US2136921A - Mining apparatus - Google Patents

Description

NOV'. 1.5,. 1938. l J, F, Joy i 2,136,921

MINING APPARATUS Filed Dec. zo, 1955 :s sheets-sheet 1 Nov. 15, 1938..

J. F. JOY v 2,36,921

MINING APPARATUS Filed'neo'. 3o, 1955 s sheetsneet 2 N Q0 *h m mmg 5 Q5 E Re 1 QQ *SIL-:It: :fi f* Q Q ll I l v N u C@ 5E Q m n Nov; 15, 193s. J, F JOY 2,136,921

MINING APPARATUS Filed Dec. so, 1955 s sheets-sheet 5 SAF Yl/ALVES i of C5 PUMP Ol L n? INE@ /POTATE a? 70 Ey. M

y if@ Llll* Patented Nov. 15, 1938 UNITED STATES MINING APPARATUS Joseph F. Joy, Claremont, N. H., assignor to Sullivan Machinery Company, a corporation o1' Massachusetts Application December 30, 1935, Serial No. 56,624

6 Claims.

This invention relates to mining apparatus, and more particularly to improvements in the control means for the adjusting and/or feeding means for the kerf cutter of a coal mining apparatus whereby an excessive load on the cutter adjusting and/or feeding means is automatically precluded.

It is very desirable, particularly in hydraulically fed and adjusted mining apparatus, to provide means for preventing deliberate overloading of the driving' motor in an attempt to effect exceedingly rapid feed, and to prevent undue. motor overload, or strains in the mechanism, in the event of inadvertent engagements of adjusted parts with obstructions.

An object of the present invention is to provide improved means for automatically precluding excessive cutter feed, thereby eliminating any possibility of motor overload due to excessive cutter feed. Another object is to provide improved means for automatically precluding overload-of the cutter driving motor due to an excessive feeding pressure. A further object is to provide an improved control means for automatically reducing the feeding pressure when the load on the kerf cutter reaches a certain predetermined amount, thereby to prevent overloading ofthe cutter driving means. A still further Objectis to provide an improved automatic control means for the hydraulic uid system so that when the kerf cutter becomes overloaded due to a too great hydraulic feeding pressure in the fluid system, the feeding pressure is automatically reduced. Still a further object is to provide improved means for preventing motor overload and/or .excessive strains in the apparatus due to inadvertent'failure to stop adjusting movements before obstruction by floor, ribs, roof, etc. provide an improved automatic control valve for the hydraulic fluid system, the valve being operated electrically by a solenoid connected in the motor circuit so that when the driving motor becomes overloaded the solenoid becomes ener'- gized to effect opening of the valve, thereby to reduce the hydraulic pressure. Still another object is to provide an improved means for automatically controlling the feeding and/or adjusting pressure on the kerf cutter, thereby removing from the operator the control of the feed beyond a certain predetermined feeding pressure, to prevent automatically overloading of the driving motor due to excessive feed and to prevent harm should there be carelessness-in adjusting the apparatus. A still further object of this invention is to provide an improved automatic con- Yet another object is toV trol means for regulating the feeding pressure substantially in accordance with the requirements of thecutting encountered by the kerf cutter, within certain predetermined limits. Further objects and advantagesv of the invention 5 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 apparatus having embodied therein one illustrative form of the improved automatic control means, with the kerf cutter in horizontal cutting position.

Fig. 2 is a side elevational view of the mining apparatus shown in Fig. 1, with the kerf cutter in vertical cutting or shearing position.

Fig. 3 is an enlarged view in longitudinal section taken substantially on line 3-3 of Fig. l, showing the kerf cutter driving means.

Fig.4 is a vertical sectional view through one illustrative form of the automatic control valve.

Fig. 5 isa View similar to Fig. 4, showing a modified form of automatic control valve.

Fig. 6 is a diagrammatic View showing the hydraulic fluid system.

7 is a `wiring diagram of the motor circuit.

