pitch so that as the feed cable is wound in by its feed drum, the machine is fed upwardly along the coal face to make a cut in the coal. Unless some safety measure is taken, there is inherent danger, due to the possibilities of feed cable breakage or release of the feed cable from its anchor, of accidental sliding of the comparatively heavy machine rapidly down the pitch with the possibility of injury to the operator andy damage to the machine. To eliminate this possibility of the machine accidentally moving with- `out control down the pitch, safety mechanism is usually provided so that in the event the feed cable breaks or releases from its anchor, or the feeding `mechanism otherwise fails to function, the safety mechanism will act automatically tol prevent undesired sliding of the machine down the pitch. Such safety mechanism usually comprises a safety drum on the `machine rotatable at the same speed as the feed drum and having its cable attached to an anchor at the top of the pitch so that if 'the feed cable breaks or releases from its anchor, the safety cable will automatically hold the machine against undesired movement down the pitch. Such safety drums usually have some form of means for effecting rotation thereof in cable winding direction and means for precluding automatically rotation thereof in unwinding direction. Also a brake device is usually associated with the safety drum so that the latder frictional control at the operators will, thereby to enable lowering of the machine down the pitch under the control of the safety cable. Due to the fact that such known types of safety winding speed as the feed drum, the safety cable u usually had to be slack, and so, in the event the feedcable failed to function and -the machine started to slide down the pitch, the safety cable would frequently break or become released from, its anchor, when the weight of the machine was suddenly taken thereby.

ter may rotate in cable unwinding direction un- .40

An object of this invention is to provide an improved safety mechanism for a coal mining movement of the machine do-wn the pitching seam is prevented, the improved safety mechanism embodying features which overcome certain disadvantages of previous known devices. Another object is to provide an improved safety mechanism for a coal mining machine embodying a safety drum mounted on the mining machine and having wound thereon a lsafety cable, the drum having improved driving and controlling means therefor whereby the safety cable is always automatically maintained taut as the machine is fed upwardly along the coal face. A further object is to lprovide an improved driving means forthe safety drum embodying frictional means whereby the safety drum at least tends to wind in its cable at a rate slightly faster than the cable winding rate ofthe feed drum of the .machine,'whereby the safety cable is always automatically maintained under the desired tension,

the vfrictional means automatically slipping when the safety cable becomes taut. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

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

In these drawings?A Fig. 1 is a plan View of a coal mining machine with which an illustrative embodiment of the invention is associated.

Fig. 2 is aside elevational View of a mining machine shown in Fig. 1.

Fig. 3 isa detail View illustrating the safety drum ratchet.

Fig. 4 is an enlargedrhorizontal sectional view, with parts shown in plan, taken substantially on line 4-4 of Fig. 2.

Fig. 5 is a view in longitudinal vertical section taken substantially on line 5-5 of Fig. 4.

Fig. 6 is a detail view of a portion of the drum driving mechanism. l

Y In this illustrative embodiment of the invention the improved safety mechanism, generally designated I, is shown associated with a coal mining. machine generally designated 2. The mining machine disclosed herein is of the flexibly fed, longwall floor cutter type, although it will be evident that the improved safety mechanism Vmay be associated with coal mining machines of various other types.

'I'he coal mining machine disclosed herein may be of the same general character as that disclosed in the-patent to Morris P. Holmes, No. 1,968,769, patented July 3l, 1934, while the safety machine whereby the possibility of undesired .QQ mechanism disclosed herein is an improvement over that disclosed in the patent to Morris P. Holmes, No. 2,053,288, patented Sept. 8, 1936.

