US1516467A - Screening ball mill - Google Patents

Description

Nov. 1s, 1924. i 1,516,461 J. -HERMAN SCREENING BALL MILL Filed Jan. 7. 1924 2 Sheets- Sheet l ll fl J. HERMAN SCREENING BALL MILL Nov, 18, 1924.

. 1924 2 Sheets-Sheet 2 Filed Jan. 7

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Patented Nov. 18, 1924.

PATENT oi-ifflcl..`v

Y JOHN OF LOS ANGELES, CALIFORNIA.

SCREENING BALI. MILL;

, Appiication ma'kraynuary 7,1924. seriaixafersgsoa.

Be it known tha I, ,J y EN HERMAN, a citizen of the United States, residingxfat Los Angeles, in the county fof Los Angeles and a novel and advantageous mill of the. general type', disclosed inI myprior Patcnt1,1'(6,896

granted March 28, 1916, .although themill upon which protection is herein soughtI does not comprise bars of the specific -cross-.sectional-'configuration disclosed .in `my mentioned patent (the area betweenthe bars .continuously decreasing 'in cross-section4 K suitably transformed rail sections to a base from the` inside) Among the objects-and advantages of my novel construction herein presented, I

ma mention not only'aii economy ofma-. ferial, which may result'from an advantageous vuse of selected sections i of secondhand special steelv rails, or their equivalent,

pulverizing andk screening elements o my novel mill as to secure a superior dra ging L progressive. although vdiscontinuous v oute diminished by the contactof the bases 'of-v ward diminution in thesucce'ssive sizes of the aperturesfthrough which material may be outwardly delivered `from the same, I

may retain all of the advantages of myl prior construction referred to and at the samer time gain-an eiiciency" of action not obtainable thereby. v

It is a furthereobject of this invention to providel a screening ball mill in which thev openings through lwhich material may;y be

delivered shall be progressively diminishing e in size but in which the effective screening area of abase screen shall not be unduly bars or rail sections therewith; and aprelferred embodiment of my invention may comprise rail sections whose bases are se# cured against or in proximityto a base screen in suchv manner as to permit an outward movement of material under upturned ,n

or suitably spaced flanges, which ma be formed by a suitable inward oru wa. de- Election of the bases of select` .to above. l but also the fact that by so constructin the A.

sections .of secondhand manganese or otherfspecial steel rails; yand when If employ, instead of` said rail sections, bars ofA rectan ular cross-section, I may so position ,the atter also thattheir ,surfaces in proximitysto a basescreen shallbe inwardly and upwardly divergent' therefrom. y v Other objects of my invention will appear yfrom vthe following. descriptionv of se ected .their equivalent.

. Fi z 2 is an enlarged .detail 'viewcoi'respon ing thereto.

y VFigg `is\a longitudinal sectional view showing a preferred manner of securing screen, as. hereinafter vreferred to. i 4 is a view correspondi but s owing. a proposed use ofnars which may square in cross-section, altho h so ,positioned'as to gain advantages re erred toy Fig. 1

n Fig. 5 isa detailor fragmentary. perspective `'view showin an organization of the general character illustrated in Fi 3.

Fi and 7 are perspective an lon 'tudina views showings. :possible lmeth of ,settingv rectangular bars of the character last referred to in the end plates'of a screeningz ball v y eferring tothe details of that specific embodiment of 11iy invention shown in Figs.-A

1 and 2, l may the substantiall circular rend lates of a mill, these end being" pre erably integral withy hollgw trun- `nions 2 through one of -which suitably .subdivided material ma be fed, an outward screening delivery being eiected in a known manner, and the product being caught and collected` in any suitable way, as by means ofv a hopper 3eonventiona1ly shown.A l f Instead of employing bars vsubstantially tra zoidal in cross-sectional outline, as described and claimed'in my mentionedk rior patent, I propose to employ, in the em iment of my invention shown in Figs.y 1 and 2, sections of secondhand rails, or their equivalent, these being preferably selected .sections of man anese or otherspecial steel rails which are o tainable at a comparative] A low cost, although the cold-rolling .to whic they may have kbeen sbjectedn in their animatie trans- Y thev samemay referred to previous use may be distinctly advantageous as contributing to theirl durability Vin a ball mill; and I propose, when I employ rail sections of the-character referred Ito, not only to space them apart in a manner Vfavorable to the outward delivery ofsuit-A ably pulverized material between the bases thereof, but also, as by upsetting or deforming said bases in the manner bestshown in Fig.V 2 or by equivalent means,-to ,avoid an undue covering of a base screen to which (which may optionally be formed, inthev case of a mill having aftransverse diameter of six feet, more or less, of 1 /1 inch material providedwith longitudinalrows 'of apertures f6, whose diameter maybe 'approximately 1/2 inchthese dimensions vbeing suggestedv` by way of illustration and not `by'wayv `of limitationyQ-'to end plates 1,'in a usual or;v preferredmanner, as by riveting through an outwardly vturned flange -upon `Asaid end plates; and I may support the rail sections 6,l or their equivalent, wholly or entirely from the mentioned base screen; When the construction last referred to is employed," I consider it advantageous vto Vdefiect'fthe bases of-*the rail sections 6, bending mtermediate portions thereof upwardly and inwardl in such manner as substantially ,i to diminish the area of their contact with said base screen, although I may optionally re-` tain, between the upwardly deflected sections 7 of the base 8 of a rail 6, un'deflected for substantially fiat areas 9 adaptedto re ceive rivets 10 extendingtherethrough andv through said base'screen; and it is of-im.

