US1754276A - Loading machine - Google Patents

Description

April 15, 1930. LEVIN 1,754,276

LOADING MACHINE Original Filed July 21, 1921 2 Sheets-Sheet l l/VVENTOR 760.1% BY J April 15, 1930. N, D, L v I 1,754,276

LOADING MACHINE Original Filed July 21, 1921 2 Sheets-Sheet 2 1N VEN TOR 01.5 Jaw A TTORNE Y Patented Apr. 15, 1930 SATES NILS D. LEVIN, OF COLUMBUS, OHIO, ASSIGNOR TO THE JEFFREY MANUFACTURING COMPANY, OF COLUMBUS, OHIO, A CORPORATION OF OHIO LOADING MACHINE Application filed July 21, 1921 Serial No. 486,650. Renewed February 19, 1929.

The present invention relates to certain new and useful improvements in loading machines adapted to gather the dislodged coal from the floor of a mine and load it into suitably disposed cars for transportation from the mine.

The usual method of mining coal comprises the drilling of holes into the body of the vein, and the explosion therein of suitable explosive to blast out fragments which are afterwards loaded into cars for transportation from the mine.

It is a common, though not universal, practice to form kerfs in the coal body, usually as near the mine floor as possible, to facilitate the breaking down of the coal above the kerf. These kerfs are commonly formed by mining machines having supporting devices positioned in a somewhat lower plane than the cutting devicesby which the kerfs are produced, resulting in an uneven floor composed of a succession of offsets, or steps. Numerous attempts have been made to adapt loading machines, comprising conveyors asa sociated with gathering devices of various sorts, to the mechanical taking up of the loose,

broken coal from the floor of the mine and loading it into suitably positioned cars for transportation from the mine. The irregularities of the mine floor produced by the action of the mining machine above referred to, or to the irregular breaking of the coal when no under kerf is formed, have constituted obstructions which seriously interfere with the economical operation of loading machines such as have been heretoforeconstructed. Frequently the force of the blast is expended without thoroughly disrupting the coal which is left standing in comparatively large fragments interlocked in a mass too compact to be handled by the gathering devices of the machine heretofore constructed. In such cases these interlocked fragments must be manually dislodged, mac terially increasing the labor of loading and correspondingly reducing the eflicieney of the machine.

It is the especial object of this invention to provide an improved machine adapted to expeditiously and conveniently remove broken coal from the floor of a mine chamber and load it into suitably disposed cars for transportation from the mine.

A further object is to provide a machine of the class described having gathering devices adapted to engage the masses of coal which have been partially shattered by the blast and complete its disruption to render possible the the class described having means to vertically adjust the bottom coal dislodging mechanism to cause it to follow the inclinations of the strata.

The devices by which I attain these objects are fully set forth in the following specification and illustrated in the accompanying drawings of which Fig. 1 is a general plan view of one embodiment of my invention.

Fig. 2 is a side elevation of the machine illustrated in Fig. 1.

Fig. 3 is a fragmentary plan view having certain parts broken away to disclose the poyger devices by which the machine is actuate Fig. 4 is a section taken along the line IVIV of Fig. 1.

Fig. 5 is a section taken along the line VV of Fig. 4:.

Fig. 6 is a detail of the feeding mechanism.

Fig. 7 is a diagrammatic view illustrating one method of operating the machine.

Like numerals refer to similar parts in the several figures.

Preferably my improved loading machine is mounted upon a base plate 1 adapted to rest upon and slide over the floor of the mine.

Extending longitudinally of the base plate 1 is a main conveyor which may be of any preferred construction. For purposes of i1- lustration I have shown a conveyor 2 of the type illustrated in Patent 1,351,953 issued to me on September 7th, 1920, which comprises an elongated trough 3 along which travels a plurality of spaced scraper cross bars 4 attached to and propelled by a pair of endless chains which are not shown in the drawings. As conveyors of this type are well known in the art and as its details form no part in the present invention further description is not thought to be required at this time. This conveyor has a receiving portion disposed in horizontal planes adjacent the mine floor, and an inclined elevating portion adapted to lift the coal to a suitable elevation above the mine floor. The trough 3 is provided with side plates 5 and 6 to prevent the overflow of material along the sides of the conveyor. At its forward end the side plate 5 is extended beyond the end of the conveyor to form a guard 7 to limit outward movement of the coal when acted upon by the gathering mechanism.

