US3078081A

US3078081A - Mining and loading machine

Info

Publication number: US3078081A
Application number: US765246A
Authority: US
Inventors: Neal W Densmore
Original assignee: Joy Manufacturing Co
Current assignee: Joy Manufacturing Co
Priority date: 1956-10-09
Filing date: 1958-10-03
Publication date: 1963-02-19
Anticipated expiration: 1980-02-19

Description

1953 N. w. DENSMORE 3,078,081

MINING AND LOADING MACHINE Original Filed 001;. 9, 1956 6 Sheets-Sheet].

, INVENTORZ NEAL W. DENSMORE ATTORNEY Feb. 19, 1963 N. w. DENSMORE 8,

MINING AND LOADING MACHINE Original Filed Oct. 9, 1956 e Sheets-SheetZ I I i qmm o) 2| INVENTORZ NEAL W- DENSMORE 3'3 ATTORNEY Feb. 19, 1963 N. w. DENSMORE 3,078,081

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MINING AND LOADING MACHINE Original Filed Oct. 9, 1956 I 6 Sheets-SheetA FIGJO.

INVENTOR! NEAL W- DE NSMORE WWW,

ATTORN EY Feb. 19, 1963 N. w. DENSMORE MINING AND LOADING MACHINE Criginal Filed Oct. 9, 1956 INVENTOR'. NEAL-W. DEN suons ATTO R N EY Feb. 19, 1963 N. w. DENSMORE 3,078,081

MINING AND LOADING MACHINE Original Filed Oct. 9, 1956 6 Sheets-Sheet.6

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INVENTOR. NEAL W. DENSMORE BYALWQ.

ATTORN EY rit-ii Patented Felix. 119, 196 3 3378,5981 MWENG AND LQADENG MACHENE Neal W. Densmore, Franklin, Pa, assignor to Joy Mann factnring t'lornpany, lPittshurgh, Pa, a corporation of Pennsylvania Griginal application Get. 9, 1956, Ser. No. 614,977, new Patent No. 2,936,334, dated May 30, 1961. Divided and this application Get. 3, 1958, Ser. No. 765,246

1.1 Claims. (iii. 262--9) This invention relates to mining apparatus and more particularly to a mining and loading machine for dislodging mineral from a solid mine vein and for loading out the dislodged mineral.

In mining and loading machines of known types the cutting, dislodging and disintegrating mechanism usually lacks sufiicient vertical compactness to obtain the desired low height for low vein work while retaining the desired lateral flexibility to provide for wide mine passages or entries without frequent repositioning of the entire machine. The cutting and dislodging mechanism and the gathering and loading mechanism of the present invention are not only extremely vertically compact but also have the desired lateral flexibility, thereby being well adapted for use in mines having low headroom.

The present invention is an improvement over those disclosed in the patents to A. L. Barrett, No. 2,776,809, dated January 8, 1957; No. 2,776,823, dated January 8, 1957, and No. 2,836,408, dated May 27, 1958, all owned by the assignee of the present invention. The machine of the present invention has its cutting and dislodging mechanism adjustable in height to accommodate itself to mine veins of varying heights thereby enabling mining out the full width of the face of the vein in one operation, and improved, more flexible floor clean-up means is provided for gathering loose mineral which has fallen to the mine floor during the mining operation, and both the cutting and dislodging mechanism and the floor clean-up means are reversible whereby the machine may operate in either of opposite directions. Further, the machine of the present invention is more vertically compact than the machines of the above mentioned patents while still retaining the desired lateral flexibility and adjustability in height to compensate for variations in mining conditions. The machine of the present invention is not only extremely low in height and flexible in operation but is also rela tively simple and rugged in design and may be readily maneuvered and controlled.

An object of the present invention is to provide an improved mining and loading machine especially designed for use in the mining of mineral in low vein mines. Another object is to provide an improved mining and loading machine which is extremely vertically compact while retaining the desired lateral flexibility and adjustability in operating height thereby to enable the machine to be accommodated to varying mining conditions. A further object is to provide an improved mining and loading machine having improved gathering and loading mechanism. Still another object of the invention is to provide improved crawler type propulsion means for propelling the machine and for moving the gathering means toward and from the work. A further object is to provide an improved mining and loading machine which is reversible and embodies reversible cutting and dislodging mechanism and reversible gathering and loading means. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

This application is a division of my copending application Serial No. 614,977, filed October 9, 1956, now Patent No. 2,986,384.

