US1337641A - Ball-mill - Google Patents

Description

F. E. CANDA.

BALL MILL.

APPLICATION FILED MAY 13, 1916.

F. E. CANDA.

BALL MILL.

APPLICATION FILED MAY I3, 1916.

Patented Apr. 20, 1920.

UITED sTATEs PATENT onnron.

FERDINAND E. CANDA, OF NEW YORK, N. Y.

BALL-Mini..

Specication of Letters Patent.

Patented Apr. 2o, 1920.

Applicationled May 13, 1916. Serial No. 97,224.

tures as hereinafter described and particularly pointed out in the appended claims,

As such mills have been generally constructed heretofore, the shell itself has been a member separate and distinct from the wearing Vface of the mill, such wearing face consisting of a hollow member insert ed within and held in place in the shell proper; and this shell proper has commonly been formed in two members7 each cylindrical and each having formed inte rally with it one of 'the heads of the mi thetwo members of the shell parting at the center of the mill in a plane of rotation of the shell. To this construction there are various objections. At the discharge head of the mill there are usually. certain radial members forming a support for the grating or screen of the mill, and which should be machined to afford an even support for the grating; but the depth of the shell is such that it is impracticable to machine such radial members by ordinary tools,.for which reason they are usually left unmachined, and therefore uneven, and therefore the grating is not evenly supported, for which reason much wear of the grate members may occur and breakage of the grate members may also occur. Also there is much leakage. through theb'olt holes through which pass the bolts connecting the wearing member to the shell. A further objection ofv the old construction of mill referred to is that the said wearing face of the mill must be a castmember,

whereas if thiswearing face may be formed of rolled members of hard steel, such for example as chrome steel, they will be much more durable.

"By my present invention l avoid occasion for use of a wearing face or member separate and distinct from the shell itself; the shell itself, the inner surface of which is also the wearing face, is formed of segments which may be fastened together to complete the shell and also the wearing face, and these segments are of such form that they may be rolled; the heads of the mill are separate from the shell segments, and

vtherefore may be machined readily; access to the interior' of the mill may be gained readily by removal of one of the heads of the mill; the several segments constituting the shell of the mill, and also its wearing face7 are so fastened together that a rigid structure is produced, and that passage of dust or mud through the joints between the segments is obviated; also Ythe millas a whole is lighter, for equal service and capacity, than the former mills above referred to.

Other features of my invention will be pointed out hereafter.

The objects of my invention are, to improve the construction of ball mills, particularly mills of the type referred to; to

. make the Wearing face of the mill of such construction that its parts may be produced by rolling'or pressing, and therefore may be formed of steel or other very hard material which nevertheless possesses the grain and fiber characteristic of metal which has been worked, as distinguished from cast metal; to construct the said wear-V ing member in such manner that it may also ferm the shell of a mill, dispensing with any separate shell; to so arrange and construct the parts of this wearing member that such parts are' readily assembled, and when assembled form a rigid structure throughrthe joints of which dust and mud will not escape; to so construct the mill that the heads thereof are readily separable from the shell proper, which heads may therefore be machined readily; to attach theseA heads to the shell proper in a `secure yet simple manner; and to make the mill of lighter weight, for equal size and service, than former mills of similar type.

l will now proceed to describe my invention with reference to the accompanying drawings and willthen point out the novel features in claims.

in the drawings: r

vFigure l shows in art afragmentary end view, looking from t e chargingend of the mill, and in parta fragmentary transverse section of the mill, showing segments of the grate.

Fig. 2 shows a fragmentary transverse section of a mill similar to that shown in Fig. 1, but embodying anI alternative construction o f shell, two grating sections only being shown, and a portion of the discharge head of the mill being shown in elevation.

Fig. 3 shows a fragmentary axial' section of the discharge end portion of a mill such as shown in Fig. 1, the section being taken on the section line 3-3 of Fig. 1.

Fig. 4 shows a fragmentary axial section of the discharge portionV of a mill such as shown in the previous figures, the section eing taken on the section line 4 4 of Fig. 5 shows in part an axial section of the charging end of 'a mill such as shown in Fig. 1, and in part a side elevation of the discharge end of the mill, one of the rows of coacting lugs on the exterior of the mill being sectioned in a plane parallel to the axis of the shell, to show the inserted Fig. 6 is a fragmentary section on the line 4-f4 of Fig. 2, but on a larger scale than Fig. 4, and shows particularly the means for pressing thegrate bars together.

Fig.y 7 is-a detail side view of one of the wedge-headed bolts shown in Figs. 4 and 6, and in other figures of' the drawings.

Fig. 8 is a fragmentar detail sectional view, the section being ta ren on the line 8 of Fig. 1, and shows improved means for clamping the grate bars at their ends.

