US1728075A - Coal-breaking machine - Google Patents

Description

p 10, 1929. B. NORTON 1,728,075

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UNITED STATES BERTRAM NORTON, OF CLAVERLEY, ENGLAND.

COAL-BREAKING MACHINE.

Application filed October 15, 1927, Serial No. 226,465, and in Great Britain June 29, 1927.

This invention relates to machines for breaking coal or other friable material and in particular to machines of the class furnished with picks which are reciprocated in a vertical direction to strike and break up the coal as it is carried into position upon a horizontal conveyor.

It is recognized that by the use of machines of this type, a smaller percentage of fine or very small particles is obtained than with crushing machines of the roller type but the present invention aims at enabling the coal to be broken with the production of even less small or waste material than heretofore. It is found that the more direct the blow delivered by the picks, the more efi'ective is the breaking of the coal and the less the production of small or'fine particles. It is a principal object of the present invention to ensure that the picks shall strike the coal in a vertical direction so that the blows shall be direct and not glancing.

A further object of the invention is to move the conveyor intermittently so that the coal is stationary when the picks strike it and the blow in consequence is more effective. Accordingly a mechanism is provided by which the conveyor is operatively connected with the mechanism by which the picks are reciprocated vertically, so that the conveyor is stationary as the pick descends and moves only during the upward stroke of the pick. A machine of this type is usually provided with sets of picks arranged at opposite ends of the oscillating side frames, usually employed so that the working stroke of the one set corresponds with the upward stroke of the other set. The coal is first struck by a set of preliminary picks which break the larger pieces and then by a set of sizing picks which reduce the pieces to approximately the desired size. The conveyor is preferably kept stationary during the working stroke of the sizing picks. It is however a further object of the invention to arrange that the two series of picks shall operate in unison and accordingly the invention also comprises a machine on which the two series of picks are mounted on the same side of the pivot points of the oscillating side frames. The same result however maybe obtained by mounting the picks in cross-heads arranged to be reciprocated in vertical guides.

With the improved machine since a verttically moving pick is striking stationary coal, there is a risk of the picks being damaged or broken through striking any very hard substance. It is another object of the present invention to reduce this risk of damage to a minimum and accordingly another feature of the invention comprises a resiliently mounted supported placed beneath the conveyor beneath the point of impact ofthe picks. Yet another object of the present invention is to arrange the mechanism sothat during the effective part of the stroke the movement of the picks is as nearly "as possible tangential to the arc of the circle which the pick-heads describe.

Yet again the present invention comprises a construction of machine in which the parallel linkage mechanism usually employed to produce the vertical motion of the picks is simplified and improved, the picks being carried by cross-heads rigidly connected to members pivoted about the ends of the oscillating side'frames usually employed.

These and other objects ofthe invention are attained by the constructions of machine which are illustrated by way of-example in the accompanying drawings andby which the invention will be clearly understood.

In these drawings, Figure 1 is "a side e'levation and Figure 2 an end view of the machine shown in Figure 1, parts being shown in section, Figure 3 is a view to an enlarged scale of a detail modification, and Figures 4, 5, 6 and 7 are side elevations of modified forms of machines.

Referring first to Figures land 2, the coal which is to be broken down from about 16 inch lumps to lumps of 2 inches or even less is discharged down a chute 1 on 'to a horizontal endless conveyor 2 which passes around two rotating sprockets 3 and 3 fixed on shafts 4 and 4 A frame 5 is arranged to straddle the conveyor 2 and two shafts 6 and 7 are fixed in this frame/5, the shaft 7 being placed vertically above the shaft 6 and both shafts 6 and 7 extending across and above the conveyor 2. Two large levers 8 and 9 are arranged one at each end to oscillate about the shaft 6 and two smaller levers 10 and 11 are similarly arranged to oscillate about the shaft 7. Pivot pins 12 and 13 are fixed in the ends of these levers and vertical links 14 and 15 are pivoted about these pivot pins 12 and 13. These vertical links 14 and 15 have crossheads 16 and 17 formed integrally with them. The cross-heads 16 and 17 have spacing plates 18 attached to them and the sizing and preliminary picks 19 and 20 respectively are secured to the cross-heads 16 and 17 by these spacing plates-18. The levers 8, 9, 10 and 11 ,-and the vertical links 14 and 15 form together a" parallel motion linkage, such that,the vertical links 14 and 15 are constrained to remain vertical and so the picks 19 and 20 have a substantially vertical motion, when the levers 8, 9, 10 and 11 are oscillated while the two sides of the linkage are constrained to move together :by-the cross-heads 16 and 17. The oscillation is efi'ectedby connecting the levers 8 through cranks'22 and connecting rods 23 to a shaft 21 carrying a fly-wheel 24 and driven from any suitable'source of power such as a motor 25.