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

In these drawings:

FIG. 1 is a plan view of the improved mining and loading machine.

FIG. 2 is a side view of the mining and loading machine shown in FIG. 1.

FIG. 3 is a longitudinal vertical section taken on line 33 of FIG. 1.

FIG. 4 is an enlarged cross section taken on line 4-4 of FIG. 2.

FIG. 5 is an enlarged detail section taken on line 55 of FIG. 3.

FIG. 6 is an enlarged longitudinal vertical section taken on line 66 of FIG. 1.

FIGS. 7 and 8 are enlarged longitudinal vertical sec-- tions taken respectively on lines 7-7 and 8-8 of FIG. 5.

FIG. 9 is a front end view of the mining and loading machine.

FIG. 10 is a fragmentary detail section taken on line iii-10 of FIG. 2.

FIG. 11 is a detail section taken on line 1111 of FIG. 7.

FIG. 12 is a detail section taken on line 12-12 of FIG. 8.

FIGS. 13 and 14 are diagrammatic views showing a mine passageway in horizontal section and with the mining and loading machine in different operating positions thereby to illustrate the manner in which the disintegrated mineral is conveyed from the working face.

In this illustrative construction, as shown in the drawings, the mining and loading machine is generally desig nated 1 and generally comprises a mobile base 2 carrying a frame 3 which is guided on the base for longitudinal sliding movement relative thereto and on the forward end of which a cutting and dislodging mechanism, generally designated 4, is adjustably mounted. Gathering devices 5 extend generally longitudinally at the opposite sides of the forward portion of the sliding frame for gathering the disintegrated mineral dislodged from the face by the cutting and dislodging mechanism and for moving the mineral gathered thereby rearwardly for discharge onto a conveying means 6 which in turn moves the disintegrated mineral rearwardly of the machine to a convenient point of discharge. A motor 7 serves to drive the cutting and dislodging mechanism while motors 8 serve to drive the gathering devices 5, the base propelling means and the conveying means. A transversely disposed propulsion device 9 (FIGS. 2 and 9) is driven by conventional reversible hydraulic motors it? for swinging the cutting and dislodging mechanism laterally in either direction along an arcuate path with the base and a rearwardly located upright jack device or spud 11 at the rearward portion of the sliding frame serves to provide a pivot point during such lateral swinging movement. The jack device or spud 11 also serves to relieve the base of a substantial portion of the weight of the machine during swinging movement of the base.

The mobile base 2 is herein in the form of a crawler base having parallel crawler treads i3 guided for orbital circulation about tread side frames 14 and extending along the inner sides of these tread frames are frame structures 15 which provide longitudinal guideways 16. The sliding frame 3 has extending longitudinally along its opposite sides lateral guides 17 which are slidingly engaged in the guideways 16. Thus the sliding frame 3 may slide longitudinally relative to the tread side frames of the base and, as hereinafter described, the tread side frames have independent sliding movement relative to the frame 3 while the latter may remain relatively stationary. Extending longitudinally within the guide structure at the sides of the sliding frame are extensible power devices 18 (FIGS. 3 and 4) desirably in the form of hydraulic jacks comprising cylinders 19 pivotally connected at 29 at their forward ends to the inner sides of the tread side frames and containing reciprocable pistons 21 having rearwardly extending piston rods 22 which are pivotally connected at 23 to lugs 24 secured to the outer sides of the rearward portion of the sliding frame 3. These hydraulic jack devices may be operated simultaneously to effect movement of the sliding frame longitudinally relative to the tread side frames, as later explained. Under certain conditions, when the tread drive clutches are released the hydraulic jacks 18 may be employed to move the tread frames longitudinally relative to the frame 3, although customarily this would be accomplished by driving the treads themselves.

The forward portion of the sliding frame is supported by the transversely disposed propelling device 9 which is herein likewise of the crawler tread type movable over the mine floor, as fully disclosed in the copending application Serial No. 614,977, above referred to. The crawler tread device 9 is reversible and when the crawler tread is driven the outer portion of the sliding frame and the cutting and dislodging mechanism carried thereby may be swung laterally about the pivotal axis provided by the rear jack 11 and when the sliding frame is fed longitudinally relative to the base the usual tread or shoe plates of the crawler tread slide over the mine floor. If desired, a conventional sliding shoe or skid may be mounted at the forward portion of the sliding frame or may be inserted beneath the transverse crawler tread to facilitate movement of the transverse crawler tread as it moves sidewise over the floor surface.

