US874244A - Grinding-mill. - Google Patents

Description

No. 874,244. I PATENTED DEC. 17, 1907.

' H. 0. ROBINSON.

GRINDING MILL. APPLIOATION FILED r33. 2a. 1907.

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GRINDING-MILL.

Specification of Letters Patent.

Patented Dec. 17', 1907'.

Application filed February Z3, 1907- Serial No. 358,880.

To all whom it may concern:

Be it known that I, HARRY C. ROBINSON, a citizen of the United States, residing at Muncy, in the county of Lycoming and State of Pennsylvania, have invented new and useful Improvements in Grinding-Mills, of which the following is a specification.

This invention relates to grinding mills.

I do not limit the use of the invention to any particular type of mill, but find it, how-. ever, of especial utility when incorporated in one of the class known as disk or attrition mills. Mills of this particular class involve two vertically disposed disks set face to face or arranged in parallelism and generally 0ppositely rotative. One of these disks usually has an eye through which the stock to be ground is fed into the space between the two disks. This disk which has the eye also has within the eye a hub and arms projecting rom the hub and joined with the wall of the eye, it being the custom to make the body of the disk, the hub, and arms or spokes integral. It is the practice to so shape these arms that they aid in positively feedin the material to the two disks. One way of oing this is to have the side faces of the respective arms angular and converging inwardly so that, when the disk equipped with such arms is rotated, the latter act to force the stock into said space, no matter in which direction the said disk rotates. These arms and the wall of the eye, as well as other points on the. disk, when the latter is in action, are subjected to an unusual amount of wear. The grain wears the edges of the arms round, and also forms pockets, cavities, or recesses in the arms, in the wall of the eye, and at other places, and these round edged arms and recesses, cavities, or pockets are so shaped as not only to retard the proper feed of the stock to the grinding area, but as to absolutely feed a large portion of the material backward.

It is primarily the object of my invention to provide a disk having an eye and of such a construction that the feed of the stock will not be obstructed or retarded to any extent. I prefer to provide a disk of substantially familiar construction having the usual eye through which the material may pass, and I combine with this disk, means for preventing wear on said arms and wall, and this means is of such a nature that, when worn by the action of the grain or other material, it may be separated bodily or as an entirety from the disk and replaced by a new and perfect device. This insures a great saving, for, with the old disks, when the same were worn as I have pointed out, it was necessary not only to wholly replace the same, but to replace the shafts which carried them, for the parts were generally permanently connected together, so that, when. the disk was discarded, the supporting shaft therefore was valueless for further use in the grinding mill, in that it could not be separated from the disk.

In the drawings accompanying and forming a part of this specification I show in detail one form of embodiment of the invention, which, to enable those skilled in the art to practice the invention, will be hereinafter fully set forth, while the novelty of said invention will be included in the claims succeeding said description.

Referring to said drawings: Figure 1 is a face view of a grinding disk including my invention. Fig. 2 is a sectional view of said disk. Figs. 3 and 4 are detail view of the shield or guard shown in the preceding figures and viewing the same from opposite sides thereof.

Like reference characters indicate like parts throughout the several figures.

As hereinbefore indicated, I do not limit myself to the incorporation of my improvements in any particular type of mill, although they are of especial utility when employed in connection with an attrition or disk mill. These attrition or disk mills take several different forms, as is well known, and I may readily adapt the invention to any of these.

In the drawings, I have shown one of the disks of an attrition or disk mill, the same being denoted in a general way by 2 and having therein an eye, as 3, through which the material to be ground by the disk 2 and the companion disk (not shown) is fed. It is customary to set these disks vertically. Within this eye is ordinarily disposed a hub, as 4, from which extend several arms or spokes 5. The hub, arms, and disk may be and generally are integral, and may be formed by casting. This, however, is not essential. The hub 4L and arms 5 constitute the customary support for the disk 2, and

this hub may be fastened to its shaft in any desirable way. For example, the hub may be shrunk on said shaft. This, however, is immaterial.

With disks of the ordinary kind, the stock is passed through the eye 3 from a hopper not shown, and it is usually the practice to make the arms 5 of wedge shape, this being accomplished by forming the sides of the arms upon angles which converge inward, these angular faces serving to aid in feeding the stock into the space between the two disks. The arms 5 unite with the wall of the eye 3 and at such places, and along the arms particularly on the edge thereof, and even upon the hub 4 the material wears so that the surfaces thus acted upon soon become abraded or pocketed, and these abraded or worn away portions frequently take such shapes or forms as not only to check the proper supply of material to the space between the disks, but actually cause a very large portion of the material to be fed backward, ruinously reducing the capacity of the mill, and causing the feed spout and other exposed parts to be rapidly worn away.

