US1291008A - Lining for tube-mills. - Google Patents

Description

. JENSEN LINING FOR TUBE MILLS.

APPLICATION FILED APR.21. I915.

Patented J an. 14, 1919.

2 SHEETS-SHEET I.

wlmessgs AWE/mm A. V. JENSEN.

LlNlNG FOR TUBE MILLS.

APPLICATION HLED APR.21.1915.

1,291,008. Patented Jan. 14, 1919.

2 SHEETS-SHEET 2. .2... 1 T I IIIII v ATTORNEY UNITED sTATEs PATENT oEEIoE.

ALEXANDER V. JENSEN, OF DEVILS SLIDE, UTAH, ASSIGNOR T AMERICAN MANGA- N ESE STEELE COMPANY, OF AUGUSTA, MAINE,

A CORPORATION OF MAINE.

LINING FOR TUBE-MILLS.

1,291,o os.

To all whom it, may concern:

Be i known that I, ALEXANDER V. JENSEN,

i1 a s'ubjectof .His ,Majesty. the King of Deni whiclitlie followingis a specification.

This invention, ,relates to a lining for grindingmills, the object. being to provide a, ampunt of agitation .to the mill contents,

resulting in, the v eiiicient' grind-ing thereof-r It'hasbecome well known inthe artz'to" which my invention relates that the grindingzaction is due to the local-motion. and agi tation ofhthe grinding balls or cylpebs; This local movement of-the balls or cylpebsv causes the contents ,of the mill to be ground I therebetween. Any, sliding action of the contents of the mill with reference to thelining plates or the mill shell, causes excesmill.

sive wear upon the lining plates, and prevents the local agitation and movement of" the balls and cylpebs one with relation to the other, so that sliding in the grinding mill takes place at the expense of the lining plates and prevents the proper grinding of the mill contents. In order to overcome this sliding of the mill contents, it has heretofore been customary to form the lining plates of various shapes and forms and to provide bars or ribs extending longitudinally of the The lining plates were of a haphazard configuration, some being provided with steps, others with sharply slanting peaked sides, while others were of a-waved configuration. Such. haphazard configuration did not, however, as will be hereinafter more apparent, produce the maximum local movement of the balls or cylpebs, and consequently the maximum grinding action was not obtained. 7

It is accordingly an object of my invention to rovide a lining plate the curvature of which follows certain definite and fixed mathematical and geometrical laws, whereby sliding is' greatly reduced; whereby the maximum local movement and rotation of the balls andcylpebs takes place, and whereby the maximum grinding efliciency is obtained. To the above end, I have formed Specification of Letters Patent.

a lining whichn will. impart av maximum.

Patented Jan. 14, 1919.

Application filed April 21, 1915. Serial No. 22,732.

my lining from a plurality of lining plates which collectively provide a wave-like or undulatory working surface for the interior of the mill casing; the cross-sections'of the individual plates upon planes transverse to the axis of the casing being in the form of i trochoidal curves, or, more'strictly speaking, the working surfaces of the several individual plates being such. that they appear in cross-section as trochoidal curves.

I have also found that, by forming adjacent lining istics, are of different wave lengths and amplates so'that adjoining portlonsthereof although of similar character-' the mill to take up, certain 'formations'is" prevented, the local agitation and rotation of the ingredients is provided for, and a breaking over of the ingredients'of the mill, similar to the surf of ocean waves, is caused to take place.

Other objects and advantages will appear" as the description proceeds, wherein it is to be understood that changes in the precise embodiment of the invention can be made within the scope of what is claimed without departing from the spirit of the invention.

The preferred embodiment of my invention is disclosed in the accompanying drawings, wherein Figure 1 is aview in end section of a grinding mill equipped with a lining embodying the characteristic features of my invention; I

Fig. 2 is a similar, but enlarged, view of a portion of the foregoing, illustrating a lining plate mathematically curved to obtain the maximum rotation and agitation of the mill contents and entirely eliminating slids;

Fig. 3 is a sectional view of a lining plate disclosing the reinforcing ribs which are formed upon the under or non-working side thereof;

Fig. 4 is a view in the lining plates;

Fig. 5 is a view in end section of a grinding mill, equipped with a somewhat modified form of lining, the modification largely residing in the manner in which the several lining plates are held in position;

Fig. 6 is a view in perspective of one of perspective of one of the holding members, by means of which the lining plates are held in place;

Fig. 7 is a view in perspective of one of the two wedge members with which each lining is provided, and whereby the several plates are wedgedly held against the inner surface of the grinding mill shell.