I have also provided a transversely extending delivery conveyor 8 adapted to receive material from the main conveyor and discharge it over the side of a mine car 9 suitably positioned upon a track 10 which extends parallel to the working face of the coal. This delivery conveyor may be of any preferred type. For purposes of illustration I have shown aconveyor of the same general class as that illustrated in Patent No. 1,246,762, issued to me on November 13th, 1917, and comprising two parallel troughs 11 and 12 positioned in the same horizontal plane one at each side of the guide frame 13. Around the guide frame 13 travels a suitable endless chain, not shown in the drawings, which propels the laterally extending scraper flights 14 by which material is propelled along the trough 11. As such conveyors are well known in the art, and as its details form no part of the present invention, further description is not thought to be required at this time.

Mounted upon the base plate 1 is a motor 15 by which the several elements of the machine are actuated. This motor may be of any preferred type suitable to the conditions under which the machine is operated. For purposes of illustration I have shown an electric motor which may receive electric current in any convenient manner from any convenient source of supply, and which may be controlled through any suitable controlling clevices, but as such devices are well known in the art and form no part in the present invention their illustration and description is not thought to be required at this time.

The motor 15 is provided with a pinion 16 connected through a train of gears 17, 18 and 19 with a power shaft 20 supported in suitable bearings of the main frame. To the power shaft 29 is attached a sprocket wheel 21 which is connected by a suitable chain 22 with a similar sprocket wheel 23 on the counter shaft 24. The counter shaft 24 is supported in suitable journal bearings of the main frame and is connected through a pair of spur gears 25 and 26 with the conveyor driving shaft 27 upon which are mounted two sprocket wheels 28 adapted to engage the chains of the conveyor 2 to drive them. Power is transmitted from the counter shaft 24 through the sprocket wheels 29 and 30 and the driving chain 31 to the driving shaft 32 of the auxiliary conveyor. The shaft 32 carries a bevel gear 33 which engages a similar bevel gear 34 upon the vertical head shaft 35 of the auxiliary conveyor to actuate it.

Fixed to the power shaft 20 is an eccentric 36 having an eccentric rod 37 connected with a rocker arm 38 adapted to oscillate about the feed shaft 39. The feed shaft 39 is supported in suitable journal bearings of the main frame and carries a ratchet wheel 40 arranged to be engaged by a pawl 41 mounted upon the rocker arm 38. When the power shaft 20 revolves the eccentric 36 causes the oscillation of the rocker arm 38 and, through the engagement of the pawl 41 with the ratchet 40 causes the revolution of the feed shaft 39. A second pawl 42 mounted upon the frame work of the machine is arranged to engage the ratchetwheel 40 to prevent retrograde movement thereof.

Mounted for free rotation upon the feed shaft 39 is a winding drum 43 which is connectable with said shaft by suitable clutch mechanism of any preferred type, but as such clutches are well understood in the art and form no part in the present invention further description and illustration is not thought to be required at this time. Suitable means, such as the operating lever 44, is provided for the control of said clutch mechanism and the engagement or disengagement of the winding drum with the feed shaft. VVindable upon the drum 43 is a feed rope 45 the free end of which is adapted to be connected with a suitable anchor jack 46 positioned in advance of the machine. When the winding drum 43 is caused to revolve to wind the rope 45 the tension upon said rope tends to draw the machine bodily towards the anchor jack 46 and thereby feed the apparatus to its work. The reaction of the gathering mechanism upon the material which is to be loaded tends to crowd the rear end of the machine outwardly from the coal face and T have provided a strut 47 having a sliding shoe 48 adapted to engage the rails of the mine track 10 to counteract such tendency and maintain the machine in proper working relation.

As shown in the drawings, the gathering mechanism comprises an elongated frame 49, similar to the cutter frame of the well known shortwall mining machine. This gathering frame 49 extends perpendicularly inward from the forward end of the main conveyor, and is provided upon its edges with guide ways in which travels an endless cutter chain having outwardly extending sockets for the attachment of renewable cutter bits 51. The gathering frame 49 is arranged to rock about its longitudinal axis and is attached to the base plate 1 by a hinge 52. The inner end of the gathering frame 49 is supported upon a similar hinge 53 mounted on a supplemental base plate 54 which is slidable upon the mine floor and is connected to the main frame of the machine by a diagonal brace bar 55. Projecting outwardly from the gathering frame 49 is an arm 56 to which is pivotally connected a nut 57 having an adjusting rod 58 screw threaded therein. The adjusting rod 58 extends rearwardly of the machine through a suitable journal bearing 59 attached to the main frame, and is provided with a hand wheel 60 by which it may be rotated to cause the gathering frame 49 to rock about the axes of the hinges 52 and 53. The cutter chain 50 is actuated in the usual manner by a suitable sprocket wheel attached to the vertical head shaft 61 which is journaled in suitable bearings 62 attached to the gathering frame. Upon the upper end of the head shaft 61 is fixed a miter gear 63 in operative engagement with a similar gear 64 attached to the driving shaft 65. The driving shaft 65 is supported in suitable bearings 66 and is provided with a sprocket wheel 67 connected by a suitable driving chain 68 with the sprocket wheel 69 upon the counter shaft 24.

