US2282749A

US2282749A - Mining machine

Info

Publication number: US2282749A
Application number: US282583A
Authority: US
Inventors: John D Russell
Original assignee: Joy Manufacturing Co
Current assignee: Joy Manufacturing Co
Priority date: 1939-07-03
Filing date: 1939-07-03
Publication date: 1942-05-12
Anticipated expiration: 1959-05-12

Description

y 12, 1942, J. D. RUSSELL MINING MACHINE Filed July 3, 1939 \illniillllllllflllJ mpfl m 3 Sheets-Sheet l v INVENTOR. Job/7 O /?w5e// Q. E 3 n.

ATTORNEY" y Jun. RUSSELL 2,282,749

' MINING MACHINE Filed July 5, 1959 3 Sheets-Sheet? INVENTORf Jo/7x7 0 @0552 I A TTORNEY May 12, 1942.

J. D. RUSSELL MINING MACHINE Filed July 3, 1939 3 Sheets-Sheet'S IN VEN TOR.

JO/w 0 Passe BY- $4494! ATTORNEY.

Patented May 12, 1942 F MINING MACHINE John D. Russell, Sugarcreek Township, Venango County, Pa., assignor, by mesne assignments, to Joy Manufacturing Company, Franklin Pa., a corporation of Pennsylvania.

Application July 3, 1939, Serial No. 282,583

23 Claims.

This invention relates to mining machines and in particular to an improved supporting carriage for a mining machine of the wheel mounted type having a universally mounted cutter bar for cutting both vertical and horizontal kerfs in a face of coal.

The principal object of this invention is to provide an improved mining machine.

Another object is to provide an improved supporting carriage for the body, operating motors and cutter bar of the mining machine, whereby it is possible to vary the position of the body of the machine relative to the supporting carriage, and adjust the position of the cutter bar to meet any conditions encountered during the cutting of coal.

A further object is to provide a 3-wheeled carriage support for a mining machine which is power operated; novel in construction; easily and mine without the necessity of having track first laid on the floor of the mine.

These and other objects which will hereafter be made apparent to those skilled in this particular art, are accomplished by means of this invention, one embodiment of which is described in the following specification and illustrated in the accompanying drawings wherein:

Fig. 1 is a top plan view of a mining machine mounted on a supporting carriage having pneumatic tired wheels and embodying my invention;

Fig. 2 is a view in side elevation of the mining machine;

Fig. 3 is a bottom plan view of the mining machine having a portion thereof broken away for convenience of illustration;

Fig. 4 is an enlarged section taken on line IV-IV of Fig. l

Fig. 5 is a diagrammatic view illustrating the hydraulic system on the mining machine;

Fig. 6 is a diagrammatic view showing the operation of my improved mining machine in making a horizontal cut in a coal face;

Fig. '7 is a diagrammatic view showing the position of the machine after the cutter bar has been sumped into the face of coal;

Fig. 8 is a diagrammatic view showing the position of the cutter bar at the end of-the arcing operation;

Fig. 9 is a diagrammatic view illustrating the position of the machine after a complete kerf has been out in the coal face;

Fig. 10 is a diagrammatic view showing the machine in position to be sumped into the coal for the purpose of making a vertical or shearing cut in the coal face;

Fig. 11 illustrates the position of the cutter bar after the sumping operation;

Fig. 12 shows the position of the cutterbar at the end of the arcing operation in making a vertical out;

Fig. 13 shows. the position of the machine at the completion of the shearing or vertical cut; and.

Fig. 14 is a front view illustrating diagrammatically the capacity of my improved machine for tilting about a longitudinal axis.

Referring now to the drawings in detail, l0 represents the body of a mining machine containing the usual motor and operating gears, and having a cutter bar I I, extending outwardly from the front end thereof which has the usual cutter chain I2 extending therearound. The cutter bar H is mounted for swinging movement about a shaft l3 carried by a turret M which is mounted for rotation on a horizontal axis through the turn-table mechanism Ma on the front of the body Ill. The body l0 carries the usual motors and gears for driving the cutter chain [2; for rotating the cutter bar ll about the shaft l3 to cause it to cut in the arc'of a circle; and for turning the cutter bar ll about a horizontal axis through the mechanism Ma so that the machine may be used to out either in a horizontal plane or a vertical plane. i

The body ID of the cutting machineas shown is mounted, for movement from place tov place in the mine and for sumping the cutter bar ll into a face of coal, on a supporting carriage l5 made in accordance with my invention, and comprising a pair of side castings I6, each of which has a bifurcated end H, the legs'of which terminate in apertured bosses llcawhich straddle asubstantially cylindrical apertured boss [8 carried by a bracket I9 which is secured to the side of the body It] adjacent the rear end thereof and opposite from that on which the cutter bar is journaled. i

The apertures in the bosses il'la areadapted to register with the apertures in the bosses l8, and the side castings [6 are journaled on the body ID by pins which extend through the registered openings and provide a pivotal connection between the body and the castings l6.

