US3595371A

US3595371A - Material reclaimer

Info

Publication number: US3595371A
Application number: US718466A
Authority: US
Inventors: Fred T Smith
Original assignee: Barber Greene Co
Current assignee: Barber Greene Co
Priority date: 1968-04-03
Filing date: 1968-04-03
Publication date: 1971-07-27
Anticipated expiration: 1988-07-27

Abstract

A self-propelled reclaimer for moving material from a stockpile. The reclaimer has a sloper for removing material from the face of the pile and a bucket wheel for removing material from in front and to the side of the reclaimer and a common conveyor receiving both streams of material. The sloper is carried by a tiltable boom which carries means for directing material which avoids the conveyor to a second means carried by the reclaimer which directs the material to the bucket wheel. The sloper is angled so that the top thereof leads the conveyor. The conveyor extends to the face of the stockpile and has a projecting edge associated therewith to seal into the stockpile. The second means also contours the slope of the stockpile below the sloper.

Description

United States Patent [72] Inventor Fred T. Smith Aurora, 111.

[21] Appl. No. 718,466

[22] Filed Apr. 3, 1968 [45] Patented July 27, 1971 [73] Assignee Barber Greene Company Aurora, 111.

[54] MATERIAL RECLAIMER [56] References Cited UNITED STATES PATENTS 2,104,928 1/1938 Jacobs 37/190 2,896,342 7/1959 Reising 37/97 FOREIGN PATENTS 599.037 10/1925 France 37/189 1,175,157 7/1964 Germany 214/10 154,185 7/1963 U.S.S.R. 37/82 Primary Examiner-Gerald M. Forlenza Assistant Examiner-- Frank E. Werner Att0rneyHill, Sherman, Meroni, Gross and Simpson ABSTRACT: A self-propelled reclaimer for moving material from a stockpile. The reclaimer has a sloper for removing material from the face of the pile and a bucket wheel for removing material from in front and to the side of the reclaimer and a common conveyor receiving both streams of material. The sloper is carried by a tiltable boom which carries means for directing material which avoids the conveyor to a second means carried by the reclaimer which directs the material to the bucket wheel. The sloper is angled so that the top thereof leads the conveyor. The conveyor extends to the face of the stockpile and has a projecting edge associated therewith to seal into the stockpile. The second means also contours the slope of the stockpile below the sloper.

PATENTED JUL27 I971 SHEET 1 OF 6 371 MATERIAL RECLAIMER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to material handling machines and more particularly to a machine for moving materials from a stockpile commonly identified as a reclaimer.

2. Prior Art Self-propelled machinery adapted to move material from a large material stockpile is known to the art. Such prior art machinery, including self-propelled frames having bucket wheels for removing material from in front of the main body of the machine and depositing it on a transverse conveyor belt, and having boom-supported slopers for removing material from the face of the stockpile above the main body of the machine and allowing it to fallv onto the conveyor, are also known to the art. Certain disadvantages in the material pickup abilities of said prior art devices have evidenced themselves. It is the purpose of the present invention to overcome these disadvantages and thereby improve the prior art-type reclaimers.

In the prior art reclaimers, as the machine moved forward generally parallel to the cut face of the stockpile, an auger dug a groove into the face of the stockpile in which groove the end of the conveyor belt projected. The sloper extended upwardly and outwardly from the end of the conveyor and dislodged material from the face of the stockpile so that it could then slide down the face onto the end of the conveyor. In the prior art reclaimers of this type, it was possible for material sliding down the face of the slope to avoid the end of the conveyor by sliding past it in the groove. Also, because of the projecting angle of the sloper, the material had a tendency to avalanche as it came down the slope, resulting in deep ravines into the face of the stockpile. It was further possible for material to miss the conveyor belt and vfall behind the reclaiming apparatus without being directed to the bucket wheel.

SUMMARY These and other disadvantages are overcome by my present invention. The invention contemplates a seal between the face of the stockpile and the conveyor belt created by a projecting edge associated with the end of the conveyor belt which cuts into the face of the stockpile at the top of the auger cut groove. In order to avoid the above-mentioned difficulty of avalanching, I have angled the sloper so that the top thereof precedes the bottom thereof, which is aligned above the conveyor belt. Further, I have provided an angled moldboard carried by the tiltable boom which both redirects material missing the conveyor belt and which contours the slope of the stockpile. The moldboard discharges into a particle crumber located to the side and behind the bucket wheel. The crumber directs material from the moldboard and from the face of the slope below the conveyor to the bucket wheel and at the same time contours the face of the slope.