When now the motor is actuated the cutter chain 50 will be driven in such direction that the cutter bits 51 travel outwardly along the forward edge of the gathering frame to engage material upon the mine floor and propel it to the main conveyor 2 and up the inclined shoe 70 onto said conveyor. Normally the gathering frame 49 is so adjusted that the lowermost cutter bits operate at the line of the mine floor and engage material at'that level to move it onto the conveyor, and the character of the bits 51 is such that bottom coal left adhering to the substratum will be cut or torn loose therefrom and loaded with the material dislodged from above the kerf. It frequently happens that the force of the blast is expended without completely dislodging the coal above the kerf, leaving it in a compact mass of partially-severed fragmentsso interlaced that they will not fall when material below them is removed by the cutter bits 51. In such a case the forward edge of the gathering frame 49 may be adjusted upwardly, by the manipulation of the hand wheel 60, to cause the cutter bits to engage the over hanging and interlocking fragments of coal and tear them apart, after which the gathering frame may be returned to its initial position with the cutter bits operating along the floor of the mine in position to engage the smaller fragments of coal and drag them onto the conveyor. A

guard plate 71 attached to the gathering frame 49 prevents the coal from falling over the gathering mechanism onto the floor of the mine in the rear thereof.

Machines such as are above described are especially adapted to use in mines operated upon the longwall system of mining. In such a mine the coal is undercut and blasted down, or otherwise prepared, along a face of considerable length, and the track 10 is arranged in suitable relation parallel to the working face. The loading machine is initially positioned at one end of the face,

the strut shoe 47 is arranged to engage the 7/ track rail 10, and the feed rope 45 sufliciently unwound from the winding drum 43 and attached to the anchor jack 46 positioned adjacent the pile of dislodged material and in advance of the machine. The mine cars 9 may be arranged in a continuous train upon the track 10 with the first car in suitable position beneath the delivery conveyor 8. As the machine advances along the coal face material is taken up by the gathering mechanism from the end of the pile, is carried rearward and upward by the main conveyor, and loaded by the delivery conveyor into the cars. Commonly a mine locomotive is provided to move the train relative to the loading machine at such a speed that the coal will be distributed throughout the entire length of the train without interrupting the operation of the machine. It is obvious however that the cars may be handled separately, but with a less efficient use of the apparatus.

What I claim is:

1. In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over-the mine floor, a conveyor extending longitudinally of said frame adapted to receive material at points adjacent the mine floor and discharge it at a suitable elevation, means upon said frame adapted to bodily move said frame over the mine floor, means to guide the machine in a predetermined path, and a plurality of coal engaging elements adapted to travel along a path extending substantially perpendicularly towards and over the receiving end of said conveyor to engage material upon the mine floor and transfer it to said conveyor.

2. In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over the mine floor, a conveyor extending longitudinally of said frame and adapted to receive material at points adjacent the mine floor and discharge 1t at a suitable elevation, means on said frame adapted to bodily move said frame over the mine floor, means to guide the ma chine in a predetermined path, and a plurality of coal engaging elements adapted to travel along a horizontal path extending towards the receiving end of said conveyor perpendicular to the longitudinal lines thereof and adapted to engage material upon the mine floor and transfer it to said conveyor.

3. In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over the mine floor, a conveyor extending longitudinally of said frame adapted to receive material at points adjacent the mine floor and discharge it at a suitable elevation, means upon the frame adapted to bodily move sai d frame over a mine floor, means to guide the machine in a predetermined path, and a plurality of coal engaging elements adapted to travel along a horizontal path extending towards the receiving end of said conveyor and perpendicular to the longitudinal lines thereof to engage material in advance of the machine and transfer it to said conveyor, and means to vertically adjust the path of travel of said coal engaging elements from positions adjacent the mine floor to positions elevated above said floor.