Referring first to Figs. 1, 3, 4 and 5: 1

designates the shell of the mill, 2 the receiv-I` ing head of the mill, 3 the discharge head thereof, 4 the hollow trunnion of the receiving end of the mill and 5 the hollow trunnion of the discharge end of the mill. It will be understood that the structure 1-2-3, is adapted for mounting in suitable bearings for rotation, the hollow trunnions 4 and 5 constituting the journals; also that the structure 1 2-3 will be provided with means of customary nature for rotating it, which means are not shown in the drawings. The shell 1 is formed of segments 1a provided at their meeting faces with lugs 6 having registering apertures for the passage of suitable fastening bolts 7. These segments 1a are provided, on their interior faces, with suitable rises 8, forming the usual ribs which cause the crusher balls, (not shown in the drawings, since they form no portion of the present invention) to lift and then fall on rock in the spaces between these rises. The segments 1u therefore form both the shell of the mill and the wearing member. That these segments 1u may be fitted together accurately and rigidly, and that passage of dust or mud through the joints of the segments may be prevented, the meeting faces -`of the various segments 1a are provided with key grooves 9 and suitable keys 10 are fitted within these grooves. The result is the formation of an'exceedover the surfaces of the radial ribs 11 and 12 formed integrally with head 3 which re-y ceive' and support the grating segments 13.

. These grating segments maybe of any usual construction, but preferably are of the construction of my application Serial No. 95,312, filed May 4, 1916. These grating segments are held in place by wedge bars 14 (Fig. 8) and bolts 15. The heads 2 and 3 are held to the shell -1 by ,means of bars 16 engaging a number of bolts 7 which hold the shell segments together, and passing through suitable apertures in said heads and provided, outside of such heads, with suitable clamping nuts. This provides a very rigid connection of the heads to the shell.

Each segment 1a is seated at its ends in grooves 17 in the heads of the mill; whereby a very tight joint is formed between the shell proper and the heads.

In the construction shown in Fig. 1, each segment 11 of the shell and wearing member isformed with two halves of rises 8; each complete rise being formed ofhalf rises of two adjacent segments. In the construction shown in Fig. 2, each segment of the shell, which segments are here designated by'numerals 8b, is provided with a complete rise 8 located at about the center of the segment. The two constructions are substantial equivalents one of another, and either may be employed as preferred.

Any suitable means may be employed for pressing the several bars of the grate sections 13 toward the center and so for holding those grate bars rigidly. I have illustrated, inthe drawings, but particularly'in Fig. 6, a preferred construction wherein the discharge head of the mill has fitted into it segments 18 each having an obliquefaced rib 19 fitting into a corresponding groove of the head 3. Wedge-headed bolts 2() such as shown in Fig. 7, fit into slots of the member 18 and pass through apertures of the head 3, and are provided outside of such head with suitable nuts, whereby they may be drawn up. Owing to the wedgeshape of the heads of these bolts 20, and the corresponding wedge-shape of the bottoms of the slots in segments 18 in which such wedge-shaped heads fit, drawing up oblique steps 22; and between the ends otl the grate bars 21 ot' adjacent grate segments 13 correspondingly stepped clamping bars 1l are placed. It will be clear that by drawing down these bars 14 by means of the bolts 15 the grate bars 21 are held firmly at their ends.

What I claim is:

1. A ball mill such as described comprising a cylindrical wearing member formed ot' a plurality of segments. bolts connecting said segments, heads for said cylindrical member, and bars directly engaging the said bolts and secured to said heads.

2. A ball mill such as described comprising a cylindrical combined wearing member and shell formed ot a plurality of radial segments secured one to another, heads secured to Asaid cylindrical member. one of said heads having a discharge opening near lits center and having integral ribs on its inner face, and a grating seated directly on said ribs and secured to such head, the construction being such that because the said heads are separate from the said combined wearing member and shell the faces of said i ibs adjacent said grating may be machined readily.

3. A ball mill such as described comprising a shell with at least one separable head, said head having a grating-support, and a grating on such support comprising a series of segments each formed of a plurality ot grate bars. and means for pressing such grate barsinward and together comprising wedge-headed bolts extending to'the exterior of the head and means-for drawing such bolts outward.

Ll. A ball mill such as described comprising a head having a grate-support provided -With a groove and a grating on such support comprising a series of radial segments each formed oi a plurality of grate bars, ring segments located across the ends of such g ate-segments and each seated in said groove of such grate support, and Wedgeheaded bolts seated in such ring segments and pressing against the outer bar or" the correspondnig grate segment and adapted to press the grate bars of that grate segment together.

5. A ball mill such as described comprising a head having a grate-support and a grating on such support comprising a series of radial segments each Jformed of a plurality of grate bars, ring segments located across the ends ot' such grate segments and each seated in a groove of such grate support and provided With an oblique-faced rib titting into a correspondingly oblique-faced groove of such support, and wedges working against such ring segments and also against the outer bar of the corresponding grate segments and adapted to press the grate bars of that grate segment together.

6. A ball mill such as described comprising a head having a grate-support having ribs, and a grating on such support comprising a plurality of radial segments each comprising a plurality of grate bars the ends ot' which rest upon such ribs and are provided with oblique steps, correspondingly obliquely-stepped clamping bars fitting between the ends of the frate bars of adjacent grate segments and having their oblique steps resting-upon the oblique steps of the corresponding grate bars, and means for holding such clamping bars down.

In testimony whereof I havesigned 'this specification in the presence of tvvo subscribing Witnesses.

FERDINAND E. CANDA. lVitnesses H. M. MARBLE, PAUL H. FRANKE.

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