The cutting and .dislodging mechanism 4 includes dual rotary boring cutters or drilling and core cutting heads 26 rotatable about parallel horizontal axes extending longitudinally of the machine and journaled on a tiltable transverse frame portion or support 27 carried by a motor frame 28 in turn tiltably mounted on the forward portion 29 of the sliding frame 3 and the frame 28 houses the motor 7 for driving the heads 26, as is also fully described in the copending application above referred to.

The gathering devices are herein desirably in the form of relatively oppositely rotatin conveyor screws or scrolls 30 having their shafts 31 forwardly and downwardly inclined and suitably journaled within scroll housings 32 mounted in inclined positions at the sides of the forward portion of the sliding frame 3. The scroll housings are open at the inner sides of their forward portions near the floor level to permit free entrance of the disintegrated mineral into the housings, as shown in FIGS. 1 and 9. Lateral chutelike discharge portions 33 at the upper rearward portions of the scroll housings overlie the side edges of the conveying means 6 so that the disintegrated mineral conveyed rearwardly and upwardly through the scroll housings by the scrolls may be discharged laterally through these chutes onto the conveying means. These scroll housings have lateral guides 34 at their inner sides, which slidingly engage longitudinal guideways 35 at the outer sides of the transverse forward portion 29 of the sliding frame 3. Gear casings or housings 36 are mounted on the inner sides of the tread side frames 14 (P16. 4) and are rigidly secured to the scroll housings. Thus when the crawler treads are driven the scroll housings, together with the scrolls, may be moved along the guideways 35 relative to the frame 3. Also the sliding frame together with the cutting and dislodging mechanism may be moved longitudinally relative to the scroll housings and tread side frames while the base remains stationary.

The motors S, which are desirably electric motors, are mounted on the gear housings 36, and secured to the motor power shafts are spur pinions 37 (FIG. 7) meshing with planet gears 38 journaled on shafts 39 secured at 40 to rotatable spiders or carriers 41. These planetcarriers are respectively secured to shafts 42 suitably journaled within the gear housings 36. The planet gears 38 also mesh with large internal gears 43 formed on the gear housings respectively, and the planet gears roll around these internal gears during drive of the carriershaft 42. Secured to the shafts 42 are spur gears 44 respectively meshing with intermediate gears 45 which in turn mesh with and drive spur gears 46 respectively secured to parallel shafts 47 likewise journaled within the gear housings. The shafts 47 are connectible by conventional fluid operated clutches 48 (FIG. 8) to the scroll shafts 31. Also meshing with and driven by the spur gears 44 are intermediate gears 49 which mesh with and drive spur gears 50 secured to longitudinally extending shafts 51 likewise suitably journaled in the gear housings. Shafts 51 are connectible by conventional fluid operated clutches 52 (FIG. 7) to extensible, telescopic, universal drive shafts 53 (see also FIG. 3) which drive shafts 54 suitably journaled within gear housings 55 mounted at the sides of the rearward portion of the sliding frame 3. Secured to the shafts 54 are worms 56 meshing with worm wheels 57 secured to the ends of a transverse shaft 58. This transverse shaft is suitably journaled within the rearward portion of the sliding frame 3 and has secured thereto a driving pulley 59 (FIG. 6) for engaglng and driving the endless conveyor belt 60 of the conveying means 6. The upper run of this conveyor belt is guided by flexible guide rollers 61 (see also FIG. 4) and at its forward portion passes around a front idler pulley 62 mounted on a transverse shaft 63 on the sliding frame 3.

Meshing with and driven by the spur gears 50 are intermediate gears 65 which in turn mesh with and drive spur gears 66 (FIGS. 5 and 8) secured to longitudinally extending shafts 67 suitably journaled in the gear housings. Secured to and driven by the shafts 67 are bevel gears 68 which mesh with and drive bevel gears 69 respectively secured to downwardly inclined shafts 70 likewise suitably journaled within the gear housings. Secured to and driven by the shafts 70 are bevel gears 71 which mesh with and drive bevel gears 72 journaled on transverse shafts 73 (see also FIG. 3). The shafts 73 are respectively connectible by conventional fluid operated clutches 74 (FIG. 12) to the shafts 73 and the latter drive chain sprockets 75 connected by endless drive chains 76 to sprockets 77 (FIG. 3) which respectively drive transverse shafts 78 suitably journaled within the tread side frames 14-. The shafts 78 are operatively connected to the endless crawler treads 13. The drive of the treads may be reversed simply by reversing the motors 8. It will thus be seen that when the motors 8 are running the conveyor scrolls, the endless conveyor belt 60 and the endless crawler treads 13 may be driven.