The front end of each of the castings l6 terminates in an enlarged substantially cylindrical boss 2| having parallel vertical faces and a horizontal bore 22 therethrough in which an axle 23 is journaled. Mounted on one end of the axles 23 are wheels 24 having pneumatic tire rims 25 which form the drive wheels for the supporting carriage l5. To drive the wheels 24, a sprocket 26 is secured to the inner end of each of the axles 23, around which pass sprocket chains 21 for connecting the sprockets 26-26 with sprockets 26 which are carried by suitable gear reduction units 29 associated with and driven by motors 30. The

gear reduction units 29 and motors 30 are both mounted on and carried by the side castings 15. The rear portion of the supporting carriage i5 comprises a platform 3| having an operators station 32 thereon, as will be more fully described hereinafter, and having a series of three parallel arms 32 connected thereto, each of which extends underneath the body ll] of the mining machine and terminates in a substantially cylindrical apertured boss 34, the apertures of which are adapted to register with the apertures in substantially. cylindrical bosses 35 depending from the bottom of the body I6. A horizontally disposed pin 36, extending through the apertures in the bosses 34-35,.forms the journal between the rear section of the supporting carriage l5 and the body ID of the mining machine.

The platform 3| is also provided with a dome shaped portion 31, which forms a housing for a pair of steering wheels 38 having pneumatic tire rims 39 .thereon, which are so mounted as to be substantially adjacent to each other, and form in effect a. single wheel for the supporting carriage l5 whereby the carriage. has substantially a 3'- point contact with the surface on which themachineis adapted to travel.

Each wheel 38 is journaled on an axle 4|, slop-. ing somewhat from the horizontal, tothrow the bottoms of the. wheels 38 intoclose proximity to each other, which is carried byia member .42, secured to thelower end of a vertically extending, hollowcylindricalv shaft 43. .The shaft 43 is journaledat its upper end for rotation. in bearings 44, which are securedto the underside of r dome shaped portion 31. In'order to turnthe wheels 38 and thus steer or guide the mining machine, the upperend of,-the cylindrical member 43 projects above the dome shaped member 31 and hasa worm gear 46 securedthereto which meshes with a worm 41 -on the end of a horizontally disposed shaft 48 which is journaled on the top of the dome-shaped portion 31, and has a hand wheel 49 secured thereto. By rotating the wheel 49,-the operator is able to guideand steer the mining machine from place-to place in the'mine, and since the steering wheels 38 form in effect, a single dual wheel,-it is apparent that the machine may be turned sharply-and can readily negotiate the sharp'turns in a mine."

In order that the'front end of body 10 of the mining machine may be readily elevated relative to the'supporting carriage l5 so that horizontal kerfs may be cut in 'a coal-face at different-elevations in the coal' face, and tilted aboutbothlon= gitudinal and transverse axes,- a hydraulic jack 50 is positioned between the body l6 and each of the supporting castings J6. Each of thejacks 50ha's its tcylinder :pivotally connected to a bracket 5l'-mounted on .the side of the body 10,