The mining machine comprises a low compact machine frame 3 having a plane bottom surface 4 adapted to rest upon and slide in any direction over the mine oor. The machine frame comprises a central motor frame section 5, a rear cutter carrying frame section 6 and a front feed frame section 1, the motor frame section being arranged between the cutter and feed frame sections, and these sections being suitably rigidly united. Pivotally mounted at 8 on the cutter frame section 5 at the rear end of the machine frame for horizontal swinging movement-relative thereto, is an elongated horizontal plane cutter bar 9 having guided for circulation about its margin an endless cutter bit carrying cutter chain I (I, the cutter bar being swingable hori zontally about its pivot into right angle positions at either side of the machine frame or into a position extending lengthwise of the machine frame, as shown in full and dotted lines in Fig. l. Mounted on the cutter bar is a usual locking element I I for locking the cutter bar in lits different positions about its pivot relative to the machine frame. Carried by the feed frame section is a horizontal feed drum I2 arranged for rotation about a vertical axis located in the central longitudinal vertical plane of the machine and having wound thereon a usual feed cable I3. Arranged at opposite sides of the feed drum are sets of horizontal guide sheaves I4 for guiding the feeol cable relative to the feed drurn during the various operations of the machine. The free end of the feed cable is attachable to the locking pin I I, and when the locking pin is released the feed cable may be wound in by its drum to effect swinging of Vthe cutter bar about its pivot. To effect feeding of the machine along the coal face during the cutting operation, the feed cable is extended from its drum in the manner indicated in full lines in Fig. 1, and is connected at its free end to a suitableanchor located in advance of the machine adjacent the coal face,`and as the feed cable is wound in, the machine is fed bodily over the mine floor in a manner well understood in the art. Arranged within the centralmotor frame section 5 kis a reversible motor for driving the cutter chain I and feed drum I2 in eitherm of opposite directions in accordance with the direction of cutting. When it is desired to reverse the direction of cutting of the machine, the cutter bits ofthe cutter chain IIB are, of course, reversed within their respective chain blocks and the feed ca ble is rewound on the feed drum. K

Now referring to the driving connections between the. motor and the feed drum, it will be noted that Xed to the motor power shaft I is a spur motor pinion I5 (see Fig. 4) meshing with a spur gear I1 which in turn drives a longitudinal shaft I8. Fixed to .and driven by the shaft I8 is aspur gear I9 meshing with a spur gear 20 having its hub keyed to .a horizontal longitudinally eX- tending shaft 2 I. Secured to the forward end of the shaft 2IY is a spur. gear 22 meshing with a spur gear 23 keyed to a parallel shaft24. Secured toand driven by the shaft 24 is a spur gear 25 meshing with a spur gear 26 arranged coaxially with the spur gear and surrounding and journaled on the shaft 2 I. J ournaled within bearings supportedwithin the gears 2l! and 26 and arranged coaxially with and surrounding the shaft 2I is a tubular shaft 21 having formed thereon a worm 28 meshing with a wormV wheel 29. The gear train, including gears I5, I1, I9 75` and 20, constitutes a high speed drive, while these gears, and additionally, the reduction gears 22, 23, 25 and 26, constitute a low speed drive, and these drives are selectively connectible with the opposite ends of the worm shaft 21 through friction disc clutches 35 and 3I respectively.