In this illustrative construction both forms of the improved control means are shown embodied in acoal mining apparatus of the same general character as that disclosed in my copending applicationSer. No. 20,826, filed May 10, 1935, although lt will be evident that the improved control means may be associated with mining apparatus of various other types. The mining appa- .ratus disclosed herein comprises a portable base l in the form of a truck frame 2 mounted on wheels 3 adapted to run along a mine trackway 4. The truck frame 2 has mounted thereon, at its forward end, a horizontal turntable 5 ro- 40 tatable about a vertical axis and in turn having pivotally mounted thereon at 6 for vertical swing'- ing movement with respect thereto an elongated arm structure or boom 1. The arm structure or boomhas mounted thereon at its forward ex- 45 rearward portion of the swingable arm structure 55 has rlxed thereto a chain sprocket 2| which' engages and drives the endless cutter chain I3. Supporte-d within the truck frame is a pump driven by a motor 26, and this -p'ump is adapted to supply hydraulic pressure to hydraulic cylinders 21, 21 for rotating the turntable 5, hydraulic cylinders 28 for vertically swinging the arm structure 1, hydraulic cylinders 29, 29 for revolving the head 8, and a hydraulic cylinder 3U for swinging the cutter support IU. Also mounted within the truck frame is transmission means driven by the motor 26 for driving the truck wheels to propel the apparatus along the mine trackway both during transport and cutting operations in a manner clearly described in the above mentioned copending application. Referring to the hydraulic system shown in Fig. 6, it w'ill be noted that the pump 25 is arranged in a tank 3| adapted to contain a liquid, preferably oil, and the pump, submerged in the liquid, is adapted to supply hydraulic pressure to the various hydraulically operated cylinder and piston devices of the apparatus. Arranged within the` truck frame is a horizontal valve box 32 similar to that described in the above mentioned copending application, and this valve box has formed therein a series of horizontal valve bores, each containing a balanced-type sleeve valve for controlling the iiow of hydraulic pressure to the various hydraulic cylinders. The discharge supply of the pump 25 is connected through a conduit 33 tothe supply passage of the valve box 32,While the discharge passages of the valve box are connected through branched conduits 34, 34 to a conduit 35 leading to the tank 3|. Conduits connect the hydraulic cylinders 21, 28, 29 and30 with thevalve box 32, and the valves in this valve box are operative to control the now of hydraulic pressure through these conduits to the cylinders. As `the various hydraulic cylinders and the hydraulic uid system are clearly described in the copending application above referred to, further detailed description of the specic structure thereof is herein considered unnecessary other than to state that the cylinders 29 may be operated to revolve the head 8 to move the kerf cutter into horizontal and vertical cutting positions, that the cylinders 21 may be operated to rotate the turntable to swing the arm structure about the turntable axisv to swing the kerf cutter horizontally during the cutting operation, and that the hydraulic cylinders 28 may be operated to swing the arm structure 1 about its pivot with respect to the turntable to swing the kerf cutter vertically .during comes overloaded, causing injury thereto, such as overheating of its armature and burning out of the motor windings. To overcome such overloading of the cutter driving motor, the automatic control valve, generally designated 46, is inserted in the hydraulic system so that when the feeding pressure on the kerf cutter reaches a predetermined amount, the valve operates automatically to reduce the pressure in the hydraulic system, thereby to preclude overloading of the cutter driving means. This improved automatic control valve, as shown in Fig. 4, comprises a valve casing 4| having a chamber 42 connected through a pipe 43 to the supply conduit 33 of the hydraulic system. Also formed in the valve casing is a chamber 44 connected through a passage 45 with the chamber 42, and this chamber 44 is connected through a pipe 46 with the discharge conduit 35 of the hydraulic system. Surrounding the passage 45 is a valve seat 41 on which a valve 48 is adapted to seat for cutting oir communica- -tion of the chamber 42 with the chamber 44.

