US2618438A - Breaker bar screen means for rigid hammer rotary impact crushers - Google Patents

Description

Nov. 18, 1952 J. CHRYSTAL 2,618,438

BREAKER BAR SCREEN MEANS FOR- RIGID HAMMER ROTARY IMPACT CRUSHERS Filed March 29. 1950 4 Sheets-Sheet 1 N a F JOHN CHRYSTAL,

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J. CHRYSTAL BREAKER BAR SCREEN MEANS FOR RIGID Nov. 18, 1952 HAMMER ROTARY IMPACT CRUSHERS Filed March 29 1950 4 Sheets-Sheet 2 vs xvfo; JOHN cHlzYsTAL, 5r

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Nov. 18, 1952 J. CHRYSTAL 2,618,438

BREAKER BAR SCREEN MEANS FOR RIGID HAMMER ROTARY IMPACT CRUSHERS Filed March 29. 1950 4 Sheets-Sheet 3 v /N\/ENTO/Q; JOHN CHRYSTAL,

J. CHRYSTAL BREAKER BAR SCREEN MEANS FOR RIGID Nov. 1 8, 1952 HAMMER ROTARY IMPACT CRUSHERS 4 Sheets-Sheet 4 Filed March 29 1950 Al m Patented Nov. 18, 1952 BREAKER BAR SCREEN MEANS FOR RIGID HAMMER ROTARY IMPACT CRUSHERS John Chrystal, Columbus, Ohio, assignor to The Jefirey Manufacturing Company, a corporation of Ohio Application March 29, 1950, Serial No. 152,529

1 Claim.

This invention relates to a rigid hammer impact type crusher, and an object of the invention is to provide an improved crusher of this type with improved breaker bar screen means cooperating with the rotor.

A further object of the invention is to provide such a machine in which there is a bar screen located below the feed chute of said crusher operative to screen out small size material and to deliver large size material into the path of the rotor.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claim.

In the accompanying drawings:

Fig. 1 is a side sectional elevational view of an impact crusher incorporating features of my invention;

Fig. 2 is a sectional view taken on the line 22 of Fig. 1, looking in thedirection of the arrows;

Fig. 3 is a side view with parts in elevation and other parts in section, showing another form of impact crusher incorporating the features of my invention;

Fig. 4 is a plan view of the rotor, with parts broken away and in section;

Fig. 5 is a sectional view of an element of the rigid hammer holding means;

Fig. 6 is an end sectional elevational view of the machine of Fig. 3, showing chains across the feed chute;

Fig. 7 is an end view of the machine of Fig. 3, with parts broken away; showing particularly the pivotally adjustable breaker bar screen portion of the unit;

Fig. 8 is a sectional View taken along the line 8-8 of Fig. 3, looking in the direction of the arrows; and

Fig. 9 is a sectional view of the machine of Fig. 3, illustrating one possible condition of material undergoing a crushing action within the unit.

In the machine of Fig. l of the drawings, which incorporates some of the features of my invention, there is included a housing IIJ formed of spaced side Walls and front and back end walls, one of which merges into a top wall, all providing an enclosure having a feed chute I I. The feed chute II and the side walls of the housing II) are provided with removable liner plates I2. Mounted for rotation within the housing Ill on a transversely extending horizontal axis is a rotor I3 having a shaft I4 carried at opposite ends on bearings, not shown, attached to the housing I0.

The rotor I3 includes a pair of similar diametrically opposite axially extending rigid hammers I5 which are mounted adjacent the periphery of the rotor I3 which is constructed to 7 provide a reinforcing backing for said rigid hammers to withstand the heavy impact forces developed by the hammers I5 striking material, such as large stones and the like, when the rotor I3 is rotated in the direction of the arrows which is its operating direction of rotation.

The hammers I5 are preferably symmetrical so that when the radially outward edges become worn said radially outward edges may become the radially inward edges, and vice versa. The radially inward edges or the rigid hammers I5 extend into radially-axially extending grooves It formed in the periphery of the body of the rotor l3 adjacent the bottom of the backing or reinforcing portions of said rotor which back up the rigid hammers I5.

As best illustrated in Figs. 1 and 2 of the drawings, the rigid hammers I5 have a pair of radially spaced keys I! cast integral with them, the bases of which are flanged and extend into axially extending grooves I8 (see Fig. 2) formed in the body of rotor I3. To clamp the rigid hammers I5 rigidly but removabiy to the body of rotor it there is a pair of aligned wedges I9 which extend into each of the grooves I8,'said wedges I9 having oppositely tapering surfaces which cooperate with oppositely tapering surfaces of the grooves I8, as clearly illustrated in Fig. 2 of the drawings.