To prolong the life of the disk 2 by preventing this wear, I provide a shield or guard, as that denoted in a general way by 6. This shield, in the present instance, is of such a nature as to protect not only the arms 5 and wall of the eye 3 from wear,-but also thehub 4. The disk 2, hub 4, and arms 5 may be in expensively made by casting from iron, while the shield 6 may consist of cast steel, and is removably or separably associated with the disk, so that the shield, and not the usually exposed parts of the disk, receives the abrasion of the material. When said shield is worn away, it can be quickly taken from the disk by separating the same from the companion disk, and a new and uninjured one put in its place without the necessity of discarding the disk having such shield. The character of the shield will, of course, vary in accordance with the particular construction ofdisk, the shield illustrated in the drawings being of such a nature as to adapt it primarily to the disk represented. The shield 6 in the present case is composed of a hub, as 7, arms, as 8, and a rim, as 9. While not essential, I prefer to make these parts in one piece, so that the shield as an entirety can be separated from the disk. This shield may be held in assembled relation with the disk in any desirable way, although I have shown and will hereinafter describe one advantageous mode of obtaining this result. The hub 7 is of a form to cover or inclose the hub 4, and this form, in the present case, is a chambered or casing one. The shape of the hub, however, is of no consequence; in fact, it is not imperative that it be employed, although its presence is advantageous during the casting of the shield, in that the hub prevents the arms 8 from springing or breaking away from the rim 9. The spokes or arms 8 are of channel form, to cover or inclose the spokes 5, their sides embracing said spokes 5. The rim 9 covers the wall of the eye 3.

I may tap into the inner surface of the disk 2 several screws, as 10, the heads of which engage over the marginal portion of the shield 6 to hold said shield removably in place. In the present case I do not rely wholly on these screws 10 for this purpose The segments 11 which are bolted or other wise suitably fastened to the inner surface of the disk 2, and which constitute the working portion of the said disk, overlie, at their inner edges, the shield 6, and thus aid the screws 10 in maintaining the shield 6 in position. Therefore, should any one of the screws 10 become accidently loosened, the shield 6 cannot be dislodged, for it would be held solidly in position by the segments 11. IVhen the shield 6 becomes worn from con stant use, it can be readily dismounted by taking off the segments 11 and removing the screws 10, following which a new shield can be put in place of the old worn one. I prefer to make the sides of the spokes or arms 8 angular and have these angular faces converge inwardly, so as to force the material into the space between the disk 2 and the cooperating disk which, as previously set forth, is not shown.

As will be obvious, the hub 4 and arms or spokes 5 present a spider, and this spider constitutes, in the present case, a main or supporting spider, an auxiliary spider being provided by the hub 7 and the arms or spokes 8. This second spider is, as will be obvious, removable. The auxiliary spider is shown as having as a part thereof the rim 9, so that said auxiliary spider with its rim can be bodily separated from the disk. In some cases this auxiliary spider with its rim may accomplish. all that the main spider does.

What I claim is:

1. A grinding mill disk having an eye, a

hub in the eye, and arms extending from the hub to the wall of the eye combined with a shield removably associated with said disk and covering said arms and wall.

2. The combination of a grinding mill disk having an eye, a hub in the eye, and arms extending from the hub to the wall of the eye, and a shield removably associated with the disk and covering the hub, arms, and wall.

3. A grinding mill disk having an eye, a hub surrounded by the wall of the eye, and arms extending from said hub to the body of the disk, combined with a shield consisting of a hub, arms, and a rim, the hub and arms of the shield being adapted to fit the first mentioned hub and arms, and the rim of the shield being adapted to cover said wall, said shield being removably associated with the disk, and the arms of said shield having their side faces angular and convergingtoward the inner face of the disk.

4. As an article of manufacture, a shield comprising a hub, arms extending from the hub, and a rim united with the arms, the hub being of chambered form and the arms being of channel form.

5. As an article of manufacture, a shield comprising a hub, arms extending from the hub, and a rim united with the arms, the hub being of chambered form and the arms being of channel form, said arms having angular converging faces.

6. A grinding mill disk having an eye combined with a shield provided with a rim rese ments on one of its side faces, an eye, a

in the eye, and arms extending from the hub to the wall of the eye, combined with a shield covering said arms and wall and engaged by said segments.

In testimony whereof I have hereunto set my hand in presence of two subscribing wit nesses.

HARRY O. ROBINSON.

Witnesses:

G. L. PAINTER, GEO. A. BARDORFF.

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