The conveyor 2 is driven intermittently by a mechanism connected to the lever 8. This mechanism comprises a long connecting rod 26 pivoted to the end of the lever 8 adjoining-the cross-head 16, the-other end being'connected-to an .arm 27 which is mounted to rock freely about the shaft 4*. A drum ordisc 28 is fixed to the shaft 4 and is driven in step-by-step fashion in an vanti-clockwise direction by a silent pawl 29 carried on the arm-27. When the lever 8 is oscillated, on the upward stroke of the sizing picks -19, thearm 27 is drawn upwards andthe silent pawl 29 grips the drum 28 effecting a partial rotation of the shaft 4 in an anti clockwise direction, and thus moving the conveyor 2 one step towards the left in the drawing. On the other hand, during the downward or working stroke of the sizing picks 19, the farm 27 drops to its lowest position and the pawl 29 rides freely over the drum 28, so that the conveyor 2 is stationary during theworking strokes. The stroke of thepicks 19 is usually constant, but it is desirable to provide for a variable stroke of the arm 27. so as to .render it possible to adjust the length of each step of movement of the conveyor 2*in' accordance with the size into which the coal is to be broken. This adjustment is provided for by slotting the end of the arm 27. I

In order to minimize the risk of damage .to the picks orother part of the machine when unusually hard material is encountered, two cross-supports or anvils 30 and 31 are mounted under the conveyor immediately beneath the sizing picks 19 and preliminary picks 20 respectively. These anvils 30 and 31 are supported by rods 33 passing vertically through them at each end, and also passing through horizontal girders 34 forming part of the frame Strong helical springs 35 are inserted between the girders 34 and washers 36 placed beneath the heads of the rods 33, so that the an vils 30 and 31 are held up against the undersides of the girders 3 but can yield downwards under very heavy blows of the picks 19 and 20, the springs 35 being compressed. Since the endless conveyor 2 will not in general be extensible, provision is made for horizontal movement of the shaft 3, when the conveyor 2 and anvils 30 or 31 are forced out of their normal position. This shaft 3 is accordingly mounted in slidable bearings 37 sliding in a horizontal guide way 38 against the action of a compression spring 39.

Various modifications may be made within the scope of the invention which is not limited to the precise constructions shown. For example, as shown in Figure 3, the vertical links 1 and 15 may be in the form of plates or strips 40 bent over the pivot pins 13 and rigidly secured to them, the cross-heads 16 and 17 then being bolted to these bent plates 40. The cross-heads in this case are pivotally mounted about the cross-bars 12. Again, with tne construction shown in Figures 1 and 2, the vertical links 14 and 15 may be pivoted about either one of the pairs of pivot pins 12 and 13 and rigidly fixed to the other.

Again as shown diagrammatically in Figure 4, the oscillating levers 8, 9, 10 and 11 instead of being straight may be arranged so that the two arms on either of the pivot shafts 6 and 7 make on their upper ends an angle of less than 180 with one another. The purpose of using these bent levers is that the parts of these levers to which respectively the cross-heads 16 and 17 are attached can lie substantially horizontally duringthe part of the stroke when the picks are actually striking the coal. It will be realized that the effective part of the stroke is different with the two sets of picks, since the depth of the coalbed upon the conveyor approaching the preliminary picks is greater than that approaching the sizing picks. The design may be such that each half of the lever arm is horizontal and therefore at right angles to the path of movement of the picks at the midpoint of the effective part of the stroke.

The result is that the crosshead is sub eCted to the minimum horizontal movement during the time that the picks are engaged with the coal, so that the amount of fine product is still further reduced.

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In the form of machine shown in Figure both the pick heads 16 and 17 are mounted upon the same side of the pivots of the oscillating frame, so that both the series of picks 19 and 20 descend while the conveyor 2 is stationary. As will be clearly seen both the oscillating levers or beams 8 and are pivotally mounted at 41 and 42 in an extension 43 of the framework 5 of the machine. The preliminary picks are of course, arranged further from the pivots 41 and 42, than the sizing picks 19, so that the picks 20 have the longer stroke.

Figure 6 shows a machine in which both the sizing picks l9 and reliminary picks 20 are mounted in a singe cross-head 44 arranged to slide in vertical guides 45, the reciprocation being obtained through a connecting rod 23 and crank 22 as before.