By drawing the wedges I9 axially toward each other by means of a wedging bolt 20 and its clamping end nuts it is obvious that a wedging clamping action may be effected on the cooperating keys I7, thereby clamping the rigid hammers I5 tightly on the body of rotor I3. It may be mentioned in passing that this particular clamping means, While quite satisfactory in many instances, does have a characteristic which is sometimes found objectionable which is overcome in the rigid hammer attaching means illustrated in the devices of Figs. 3 to 9, inclusive. For example, by referring to Fig. 2 of the drawings, it will be seen that as the wedges I9 are drawn toward each other they will exert equal and opposite forces on opposite sides of the groove I8 which will tend to expand this groove'radiah' 1y. This action, of course, means that the outermost portion of the body of the rotor I3, in

to the body of the rotor I3 is under stress, tending to break off the cantilever from the rest of the body of the rotor [3. This breaking off force developed by the wedges I9 is supplemented by the radially outward component of the centrifugal force developed by the relatively high speed rotation of the rotor I3 which conceivably could develop a dangerous situation in a very large machine, particularly if any crack or fault should develop at a critical area at the base of a groove I8. Under other circumstances, however, the particular form of attaching means for the rigid hammers [5, as illustrated in Figs. 1 and 2 of the drawings, is quite satisfactory.

Within the main body of the housing'lfi and below the feed chute H and between one wall thereof and the rotor I3 there is a bar screen 2| including a plurality of spaced apart transversely or axially extending bars 22 which are relatively close together to provide a screening action fo'rmaterial deliveredby the'chute H to the interior of the housing H) for reduction. The bar screen 2| slopes downwardly froma position below the feed chute ll withthe bottom thereof near to but spaced from the path of travel-of the outer edge of each rigid hammer i5.

It is also to be noted that the bottom of the bar screen 2! is below a horizontal plane passing through the'axis of the rotor i3, as a consequence of which large particles of material, such as stone, which are fed to the interior or the housing or casing [0, will be struck by a hammer I5 as it is traveling substantially vertically. The relatively fine material, or, in other words, any material which is of adequate fineness to pass through the'screen 21, will do so and be discharged out the open bottom of the housing ID.

The reducing chamber'23 of the housing it is defined by the opposite side walls having liner plates 12 and by a breaker bar'screen 2 1 which, as illustrated in Fig. l of the drawings, extends generally horizontally across the top of the housing I0 and curves downwardly, terminating at a position close to the rotor I3,'being spaceda small distance from the outermost path of travel of the hammers I5.

The breaker bar screen '24 is made up of a plurality of breaker bars 25 which are preferably cylindrical in form, the axes of which extend transversely of the housing H), or, in other words, parallel with the axis of the rotor l3. The bars 25 are close together, yet spaced apart so as to form a screen. It is to be particularly noted that the axes of the bars 25 are positionedto form points of a smooth concave curve which is generally horizontal'adjacent the top of the housing or the top of the reducing chamber 23, which curve then extends downwardly so that adjacent its bottom it is generally radialwith the rotor as it approaches said rotor. In'other words, a continuation of the curve formed by connecting the points which constitute the'axes of the bars 25 from its lowermost position would pass through or substantially through the "axis of the rotor I3 and shaft M. This lowermost point of termination of the concave screen 241s generally diametrically opposite the bottom of a the screen 2 I I -er'y iof the rotor I3 is exposed to the material within the reducing chamber 23.

so that, roughly, half of the periph- It is obvious that a substantial portion of the breaker bar screen 24 is spaced from the closest end or top wall of the housing 10 so that material which has 'been adequately reduced in size by impact with the hammers l5 or the breaker bars 25 can pass through said screen 24 and fall by gravity out the open bottom of the housing II]. The bars 25 are carried in groups or individually on integral arcuate end plates 26 which are radially slidable into and out of holding and receiving grooves 27 formed in the liner plates i2.

Directly below the breaker bar screen 24 is an additional or supplementary breaker bar screen 28 which is made up of a plurality of transversely extending breaker bars similar to the breaker bars 25. This is essentially a supplemental breaker screen by which material which passes between the rotor i3 and the lowermost of the bars 25 may be subjected to a reducing action.