The angle of the sloper, the seal at the end of the conveyor, the moldboard, and the improved crumber all combine together to insure that all material dislodged by the passing of the reclaimer is directed to the conveyor and that the slope of the stockpile is effectively contoured without ravines therein so as to accommodate the next passing of the reclaimer.

It is then an object of this invention to provide a new and improved material handlingmachine for reclaiming stockpiled materials.

It is another object of this invention to provide an improved reclaiming machine having means associated therewith to assure that substantially all of the material dislodged from the stockpile by the machine is directed to a conveying means for removal from the stockpile.

It is a further object of this invention to provide a reclaimer having a sloper for dislodging material from the face of the stockpile and means to assure that substantially all of the dislodged material is directed to a conveyor belt for removal from the stockpile.

It is a further and more specific object of this invention to provide a reclaimer having a sloper with a top which precedes the bottom in the direction of operative movement of the reclaimer.

It is a further object of this invention to provide an improved reclaimer having a forwardly angled sloper for dislodging material from the face of the stockpile, a transverse conveyor for receiving the dislodge material, a seal at the end of the conveyor to direct the material dislodged by the sloper onto the conveyor and a moldboard and crumber to assure that substantially all of the dislodged material is eventually directed to the conveyor and to insure that the face of the stockpile is left in a desirably contoured shape after passage of the reclaimer.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of my reclaimer.

FIG. 2 is a fragmentary diagrammatic top view of the reclaimer of FIG. 1.

FIG. 3 is a perspective view of the improved crumber of my invention.

FIG. 4 is a fragmentary plan view of the digging wheel with the crumber of FIG. 3 in position therebehind.

FIG. 5 is a fragmentary side view of the bucket wheel and crumber area of the reclaimer of FIG. 1.

FIG. 6 is a view similar to FIG. 5 taken from a different an- 8 FIG. 7 is a diagrammatic view illustrating the conveyor end seal of this invention.

FIG. 8 is a diagrammatic side illustration of the machine illustrating the tilt of the sloper.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates generally a reclaimer 10 for moving material from a stockpile. The reclaimer 10 is a self-propelled machine having a frame 11 mounted on a plurality of tractor crawlers 12. The machine consists basically of a sloper 13 including a supporting structure such as a boom for dislodging material from the face ofa stockpile above the main body section, a bucket wheel I4 for picking up material from in front of the main body section, and a conveyor belt 15 onto which the material from the bucket wheel 14 and the material dislodged by the sloper 13 is deposited. The conveyor belt 15 extends transverse of the main body of the machine and has an extension 15a which discharges the reclaimed material either into a truck or a further conveyor system.

The reclaimer I0 is designed to move alongside a stockpile of material in a path generally parallel with a cut face of the stockpile dislodging and picking up the material therefrom. The machine is adapted to contour the face of the stockpile to a given slope thereby grooming it for another pass by the machine. It is to be understood that describing the machine as moving parallel to a cut face is to differentiate this reclaimer from the type of material handlingmachine which moves into a stockpile rather than across a face thereof.

As the machine moves past the face of the slope, an auger 16 mounted in front of the conveyor belt housing 17 cuts a groove in the face of the stockpile slope. The conveyor belt housing 17 extends into this groove. The sloper 13 consists of a boom I8 supported rotatable rod 19 from which projects a plurality of dislodging paddles 20. The rotation of the sloper l3 dislodges the material from the face of the stockpile, allowing it to run down the slope thereof to fall onto the end of the conveyor belt 15. The material from below the conveyor belt 15 is picked up by the rotating bucket wheel 14 which in turn deposits it on the conveyor I5 which runs transversely through the center of the bucket wheel. The boom 18 is mounted to the frame 11 on hinges 21 as illustrated in FIG. 5 and is tiltable at an angle transverse to the frame 11 thereby allowing the sloper 13 to produce substantially any desired angular slope of the stockpile face. 7