The particular clutch mechanism and the actuating and controlling means therefor are similar in design to those described in the above mentioned Holmes Patent 1,968,769. Continuous high speed rotation of the worm shaft 21 is effected by direct connection of the worm shaft 21 with the high speed gear 2i), while continuous rotation of the shaft at a low speed and intermittent rotation at a number of different still lower mean speeds are effected by the following mechanism. A clutch-applying element 32 reciprocably mounted on the worm shaft 21 is operative to transmit the pressure of a clutch shipper yoke 33 which is pivotally supported at 34, to effect loading ofthe high speed frictionV clutch 30, and thereby to effect connection between the high speed gear 20 and the worm shaft 21. A similar clutch-applying element 35 is arranged adjacent the opposite end of the worm shaft 21 and is movable by a clutch shipper yoke 36 pivotally mounted at' 31 to effect loading of the low speed friction clutch 3| and thereby to effect connection of the low speed gear 26 to the worm shaft 21. Formed integral with the low speed gear '26 is a cam 33 (see also Fig. 6) with which Yengages a plunger 39 slidably guided in a boreV 4U.` This plunger is pivotally connected at 4I with one end of a horizontally swingable lever'42 whose opposite end is pivotally connected at 43 to a member 44 secured to a rod 45. Thebuter end of this rod is provided with a cylindric enlargement 45 providing a shoulder 41, and a spring 48 is compressed between an abutment 49 on the rod and a washer 50 slidably mounted' upon the rod and normally engaging the shoulder 41 under the influence of the spring. The cylindric enlargement 45 on the rod passes through a trunnion device 5| supported by the shipper yoke 3G. It will be evident from the foregoing description that, if the lever 42 is fulcrumed at a properly located point, movement of the plunger 39 by the cam 38 to the right in Fig. 6 effects, through the lever 42, endwise movement of the rod 45 to the left as viewed in Fig. 4, and such movement of the` rod, through the spring 48 and the washer 5B, imparts a load to the shipper yoke 36. The load imparted will be determined by the extent of movement of the rod and the degree of compression of the spring, and these will depend upon the position ofthe fulcrum of the lever 42. A movable fulcrum for the lever 42 is provided by trunnion devices 52 which are held upon a longitudinally movable rod 53 between a collar 54 on the rod and the inner end of a sleeve 55 which surrounds and isA movable backwardly and forwardly with therod. The opposite end of the rod 53 has secured thereto an abutment 56 which, on movement o f the rod 53 to the right as viewed in Fig. 4, applies pressure to trunnion devices 51 surrounding the rod and pivotally mounted in the adjacent end of the shipper yoke 33. The rod 53 extends, as noted above, through the sleeve 55, and has formed thereon an abutment 53 engageable with a rotatable hand nut 59, the latter being rotatably mounted between the abutment 58 and the outer end of sleeve 55, on the rod in the manne;` shown, and threadedly engaged at 6) toa member 5I secured within the machine frame, Obviously, the collar 54 and abutment 58 hold the trunnion devices 52, sleeve 55 and hand wheel nut 59 against longitudinal movement relative to the rod 53; and longitudinal movement in either direction of the rod, the trunnion devices 52 and the sleeve is eifected by proper rotation of the hand wheel nut 59 relative to the threaded member 6|. Rotation of the hand wheel nut 59 in a direction to cause movement of the rod 53 toward the right in Fig. 4 results in loading of the high speed friction clutch 30 and driving of the worm shaft 21 directly by the high speed gear 20, and the movement of the fulcrum of lever 42 which is also effected precludes loading of clutch 3| while high speed drive is taking place. Rotation of the hand wheel nut in a ldirection to effect movement of the rod 53 toward the left in Fig. 4 tends to move the lever 42 bodily towards the left, and causes the end of the lever 42 connected to plunger 39 to move the latter toward the left and thereby into engagement with the cam 38; and upon movement of the fulcrum sufficiently far to the left, the other end of the lever 42 will have sufficient throw so that the shoulder 41 will pass inside the trunnion devices 5I and permit the washer 50 to coact with the trunnion devices and the spring 48 to load the low speed friction clutch 3|. Obviously, when the spring is under sufficient compression so that it will yield only when a pressure adequate to effect power transmission through the low speed friction clutch 3| is applied to the clutch-applying element 35, the proper leftward adjustment ofthe fulcrum devices 52 may effect rotation of the worm shaft 21 at a low speed by the low speed gear 26 for any desired part of each revolution of the latter. When the rod 53 is moved to the left so far that the washer 50 continuously presses under the pressure of the spring 48 against the trunnion devices 5|, continuous rotation of the worm shaft 21 will take place, and the spring will compress during each rotation of the low speed gear 26 an amount substantially equal 4to the full throw of the cam; but since the load of the spring is desirably above the minimum necessary to effect power transmission through the friction clutch, there will be no release even when the lowest point in the cam is opposite the plunger. However, by moving the rod 53 graduated amounts toward the right in Fig, 4 from its extreme left position mentioned, the period of drive during each rotation of the gear 26 may be progressively reduced until it is entirely discontinued. It is accordingly evident that the worm shaft 21 may be driven continuously at a relatively high speed, continuously at a relatively low speed and intermittently at low speeds at any desired point between the maximum low speed and zero.