Figure 7 shows another construction of machine in which both sets of picks 19 and 20 are mounted in a single cross-head 44 disposed longitudinally of the conveyor 2, and arranged to slide in vertical ides 45. In this case however the reciprocatlon of the cross-head 44 is not obtained directly from a crank and connecting rod but through the medium of'a parallel linkage mechanism 8, l0 and 15 pivoted, as in the construction shown in Figure 5, at 41 and 42 in an extension 43 of the frame 5. The beam 8 is oscillated by means of a connectin rod 23 and crank 22 driven from any suitable source of power.

Various other modifications may also be made, for instance the intermittent motion of the conveyor may be obtained in a variety of ways. For example, instead of operating the arm 27 direct from the lever 8, the rocking movement of the arm may be taken from any other convenient moving part of the machine. Instead of the silent pawl 29, a free-wheel roller may be employed or an ordinary pawl and toothed ratchet wheel may be fitted. Further the adjustment of the stroke of the arm 27 may be provided for in any convenient way.

Finally it will be realized that the invention is not limited to machines having two sets of picks, and that one set may be reciprocated independently of another set by separately operating mechanism, if desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. A machine for breaking coal upon a conveyor, comprising in combination a horizontal endless conveyor, a parallel motion linkage mounted above said conveyor, means for oscillating said linkage in a vertical plane, a pair of pick-heads mounted on said linkage so as to be subject to substantially vertical reciprocation, a series of preliminary picks mounted in one of said heads, and a series of sizing picks mounted in the other of said heads, and means in operative connection with said linkage for moving said conveyor during the downward movement of said sizing picks in a direction to bring the coal to be broken below said prehminary picks and subsequently below said sizing picks during the upward stroke of said sizing picks, but for maintaining said conveyor stationary during the working stroke of said sizing picks.

2. A machine for breaking coal upon a conveyor, comprising a pair of spaced parallel shafts, sprocket wheels mounted thereon, an endless conveyor passing over and driven by said sprocket wheels, a series of picks adapted to be reciprocated at right angles to said conveyor to strike the coal upon said conveyor, and a yiel-dingly-held bearing for one of said shafts enabling the supporting surface of said conveyor to yield under the impacts of said picks.

3. A machine for breaking coal upon a conveyor, comprising in combination a pair of spaced parallel shafts, sprocket wheels mounted thereon, a horizontal endless conveyor passing over and driven by said sprocket wheels, a series of picks adapted to be reciprocated vertically to strike the coal upon saidconveyor, a resiliently mounted support disposed beneath the supporting surface of said conveyor at a position below said picks, and a yieldingly-held bearing for one of said conveyor shafts, enabling said shaft to move inwards towards the other of said pair of shafts when said support and said conveyor yield under the impact of said picks, said resiliently supported anvil and yieldingly held bearing cooperating to permit unbreakable matter to pass through said machine without injuring the same.

4. A machine for breaking coal upon a conveyor, comprising in combination a pair of spaced parallel shafts, sprocket wheels mounted thereon, a horizontal endless conveyor passing over and driven by said sprocket wheels, a parallel motion linkage mounted above said conveyor, means for imparting an oscillatory movement to said linkage, a head for preliminary picks and a head for sizing picks mounted on said linkage and thereby reciprocated substantially vertically towards and from the supporting surface of said conveyor, a pair of transverse anvil members disposed below said supporting surface at positions below the respective pick-heads, and spring supports carrying each of said anvil members at their opposite ends.

5. A machine for breaking coal upon a conveyor, comprising in combination an endless conveyor, a framework straddling said conveyor, a parallel motion linkage pivoted in said framework, means for imparting an oscillatory motion to said linkage about its pivots, a pair of pick-heads mounted lOO on said linkage both on the same side of pick-head remote from said pivots, and a;

series of sizing picks mounted in the nearer of said pick-heads to said pivots.

6. A machine for breaking coal upon a conveyor, comprising in combination a horizontal endless conveyor, a pair of parallel motion linkages spaced laterally of the conveyor and each disposed above the conveyor to lie in a vertical plane, a driving shaft for said conveyor, mechanical connections between said'shaft and said linkages for causing said linkages to oscillate as said shaft rotates, a pick head extending transversely of said conveyor and connecting together said linkages and a plurality of picks mounted in said pick head.

7. A machine for breaking coal upon a conveyor, comprising in combination a horizontal endless conveyor, a pair of parallel motion linkages spaced laterally of the conveyor and each disposed above the conveyor to lie in a vertical plane, each of said linkages comprising a pair of beams rocking about fixed pivots and carrying short pivot pins fixed in said beams and vertical links connecting corresponding pivot pins of the respective pairs of beams and providing bearings for said pins, a driving shaft for said conveyor, mechanical connections between said shaft and said linkages for causing said linkages to oscillate as said shaft rotates, a pick head extending transversely of said conveyor and connecting together said linkages and a plurality of picks mounted in said pick head.

