US1525790A - Grinding mill - Google Patents

Description

\ J. s. BARTLEY GRINDING MILL Origihazl Filed Nov. 14, 1919 INVENTOR. J 6 BARTLE 4 BY 9 W I A TTORNE Y.

Patented Feb. 10, 1925.

u T-En, s'rArE-s JOSEPH s. BARTLEY, or nnnvnn, oononnno.

GRINDING MILL;

Application filed November 1 4, 1919, Serial No. 338,019. Renewed May 14, 1924.

To all whom it may concern:

Be itknown that I, Josnrn S. Banner, a citizen of the United States,- residing at Denver, in the county of Denver and State of Colorado, have invented certain new and useful Improvements in Grinding Mills, of

" which the following is a specification.

This invention relates to grinding mills of the type commonly known as rod mills in which a mass of loose rods have atumbling motion in a rotating drum.

The primary object of the invention istoprovide in a .mill of the above described character, a plurality of loose grinding 'rolls which are longitudinally fluted to provide rounded teeth or ridges which altemate with furrowsordepressions of greater width.

A mass of rolls of this form loosely placed within the cylinder will mesh with each other and with the lifting or tumbling. ribs usually providedon the. inside of the rotating cylinder," thereby increasing the p the line 2.2, Figure 1.

Referring to the drawings by numerals, 2 designates the grinding drum of the mill which is mounted for rotation about a horizontal axis, upon two pedestals 3. i The drum is composed of a cylindrical shell 4 which isclosed at its ends by heads 5 and 6 provided with central hollow trunnions 7 and 8, resting in pillow boxes 10' on, the pedestals 3.

The trunnions 7 carries a scoop 12 for feeding ore pulp or other material in liquid into the cylinder-and the opposite trunnion 8 serves for the discharge of the disintegrated product which risesin the liquid and is displaced by the constant inflow of fresh material.

. Bolted upon the interior surface of the shell are equidistant lifting ribs 13 of rounded section which in the operation of the mill serve to lift the grinding bodies and the material under treatmentfrom the bottom of I thei'otating cylinder to produce a tumbling and cascading movement thereof.

- tering through The grinding bodies of the present invention consist of rolls 14: which are fluted to provide longitudinal-teeth or ridges l5 alternating with depressions or furrows 16 of greated width.

equally spaced around the tumbling rolls at an angle of 120 degrees, producing a substantially triangular formation of the tumbling rolls.

The rolls are preferably madehollow for the reception of rods 17 which augment their grinding action and increase their weight.

The rods extending loosely in the bores of the rolls, permit of the passage of material around them and thus cooperate with v the rolls to increase their grinding capacity.

. The rods furthermore serve as a filler which is readily removed when the roll is worn out, and placed in another roll, thereby preventing the waste of metal which would be unavoidable in case the rolls were solid.

A mass of the rolls laced loosely in a rotating grinding cylin er, have a triturating act1on uponthe material constantly-enthe trunnion 7 at the feed end of the same, by their tumbling and rotating movements.

The outermost rolls of the mass congre ating in the bottom portion of the cylin er, mesh with the lifting ribs .011 the inner circumference of the same and all the rolls contained in the mass intennesh with each other as closely as the presence of the material under treatment permits.

-' During rotation of the cylinder in the direction of the arrow A, Figure 2, the several rolls are thus lifted to a point of release by gravitation and, togetherwith material carried in their furrows, are caused to drop successively to the bottomof the drum;- The falling rolls meshing with those adjoining, impart a rotary motion thereto which is again transmitted to the next following rolls and so on mass. I J

The rotary movement of the cylinder thus produces a continuous cascading movement of rotating bodies and interflowing ore pulp,

through the entire that the fu rows] in the rolls serve as carriers to lift the material accumulating ii. the bottom portion of the cylinder, and that the peculiar form of the rolls permits of their approaching each other sufficiently near to .have a direct crushing action upon all the ore between them.

A great advantage is thus obtained over existing machines in which the grinding bodies are of circular section and contact with each other and with the lifting ribs only along tangent lines.

What I claim and desire to secure by Letters-Patent is:

'1'; *In a mill of the class described, the combination of a rotating grinding drum rovided at its inner surface with relatively arge longitudinal lifting ribs, and a plurahty of loose tumbling rolls provided with relatively large ribs disposed in substantially trian ular formation and said tumbling rolls eing adapted'to engage the lifting ribs and mesh with one another whereby they will be rotated 'by the rotary move ment of the drum.

2. In a mill of. the class described, the combination of a rotating grinding drum provided at its inner surface with relatively large longitudinal lifting ribs, presenting rounded engaging surfaces, and a plurality of loose tumbling rolls filling approximately one-half of the drum and. provided with relatively large ribs disposed in substantially triangular formation and presenting rounded projecting surfaces and having intervening concave surfaces.

3. In combination, a grinding 1nill, and a plurality of freely tumbling elongated bars, certain of said bars having longitudinally extending domes or convex portions and certaing of said bars having longitudinally ex tending concaved portions to cooperate with said domes or convex portions, the radii of said convex and concave portions being substantially equal.

In testimony whereof I have 'afiixed my signature.

JOSEPH S. .BARTLEY.

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