The

clutches

48, 52 and 74 for respectively controlling the drive of the gathering scrolls, the conveyor belt and the endless crawler treads are fluid operated and are provided with hydraulic

actuators comprising cylinders

89, 81 and 82. The cylinder contains a reciprocable piston 83 (FIG. 8) having its piston rod 84 operatively connected to a shifter yoke 85 engaging a shifter ring 86. The

clutches

52 and 74, as shown in FIGS. 11 and 12, are respectively provided with similar shifter rings and yokes and the

cylinders

81 and 82 likewise contain reciproca'ble pistons having their piston rods operatively connected to the shifter yokes.

The pivot providing jack or spud 11 is of the hydraulic type comprising a vertical cylinder 89 (FIGS. 4 and 6) mounted on the rearward portion of the sliding frame 3 and containing a reciprocable piston 90 having its piston rod 91 extending downwardly and provided with a floor engaging point 92. When liquid under pressure is sup plied to the upper end of the cylinder the piston is forced downwardly to cause the point 92 to engage and penetrate the floor, thereby to provide a relatively stable pivot point for the swivelled frame about which the cutting and dislodging mechanism 4 is horizontally swingable into different laterally located positions. This jack device may relieve the base of a substantial portion of the weight of the machine during horizontal swing of the base and slid ing frame.

The general mode of operation of the improved mining and loading machine is as follows. The machine may be trammed about the mine under the propulsion of the crawler base and the crawler treads may be separately or simultaneously driven by one or both of the motors 8 under the control of the fluid operated clutches 7 4 to effect steering of the machine. When the Working face is reached the machine may be positioned ready to sump at the right-hand rib and the feed cylinders 19 may be operated to sump the rotary cutting and dislodging heads 26 into the mineral of the mine vein. Upon completion of the sumping operation the rear jack or spud 11 may be lowered into contact with the mine floor as indicated at A in FIG. 14 to relieve the base of a substantial portion of the weight of the machine and fluid under pressure may be supplied to the proper one of the hydraulic motors 10 to eifect drive of the front transverse crawler tread 9 to swing the entire machine horizontally about the axis of the rear jack 11 thereby to move the cutting and dislodging heads along an arcuate path extending across the working face.

The dual cutting and dislodging heads 26 are shown moving from left to right with both heads in lowered position to operate at the fioor level. If it is desired to adjust the heads to mine out a mine vein of greater height one of the heads may be swung unwardly along an arcuate path about an axis coincident with the axis of rotation of the advancing head, thereby to increase the operating height of the cutting and dislodging mechanism, as disclosed in the copending application above mentioned. As the dual cutting and dislodging heads start to move laterally from their sumped positions from right to left the right-hand crawler treads 13 maybe advanced to feed the right-hand gathering device 5 forwardly into the position shown in FIG. 14 within the cut at the rear side of the trailing head so that the disintegrated mineral moved outwardly from the face by the cutting and dislodging heads may be gathered and conveyed rearwardly and upwardly and then laterally onto the conveyor belt 6% When the dual cutting and dislodging heads complete the swinging cut from right to left and the heads are located at the left-hand rib, the rear jack or spud 11 may be released and the feed cylinders 19 may be operated first to advance the retracted tread and thereafter to slide the frame 3 forwardly relative to the treads to sump the dual cutting and dislodging heads into the face at the left-hand rib. Thereafter the jack device or spud 11 may again be lowered into contact with the mine floor, as indicated at B in FIG. 13. The other of the hydraulic motors It may then be operated to drive the transverse crawler tread 9 in the opposite direction to swing the frame 3 together with the dual cutting and dislodging heads from left to right laterally across the working face and in FIG. 13 the machine is shown in its position at the completion of this swinging operation. The rear jack device 11 is then again released and the operations above described are repeated to continue the advance of the working face.