and its operating piston connected by a rod 52 to a pin 5-3 which has its ends journaled in cylindrical bosses 54 carried by the casting l6. To elevate the rear end of the body ID of the mining machine, and to assist in tilting the body about both a longitudinal axis and a transverse axis, a pair of hydraulic cylinders 56 are provided, the cylinders of which are pivoted at 56a to the rear end of the body In, and their operating pistons are pivotally connected by rods 51 to a shaft 58 which is journaled at each end in members 59 secured-to the arms 33. Each of the cylinders 56-56 is independently operated, while the cylinders 56-56 are operated simultaneously, and in order to'operate the jacks 56-50, 56-56 to vary the position of the body relative to the supporting'carriage |5,'a hydraulic pump 60 (Fig. 3) is mounted in the body l0 of the mining machine which is driven from the motor (not shown) carried thereby. The pump 60 has its intake 6| connected by conduit 62 to a suitable storage tank 63 carried by the body l0, and its outlet 64 connectedby conduit 65 with a control box 66 mounted on the rear end of the body l6 adjacent the operators station 32 in position to be readily accessible to the operator. The control box 66 is provided with valve 61 which, when actuated in one direction admits hydraulic fluid into the lower end of the jack 50 on the left hand side of the machine as viewed in the drawings, through the conduit 68, to expand the jack and elevate the body of the machine. When the valve is actuated in the opposite direction the jack 5!] is connected with the storage tank 63 through the conduit 69 lea-ding from the control box 66 to the tank, and, when the valve is so positioned, the left side, of the body is free to gravitate to its lowermost position. A valve 10 in the control box 66 likewise controls the admission and exhaust of hydraulic fluid to and from the jack 56,

on the right hand side of the machine, which has a conduit 1| connecting the jack with the control box 66. The admission of hydraulic fluid to the jacks 56-56, which are of the double acting type and simultaneously operated, is controlled by a valve 12 in the control box.66. The valve 12 has two conduits 13-14 leading therefrom which are connected by branches 15-16, respectively, with the lower and upper ends of each of the jacks 56. When the valve 12 is actuated in one direction, fluid under pressure is delivered through the line 13 and branches 15 to the lower ends of the jacks 56, and the upper'ends are connectedithrough the. line 14 and branches 16 with the conduit 69. When the valve 12 is actuated in the opposite direction; lines 14-16 are energized and line 13-15 are connected to exhaust. 7

From the foregoing description of my invention it is apparent that I have produced a mining machine of the-universal arc wall type, which is capable of operating under any conditions encountered in a mine. Byactuating the jacks 50-50 and 56-56 the body of the machine may be readilyelevated or loweredrelative to the frame l5 so that the cutter bar may be used to cut horizontal kerfs at different elevations therein. Further, by operating one of the jacks 50 relative to the other, the machine may be readily tilted about its longitudinal axis and either side thereof raised or-lowered to any desired-extent.- It should be noted that-this sidetilting can be readily secured withoutoperating the-jacks 56- 56,. since. the carriage, being. supported on three wheels, is free to rock-onits. wheels. By raising both front jacks ll50 without operating the back jacks 5656, the front end of the cutter bar H may be raised, and by operating the back jacks 5G.56,the front end of the bar II. will be moved down or lowered. Thus, with my improved carriage, the cutter bar H may be adjusted to any desired position and then be readily leveled, even though the machine is operating on a floor which is rough and uneven, and even though one wheel 24 may be elevated relative to the other wheel.

Power for operating the motors 30-130 and the motors contained in the body In of the mining machine is supplied through a cable I5 wound on a reel 15 mounted on the platform 3| and having one end connected to a suitable source of supply, and the other to themotors 30-30, etc. The cable reel 16, which is adapted to play out the cable as the machine is traveling in a direction away from the source of supply; and to automatically reel the cable in as the machine is traveling toward said supply, is mounted on a shaft 11 journaled in brackets 18 on the platform 3|. One end of the shaft 11 has'a grooved pulley (not shown) secured thereto, around which passes a cable 19 which connects the shaft 18 with a grooved pulley 80 on a shaft 8| which is journaled on the top of the dome 31. The inner end of the shaft 81 has a bevel gear 82secured thereto which meshes with a bevel gear 83 on the upper end of a vertical shaft'84. Shaft 84 is journaled within the cylindrical member 43 and has a gear 85 secured to its lower end which meshes with a ring gear 86 secured to the hub of one of the wheels 38.

From this construction it is apparent that as the mining machine is driven in opposite directions, the wheel 38, through the train of gears above described, will cause the cable reel 16 to be rotated in opposite directions to play out an wind up the cable thereon.

The speed reducing units 2929, associated with the motors 3%, are preferably of the'typ e having two forward speeds to afford a lowsumping speed and a relatively high traveling speed, The gear change may be made independently on each motor in the usual manner. The operation of my improved mining machine is clearly illustrated in Figs 6 to 9, inclusive; which show the position of the bar H and the body ID at the beginning of the sumping-in operation (Fig. 6), and the position at the completion of the sumping-in operation (Fig. 7). After the bar has been sumped into the coal, it is turned through an arc of approximately 180 degrees (Fig. 8), and then the motors 30 are reversed and the machine sumped out (Fig. 9) to complete the formation of the kerf.