It is desirable that the face of the slope be completely groomed by the passing of the reclaimer 10. The angle of the slope chosen is dependent upon the material which is being reclaimed and other considerations. In order to further groom the slope, below the conveyor belt a crumber 22 is positioned alongside and behind of the bucket wheel 14. The crumber 22 has an edge thereon 23 which is angled with respect to the frame 11 and which cuts into the side of the stockpile thereby grooming it. The crumber 22 further channels the material cut by the edge 23 into an area where it will be picked up by the bucket wheel 14. Additionally, a moldboard 24 is affixed to the boom 18. The moldboard 24 is also angled with respect to the frame and directs material coming down the face of the stockpile which misses the conveyor belt into the crumber 22. The moldboard 24 also acts as a scraping edge to groom the face of the slope preventing a buildup of material thereon which has been dislodged from above. Because the moldboard 24 is attached to the boom 18 the contour which it imparts to the face of the slope is dependent upon the angle at which the boom is operating, thereby allowing a slope cut by the edge 23 of the crumber 22 to be carried out up the face of the stockpile at an angle which may be the same or different, depending upon the positioning of the boom.

FIG. 3 illustrates the crumber 22. The crumber 22 has a sidewall 26 adapted to run parallel to the face ofthe slope. Extending outwardly at an angle to the sidewall 26 is a flange 27 which defines the cutting edge 23. The edge 23 terminates in a plowlike cutting point 28 which first cuts into the stockpile. A backwall 29 acts as a guide to direct the material to an area behind the digging wheel. An attachment wall 30 extending downwardly from the backwall 29 acts as a bracketing wall for attaching the crumber 22 to the reclaimer 10. A second backwall 31 angling from the backwall 29 acts as a backstop. A sidewall 32 further cooperates with the backwall 29 to direct material to the area behind the digger wheel.

As can be seen in FIGS. and 6, the crumber 22 is mounted at a double angle to the reclaimer 10. The sidewall 26 angles upwardly, outwardly and backwardly from a point to the side of the bucket wheel below the conveyor belt end. Because of the outward angle the face of the stockpile is contoured to the desired slope by the cutting edge 23. The backward angle allows the crumber 22 to extend in back of the conveyor belt end 17 to a point below the boom 18 with the wall 31 terminating approximately level with the bottom of the boom. In this manner, reclaimed material coming down the face of the slope which misses the conveyor belt falls into the crumber 22 where, because of the backward inward angle ofthe wall 29, it is directed to the area of the bucket wheel in front ofa backup crumber 33 which is arcuately curved to serve as a backup plate to the wheel area directly behind the bucket wheel 14. As can be seen from FIG. 5, support beams 34 extend out from the framework ofthe reclaimer to the back ofthe wall 29 near the outer edge thereof to buttress the crumber 22. The wall 30 can be attached to the frame 11 of the vehicle by means such as bolts, welding or the like.

Because the slope cut by the edge 23 into the face of the stockpile is fixed by the angle at which the crumber 22 extends outwardly while the slope which is cut by the sloper 13 is dependent upon the angle at which the boom is operating, it is possible that the crumber cut slope will be at a greater or lesser angle than the slope of the stockpile face above it. It can, however, be readily seen that the crumber 22 effectively assures that the face of the stockpile will be contoured and cut below the conveyor belt and that material moving down the face of the stockpile which misses the conveyor belt will be channeled through the crumber 22 to the backup crumber 33 and the area of the bucket wheel 14. Additional features found in the crumber 22 lie in the fact that it is braced from behind and that it is angled backwardly and upwardly. The backward and upward angle of the crumber presents a sloping cutting edge 23. This slope of the cutting edge reduces the drag of the crumber as it passes along the face of the slope. This is because the angled cutting edge lifts the material being cut as well as cutting it on a diagonal thereby allowing the material to be cut with less effort. Further because the support beams 34 brace the crumber from the back thereof, the crumber is effectively pushed into the face of the stockpile slope. Of course because of the location of the braces behind the crumber it is not necessary to move the braces through either the uncut stockpile material or the material which has been loosened by the crumber. This also provides for a more secure method of attaching the crumber to the remainder of the reclaimer.