During the horizontal swinging operation of the machine about the pivot provided by the rear jack device the front transverse crawler tread 9 effects arcuate movement of the dual cutting and dislodging heads across the face and as the machine swings laterally the rear crawler treads 13 may slide laterally over the mine floor. If desired, however, during the lateral swinging operation conventional skid devices may be associated with the rear crawler treads 13 to facilitate lateral movement thereof over the mine floor.

As is fully disclosed in the above mentioned Patent No. 2,776,809, each of the cutting and dislodging heads 26 as they are sumped into the working face of the mine vein form a hole with a rotary boring action and as the heads are swung laterally the advancing head cuts a slot S in the mineral inside of the face to form a core C of mineral and the rotary breaker device, which rotates relatively slowly about the axis of head-rotation, engages and dislodges the core. The machine of the present invention is reversible and may cut and dislodge the mineral by lateral swinging movements across the face in either direction. During the mining operation from left to right the advancing gathering device 5 is retracted by its crawler tread while the other gathering device is moved forwardly by its crawler tread into a position wherein its forward portion lies rearwardly of the trailing head in a reverse manner. During swing of the dual cutting and dislodging heads in either direction the trailing one of the gathering devices 5 engages the loose mineral on the mine floor and conveys it rearwardly and upwardly to discharge through the lateral chute 33 onto the conveyor belt 60 and the latter conveys the mineral received thereby rearwardly of the machine to a convenient point of discharge at the rear end of the machine.

As a result of this invention an improved mining and loading machine is provided whereby mineral maybe removed from a solid mine vein in mines having relatively low headroom. By the provision of the improved gathering devices, one may be located at the rear side of the cutting and dislodging mechanism within the cut during either direction of operation of the machine, thereby effectively to engage and load out the disintegrated mineral. By associating each gathering device with a crawler tread and by separately adjusting the treads relative to the frame of the machine either of the gathering devices may be advanced into gathering position and retracted, as desired. By the provision of the rear jack device or spud which engages the mine floor to provide a pivot the entire machine may be swung horizontally to move the cutting and dislodging mechanism and the gathering mechanism along arcuate paths across the working face, and this jack device may relieve the base of a substantial portion of the weight of the machine as the machine swings horizontally. These and other advantages of the invention 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 claims.

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

1. A mining machine comprising, in combination, a mobile base having independently operable supporting and propelling means at the sides thereof for propelling and steering said base, a frame carried by said base, said frame having a forward outer portion, each of said supporting and propelling means having longitudinal movement relative to said frame, cutting and dislodging mechanism mounted on said outer portion of said frame, a gathering device extending along each side of said frame and guided for longitudinal movement relative thereto, and a connection between said gathering devices respectively and said longitudinally movable supporting and propelling means whereby the latter may move said gathering devices longitudinally relative to said frame.

2. A combination as set forth in claim 1 wherein said mobile base is a crawler base and said supporting and propelling means are crawler treads.

3. A combination as set forth in claim 1 wherein said supporting and propelling means are respectively separately movable longitudinally relative to said frame and relative to each other, said cutting and dislodging mechanism being reversible and adapted to cut and dislodge the mineral in either of opposite directions across the face of a mine vein, said gathering devices extending along the sides of said frame respectively for gathering the disintegrated mineral during either direction of operation of said cutting and dislodging mechanism, and said gathering devices are respectively connected to and are movable relative to said frame by said separately movable supporting and propelling means.

4. A reversible driven mining machine comprising a mobile base having independently operable supporting and propelling devices, a frame carried by said base, said frame having an outer forward portion and opposite side portions, mounting means between said base and said frame respectively whereby either of said devices may move longitudinally relative to each other and to said frame, cutting and dislodging mechanism carried at the outer portion of said frame, gathering devices slidably eX- tending along said opposite side portion of said frame respectively, and means for connecting said gathering devices to said supporting and propelling devices respectively whereby said supporting and propelling devices independently move said gathering devices longitudinally relative to said frame.

5. A mining machine comprising a mobile base having separate supporting and propel-ling devices at the sides thereof, a frame carried by said base, means on said frame for guiding said devices for independent movement longitudinally relative to said frame, gathering devices slidably guided along the sides of said frame respectively, and means for connecting said gathering devices to said supporting and propelling devices respectively for independent longitudinal movement therewith relative to said frame.