Referring specifically to the several vlews, the grinding mill shell 11 is provided with my liner 12. The liner 12 is formed or composed of a number of Separate lining plates 13, each of which is curved to conform to, or in accordance with, a curve which is traced by a point within a generating circle which rolls, without sliding, within a larger base circle. This curve is known as the trochoid, sometimes called the hypotrochoid, and belongs to that class of second degree curves known as the cycloidal family. As the mill is rotated, the ingredients thereof partake of a motion similar to the motion of the generating circle, by which the curvature of the lining plates was constructed, and this local agitation and forward movement, as well aS the local rotation of each of the cylpebs or balls, causes the contents of the mill to be efiiciently ground, the entire action taking place without sliding, and therefore with a minimum amount of wear upon the lining plates. In order to cause the ingredients to break over, similar to the surf of the ocean waves, and in order to break up any particular formation within the mill, the adjacent trochoidal arcs, or more specifically the adjacent hypotrochoidal arcs, are formed from different generating circles, so that while they still are trochoidal' in form they are of different wave lengths and amplitudes; thus the trochoidal arc AB in Fig. 2 is of greater wave length and amplitude than the adjoining trochoidal arc BX.

In order that the various plates may be held in their proper positions, they are arranged to overlap, the toe end 15 at each plate being provided with the bolt openings 16, and the beveled under surface 17. top surface 18 of the heel end of the plate is correspondingly beveled so as to nicely receive the beveled toe end of the next adjacent plate thereon: Suitable slots 19 are formed in the heel end of the plate and in connection with the bolt openings 16 of the adjacent plate, are adapted to receive the holding bolts 20 therethrough, which latter extend through suitable openings in the mill shell andsecure the lining plates thereto.

The lining plates are provided. with the strengthening and longitudinally extending ribs 21, which extend beneath, and are formed integral with, the crest portion of the waves of. the plates, so as to reinforce and strengthen the plates against the severe hammering action which they necessarily re- The ceive, and also materially reducing the elongation of the plates which is especially likely to take place when they are formed of manganese steel, the preferred metal for such structures.

A somewhat modified form of liner is illus trated in Fig. 5, wherein the ends of the lining plates 24 do not overlap but are each provided with the transversely extending ribs 26 which contact with the inner surface of the shell 25 and provide for the proper support of the lining plate. The ends of the lining plates, in addition to the ribs 26, include the tongues 27 which fit within and interlock with the grooves or recesses 28 provided within the holding members 29. The holding members are of H-shape so as to receive'the projecting tongues of adjacent lining plates therein and hold them against inward displacement.

Each complete lining is provided with two wedge members 29, and which include the tapering sides 30, adapted to fit between,

and engage, the beveled ends 31, which areprovided upon four of the lining plates. Suitable bolts 32 extend through these wedge members and draw them down toward the shell 25, and in so doing, force the lining plates into their interlocked positions with the holding members 29 and thus hold the various lining plates against the inner periphery of the mill shell. As disclosed in Fig. 5, each lining is preferably formed with two diametrically positioned wedge members, thus insuring the proper retention of the lining plates, even though they become somewhat elongated or distorted under the severe conditions under which they operate. A material saving in bolts will thus be effected in this manner of securing the plates in position, and does not interfere with the agitation of the mass disposed within the mill which results in the efficient grinding thereof.

What I claim is 1. A lining plate for a grinding mill the working surface of which is wave-like or undulatory in form, and of tr'ochoidal shape in cross-section on a plane perpendicular to dicular to the axis of the said shell being trochoidal in form relative .to the inner surface thereof, so far as regards their respective working surfaces; andmeans for securing said plates in place within and upon the inner surface of said shell; the sucof San Francisco and State of California, cessive Waves or undulations provided by the this 12th day of April, A. D. 1915.

Working surfaces of said plates, collectively ALEXANDER V. JENSEN. considered, differing from one another in Witnesses: 5 Wave length and in amplitude. M. V. COLLINS,

Signed at San Francisco, in the county J. W. PLANT.

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