As the reclaimer 10 moves across the face of the stockpile, the sloper 13 through the rotation of the rod 19 and the paddles 20 thereon, dislodges material from the face of the stockpile. This material then runs down the face of the stockpile by the force of gravity and by the angle cut by the sloper. The sloper extends upwardly from adjacent the leading edge of the conveyor belt 15. Therefore, the majority of the material cut by the sloper will drop onto the conveyor belt. It is, however, possible that some of the material dislodged will fall to the rear of the conveyor belt. in order to prevent this occurrence, it has been known in the prior art to have the leading upright column of the boom rest against the face of the cut slope thereby providing a backstop adjacent the trailing edge of the conveyor belt against which the dislodged material will strike, thereby channeling it down onto the conveyor belt area. However, it is still possible for dislodged material to overrun this leading upright column as well as it is possible for the column itself to dislodge further material by its passing. This material in the prior art devices could then slide down the face of the slope, missing the conveyor and the bucket wheel.

In the present invention, part of this material is recovered simply because the crumber 22 extends rearward of the conveyor belt and the leading upright column 35 of the boom. Therefore material falling between the back of the crumber 22 and the trailing edge of the conveyor is reclaimed by the crumber which directs it to the bucket wheel area. In order to insure that all of the dislodged material is directed to either the conveyor or the bucket wheel area, a moldboard 24 is mounted on the boom 18. The moldboard is an arcuately contoured chute which has an outer scraping edge 36 adapted to scrape the face of the stockpile. The moldboard 24 extends across the boom from the trailing column 37 thereof to an area directly above the crumber 22. The moldboard 24 is angled so that its trailing or upper end extends well above the end 17 of the conveyor belt. In this manner, as the reclaimer 10 moves across the face of the stockpile, any material dislodged by the sloper which would fall behind the crumber 22 is redirected by the moldboard into the crumber and thence, of course, into the bucket wheel area. The moldboard 24 also serves the additional function of further contouring the slope.

In order to allow the material dislodged by the sloper 13 to fall directly onto the conveyor 15, as the reclaimer moves across the face of the stockpile, an auger 16 positioned immediately in front of the end 17 of the conveyor 15 forms a ledge in the face of the stockpile. The auger 16 has a diameter slightly greater than the height of the end 17. The ledge is created so that the conveyor, which of necessity has a height dimension at the end thereof to allow reversal of the endless belt, to be brought as close as possible to the angled face of the stockpile.

FIG. 7 illustrates the ledge and conveyor end. The ledge 40 formed by the auger 16 is cut into the face 41 of the stockpile 42 with a bottom wall 43 parallel to the ground and a backwall 44 extending at right angles thereto vertical to the ground. The ledge 40 may at times be cut into the face 41 to an extent great enough to produce a top wall which may thereafter crumble onto the conveyor. However, because the auger 16 extends out beyond the end face 45 of the end 17 of the conveyor housing, the conveyor housing never contacts the backwall 44. This provides a vertical channel 46 between the backwall 44 and the front wall 45 of the end of the conveyor housing. Combined with this is a space 47 below the end 17 of the conveyor housing and above the bottom wall 43 of the ledge 40. Material dislodged by the sloper 13 which slides down the face 41 of the stockpile can enter the

space

45 and ,40 thereby missing the conveyor 15. In order to prevent this, I

have provided a seal 48 to close the space 46.

The seal 48 consists, in a preferred embodiment, of a triangular-shaped projection extending outwardly from the end wall 45 of the end 17 of the conveyor housing. The point 49 of the seal 48 then projects into the stockpile 42 through the backwall 44 of the ledge 40. The top 50 of the seal 48 is coplanar with the top of the housing 17. Therefore, material running down the face 41 of the stockpile 42 is prevented by the seal from entering the space 46 of the ledge and is directed onto the conveyor belt I5. Because of the small axial height and pointedness of the seal 48, the drag created by its movement through the stockpile 42 is not great. It is of course to be understood that the seal could take the form simply ofa planar projection of small axial height. It is also anticipated that the seal 48 can be doubly tapered having a shorter axial height at its leading edge to aid in cutting into the stockpile.

As can be seen from FIG. 5, the seal 48 extends across the entire width ofthe end 17 of the conveyor belt housing. In this manner, an effective continuous seal is obtained for the full width ofthe conveyor belt.