The driving connection between the worm wheel 29 and the feed drum |2 comprises a vertical shaft 65 to which the .worm wheel is keyed, and rotatable with and driven by this shaft at the lower end thereof is a spur gear 66 meshing with the teeth of an internal gear 61 formed on the feed drum l2.y From the foregoing, it is evident that the feed drum may be rotated in cable winding direction at a relatively high speed under the control of the friction clutch 30, at a rela- Y 'slightly faster than the feed cable.

vertical plane as the axis of rotation of the feed drum l2, and this stub shaft supports bearings 10 on which is journaled the hub of a cylindric member 1|. This cylindric member has formed thereon internal gear teeth 12 with which mesh the teeth of a spur gear 13 keyed to the upper end of the vertical shaft 65. Journaled on a bearing sleeve 14 supported by the cylindric member 1| is a safety drum 15 having wound thereon a safety cable 16. The safety drum 15 is arranged at the top of the machine frame in horizontal planes above the feed drum l2, in the manner shown. Formed integral with the hub of the cylindric member 1| is a sleeve-like portion 11 having keyed thereto a series of clutch discs 18 which are interleaved with a series of clutch discs 19 keyed to the hub 80 of the safety drum T5. Threaded at 8| within 'an opening formed axially within the stub shaftl 69 is a screw 82 having formed integral therewith a hand wheel 83 herein disposed above the top of the safety drum. Connected by aV semi-permanent Yclutch 84, having slidingly interlocked teeth, to the upper end of the stub shaft 69 is aV ly engages the walls of the bore in the hub to' prevent access of foreign matter to the 'internal structure and oil leakage. The cylindric member is annularly grooved at 81 at its lower face, and extending upwardly from its groove are vertical recesses receiving a series of coiled springs 8S. These springs act on the upper race of a ball-bearing clutch-applying element 89 so that at times the .springs act to load the friction clutch 13, 19 through the element 89. The clutch connection 84 serves to hold the cylindric member 85 against rotation, and there is a limited sliding movement between the interlocking clutch teeth so that the cylindric member 85 may be moved slightlyupwardly and downwardly, and the springs 88 urge the member 85 upwardly against the hub of the hand wheel 83. When the gear 13 is driven by the shaft 65 through the gearing above described in connection with the feed drum I2 and the hand wheel is rotated to move the screw 82 downwardly relative to the ystub shaft 69, the springs 88 are compressed sufciently to effect loading of the friction clutch discs, and as a result the safety drum 15 is rotated concurrently with the feed drum i2 in cable winding direction. Upon continued rotationV of the hand wheel, the bottom of the annular groove 81 will come vinto contact with the upper ball race of the element 89, thereby positively to increase the loading of the friction clutch. Various means may be utilized to provide a slightly higher maximum winding speed for the drum 15, and herein the safety drum 15 is of aY slightly larger diameter than the feed drum |2, and both drums are adapted to be driven concurrently by the shaft 65 through identical gearings, and accordingly the safety cable 1S will, barring clutch slippage, be wound in at a rate If desired the safety drum may be of the same diameter as the feed drum and the latter be driven at a slightly higher speed. Suitable vertical guides 90 having cable-receiving grooves are provided on` the feed frame section for 'guiding the safety cable with respect to the safety drum.

Associated with the safety drum 15 is a ratchet mechanism comprising ratchet teeth 9| formed on the periphery of an annulus 92 secured, as by riveting, to the lower ange of the safety drum. Engageable with the ratchet teeth is a doubleended reversible pawl 93 pivotally mounted at 94. Engageable with the pawl is a spring-pressed plunger 95 mounted in a shiftable member 96 pivotally mounted at 91 and having a handle 98 for swinging it. This pawl, by its engagement with the ratchet teeth, serves to prevent undesired rotation of the safety drum 'l5 in cable unwinding direction. Accordingly reliance need not be placed on the friction device 18, 19 to hold the machine weight if the feed cable breaks, and power consumption may be kept low by relatively light loading of the clutch discs mentioned. As are the cutter chain and feed drum,

the safety drum 'I5 is reversible, and when the motor of the mining machine is reversed to effect cutting in the opposite direction, it is necessary to rewind the safety cable on the drum. Byl

shifting the member 96, the pawl may be reversed whenever the safety drum is reversed and the drum may be freed for quick unwinding of the safety cable. In Fig. 1 the pawl is shown in its released position.