This valve has a valve stem 49 passing through a stuiling box 50 mounted Within the valve casing, and the upper extremity of this valve stem is connected to the armature 5I of a solenoid 52. This solenoid is supported by a frame 53 securedy by bolts 54 to arms 55 formed integral with the valve. casing 4|, and interposed between the top plate 56 of the solenoid frame and the upper end of the cylinder armature 5| is a'coil spring 51 constantly urging the valve 48 toward its seated position. As shown diagrammatically in Fig. 7, the series field of the cutter driving motor |4 is indicated by the numeral 58, the shunt iield by the numeral 59 and the contactor controller generally at 60. The coil 6| of the solenoid 52 is connected by a line 62 in the series iield of the motor. When the motor |4 becomes overloaded for any reason, and the electrical energy in the series field 58 and the line 62 becomes sumciently high, the coil 6| is energized so strongly that the armature of the solenoid is drawn upwardly from the position shown in Fig. 4 to open the valve 48. As a result, uid in the supply conduit 83 is bypassed through the pipes 43 and 46 to the discharge conduit 35, reducing the pressure of the iluid in the supply conduit. In the event of carelessness in adjusting the apparatus during movement of the kerf cutter in the desired relation with respect to the work, for instance if the arm structure should strike the mine wall or the roof or floor during adjustment of the kerf cutter, means is provided for preventing automatically overloading of the pump driving motor. This improved control means is similar to that for the cutter driving motor and comprises an automatic control valve 63, similar to that shown in Fig. 4, having its solenoid 64 connected by a line 65 in the series eld 66 of the motor 26. The numeral 61 designates the contactor controller for the motor 26. As in the control for the motor I4, when the load on the motor 26 becomes too great, the electrical energy in the series eld 66 and the line 65 becomes suiciently high so that the coil of the solenoid is energized, drawing its solenoid core upwardly to open the valve, and as a result the liquid in conduit 33 is by-passed through conduits 43 and 69, through the conduit 46 and back to the tank 3|.

In the modified construction shown in Fig. 5, the pressure of the iluid in the hydraulic system is controlled automatically in accordance with `the -requirements of the cutting encountered by the kerf cutter during the cutting operation. In

this construction there is shown a valve casing 10 having formedtherein a valve chamber 'Il in which is reciprocably mounted a slide valve 12 having an upward projection, herein forming the armature of a solenoid 13, mounted on the upper portion of the valve casing. A coil spring 14 acting on the upper end of the slide valve constantly urges the latter toward its lowermost position. This slide valve is of the balanced type having spaced piston heads 15, 16 connected by the reduced body portion 11 providing an annular groove T8 surrounding the valve body between the piston heads. Communicating with this groove is a passage I9 connected by a pipe 80 to the supply conduit 33 of the hydraulic system. Formed in the wall of the valve chamber is a groove BI connected by a passage 82 through a pipe 85 to the discharge conduit 35 of the hydraulic system. V-shaped notches 83 are formed in. the wall of the valve chamber and communicate with the annular groove so that a graduated flow of uid from the supply passage to the annular groove is obtained. The coil 84 of the solenoid is connected by the wire 62 in the series eld of the cutter driving motor so that when the load on the motor varies, the amount of current supplied by the wire 62 to the solenoid coil is correspondingly varied, and as a result, the slide valve is moved within its bore to vary the flow of fluid from. the supply passage to the discharge passage automatically in accordance with the motor load.

The mode of operation of both forms of improved control means for the kerf cutter feeding means will be clearly apparent from the description given. During either the horizontal cutting operation, as shown in Fig. l, or the vertical cutting operation, as shown in Fig. 2, the hydraulic system is operated under the control of the manual control valves in the valve box 32 to supply liquid under pressure to the hydraulic cylinders to effect swinging of the arm structure to move the kerf cutter arcuately in its plane. In the form of the inventionshown in Fig. 4, in case the feeding pressure becomes too high during the arcuate swinging feeding movement of l the kerf cutter during the cutting operation, the

load on the driving motor I4 for the kerf cutter increases to a point Within its maximum load range so that the electrical energy in the motor windings becomes sufficiently high, the coil 6l of the solenoid 52 is energized to draw the armature 5l of the cylinder upwardly, opening the valve 48 and by-passing the fluid in the supply conduit 33 through which hydraulic pressure is supplied to effect feed, through the pipes 43 and 46 to the return conduit 35, and as a result, the feeding pressure in the hydraulic system is substantially reduced. When the load on the cutter driving motor decreases to a point within its normal range of operation, the coil 6I of the cylinder 52 is substantially de-energized, thereby causing the coil spring 51 to move the armature 5| downwardly to close the by-pass valve 48 so that normal pressure within the hydraulic system is again attained. Overload of the motor 26, during adjustment of the kerf cutter, is automatically prevented by the automatic control valve 53, so that the pressure in the fiuid system is automatically reduced in case the adjusting structure should strike an abutment, such as the mine wall, or roof or oor. It is accordingly evident that the improved electrically actuated valves in the hydraulic system are so: arranged that when the current of the driving motors I4 and 26 reaches a predetermined amount, the hydraulic pressure is by-passed sufiiciently to control the load on the driving motors within their maximum load range, thereby precluding the possibility of the machine operator overloading the driving motors, and any attempt on his part to supply excessive feeding and/or adjusting pressure to the kerf cutter is automatically prevented. Y