In making a vertical or shear cut, the bar II is turned so that the cutter chain [2 travels in a vertical plane and the machine is then moved forward to sump the bar into the coal adjacent the floor" of the mine. When the bar has been completely sumped-in, it is swung upwardly until the end of the bar reaches the topof the seam,

,after which the driving motors are reversed and the machine sumped out to complete the shearing without departing from the spirit of my invention'and the scope of the appended claims.

What I claim as new and desire to secure 2. The combination in'a mining machine having a body, of a supporting carriage for said machine, comprising a member having one end pivotally connected to saidbody on each side thereof and adjacent the rear end thereof, a pneu-- matic tired traction wheel journaled on the free" end of each of said members, an hydraulically operated elevating device, positioned between each of said members and said body,,a platform at the rear of said body, arms on said platform pivotally connected to the front of said body, a pneumatic tired steering wheen of dual construction supporting said platform, an hydraulically operated elevating device positioned between said arms and said body, and means'for independently operating each of said elevating devices to vary the position of said body relative to the wheels of said carriage.

3. The combination with a mining machine having a body provided with a cutter baron the front end thereof, of a' carriage for supporting said body during the cutting operation and including a pair of side members extending along the sides'of said body, one side member being pivoted to said body on each side thereof, a wheel mounted on each of said members, a frame pivoted to said'body and extending therefrom in opposite direction to said, members, a wheel supported steering structure mounted centrally in said frame, and means for independently adjusting said frame relative to said body and to eachv of said side members.

' 4. A supporting carriage for a mining machine having a body and a cutter bar mounted on the forward end of said body, comprising a member pivotally mountedon' the side of said body adjacent the rear end thereof and extending forwardly of said body, there being one member on each side of said body, a traction wheel journaled on each of said members, a frame pivotally mounted on the bottom of said bodyand extending rearwardly thereof between said side members, a platform mounted on said frame, a dual wheel centrally of said frame and supporting said platform, andfiuid actuated means for varying the distance between said traction wheels and said dual wheel tovary the elevation of said body and the cutter bar carried thereby.

' 5. A supporting carriage for a mining machine body having a cutter bar universally mounted on the front end thereof, comprising a member pivotally mounted on each side' of said body adjacent the rear end thereof and extending forwardly along the sides thereof, a traction wheel mounted on each of said members, a frame pivotally mounted on the bottom of said body adjacent the front end thereof and extending rearwardly thereof betweensaid side members, a carriage steering wheel mounted centrally in said frame at the rear of-said body, means for driving said traction wheels, means :for turning said steering wheel, and means for independentlyadjusting said body relative to said frame andto each of said traction wheels to :vary the elevationof said body.

6. Asupporting carriage for a mining machine body having a cutter bar mounted on :thefront end thereof, comprising a member ipivotally mounted on each side ofsaid bodyadjacent -the rear end thereof and extending forwardly along the sides thereof, ,a traction wheel mounted on the freeend of each of said members, a frame pivotally mounted on the bottom of said body adjacent the front end thereof and extending rearwardly of said body between said side members, a dome like structure on said frame, a dual wheel mounted withinthe dome like structure for supportingsaid frame, ,meansfor driving each of said traction wheels, means for turning said dual wheel to guide said carriage, mean between each of said members and said body for moving said body relative to said members, means between said frame and said body for moving said body relative to said frame, and independent means for actuating each of said body moving means.

7. A supporting carriage for a mining machine having a cutter bar universally mounted on one end thereof, comprising a frame pivoted to the bottom of said machine adjacent the end carrying said cutter bar and extending rearwardly thereunder, a dual supporting wheel mounted centrally of said frame adjacent the rear ,end thereof, a piston attached to said frame-:between said wheels and said pivotal connection, a cylinder in which said piston operates connected to said mining machine, a member on each side of said machine pivoted to the side thereof and extending forwardly therealong, a wheelmounted on the forward end of each of said members, means for driving the wheels carried by said members, a piston attached to each of said members between the wheel mounting and said pivotal connection, a cylinder for each piston con-- nected to sides of said machine, and means for independently introducing actuating fluid into each of the cylinders to elevate,and adjust said machine relative to said supporting carriage,