It is to be noted particularly that the screen 28 includes a lowermost breaker bar 29 which is adjustable by adjusting means 3i) so that its clearance with reference to the-rotor l3 may'be adjusted. It is furthermore to-be'notedth-at-its clearance with the rotor lS-is considerably less than that between the lowermost breaker bar 25 and said rotor 43. Consequently any-large*par ticles which may get past the'lo'wermost breaker bar 25 cannot be discharged until reduced adequately to clear the screen 28-or pass between the bar 29 and the rotor I3.

In Figs. 3 to 9, inclusive,'of'the-drawings, another form of impact crusher incorporatingth'e features of my invention is disclosed. This machine incorporates a number of the features above described and also includes important-features of my invention which are notembodied in the machine of Figs. 1 and 2.

The machine of said Figs. 3 to 9, inclusive, includes a housing or casing 3| having a 'palrof parallel laterally spaced up'rightside walls-32,32 provided with removable liners 33. The housing or casing 3| also includes a transversely extending upright end wall '34, the upper portion of which is provided with removable liners'3 5. Opposite the end wall 34 is an end wall 36 which curves into an integral top wall 31. The side, end and top walls areall rigidly attached together and are supportedon and removably attached to a heavy rectangular base 38 which may be anchored above an opening in the supporting fioor, through which opening reduced material is discharged from the open bottom of the housing or casing 3|.

Within the housing 3! there isa rotor 39 which, as illustrated, is built up of'a plurality of steel discs 65 stacked on a rotor shaft 40 andkeyed thereto. The rotor 39 is supported for rotation on a transverse horizontal axis by spaced bearings carried in appropriate bearing boxes M at opposite sides of the housing 3!. A selected one of the side walls 32 is provided with a feed chute 42 which, if desired, may be provided with chain screen 43. Opposite the chute 42 is a remov 1e. door interchangeable therewith. The top wall 31 is preferably provided with removable iner g; breaker plates as directly above the feed chute Within the housing 3| and spaced'fro'm the adjoining end and top walls 36 and'3l there is a breaker bar screens5 which has the same essential characteristics as the breaker bar screen 24 above described in connection with the device of Figs. 1 and 2. That is, it is made up of a plurality of closely adjacent but spaced apart breaker bars 66 preferablyof cylindrical shape, which extend transverselyor axially of the rotor between the side walls 32. The axes of said bars 46 are points along a smooth concave curve which is generally or substantially horizontal at the top of the chamber 3| where it is radially the greatest distance from the axis of the rotor 39, this curve being substantially radial with the rotor 39 at its bottom.

The bars 46 are provided with individual end plates by which they are slidably carried in guides on the opposite side Walls 32 provided by liners 33 and guide ribs 41. The breaker bars 46 may be inserted and removed by extending them transversely through an opening 48 (see Fig. 3) in one of the side walls 32, which opening may be closed by a filler typecover plate after the breaker bars 46 are all inserted. They may be clamped with their end pieces held tightly together by abutting clamping bars 49 and associated clamping screws 50.

There is one difference between the breaker bar screen 24 of the device of Figs. 1 and 2 and the breaker bar screen 45 of the device of Figs. 3 to 9; that is, as clearly illustrated in Fig. 9, there is a larger and heavier breaker bar or anvil 5| which is the lowermost of those forming the screen 45 or which is the closest of this screen to the rotor 39 it being closely adjacent the hammer circle of said rotor 39. The breaker bar 5| is not inserted, as are the breaker bars 46, but it is carried at opposite ends in receiving cups on the side Walls 32 and is individually removable laterally through holes in the side walls 32 covered by the cover plates 52. It has been found desirable to make this breaker bar 5| heavier than the others because it is subjected to severe shocks occasioned by large particles being caught between it and one of the rotor hammers.

Below the feed chute 42 there is a bar screen 53 which, as illustrated, is formed by a plurality of parallel laterally spaced downwardly sloping screen bars 54 which extend at right angles to the axis of the rotor 39 and are held together by a pair of transversely extending rods 55. If de: sired, the form of bar screen illustrated at 2| may be employed in this position. It is to be noted that the bar screen 53 extends from the end wall 34 sloping downwardly therefrom to a position close to the rotor 39, the bottom thereof being below a horizontal plane passing through the axis of said rotor 39. This cooperates with the breaker bar screen 45 to provide a large reducing chamber 56 in which substantially 180 of the rotor 39 is exposed to the material undergoing reduction.