4. In a machine for loading coal in mines, the combination with a suppor ing frame adapted to rest upon and slide over the floor of the mine, a conveyor extending longitudinally of said frame and adapted to receive material at points adjacent the mine floor and discharge it at a suitable elevation, means upon said frame adapted bodily to move said frame over a mine floor, means to guide the machine in a predetermined path, a horizontally extending guide frame projecting perpendicularly from the receiving end of said conveyor, an endless chain adapted to travel in guide ways along the edges of said frame, renewable cutter bits attached to said chain, means to drive said chains in a direction to cause said cutter bits to travel along the advancing side of said guide frame towards and over the receiving end of said conveyor to engage material upon the mine floor and transfer it to said conveyor.

5. In a machine for loading coal in mines, the combination with a supporting frame ada ted to rest upon and slide over the floor of t e mine, a conveyor extending longitudinally of said frame and adapted to receive material at points adjacent the mine floor and discharge it at a suitable elevation, means upon said frame adapted bodily to move said frame over a mine floor, means to guide the machine in a predetermined path, a horizontally extending guide frame projecting perpendicularly from the receiving end of said conveyor, an endless chain adapted to travel in guide ways along the edges of said frame, renewable cutter bits attached to said chain, means to drive said chain in a direction to cause said cutter bits to travel along the advancing side of said guide frame towards the receiving end of said conveyor to engage material in advance of the machine and transfer it to said conveyor, and means to vertically adjust the chain guide ways to cause the cutter bits to travel in planes adjacent the mine floor or elevated above said floor.

6. In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over the floor of the mine, a conveyor extending longitudinally of said frame and adapted to receive material at points adjacent the mine floor and discharge it at a suitable elevation, means upon the frame adapted bodily to move said frame over a mine floor, means to guide the machine in a predetermined path, a horizontally extending guide frame projecting perpendicularly from the receiving end of said conveyor, an endless chain adapted to travel in guide ways along the edges of said guide frame, renewable cutter bits attached to said chain, means to drive said Chain in a direction to cause the cutter bits to travel along the advancing side of said guide frame toward the receiving end of said conveyor, and means to rotate said guide frame about an axis extending longitudinally thereof to cause said cutter bits to travel in planes at the level of the mine floor or at levels above said floor.

7. In a machine for loading coal in mines, the combination With a conveyor adapted to receive material at points adjacent the mine floor, means to move said conveyor bodily relative to the material to be loaded, a plurality of coal engaging elements adapted to travel along a non-circular orbital path to engage material in advance and at one side of the machine and transfer it to said conveyor, and means to adjust said coal engaging elements to operate at planes at the level of the mine floor or planes above said floor.

8. In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over the mine floor, a conveyor extending longitudinally of said frame adapted to receive material at points acent the mine floor and discharge it at a suitable elevation, means upon the frame adapted bodily to move said frame over a mine floor, means to guide the machine in a predetermined. path, and a plurality of coal engaging elements adapted to travel along a horizontal path extending towards the receiving end of said conveyor and perpendicular to the longitudinal lines thereof to engage material in advance of the machine and transfer it to said conveyor, and means to vertically adjust the path of travel of said coal engaging elements from positions adjacent the mine floor to positions elevated above said floor.

9, In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over the floor of the mine, a conveyor extending longitudinally of said frame and adapted to receive material at points adjacent the mine floor and discharge it at a suitable elevation, means upon said frame adapted bodily to move said frame over a mine floor, means to guide the machine in a predetermined path, a horizontally extending guide frame projecting perpendicularly from the receiving end of said conveyor, an endless chain adapted to travel in guide ways along the edges of said frame, coal engaging elements attached to said chain, means to drive said chain in a direction to cause said coal engaging elements to travel along the advancing side of said guide frame towards the receiving end of said conveyor to engage material in advance of the machine and transfer it to said conveyor, and means to vertically adjust the chain guide ways to cause the coal engaging elements to travel in planes adjacent the mine floor or elevated above said floor.

10. In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over the floor of the mine, a conveyor extending longitudinally of said frame and adapted to receive material at points adjacent the mine floor and discharge it at a suitable elevation, means upon the frame adapted bodily to move said frame over a mine floor, means to guide the machine in a predetermined path, a horizontally extending guide frame projecting perpendicularly from the receiving end of said conveyor, an endless chain adapted to travel in guide ways along the edges of said frame, coal engaging elements attached to said chain, means to drive said chain in a direction to cause said coal engaging elements to travel along the advancing side of said guide frame towards the receiving end of said conveyor, and means to rotate said guide frame about an axis extending longitudinally thereof to cause said coal engaging elements to travel in planes at the level of the mine floor or at levels above said floor.