8. A supporting carriage for a mining machine having a cutter bar universally mounted on one end thereof, comprising a frame pivoted to the bottom of said machine adjacent theendcarrying said cutter "bar and extending rearwardly thereunder, a dual supporting wheel mounted centrally of said frame adjacent the rear end thereof, a piston attached to said frame between said wheels and said pivotal connection, a cylinder in which said piston operates connected to said mining machine, a member on each side of said machine pivoted to the sidefthereof and extending forwardly therealong, a wheel mounted on the forward end of each of said members, means for driving the wheels carried by said members-means for steering said dual wheels, a piston attached to each of said members between the wheel mounting and said pivotal connection, a cylinder for each pistoriconnected to sides of said machine, and meansfor independently, introducing actuating fiuidinto each ,of saidcylinders to elevate and adjust said machine relative to said supporting carriage.

9. A supporting carriage for a miningrnachine having a cutter bar universally mounted on one end thereof, comprising a frame pivoted to the bottom of said machine'adjacent the end carrying said cutter bar and extending rearwardly thereunder, a dual supporting wheel mounted centrally of said :frame adjacent the rear end thereof, a piston attached to said frame between said wheels and said pivotal connection, acylinder in which said piston operates connected to said mining machine, amember on each side of said machine'pivoted to the side thereof and extending forwardlytherealong, a wheel mounted on the forward end of each of said members, a motor mounted on each of said members for driving the wheel carried thereby, a piston attached to each of said members between the wheel mounting andsaid pivotal connection, a cylinder for each piston connected to sides of said machine, and means for independently introducing actuating fluid into each of said cylinders to elevate and adjust said machine relative to said supporting carriage,

, 10. A supporting carriage for a mining machine body having a cutter bar mounted on the one end thereof, comprising a mono-wheeled frame-pivoted to the bottomof said body adjacent the front-endthereof and extending rearwardly thereunder, a wheeled side member pivotedon each side of said body adjacent the rear end thereofand extending forwardly along the sides of said frame, and means for independently varying the elevation of said body relative to each of the side wheeled membersto tilt said body about its longitudinal axis. .11. A supporting carriage for a mining machinev having a body and a cutter bar mounted on the front end of said body, comprising a frame pivoted to the bottom of said body adjacent the front end thereof and extending rearwardly thereunder, a wheel of dual construction supporting the rear end of said frame, a hydraulic jack positioned between said body and same frame, ,a member pivoted on each side of said body adjacent the rear end thereof and extending forwardly along the sides of said frame, a drive wheel mounted onthe forward end of each of said side members, a hydraulic jack positioned betweeneach of said side members and said body, and means ,forselectably operating said jacks to vary the position of said body relative to said frame and to each'of said members.

1 Z. A supporting carriage for a mining machine having a body and a cutter bar mounted on the front end of said body comprising a frame pivoted to the bottom of said body adjacent the frontend thereof and extending rearwardly thereunderya centrally mounted steering wheel of dual construction supporting the rear end of said frame; a member pivoted on each side of said body adjacent the rear end thereof and extending forwardly along the sides of said frame, a drive wheel mounted on'the forward end of each ofsaid side members, hydraulically operated means for varying the elevation of said body relative to said frame, and independent hydraulically operated means for varying the elevation of said body relative toeach of said side members.

1 3.,A supporting .-carriage for a mining machine-body having a cutter bar mounted on the frontend of said body, comprising a frame pivoted to the bottom of said body adjacent the frontend thereof and extending rearwardly thereunder, Zsaidframe having a dome like portion at its rear end, a dual wheel mounted within said dome like portion. for supporting said frame, a member pivoted oneach side of said body adjacent the rear end thereof and extending forwardly along the sides of said frame, adrive wheel mounted on the forward end of each of the elevation of said body relative to the rear end of said frame, and independently operated means for varying the position of said body relative to each of said side members.

14. A supporting carriage for a mining machine body having a cutter bar mounted for arcing movement on one end thereof, comprising a frame pivoted to the bottom of said body adjacent the end carrying said cutter bar and extending rearwardly underneath and beyond said body, a single wheel of dual construction supporting said frame, a member pivoted on each side of said body and extending forwardly along the sides of said frame, a drive wheel mounted on the forward end of each of said side members, means for driving each of said drive wheels, means for steering said frame supporting wheel, and fluid actuated means for independently varying the elevation of said body relative to each of said side members to tilt said body about its longitudinal axis.