Below the bar screen 45 there is another or supplemental bar screen 51, which as illustrated, includes three cylindrical transversely extending breaker bars 58 extending between and rigidly attached to end plates 59. The top-most of the breaker bars 58 extends axially beyond the end plates 59 and through sleeves 69 (see Fig. '7) formed integral with the plates 59, which sleeves 66 are journaled in appropriate journal bearings formed on the base 38. This top braker bar 56 is keyed or otherwise rigidly attached to the sleeves 69 and at one end is provided with a locking collar 6|, the other end being provided with an upstanding lever 62 bolted thereto. Lever 62 is keyed by a shear pin 63 at any one of a plurality of positions provided by threaded openings in a pair of spaced apart holding straps 64 between which lever 62 extends and which are attached to and spaced from one of the side walls 32 of the housing 3|.

By adjusting the lever 62 the clearance between the bottommost breaker bar 58 and the rotor 39 may be adjusted. This bottommost breaker bar 58 is preferably heavier than the other two since it is subjected to more severe shocks. The shear pin 63 constitutes an overload release in case too severe a shock is transferred to the lowermost breaker bar 58. The adjustability of the screen 51 provided by the lever 62 makes for a rough adjustment of the fineness of the material produced. A stationary transversely extending plate 11 extends between the bottom of the screen 45 and the screen 41 and in effect forms a stationary part of said supplementary screen 51.

Attention is now directed particularly to Figs. 3, 4, 5 and 6 and to certain significant details of construction of the rotor 39. As above set forth, the body of the rotor 39 may be built up of a plurality of heavy steel discs 65 stacked on the shaft 40 and keyed thereto. The discs 65 are also preferably tack welded together. At diametrically opposite positions the body of the rotor 39 is provided with peripheral axially extending grooves 66 adapted to receive rigid hammers 61 which, as illustrated, are two-piece members (see Fig. 6).

The rotor body is so formed that the leading edge and a substantial portion of the leading face of each of the hammers 61 is exposed so that it may strike the material, such as stone, to be reduced. The rear or trailing side or face of each hammer 61 is provided with an axially extending groove 68 adapted to receive a projecting tongue 69 formed on the back or trailing face of the groove 66 and on a backing or reinforcing portion of the body of the rotor 39. The tongue 69 and groove 68 cooperate so that it is impos sible for the rigid hammer 61 to be inserted or removed radially from the groove 66, having regard for the depth of groove 66, the limited clearance provided by the opposite walls of said groove 66, and the pertinent dimension (thickness) of the hammer 61. This interlock prevents the hammer 61 flying off the rotor 39 in case its holding means, hereinafter described, becomes broken or inoperative for any reason.

As above stated, each of the rigid hammers 61 is made up in two parts. In other words, it is split at its longitudinal center, the two parts being individually removable by being moved axially of the rotor 39 in opposite directions. To hold each rigid hammer 61 removably to the body of the rotor 39 a one-piece symmetrical tie rod 16 is provided, the center of which is bolted adjacent the axial center of the body of the rotor 39 with in the groove 66. Each half of the rigid hammer 61 is of similar construction and is hollow and is adapted to slide over the laterally extending wings of the tie rod 10, said hammer halves and tie rods having cooperating frusto-conical bearing areas so that when clamped in position the rigid hammer halves are held rigidly to said tie rod 10.

At each outer end of each tie rod 18 there is a pivoted clamping strap 1| having integral frusto-conical projections 12 and 13 adjacent opposite ends thereof. The projections 12 are received in cooperating frusto-conical bearing areas of the hollow rigid hammers 61 to which the straps are rigidly but removably clamped by nuts cooperating with the threaded ends of the wings of the tie rods 10. The frusto-conical projections 13 are received in similar recesses in the body of the rotor 39. Machine screws 14 ex- :aersnae :tendEfreely throughethe clamping straps Il -and arethreaded into the'body of the rotor 39.

Therparts areso dimensioned that as the screws 14 are tightened a' clamping action will be efiected so" as to place-the straps H under tensiomthereby pullingthe rigid-hammers 61 against one of the side walls of-thegroove '66 and awayirom the -opposite 'sidewall thereof. In other words, thistension 'on the sidestraps "H'efiects a: tight engagement 'between the areas defining the tongue "59 and the groove 68.

