US1529410A - Abrasive disk - Google Patents

Description

A. J. DOERMANN ABRASIVE DISK March 10. 19 25 File d Jan. 18, 1922 Patented Mar. 10, 1925.

LALBERT J'QDOEBMANN, OF CHICAGO, ILLINOIS.

ABRASIVE DISK,

Application filed January 18, 1922. Serial No. 530,}72.

To all whom it may concern:

Be it known that I, ALBERT J. DonR uANN, a citizen of the United States, residing at 1839 West Garfield Boulevard, Chicago, n the county of Cook and State of Illinols, have invented a new and useful Improvement in Abrasive Disks, of which the following is a specification.

' This invention relates to improvements n grinding disks, and more particularly 1n disks which are mounted upon fabric backs, the faces of the disks being used in the grinding operation. It will be fully understood from the following description, 1llu strated by the accompanying drawings, in which F i re 1 is a side elevation of a disk prepare in accordance with the present invention, shown face down;

Fig. 2 is a face view of the disk, broken away to show the construction of the disk, and

Fig. 3 is an enlarged detail view, showing in diagrammatic form the character of the material forming the face of the disk.

. In accordance with the present invent on the abrasive body of the grinding d sk, which, in the case of a fabric-backed disk, forms the face of the disk, is formed ofparticles of abrasive material and a binder. The binder preferably employed is a magnesium o chlorid cement, into which is incorporate a finely divided corrodible material, such as finely powdered cast iron. The addition of this material materially lengthens the grinding life of the disk and permits of the use of a harder binder or cement than would be otherwise possible. It

is readily apparent that other binders may-case,

be employed than magnesium oxychlorid cements: for example, oxyphosphate cements. The abrasive material may be any suitable material, for, example carborundum, alloxite, alumdum or the like, the particles of abrasive material being hereinafter designated grit.

In forming the fabric-backed disk, the abrasive disk may be formed and subsequently secured to the fabric back, for example, by means of casein glue, formaldehyde treated glue, sodium silicate solution or the like. In some cases, the facing of abrasive material may be directly formed upon the fabric back, this being particularly a'dvantageous when the binder for the abrapreviously been inserted.

chlorid solution may suitably be from 24 sive is of magnesium oxychlorid cement.

The drawin gs illustrate a disk made upv of a face or disk of abrasive material 5 se cured. by an intermediate layer 6 of glue or sodium silicate to a fabric back 7. The abrasive facing ma in the core be molded on an oiled paper b or press and stripped therefrom to be secured to the fabr1c back. In making up the abrasive face, the grit may be bonded with magnesium oxychlorid cement containing powdered cast iron, the corrosion of which is effected by the chlorid material of the cement. For example,to 16 parts grit and 4 to 5.5 parts of. calcined magnesite 0.3 to 1 part of powdered cast iron may be added and the mixture thoroughly kneaded with suflicient magnesium chloride solution to make it damp and pasty. It is then stamped down into a mold, in which an oiled paper back or a fabric back may have The magnesium to 34 B. (saturated). The saturated solution is preferred, as it causes the formation of a harder and stronger bond.

In preparing .the abrasive body of the disk the cutting" grits are chosen for the particular purpose'in view, as is well known in the art. Thus, for rapid work on large malleable castings, 16 mesh grit may be used for the cutting grit. In accordance with the present' invention, the cutting grits are reinforced with finer grit u .to for example, in the above case, rom 10 to 20% of finer grit, say 24 mesh, may be added to make up the grit mixture for ack in a suitable form the abrasive body of the disk. In another in which'the cutting grits were made up of 16 and 24 mesh grits in about equal proportions, from 5 to 25% of 30 mesh grit was added. In Fig. 3 the reinforcement of the cutting grit withfiner grit is indicated in an exaggerated manner, the bond being indicated in black. I,

The oiled paper back may be removed from the abrasive disk body after its formation; the abrasive body being subsequently secured to a fabric back by'asuitable adhesive, as hereinbefore set forth. If desired, the abrasive disk body formed directly upon the fabric back by placing the fabric back in the mold, coating its surface with a mixture of magnesite with suflicient magnesium chloride solution may be 1 therefor, the hon to permit of a plication with a brush, and forming the a rasive body on the coated back I claim: t 1. In an abrasive disk body, abrasive grit and a cementitious bond therefor, the

0nd containing finely divided iron.

2. In an abrasive disk body, abrasive grit and a ma esium oxychlorid bond d containing finely divided iron.

3. In an abrasive disk body, abrasive grit, the grit comprising cutting grit and s 5 to 25% of finergrit, and a cementitious bond containing from 0.3 to 1 part of finely divided iron to 16 parts of grit.

4. an abrasive disk body, abrasive grit, magnesium oxycblorid bond formed with saturated magnesium chlorid solution,

and finely divided corrodible material ii corporated in said bond. p

5. In a face-grindin disk, a body coinprising a binder and a rasive grit incorporated therein, the cutting grit being reinforced by upon which said body is mounted.

6. In aface-grinding disk, a body comprising a binder, cutting grit incorporated therein, and finer grit incorporated in the finer grits, and a fabric back

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