15. A supporting carriage for a mining machine, comprising a frame pivoted to the bottom of said machine at one end thereof and extending underneath and beyond the other end thereof, said frame having a dome on the extended portion thereof, a substantially vertical shaft mounted in said dome, a wheel carried by said shaft for supporting said frame, 'a member pivoted on each side of said machine adjacent the end opposite from that to which the frame is pivoted and extending along the sides of said body, a wheel mounted on each of said side members, means for driving said last mentioned wheels and means for turning said frame supporting wheel to guide said carriage and the mining machine carried thereby.

16. A supporting carriage for a mining ma-' chine, comprising a frame pivoted to the bottom of said machine at one end thereof and extending underneath and beyond the other end thereof, a wheel capable of being steered supporting the extended portion of said frame, a member pivoted on each side of said machine adjacent the end opposite from that to which the frame is pivoted and extending along the sides of said body, a driven wheel mounted on each of said side members, means for varying the position of said body relative to said frame to tilt said body about its transverse axis, and independently operated means for varying the position of said machine relative to each of said side members to tilt said body about its longitudinal axis.

17. A supporting carriage for a mining machine, comprising a frame on which the body of said machine is mounted, a pair of drive wheels supporting one end of said frame, a centrally mounted dual wheel supporting the opposite end of said frame, a motor for driving each of said drive wheels, a cable for delivering power to said motors, a reel mounted on said frame and on which said cable is wound, and means for driving said cable reel from said dual wheel to play out and wind up said cable as the machine i moving in opposite directions. 7

18. A supporting carriage for a mining machine having a cutter bar mounted on one end thereof, comprising a mono-wheeled frame pivoted to the bottom of machine adjacent the forward end thereof and extending rearwardly thereunder, a wheeled side member pivoted on each side of said machine adjacent the rear end thereof and extending forwardly along the sides of said frame, fluid actuated means for independently varying the elevation of said machine relative to each of the side wheeled members to tilt said body about its longitudinal axis, and fluid actuated means for adjusting said machine relative to said frame to tilt said body about its transverse axis.

19. The combination with a mining machine having a body and a cutter bar projecting from the forward end thereof, of a supporting vehicle therefor, comprising a pair of body supporting drive wheels adjacent the end of said body carrying the cutter bar, a pair of steering wheels adjacent the rear end of said body, a pair of axles on which said steering wheels are mounted, a frame supporting said axles and pivotally connected to said body, and means for varying the angle between said frame and said body to tilt said body about a transverse axis.

20. The combination with a mining machine having a body and a. cutter bar projecting from the forward end thereof, of a self-propelled vehicle for supporting said body, comprising a pair of body supporting drive wheels adjacent the end of said body carrying said cutter bar, a frame pivoted to said body for turnin movement about a horizontal axis, a pair of axles carried by said frame, steerable wheels mounted on said axles, and means for varying the angle between said 3 frame and said body to tilt said body about a A transverse axis.

21. The combination with a mining machine having a body and a cutter bar projecting from the forward end thereof, of a self-propelled-vehicle for supporting said mining machine, comprising a pair of body supporting drive wheels adjacent to said cutter bar, means for independently driving each of said drive wheels, 2, frame pivoted to said body for turning movement about a horizontal axis, a pair of axles carried by aid frame, steerable wheels mounted on said axles, means for turning said steerable wheels, and means for varying the angle between said frame and said body to tilt said body about a transverse axis.

22. The combination with a mining machine" having a body and a cutter bar projectin from the forward end thereof, of a supporting carriage therefor comprising body supporting drive wheels adjacent to said cutter bar, a pair of steerable wheels, a pair of axles upon which said steerable wheels are mounted, and a frame supporting said' axles and pivotally connected to said body, said frame being capable of angular displacement relative to said body to rotate said body about a transverse axis.

23. The combination with a mining machine having a body and a cutter bar projecting from the forward end thereof, of a supporting carriage therefor, comprising body supporting drive wheels adjacent to said cutter bar, a pair of steerable wheels, a pair of axles upon which said steerable wheels are mounted, a frame carrying said axles and pivotally connected to said body for turning movement about a horizontal axis, a hydraulic jack disposed between said body and said frame for varying the angular displacement of said body relative to said frame, and means for energizing said jack.

JOHN D. RUSSELL.