11. In a machine for loading coal in mines, the combination with a supporting frame adapted to rest upon and slide over the mine floor, an elongated conveyor extending longitudinally of said frame and adapted to receive material at points adjacent the mine floor and discharge it at suitable elevations, means upon the frame adapted bodily to move said frame over a mine floor, means to guide the machine along lines parallel with a coal face, and gathering devices disposed laterally of and moving substantially perpendicularly to the conveyor adapted to engage material upon the mine floor and move it laterally towards and onto the conveyor.

12. In a machine for loading coal in mines, the combination of a conveyor adapted to receive material at points adjacent the mine floor, a plurality of coal engaging elements disposed laterally of said conveyor and traveling in a non-circular path to engage material and transfer it to said conveyor, and

means to adjust said coal engaging elements relative to said conveyor to operate in difierent planes.

13. In a-machine for loading coal in mines, the combination with a conveyor adapted to receive material at points adjacent the mine floor, a plurality of coal engaging elements disposed laterally of said conveyor and traveling in. a non-circular path to engage material in advance of the machine and transfer it to said conveyor, pivotal support for said coal engaging elements, and means to adjust Said coal engaging elements on said pivotal support relative to said conveyor to operate in difierent planes.

1d. I11 a machine of the class described, the combination of a main conveyor section, a material gathering and conveying section extending laterally from one end of said main section and adapted to gather and deliver material thereto, means for raising and lowering said gathering and conveying section, and a material delivering conveyor section 8X- tending angularly from the other end of said main section adapted to receive material and deliver it. from said main section to suitable receptacles.

15. In a machine of the class described, the combination of a main conveyor section adapted to be disposed laterally parallel to a mine track, a material gathering and conveying section extending laterally from one end of said main section and adapted to gather and deliver material thereto, a material delivering conveyor section extending angular- 1y from the other end of said main section adapted to receive material and deliver it from said main section to suitablereceptacles, power mechanism to advance said machine, and means cooperating with the mine track tending to maintain said advancing machine parallel to the mine track.

16. In a machine of the class described, the combination of a main inclined conveyor section, adapted to be disposed laterally parallel to a mine track, a material gathering and conveying section extending laterally from the lower end ofsaid main section at right angles thereto, and close to the mine floor and adapted to gather and deliver material to said main section, amaterial delivering conveyor sectionextending in an opposite direction from the upper end of said main section and adapted to receive and deliver material therefrom to suitable receptacles, power mechanism to advance said machine, and means at the rear of the machine cooperating with the mine track to resist turning thrusts against said gathering and conveying section and tend to maintain the machine parallel to the mine track.

17. In a machine of the class described, the combination of a main inclined conveyor section, adapted to be disposed parallel to a mine track, a material gathering and conveying section extending laterally from the lower end of said main section at right angles thereto and close to the mine floor and adapted to gather and deliver material to said main section, a material delivering conveyor section extending in an opposite direction from the upper end of said main section and adapted to receive and deliver material therefrom to suitable receptacles, power mechanism to ad- Vance said machine, and a thrust bar extending from the machine near the rear and adapted to engage a fixed abutment to resist turning thrusts against said gathering and conveying section and tend to maintain the machine parallel to the mine track.

18. In a machine of the class described, an elongated conveyor, a gathering device extending angularly from the receiving end of said conveyor and rigidly connected to the frame of the latter, means for advancing said conveyor and therewith said gathering device into a pile of material, and a strut at the opposite side of said conveyor from said gathering device adapted for slidable contact With a fixed exterior abutment extending longitudinally of said conveyor, whereby the latter is guided substantially parallelly to said abutment.

19. In a machine of the class described, the combination of a main conveyor section, a material gathering and conveying section laterally disposed at one end of said main section, means for adjusting said gathering and conveying section to Work in different horizontal planes relative to said main section, and longitudinally traveling means on said gathering and conveying section to gather and deliver material to said main section.

20. In a machine of the class described, the combination of a main conveyor section, a material gathering and conveying section laterally disposed at one end of said main section and pivotally mounted for adjustment to Work in different horizontal planes immediately adjacent the receiving end of said main conveyor section, and longitudinally traveling means on said gathering and conveying section to gather and deliver material to said main section.