In the prior art reclaimers, the sloper has extended perpendicularly above the reclaimer at an angle to the side thereof. In this manner, the top and the bottom of the sloper lay in the same plane and the sloper dislodged a straight line of material as it moved across the face of the stockpile. In reclaiming relatively loose materials, as the material begins to slide down the pile, it tends to avalanche the loose material on the face of the pile. This can bring down greater quantities of material than would simply be dislodged by the action of the sloper. Further, because of the avalanche effect, the materials tend to erode themselves forming ravines into the face of the stockpile which may move the face back by as much as 20 or 30 feet. Not only does this provide uneven removal of material during the initial pass of the reclaimer across the face, but because of the ravines thereby created it becomes extremely difficult to create a continuous flow of material on subsequent passes.

In order to overcome this, I have angled the sloper on my reclaimer 10. The top of the sloper 51 projects in front of the bottom 52 thereof. The desired degree of projection depends upon the material being reclaimed and the length of the sloper.

The forward projection of the top 51 of the sloper 13 is illustrated in FIG. 8. The line 53 represents the greatest forward projection of the sloper cutters 20 at the bottom 52 of the sloper. The line 54 represents the greatest forward projection of the cutters 20 at the top SI thereof. It is anticipated that the distance D between the

lines

53 and 54 may vary dependent upon stockpile material from as little as 6 inches to as much as 6 feet. It is also to be noted that the line 53 is adjacent the leading edge 55 of the conveyor and is spaced just slightly behind it. In this manner, material dislodged by the bottom 50 of the sloper will fall to the conveyor belt. Although material dislodged by the top 51 of the sloper, which would fall in a vertical line therefrom, would miss the conveyor belt, this is provided for by the forward movement of the reclaimer 10. That is to say that by the time the material dislodged by the top 51 of the sloper has traversed the height of the stockpile to the point of the conveyor belt 15, the forward movement of the reclaimer will have brought the conveyor belt underneath the falling stream.

The angular lead of the sloper effectively prevents erosion of the face of the stockpile by causing the initially dislodged material to fall down the face of the slope over material which has not yet been dislodged by the sloper. Therefore, any initial part of erosion is stopped by the passing of the sloper over that point. In this manner, although erosion can still occur due to the falling of the dislodged material, it is immediately checked by the effect of the sloper passing over the point where the erosion is beginning to occur.

Angling the sloper forward also has the additional advantageous effect of compensating for the forward movement of the reclaimer 10 during operation. It is obvious that it takes a longer period of time for material dislodged at the top of the sloper to reach the level of the conveyor than for material dislodged by the bottom. This increased length of time can cause the material dislodged by the top of the sloper to miss the conveyor belt in that by the time it reaches the bottom of the sloper, the conveyor belt has moved past that point due to the foreward movement of the reclaimer 10. As is discussed above, this is now compensated for by dislodging the material at the top of the sloper prior to the time the conveyor belt reaches a point vertically below the dislodging point.

FIG. 2 illustrates the reclaimer 10 in a fragmentary birds eye view. The crawlers 12, the bucket wheel 14, the auger l6, and the sloper rod 19 as well as the other operating elements of the reclaimer 10 are all powered by an engine 55 carried by the frame 11. As can be seen from FIG. 2, the bucket wheel 14 is offset to one side of the main frame 11 of the reclaimer. This allows the bucket wheel area to be closely spaced to the foot of the stockpile slope. FIG. 2 also illustrates how the bottom 52 of the sloper is positioned above the leading edge 56 of the conveyor 15. This allows the sloper to contour the face of the stockpile and to dislodge material therefrom almost directly to the point where the auger l6 begins to cut into the face of the slope to prepare the ledge for the conveyor belt housing.

It can therefore be seen from the above that my invention provides for a new and improved reclaimer which is designed to insure the fact that the totality of the material dislodged by the sloper is directed to the conveyor belt either by falling directly thereonto or by channeling material which misses the conveyor to the bucket wheel area. The improved reclaimer alleviates the problems of avalanche and erosion and provides a method effectively contouring the slope in preparation of subsequent passes by the reclaimer.

Although I have herein set forth my invention with respect to certain specific principles and details thereof, it will be understood that these may be varied without departing from the spirit and scope of the invention as set forth in the hereunto appended claims.