The general mode of operation of the mining machine will be clearly apparent from the description given. When it is desired to make a cut along a coal face of a steeply inclined or pitching coal seam, the machine is initially located with respect to the coal face at the bottom of the pitch. The locking pin Il is then released, and the feed cable I3 is attached to the locking pin, and as the feed cable is wound in by its drum thecutter bar 9 is swung horizontally about its pivot to effect a sumping cut beneath the coal. Thereafter, the feed cable is detached from the locking pin and the latter is operated to lock the cutter bar to the machine frame. The feed cable is then extended forwardly of the machine up the incline and is attached to an anchor jack located at the top of the inoline. The safety cable 'H6 is also extended forwardly from the machine up the incline and is similarly anchored at the top of the incline. The Vlow speed clutch 3| of the low speed drive is then applied to effect rotation of the feed drum I2 at the proper speed to wind in the feed cable, thereby to feed the machine up the incline at a cutting speed, moving the cutter bar along the coal face to make a out along the base of the coal seam. As the feed drum is rotated, the safety drum 'l5 is concurrently rotated in a direction to wind in the safety cable '16, and since the safety cable tends to be wound in at a slightly higher rate than the feed cable, the safety cable is always automatically maintained taut under the control of the friction clutch, the latter slipping automatically when the safety cable is under sufficient tension. The friction clutch normally limits the traction exerted by the safety cable to a value less than sufficient to feed the machine up the incline. In the event of breakage of the feed cable or its release from its anchor, the safety cable 19 will automatically prevent movement of the machine down the incline, the pawl 93 of the ratchet mechanism automatically locking the safety drum against rotation in cable unwinding direction. When it is desired to lower the machine down the incline under the control of the safety drum, this may be accomplished by releasing the pawl Y(see Fig. l) to permit rotation of the safety drum in cable unwinding direction, and the friction clutch at that time serves as a frictional resistance means for braking drum' rotation. Of course, during this braking operation the rotation of the shaft is interrupted and the shaft is held against rotation by the worm gearing 23, 29 of the drum driving means. By releasing the friction clutch 3l of the low speed drive and applying the high speed drive clutch 30, the feed and safety drums may be concurrently driven at a relatively high speed. When the friction clutch for the safety drum is fully loaded, the safety cable may be employed to feed the machine up the incline. Further, by properly adjusting the fulcrum of the lever 42 of the intermittent applying means for the low speed clutch 3l the safety drum may be intermittently driven concurrently with the feed drum in cable unwinding direction at any desired speed between the maximum low speed and zero.

As a result of this invention, it will be noted that an improved safety mechanism for a coal mining machine of the flexibility fed, floor cutter type Aadapted to operate on a steeply inclined coal seam, is provided whereby the possibility of undesired movement of the machine down a pitching coal seam is prevented. It will further be evident that by the provision of a safety drum which acts to wind in the safety cable at a rate slightly higher than the feed cable and under frictional control, the safety cable is always automatically maintained taut, thereby eliminating undesired slackness in the cables of previously known devices. Further, by the provision of a friction clutch which may serve as a brake, the machine may be lowered down the incline under the control of the safety drum. Other uses and advantages of the improved mining machine will be clearly apparent to those skilled in the art.

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

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

In combination, a machine body adapted to rest upon and slide over a mine oor, means for moving said body up an incline including a cable connectible at a point above and in advance of said body, a feed drum mounted to move with said body and coacting with said cable and means for rotating said feed drum in a direction to shorten the length of said cable in advance of said machine body, and means for precluding the sliding back of the machine in the event of sudden failure of said machine moving means including a safety cable also connectible at a point above and in advance of said body, a safety drum mounted to move with said body and of slightly larger effective diameter than said feed drum and coacting with said safety cable and means for rotating said safety drum at the same angular rate as said feed drum in a direction to shorten the length of said safety ycable in advance of said machine body, said safety drum rotating means including a yielding connection set at a predetermined load for normally automatically limiting the traction exerted by said safety drum and cable to a value less than suiiicient to move said body up the incline.

JOSEPH F. JOY.

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