21. In a machine of the class described, the combination of a main conveyor section, a material gathering and conveying section laterally disposed at one end of said main section, a gathering and conveying chain mounted on said gathering and conveying section to gather and deliver material to said main section, and a substantially vertical guard plate on said gathering and conveying section to prevent material from passing to the rear thereof.

22. In a machine of the class described, the combination of a main conveyor section, a material gathering and conveying section laterally disposed at one end of said main section, a gathering and conveying chain mounted on said gathering and conveying section to gather and deliver material to said main section, and a substantially vertical guard plate between the runs of the chain to prevent material from passing to the rear thereof.

23. In a machine of the class described, the combination of a main support adapted to be moved over a mine floor, a main conveyor section mounted on said support, a fixed auxiliary support extending laterally from said main support at a point adjacent one end of said main conveyor section, material gathering and conveying means mounted for adj ustment to Work in different horizontal planes on said auxiliary support relative to said main conveyor section, and a gathering and conveying chain mounted on said gathering and conveying means to gather and deliver the material to said main conveyor section.

24.. In a machine of the class described, the combination of a main support adapted to be moved over a mine floor, a main conveyor section mounted on said support, a fixed auxiliary support extending laterally from said main support at a point adjacent one end of said main conveyor section, an arm extending longitudinally of said auxiliary support and pivoted thereto and a gathering and conveying chain mounted on said arm to gather and deliver the material to said main conveyor section.

25. In a machine of the class described, the combination of a main support adapted to be moved over a mine floor, a main conveyor section mounted on said support, an auxiliary support extending laterally from said main support at a point adjacent one end of said main conveyor section, an arm extending longitudinally of said support and pivoted thereto, manually operable means to rock said pivotally mounted section on said auxiliary support for operation in different horizontal planes, and a gathering and conveying chain mounted-011 said arm to gather and deliver the material to said main conveyor section.

26. In a machine of the class described, the combination of a main support adapted to be moved over a mine floor, a main conveyor section mounted on said support, a fixed auxiliary support extending laterally from said main support at a point adjacent one end of said main conveyor section, an arm extending longitudinally of said auxiliary support and pivoted thereto at one side of its longitudinal center, and a gathering and conveying chain mounted on said arm to gather and deliver the material to said main conveyor section.

27. In a machine of the class described, an elongated frame, an endless chain traveling around said frame, cutter bits carried by said chain, and a support adjacent each end of said frame adapted to support the frame in transversely tilted operative position with the outer ends of the bits on the lower run of ill the chain in proximity to the surface on which the supports rest.

28. In a machine of the class described, an elongated frame, an endless chain travelling around said frame, cutter bits carried by said chain, and a support connected to said frame therebeneath substantially within the vertical projection thereof and adapted to sup- .port the frame for transverse tilting movements about a fulcrum disposed beneath the frame.

29. In a machine of the class described, an elongated frame, an endless chain travelling around said frame, cutter bits carried by said chain, and a plurality of pedestals connected to said frame adj acent' its ends and substantially within its lateral vertical bounding planes and adapted to support the latter in transversely tilted operative position.

80. In a machine of the class described, an elongated frame, an endless chain travelling around said frame, cutter bits carried by said chain, a plurality of shoes supporting said frame adjacent its ends, and means for tilting the frame transversely on said shoes.

31. In a machine of the class described, an elongated frame, an endless chain travelling around said frame, cutter bits carried by said chain, a support connected to said frame therebeneath and adapted to support the latter in transversely tilted operative position, and a horizontally and rearwardly extending bar attached to said support and operable to exert moving effort on said support to move the frame and thereby operatively engage the cutter bits.

32. In a machine of the class described, an elongated frame, an endless chain travelling around said frame, cutter bits on said chain, a plurality of shoes in connection with said frame adjacent its ends and supporting the frame in transversely tilted operative posi tion with the outer ends of the bits on the lower run of the chain in proximity to the surface on which the shoes rest, and means to exert simultaneous moving efiort on said shoes to move the frame and thereby operatively engage the cutter bits.

33. In a machine of the class described, an elongated frame, an endless chain travelling around said frame, cutter bits on said chain, a plurality of supporting shoes in connection with said frame adjacent its ends, means to exert simultaneous motive effort on said shoes to move the frame and thereby operatively engage the cutter bits, and means to tilt the frame transversely to bring the longitudinal runs of the chain into different operating planes With the bits on the lower run closely adjacent the floor upon which the shoes rest.

34:. In a machine of the class described, the combination of a main conveyor section adapted to receive material at points adjacent the main floor and comprising an elonture.

NILS D. LEVIN.

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