The ends of'the bodyofthe rotor 39 are provided with appropriate receiving pockets so that the ends of the tie rods Hi-do not extend axially beyond the ends of the body of the rotor 39 'andso that the'straps 'H' and machine screws 14 'arewithin theaxial dimensions of the body of said rotor'39j thus'protecting all of these parts from damage, The rigid hammersel are also formed at their outer ends so as to shroud or protect -the clamping parts just mentioned-as clearly illustrated in Fig. 4 of the drawings.

Thisis'believed to beef considerable'importance 5 and-"constitutes a feature of my invention.

"The two'p'ar'ts ofthe rigid hammers 5? may be removed through the opposite side walls 32 which are provided with access openings and removable cover plates 18 (see Fig. 6) whichare essentially similar to the cover plates 52 and that provided for the opening at. No claim is made to any'of these features forremovingparts of the crusher which may become worn, as thishas been standard practice for many'years inconnection with similar construction providing for the ready axial removability of breaker bars, hammer pins, and equivalentrparts of crushers .which become worn in operation.

In the'operation'of the crusher ofFigs- 1 and 2 or of Figs. 3 to 9,'material to'bereducedwhich maybe any hard friable material, of which stone is illustrative, will be delivered to the interior of the housing 10 or is, as the case may be, through the feed chute l or 42. Most of the fine material will escape radially through the screen 2 l or 53, as the case may be, and be discharged through the open bottom of the housing. The oversize material incapable of passing through this screen-will be 'struck'a shattering blow byone of the rigid hammers'of the rotor, which rotor willbe traveling at a relatively high speed in thedirection indicated by the arrows. The rigid hammers on striking the material will initially shatter it and. propel it through the reducing chamber where it will strike a liner or breaker plate of the reducing chamber, such as therliner I2, 33, or 44, or some of it maystrike the breaker bar screen 24 or .5, as the case may be, following the initial impact of the rigid hammer.

Material which strikes the breaker bar screen 24 or and which is adequately reduced to pass through said screen, may do so whereupon it will be free to fall downwardly. thrcughxthe housing andiout' the bottom thereof. .oversize'lmaterial will be retained? inthe Jreducing chamber mm] adequately reduced to 1 pass through this screen or the screen 2| or"53,ias thecasemaybe, -or some 01" it may pass below the. breaker bar screen and be further treated until it can pass through the screen23or 57, asnthe 'casemay be.

The structure oflthe rotor,"hammers 'and holding means therefor :is" claimedin my "divisional applicationQS'erial No 230,862, filed Mania-"1951.

Obviously-those skilled J in the art may make various changes in the details/and arrangement of 1 parts -without departing from the spirit "and scop'e'of the invention as defined by the claim hereto a'ppended, andappIicant therefore' wishes not w be restricted' to the preciseficonstruction herein disclosed. 7

Having thus described and shown anembo'diment-of the invention, what it is desired to secure by Letters Patent ofthe United States is:

A rigid hammer crusher including a housing having a feed.- opening," a'rotor insaid housing, a rigid hammer attached to the sai'd rotor and ei tending radially beyond the periphery of the rotor and axiallythereof, a breaker barscreen including a plurality-of spaced apart closely adjacent breaker bars in said housingspaced radially'from said rotor, said breaker bars extending parallel with theaxis of said rotor and positioned so that their axes form points of a smooth concave "curve which extends downwardly from a top generally horizontal position above said rotor to a bottom position closely adjacent said rotor, said curve being'generally' radial withsaid rotor as it approaches it, said curve also being concave relative to the line of trajectory of materialstruck and impelled by said rigid'hammer, and abar screen located below said feedopening and sloping downwardly from awall of said housing to'a position adjacent said rotor, the lower-edge of said bar screen being below"ahorizontal'plane through the axis'of said rotor.

JOHN CHRYSTAL.

REFERENCES CITED "Ihefollowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 198,993 -Moore Jan. 8,1878 392,488 'Behm "Nov.' 6, 1888 589,236 Williams Aug. -31, 1897 211,688 Wil1iams Oct. 21,1902 1,144,102 Brainard June 22,1915 1,446,221 Starr Feb. '20, 1923 1,751,009 Liggett Mar. 18, 1930 2,278,274 Lend 'Mar.'31, 1942 2,373,691 'Kessler Apr. 17, 1945 2,486,421 Kessler Nov. 1,19% 2,540,021 Wright Jan. "30', 1951 FOREIGN PATENTS Number Country Date 53,549 Norway.- "Feb. 12, 1934 174,148 "Switzerland 1.. Mar. 16,1935

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