6. In combination, a crawler base having an endless crawler tread device, a frame slidably carried by said base, means for guiding said crawler tread device for movement longitudinally relative to said frame, a gathering device slidably guided on one side of said frame, and means for connecting said gathering device to said crawler tread device for longitudinal movement therewith relative to said frame.

7. A reversible mining machine adapted to cut and dislodge mineral from a mine vein during movement thereof in either direction across the face of the vein, the machine comprising, in combination, a base, said base having independently operable supporting and propelling means at the respective sides thereof for propelling and steering said base, a frame slidably carried by said base and mounted to swing with said base horizontally across the face, said frame having a forward portion and opposite side portions, reversible cutting and dislodging mecha nism carried by said swingable frame for cutting and dislodging the mineral of the mine vein during either direction of operation thereof, a reversible gathering mechanism slidably guided on each opposite side portion of said frame selectively operable with said base to gather the disintegrated mineral dislodged from the mine vein during either direction of operation of said cutting and dislodging mechanism, and means for connecting each of said gathering mechanisms to the said supporting and propelling means adjacent thereto respectively whereby said gathering mechanism moves with said adjacent propelling means as a unit.

8. A combination as set forth in claim 7 wherein said cutting and dislodging mechanism comprises dual cutting and dislodging heads and said gathering mechanism comprises a pair of spaced gathering heads separately operable and each adjustably positionable to extend rearwardly of said cutting and dislodging mechanism irrespective of the direction of operation of said mechanism.

9. A mining machine comprising a pair of spaced frame members, a support member slidably supported by said respective frame members for rectilinear movement thereon, propelling and steering means mounted on each of said frame members respectively for propelling and steering said frame members, adjusting means mounted on said respective spaced frame members operatively conmeeting said respective frame members to said support member, a cutting mechanism mounted on said support member for movement therewith, a pair of spaced gathering mechanism slidably mounted on said support member, said gathering mechanisms being operatively connected to their respective adjacent frame members for respective movement therewith, and motor operated means mounted on each of said frame members operatively connected to said propelling means adjacent thereto for selective operation.

10. A mining machine comprising a pair of spaced frame members adapted to engage the ground supporting surface, a support member slidably supported by said respective frame members for rectilinear movement thereon, said support member having a forward portion and a rearward portion, an extensible support mounted on said rearward portion for engagement with such supporting ground surface, propelling means mounted on said frame members respectively for propelling and steering said support member, adjusting means mounted on said respective spaced frame members operatively connecting said respective frame members to said support member, a cutting mechanism mounted on said forward portion of said support member for movement therewith, a pair of spaced gathering means slidably mounted on said forward portion of said support member, said gathering means mounted on said frame members respectively, and a crawler device mounted on said forward portion of said support member for arcuately swinging said forward portion relative to said stationary extensible support.

1 1. A mining machine comprising a longitudinal extending support having a pair of opposed sides, propelling means slidably mounted on said sides respectively, adjusting means connecting said propelling means to said sides respectively, a cutting mechanism mounted on said support, a gathering mechanism mounted on each of said propelling means respectively for movement therewith, and drive means mounted on said gathering means operatively connected to said propelling means for driving said propelling means selectively and separately respectively.

References Cited in the file of this patent UNITED STATES PATENTS 2,606,643 Tidwell Aug. 12, 1952 2,751,208 Russell June 19, 1956 2,760,767 Barrett Aug. 28, 1956 2,776,809 Barrett Jan. 8, 1957 2,920,879 Driehaus Jan. 12, 1960 2,973,949 Densrnore Mar. 7, 1961 FOREIGN PATENTS 177,813 Great Britain Apr. 13, 1922

Claims

5. A MINING MACHINE COMPRISING A MOBILE BASE HAVING SEPARATE SUPPORTING AND PROPELLING DEVICES AT THE SIDES THEREOF, A FRAME CARRIED BY SAID BASE, MEANS ON SAID FRAME FOR GUIDING SAID DEVICES FOR INDEPENDENT MOVEMENT LONGITUDINALLY RELATIVE TO SAID FRAME, GATHERING DEVICES SLIDABLY GUIDED ALONG THE SIDES OF SAID FRAME RESPECTIVELY, AND MEANS FOR CONNECTING SAID GATHERING DEVICES TO SAID SUPPORTING AND PROPELLING DEVICES RESPECTIVELY FOR INDEPENDENT LONGITUDINAL MOVEMENT THEREWITH RELATIVE TO SAID FRAME.