8. A machine for breaking coal upon a conveyor, comprising in combination a horizontal endless conveyor, a parallel motion linkage mounted above said conveyor, said linkage having double-armed rocking beams with the two arms of each beam inclined to each other, means for oscillating said linkage in a vertical plane, a pair of pick-heads mounted respectively on the arms of said linkage so as to be subject to substantially vertical reciprocation, a series of preliminary picks mounted in one of said heads, and a series of sizing picks mounted in the other of said heads, and means in operative connection with said linkage for moving said conveyor during the downward movement of said sizing picks in a direction to bring the coal to be broken below said preliminary picks and subsequently below said sizing picks during the upward stroke of said sizing picks, but for maintaining said conveyor stationary during the working stroke of said sizing picks.

.9. A machine for breaking coal. upon a conveyor, :comprising' in combination an endless conveyor so supported as to .be capable of substantially equal local depression at anypoint on its supporting surface, a series of picks adapted .to be reciprocated towards and away from said conveyor, driving means for said conveyor. operatively connected withsaidseries of picks, and a resilient support independent of said driving means and ofsaid conveyor disposed under said conveyor at a position beneath said picks, said support being entirely resiliently mounted.

10. A machine for breakin coal upon a conveyor, comprising in combination a conveyor, a framework straddling said conveyor, an oscillating frame pivoted in said framework, means for imparting an oscillating motion to said frame about its pivotal axis, a pair of pickheads both mounted on said oscillating frame on thesame side of its pivotal axis, and adapted to be reciprocated at right anglesto'the supporting surface of said conveyor, a series of preliminary picks mounted in the pick head remote from said pivotal axis, and a. series of sizing picks mounted in the nearer of said pick heads tosaid pivotal axis.

11. A machine for breaking coal upon a conveyor, comprising in combination a conveyor, aframework straddling said conveyor, an oscillating frame pivoted in said framework, means for imparting an oscillating motion to said frame'about its pivotal axis, a series of preliminary picks and a series of sizing picks, both of said series of picks being mounted on said oscillating frame on the same side of its pivotal axis so as to be lowered simultaneously to strike the coal upon'said conveyor, and means for transmitting'an endwise movement to said conveyor when said picks are out of engagement with the coal upon said conveyor, but for maintaining said conveyor stationary during the time that said picks are in engagement with the coal upon said conveyor.

12. A machine for breaking coal upon a conveyor, comprising in combination a con- .veyor, a framework straddling said conveyor, an oscillating frame pivoted in said framework, means for imparting an oscillating motion to said frame about its pivotal axis, a'pair of pick heads both mounted on said oscillating frame on the same side of its pivotal axis, and adapted to be reciprocated atright angles to the supporting surface of said conveyor, a series of preliminary picks mounted in the pick head remote from said pivotal axis and a series of sizing picks mounted in the nearer of said pick heads to said pivotal axis, the distance between the last row'of said preliminary picks and the first row of said sizing picks being greater than that between two adjacent rows of said preliminary picks, both distances being measured in the direction of movement of said conveyor.

13. A coal breaking machine comprising an endless conveyor, a plurality of pick members adapted to be reciprocated toward and away from said conveyor, a plurality of independent resiliently mounted anvils supporting said conveyor and positioned under said pick members, said anvil construction adapted to permit unbreakable material to pass through said machine without injuring the same.

14. A coal breaking machine comprising an endless conveyor, a plurality of pick members adapted to be reciprocated toward and away from said conveyor, a plurality of independent resiliently mounted anvils supporting said conveyor and positioned under said pick members, said conveyor being mounted on a shaft yieldingly supported, said anvils and conveyor being adapted to cooperate to permit unbreakable material to pass through said machine.

15. A machine for breaking coal upon a conveyor, comprising in combination a conveyor, a framework straddling said conveyor, an oscillatin frame pivoted in said framework, means or imparting an oscillating motion to said frame about its pivotal axis, a pair of pick heads both mounted on said oscillating frame on the same side of its pivotal axis, and adapted to be reciprocated. at right angles to the supporting surface of said conveyor, a series of preliminary picks mounted in the pick head remote from said pivotal axis, and a series of sizing picks mounted in the nearer of said pick heads to said pivotal axis, a plurality of resiliently supported anvils positioned directly under said pick heads to permit unbreakable material to pass through said machine without injuring the same.

In witness whereof I hereunto subscribe my name this 5th day of October, A. D.

BERTRAM NORTON.

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