US642017A - Crushing-mill. - Google Patents

Description

Nu. fi l-LOU. P

T. L. & T. J. STURTEVANT.

CRUSHING MILL.

(Application filed May 18, 1899.)

atented Jan. 23, I900.

(No Model.)

3 Sheets-Sheet l,

Nu. 642,0I7. Patented Ian 23, I900 T. L. & T. J. STURTEVANT. CRUSHING MILL.

(Application filed May 18, 1899.;

3 Sheets-Sheet 2.

(No Model.)

Patented Jan. 23, I900.

T. L. & T. J. STURTEVANT.

CRUSHING MILL.

(Application filed May 18, 1899.)

3 Sheets-Sheet 3.

(No Model.)

llh STATES PATENT OFFICE.

THOMAS L. STURTEVANT, OF QUINCY, AND THOMAS J'. STURTEVANT, OF NEl/VTON, MASSACHUSETTS.

CRUSHlNG--MILL.

SPECIFICATION formingpart of Letters Patent No. 642,017, dated January 23, 1900.

Application filed MaylB, 1899. Serial No. 717,349. (No model.)

To aZZ whom it may concern:

Be it known that we, THOMAS L. STURTE- VANT, residing at Quincy, in the county of Norfolk, and Tnonas J. STURTEVANT, residing at Newton, in the county of Middlesex, State of Massachusetts, citizens of the United States, have invented certain new and useful Improvements in Crushing-Mills, of which the following is a specification, reference being had therein to the accompanying drawings.

Our invention relates to crushingnnills for pulverizing ore-bearing rocks and the like, and particularly to that type of mill in which rotary crushing-rolls are used, the material to be reduced being fed from a suitable hopper or from feeding-ways between the rolls by which it is crushed and after pulverization passing out through a suitable dischargeopening in the bottom of the mill-casing.

The main feature of invention of our improved crushing-mill is the novel construction of the crushing-rolls, which have as their distinguishing characteristics loose movable tires of hard steel which form continuous circumferential crushing-faces for the rolls, said tires being carried by flanged hubs mounted on the roll-shafts, radially-movable weights or hammers being arranged inside of the tires between the flanges of the supporting-hubs, so that when the mill is running the weights will be forced outwardly by centrifugal action and will thus yieldingly press the tires together, so as to effectually crush the material. By this construction a certain amount of flexibility, as it were, is given to the crushing-faces of the rolls, so that much of the strain incident to crushing is absorbed by the flexible or yielding crushing-faces and less is transmitted to the shafts. The shocks and stress of crushing are not therefore thrown so strongly upon the shafts or mill-casing as is the case where the rolls are unyielding, and this fact enables a lighter mill structure to be used than heretofore. At the same time the roll-shafts maybe mounted in fixed bearings and the objections to springbearings are avoided.

In the accompanying drawings, in which we have shown a mill embodying our invention, Figure 1 is a side elevation of a mill containing our improvements. Fig. 2 is a vertical section of the mill transverse to the shafts, showing the interior construction. Fig. 3 is a vertical section on the line 3 3 of Fig. 2. Fig. 4 is a detail sectional view of a modified form of crushing-mill.

Referring to the drawings by letter, A de notes suitable supports for the lower half of the mill-casing a, which is provided with a discharge-spout, and (1 denotes the upper half of the mill casing, said part a being bolted to the part a, as shown in Fig. 1, and removable therefrom to allow access to the interior. A feeding-hopper a is mounted in the upper half a of the casing, said hopper having the adjustable feed-regulating slide a (See Fig. 2.)

Mounted in boxes 13 on bearing-blocks b are two driving-shafts 0, each of said shafts being provided with a driving-pulley 0. One of said boxes B is adjustable on the blocks 12 by means of shims b and adjusting-bolts 19 as indicated in Fig. 1. Keyed to each of said shafts O are flanged hubs c, and as these hubs and their attached parts are alike in construction We will describe but one of them. One of the flanges of the hub is of less diameter than the other, the reason for which will presently appear. Between the flanges of the hub c are radially-movable weights 0, pivoted to rods or pivot-bolts 0 passing through the flanges, said weights having slots 0 in them to allow radial movements. Surrounding said weights 0 and lying between the flanges of the hub c is a hard-steel tire D,which is slipped into place over the smaller flange of the hub c and secured in place by means of a removable ring d, which is bolted to the flange of the hub c, as clearly shown in Fig. 3. The pivot-bolts c serve as stops to limit the outward movements of the weights 0 and also as positive connections between said weights and the rotary hub 0, while the frictional pressure of the said weights against the loose tire D will cause the latter to rotate with the said hub c and its shaft with but little circular slip or lost motion. It is this tire D which When the directly to the roll-shafts.

mill is running and the roll-shafts are driven at high speed, the slotted weights 0 will be thrown outward by centrifugal force and, pressing against the inner side of the tire D, will force it toward the tire of the other crushing-roll or against the material between the two rolls. It will be seen from Fig. 2 that the weights 0 are effective only on the crushing side of the roll and press against the said tire D only on that side, the tire D having preferably an internal diameter equal to the diametric extent of the radially projected Weights. When the rolls are relatively adjusted, as shown in Fig. 2, the tire D is cocentric to its roll-shaft, so that the weights 0 can, as above stated, only press against the tire on the crushing side of the roll. In other words, the loose tire will when in crushing operation be forced into an eccentric position relative to the shaft of its roll by the companion roll or cooperating crushing memberor by the material being crushed, while the weights 0 will have a constant tendency, to press said loose tire into a central position relative to its roll-shaft.