portancethat the rails '6 shall' be so'spaced throu hout the circumferenceofa shell or s lcylin er provided therewith that the inter- 4 vals between the heads 9 of a pairof lsubstantially parallel rails 6 shalliexceed the v"interval between a pair of'upturned flanges 7, and v'that the elements referred to should beused-in conjunction with'balls' andl materials of such size as to be capable toffree lateral lmovement between the headsy 9, al-y thoughthe diameter of the mentioned balls should exceedv the distance between the f `flanges 7 and the'intervals between thesaid' upwardly deiiected iianges should'be not less than `twice the perpendiculardistance vthereof from the base screen 5, whosev apertures 10 should either beinwardly expanded or of a uniforindiameter less thanthe distancebetween the upturfned anges 7 andv greater than .the mesh of the outer screen 11,

`myinvention shown in Figs. 4 to 7 inclusive,

shown as in contact with said base screen. Referring to the specific embodiment of it will .be obvious that lthe'relationshipsbetweenfthe parts herein referred to may be substantially the same as have been described above, inr the' sense that the distances `bebe secured.l For the'purposes may secure a' base screen 5 .'twe'enthe llateral edges 12 ofthe bars '13 may be substantially greaterthan the diameter of the openings -14 in the base plate 15 and such as to permita free movement of balls and subdivided material either inwardly or outwardly in a radiall direction therebetween, the mesh of the wire screen 16, shown as incontact Awith'the outer surface of the base screen 15 being, moreover, preferably such that the successive diameters of the yapertures through which material may pass outwardly are progressively, although *not continuously, dimlnishing.- `The configuration of the bars 13is advantageousnot'only in causing drag of material'therewith'l but in permitting a comparatively freeaccess of nely subdivided material tothe base screen v 15, through whichl it may Vpromptly find enit, if.' capable of passing valso through the '.wirel screen 16, or from which" it may'freely returninto a osition suitable forV further lcomminution, 1n case it has not-been suiiiciently ground.. v

Instead of securing thebars 13, or their equivalent, directly to aipsocketxplate rigidly connected with'the end plate 1,orits ,equivalent, I may optionally j rovide this"v end'fplate l -not only with a `ollow trun-l nion 2- but also with rectangular seats'17 cooperating with a' flange 18'invthel retentio'n'of the ends 19 of said bars, these'ends beings'hown asY halved Aaway in a manner permitting themto overlap the flange 18 and to bev secured thereto ink anysuitable Way, as vby means of bolts or rivets.

20, shown' as extending also through the base screen 16an'd'maintaining all of the mentioned parts in their intended relationships.

By either of the constructions abovezde-' scribed it kwill be obvious-that 'I have provided a construction Vcomprising rails orv ously decreasing in cross-section, as required by said prior patent, they are progressively the openings in the base screens employed is vlessthan vthe vdistance between the bars or 'rails used, and inthe 'sense' that when rails of `a character best shown in1Fig.".2

are employed, the distance vbetween the upwardly deflected anges "7 is less than the distancebetween the heads `9 thereon-the ,y mesh of the'outermost'screening element, to

being the finest of `all.`

Itl may be understoodthat when bars` or wit, the wire' screenll; or its equivalent,

rails of the character hereinv described are.

employed,both the materials fed to my millV andthe balls used therein shouldbe small 115 decreasing in lthe sense that thediameter lol.

enough to permit their free movement in either an inward or outward radial direction between the heads 9 of the mentioned eral character described,

rails or between the lateral edges 12 of the mentioned bars, thereby practically obviatin the risk of a permanent lodgement of bals or materials in a manner detrimental to the' efficiency of my mill.

In the operation of a mill of the gena mill may advanta eously be initially filled practically half ful ofv balls, either of uniform or of graduated sizes, the interstices between the balls being initially occupied by material to be ground, and balls and addltional material being thereafter fed, preferably through one of the hollow trunnions, at a suicient rate and in a suitable ratio to substantially maintain the condition initiall established; and it will be obvious that botii the rompt elimination of suitably subdivided, material), by reason of the extensive exposition of the base screen employed, and the cascading of balls from a comparatively high elevation, as may result from the rotation of a 6 foot mill, or the like, at a rate of about twenty revolutions, more or less,

per minute, may and do cooperate effectively in a rapid and economical grinding of ores or other materials.

Although I have herein described two advanta eous embodiments of my invention, it will be understood that various features thereof might be independently emplo ed and also that various additional modi cations'might be made by those skilled in the art without involving the slightest departure from the spirit and scope of my invention as the same is indicated above and in the following claim.

What I claim is:

In a screening ball mill, a base screen forming a cylinder, railroad rails fitting against the inner face of the base screen and extending longitudinally, portions of the bases of the rails being riveted to the base screen and the remaining portions of the bases being bent inwardly away from the base screen, and therails being so spaced apart that the balls will not pass between the rail bases,

In testimony whereof I have signed my name to this specification.

JOHN HERMAN.

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