In the operation of the automatic control valve shown in Fig. `5, as the kerf cutter is fed arcuately in its plane during the cutting operation, the feeding pressure applied to the kerf cutter is automatically regulated in accordance with the requirements of the cutting encountered, and as the load on the cutter driving motor varies within certain limits the position of the slide valve is automatically varied, the valve moving up and down automatically to regulate the pressure in the hydraulic system, the slide valve controlling the amount of fluid by-passed past the valve automatically substantially in accordance with the load on the cutter driving motor, within certain predetermined limits. It will thus be seen that when the hardness of the coal encountered by the kerf cutter varies, the pressure in the hydraulic system is correspondingly varied, so that the feeding pressure is regulated automatically substantially in accordance with the requirements of the cutting encountered. Other uses and advantages of the improved automatic feed and/or adjustment control means 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 areV 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 I claim as new and desire to secure byl Letters Patent is:

1. In a kerf-cutting machine, in combination, a kerf cutter, hydraulically operated means for feeding the kerf cutter during the cutting operation, an electric motor for driving the kerf cutter, and means governed by the power taken by said motor for automatically reducing the pressure exerted by said hydraulically operated feeding means when the difficulty of cutting increases, said automatic pressure reducing means including a device movable to regulate the hydraulic pressure and a solenoid for controlling said device, said solenoid so connected relative to the motor circuit that a variation in motor current is attended by an alteration in the force exerted by said solenoid and said controlling device, when the current taken by said motor exceeds .a predetermined amount, operating to preclude overloading of said cutter driving motor.

2. In a mining apparatus, in combination, a kerf cutter, an electric motor for driving said kerf cutter, hydraulically operated means for feeding the kerf cutter during the 'cutting operation, a by-pass valve for controlling the pressure in said hydraulically operated means, and a solenoid connected in the motor circuit for automatically opening said valve when the current taken by said motor exceeds a predetermined amount, thereby to preclude overload of said cutter driving motor.

3. In a mining apparatus, in combination, a kerf cutter, an electric motor for driving said kerf cutter, hydraulically operated means for feeding the kerf cutter during the cutting operation including a hydraulically operated feeding motor, a pump, and a pump driving motor, and means for precluding overload of said kerf cutter driving motor while providing for rapid feed including a balanced valve for governing the pressure supply to said feeding motor, and controlling means for said Valve including a solenoid traversed by the current supplied to said cutter driving motor for opening said Valve on current increase.

4. In a mining apparatus, in combination, a kerf cutter, hydraulically operated mechanism for adjusting said kerf cutter into and supporting it in different planes, hydraulically operated means for effecting cutting feed of said kerf cutter when it is in any of said planes, a hydraulic system for supplying and controlling the fluid supplied to said hydraulically operated mechanism and means, means including an electric motor for actuating said kerf cutter to effect its cutting operation when fed in any of said planes, and means for precluding excessive overloading of said motor including valve means movable to reduce the pressure at which fluid is supplied to said hydraulically operated means, and controlling means for said valve means including a solenoid arranged to have the motor current pass therethrough.

5. In a mining apparatus, in combination, a kerf cutter swingable upwardly to out a vertical kerf, hydraulic feeding means for effecting such swinging movement, an electric driving motor for said kerf cutter, and means for precluding feeding pressures overloading said motor but precluding reduction in feeding pressure to a value insufficient to support the kerf cutter, including a bypass and a controlling valve therefor governing the pressure at said hydraulic means, and a solenoid connected in series with said motor for controlling the position of said valve.

6, In a mining apparatus, in combination, a kerf cutter, an electric motor for driving said kerf cutter, hydraulically operated means for swinging the kerf cutter to effect a cutting operation, means for effecting operating-medium supply to said hydraulically operated means, and means for controlling the pressure supplied to said hydraulically operated means automatically to limit the load on said kerf-cutter driving motor, including a valve openable to reduce the feeding pressure and a solenoid for controlling said valve connected in series with said motor.

JOSEPH F. JOY.

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