Instead of the single solid crushing-tire D a series of narrow tires D D? D (see Fig. 4) may be employed, said narrow tires being locked in place between the flanges in the same manner as the single tire. With this construct-ion of sectional tire sectional weights 0 may be employed, if desired, so that one section of the tire may yield to undue resistance without arresting the crushing action of the other sections. This construction of roll, it will be seen, affords a continuous circumferential but yielding crushing face, so that if the resistance of the material between the rollsbecomes greater than the crushing force of the outwardly-pressing weights the stress incident tocrushing isentirely absorbed by the tires and Weights and is not transmitted We are enabled because of this to make the shaft-bearings andmill-casing of much lighter construction than is practicable where the crushing strain is borne by the shafts and mill-frame, and yet the crushing power ofthe rolls is not diminished because of this lighter construction.

The tires D, since they fitin the flanged hubs loosely, do not have to be machined to insure a closefit, as is the case in the solidroll type of mill, and we are able to use tires made of ,very hard metal, such asmanganese steel, and capable of resisting wear for a long period.

The pressure of the weights 0 againstthe tires D of the crushing roll-or rolls, and which pressure results from centrifugal action when the roll or rolls are in rotation, is sufficient to prevent the tires from slipping'seriously relative to the rotating shaftson which the rolls aremounted. It will be apparentthat one of said'crushing-rolls mightbe dispensed with and a resisting member consisting of a stationary anvil or surface substituted therefor,and with which anvil or surface a single roll of the construction hereinbefore described would cooperate, the material to be reduced being fed from the hopper between the said roll and the anvil-surface, and we do not wish to be understood as limiting ourselves to the use of two rolls, as shown, or to the other details herein illustrated, since our invention resides in the novel type of roll,,with out regard to the particular arrangement of cooperating parts or details of construction.

Having thus described our invention, we claim and desire to secure by Letters Patent- 1. In a crushing-mill, the combination with a resisting member, of a crushing-roll comprising a shaft, a hub, a tire loose relative to said hub and affording a circumferential crushing-surface, and a series of weights located inside of said tire and tending, by centrifugal action, to force the latter into a central position relative to the said shaft of the said roll. I

2. In a crushing-mill, the combination with a resisting member,'of a driving-shaft, a hub fixed to said shaft, a tire loose in relation to said hub and affording a circumferential crushing-surface and a series of weights interposed between said tire and shaft and tending, by centrifugal action, to force said tire into a central position relative to said shaft. 7

3. In a crushing-mill, the combination with a yielding resisting member, of a drivingsha'ft, and a crushing-roll having a loose tire forming a circumferential crushing-surface, and a series of weights interposed between said tire and shaft and tending, by centrifugal action, to force said tire toward said yielding resisting member.

4. In a crushing-mill, a rotating shaft, and

'a crushing-roll comprising a loose tire forming a circumferential crushing-surface, and a series of movable weights interposed between said tire and said shaft, combined with a resisting member cooperating with said loose tire.

5. In a crushing-mill, a rotating shaft, and

a crushing-roll comprising a loosetire'forming .a tire looselymo'u'nted between said flanges and affording a circumferential crushing-surface, and a series of weights interposed between saidtire and shaft and tending, by centrifugal action, to force said tire into a central position relative to said shaft.

7. In a crushing-mill, the combination with two rotatingshafts, of two crushing-rolls each of which comprises a loosely-mounted tire and a series of weights interposed between said tire and its shaft, said weights tending, by cen= trifugal action, to force each loosely-mounted tire into a central axial position, when said shafts are in rotation.

8. In a crushing-mill, the combination with two rotating shafts, of two crushing-rolls each of which comprises a loosely-mounted tire and a series of weights interposed between said tire and its shaft, said weights tending, by centrifugal actiomto force the loosely-mounted tires of the two rolls into central positions relative to their shafts when the latter are in rotation, one of said rolls being mounted in adjustable bearings whereby its position relative to the other roll may be varied.

9. In a crushing-mill, the combination with a rotating shaft, of a hub fixed to said shaft and provided with two separated flanges of unequal diameter, a tire loosely mounted between said flanges, a series of movable weights interposed between said tire and shaft, and a removable ring serving to hold the said tire in place after said tire has been placed in position by being slipped over the smaller of said flanges.

10. In a crushing-mill,the combination With a driving-shaft, of a flanged hub fixed to said shaft, a tire loosely mounted between the flanges of said hub, and a series of pivoted and inwardly and outwardly movable weights mounted between the flanges of the hub and interposed between said tire and shaft.

11. In a crusl1ing-n1ill,the combination with a resisting member, of a crushing-roll having a loose tire affording a circumferential crushing-surface, a series of weights located inside 3 5 said tire and tending, when the said roll is in rotation, to force said tire into a central position relative to the shaft of the said roll, and stops to limit the outward movements of the said weights.

12. In acrushing-mill,the combination with a resisting member, of a driving-shaft, a hub fixed to said shaft, a tire loosely mounted on the said hub and affording a circumferential crushing-surface, a series of weights inter- 45 posed between said shaft and tire, and stops serving to limit the outward movements of said weights and to connect the latter with said shaft through said hub.

13. A roll comprising a shaft, a hub, a tire 5o loose relative to said hub and a series of Weights located inside said tire and adapted to be pressed against the latter by centrifugal action as the said roll and weights rotate.

In testimony whereof we affix our signa- 55 tures in the presence of two Witnesses.

THOMAS L. STURTEVANT. THOMAS J. STURTEVANT.

Witnesses:

W. H. ELLIS, FRED W. OoNNoLLY.

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