Iclaim:

I. A material handling machine for recovering material from a stockpile comprising: a frame having frame propelling means, a digging wheel secured to said frame, a conveyor positioned on the frame receiving materials from the digging wheel, a sloper mounted on the frame and angled upwardly and away from one side of the digging wheel for dislodging material from the stockpile so that it may run down the face of the stockpile and be deposited directly on said conveyor. means for varying the angle of the sloper to the side of said frame, and said sloper being disposed at a second angle to the frame with the top of said sloper preceding the bottom thereof in the operating direction of movement of said machine.

2. A reclaimer comprising a main frame, means for propelling said frame, a digging wheel mounted on one side of the frame, a sloper pivotally mounted on said one side of the frame and extending on an inclined angle upwardly and outwardly to one side of the wheel for resting on a surface of a pile to be reclaimed and to cut the surface thereof, a crossconveyor positioned adjacent a lower end of the sloper and extending through the digging wheel for receiving dug materials from said digging wheel and for also directly receiving material cut by said sloper, means for changing the inclined angle of the sloper relative to the main frame, and said sloper having an upper portion positioned in front of the lower portion in a direction of operative movement and extending in front of said cross-conveyor so that material cut from the surface of the pile by the upper portion of the sloper is being acted on by the lower portion of the sloper as it cuts the surface of the pile.

3. A reclaimer of claim 2 wherein the said upper portion is positioned in front of the bottom of the lower portions a distance from 6 inches to 6 feet.

4. A material handling machine for reclaiming material from a stockpile of bulk material while moving generally parallel to a face thereof comprising a frame having a wheel area on one side, means for propelling said frame, a bucket wheel mounted on said frame in said wheel area to pick up material from the wheel area and deposit it on a conveying means, said conveying means extending substantially transverse to said frame and beyond the one side of the frame to terminate in close spaced relationship to a portion of the face of the stockpile, and a sloper carried by a boom to dislodge material from the face of said pile above said conveying means, said boom carried by the frame and being tiltable with respect thereto to the one side thereof to control the slope of the face, the bottom of said sloper lying above the plane of said conveying means and spaced therefrom a short distance, said sloper being tilted with respect to the frame with the top thereof lying in a plane in front of the plane of the bottom thereof and preceding the conveyor means in a direction of operating movement of said machine whereby during operation of the machine the bucket wheel picks up and deposits material on the conveying means while material dislodged by said sloper falls down the face by force of gravity onto the conveying means which is moving across the face in an operative direction of the machine.

5. A reclaimer comprising a main frame, means for propelling said frame, a digging wheel mounted on one side of the frame, a sloper mounted on said one side of the frame and extending on an inclined angle upwardly and outwardly to one side of the wheel for resting on a surface of a pile to be reclaimed and to cut the surface thereof, and a cross-conveyor positioned adjacent a lower end of the sloper and extending through the digging wheel for receiving dug materials from said digging wheel and also directly receiving material cut by said sloper, said sloper having an upper portion positioned in front of the lower portion in a direction of operative movement and extending in front of said cross-conveyor so that material cut from the surface of the pile by the upper portion of the sloper is being acted on by the lower portion of the sloper as it cuts the surface of the pile.

Claims

1. A material handling machine for recovering material from a stockpile comprising: a frame having frame propelling means, a digging wheel secured to said frame, a conveyor positioned on the frame receiving materials from the digging wheel, a sloper mounted on the frame and angled upwardly and away from one side of the digging wheel for dislodging material from the stockpile so that it may run down the face of the stockpile and be deposited directly on said conveyor, means for varying the angle of the sloper to the side of said frame, and said sloper being disposed at a second angle to the frame with the top of said sloper preceding the bottom thereof in the operating direction of movement of said machine.

2. A reclaimer comprising a main frame, means for propelling said frame, a digging wheel mounted on one side of the frame, a sloper pivotally mounted on said one side of the frame and extending on an inclined angle upwardly and outwardly to one side of the wheel for resting on a surface of a pile to be reclaimed and to cut the surface thereof, a cross-conveyor positioned adjacent a lower end of the sloper and extending through the digging wheel for receiving dug materials from said digging wheel and for also directly receiving material cut by said sloper, means for changing the inclined angle of the sloper relative to the main frame, and said sloper having an upper portion positioned in front of the lower portion in a direction of operative movement and extending in front of said cross-conveyor so that material cut from the surface of the pile by the upper portion of the sloper is being acted on by the lower portion of the sloper as it cuts the surface of the pile.