US2496352A - Abrasive wheel - Google Patents

Description

Feb. 7, 1950 L. H. METZGER ETAL 2,495,352

ABRASIVE WHEEL Filed April 2, 1945 4 V////// A! g; a

: 513 Feb. 7, 1950 ABRASIVE WHEEL Leopold H. Metzger and Vincent John Fantoui, Chicago, 111., assignors, by mesne assignments, to Super-Cut, Inc., Chicago, 111., a corporation of Illinois Application April 2, 1945, Serial No. 586,050

4 Claims.

The present invention relates generally to abrasive wheels. More particularly the invention relates to that type of abrasive wheel which is primarily adapted to grind the tips of cutting tools, and comprises a disc-like body having means for connection to a power driven shaft and embodying on the outer side face thereof a fixedly mounted outer annular band with diamoncl particles of coarse -mesh and a fixedly mounted concentric inner annular band with diamond particles of fine mesh.

In utilizing an abrasive wheel of this type to grind cutting tools, such, for example, as those having tungsten carbide tips, the outer annular band with diamond particles of coarse mesh is used to grind the tips of the tools to a finished I dimension and the concentric inner band with diamond particles of fine mesh is used to provide the tips with a final or so-called mirror finish. In fabricating an abrasive wheel of the type under consideration it has heretofore been proposed to arrange the outer and inner annular bands so that they are contiguous and in addition to form the cutting or outer side face of the outer band so that it is frusto-conical and extends at a comparatively small angle to a plane at right angles to the axis of the body and to form the cutting or outer side face of the inner band so that itis fiat and extends at true right angles to the axis of the body. The

purpose of arranging the cutting faces of the two diamond carrying bands so that they are not in the same plane is to reduce, in connection with use of the inner band to provide a final or mirror finish on the tip of the tool being ground, the possibility of the tip being inadvertently brought into contact with the coarse diamond particles in the outer annular band and as a result acquiring a rough finish instead of the desired final or mirror finish. In connection with use of a wheel of the type under consideration it has been found in practice that when the cutting face of the inner band is not worn to any appreciable extent the frusto-conical contour or shape of the outer band satisfactorily eliminates the normal possibility of the tip of the tool being moved into contact with the outer band while it is being given its final or mirror finish by the inner band. However, when the cutting face of the inner band becomes appreciably worn the coarse diamonds in the inner marginal portion of the cutting face of the outer band become so exposed that the tool tip in connection with acquisition of its final or mirror finish is likely to be brought into contact with such diamonds and thereby acquire a rough finish.

The primary object of the present invention is to provide an abrasive Wheel of the type and character under consideration which is an improvement upon, and eliminates the defects of,

previous wheels by reason of the fact that its design and construction are such that regardless of whether the cutting face of the inner band with diamond particles of fine mesh is appreciably worn, the normal possibility of the tip of the tool being ground being moved into contact with the outer band while it is given its final or mirror finish by the inner band is effectively eliminated.

In general the new abrasive wheel is charac terized by the fact that the outer marginal portion of the cutting face of the inner band is formed so that it is frusto-conical and conforms to, and forms a continuation of, the inner marginal portion of the cutting face of the outer band with coarse mesh diamond particles. By having the outer marginal portion of the cutting face of the inner band of frusto-conical contour or, in other words, so that it tapers towards the wheel body and conforms to the inner marginal portion of the outer band, wearing away of the cutting face of the inner hand does not so expose the coarse mesh diamonds in the inner marginal portion of the cutting face of the outer band that the tool tip, in connection with acquisition, of its final or mirror finish, is likely to be brought into contact with such diamonds and hence acquire a rough finish.

Another object of the invention is to provide an abrasive wheel which is characterized by high efficiency and has certain inherent advantages over previous wheels, including that which is disclosed in, and forms the subject matter of, an application for United States Letters Patent filed by us on November .8, 1944 and serially numbered 562,435, which matured as Patent No. 2,451,295, dated October 12, 1948.

Other objects of the invention and the various advantages and characteristics of the Present abrasive wheel will be apparent from a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by claims at the conclusion hereof.

In the drawing which accompanies and forms a part of this specification or disclosure and in which like letters and numerals of reference denote corresponding parts throughout the several views:

Figure l is an outer side view of a diamond abrasive wheel embodying the invention;

Figure 2 is a section taken on the line: 2-2 of Figure 1 and illustrating in detail the construction, design and arrangement of the outer and inner annular diamond carrying bands; and

Figure 3 is an enlarged fragmentary section showing the frusto-conical arrangement or contour of the outer marginal portion of the cut ting face ofthe inner annular band with diamond particles of fine mesh.

The abrasive wheel which is shown in the drawing constitutes the preferred form or embodiment of the invention. It is adapted for use in. grinding the tips of cutting tools and is shown in the drawing as being mounted on one end of a horizontally extending power driven shaft 3. As its parts or components the wheel comprises a circular or disc-like body 4, an outer annular band 5 and an inner annular band 8.

The wheel body 4- is formed of any suitable material such, for example,- as bronze or brass, and has in the center thereof a circular hole I in which said one end of the shaft 3 fits. The shaft is provided inwards of said one end with a fixed collar s having at its outer end an annular outwardly extending flange s". The inner and central portions of the inner side of the body are fiat and fit flatly against the flange s on the collar s The body is secured in fixed relation with the shaft by way of an annular series of screws 8. The latter extend through holes 9 in the central or intermediate portion of the body and fit within internally threaded sockets l in the flange.

The outer annular band is fixedly mounted on the outer margin of the front or outer side of the wheel body 4 and consists of diamond particles of coarse mesh and a matrix for the particles. If desired the diamond particles in the band 5 may have a mesh of approximately 100. The

matrix of the outer annular band 5 is preferably an alloy although, if desired, 'it may be formed of resin or any other type of bonding material. The outer band is adapted to be used to grind the tips of cutting tools to a finished dimension after they have been rough ground by a silicon carbide or other abrasive wheel (not' shown) In utilizing the outer band 5 for tip grinding purposes the tip of the cutting tool to be ground is placed against the outer side face of the band 5 while the wheel is being rotated in response to drive of the shaft. Said outer side face constitutes the cutting face of the outer annular band 5. The outer margin of the front or outer side of the wheel body 4, i. e., the portion of the wheel body to which the band 5 is secured fixedly, is frusto-conical and extends at an angle of approximately 7 with respect to a plane at right angles to the axis of the wheel. The outer band 5 is preferably of uniform thickness throughout and is so formed that its cutting or outer side-face is frusto-conical and extends at substantially a 7 angle with respect to a plane that is normal to the axis of the wheel body.

The inner annular band 6 is contiguous to, and positioned in concentric relation wtih, the outer annular band 5 and is fixedly mounted on the outer portion of the wheel body 4 that is directly inwards of the frusto-conical outer marginal portion. It consists of diamond particles of fine mesh together with a matrix and is adapted to be used to provide a final or mirror finish to the tips of cutting tools after they have been ground to a finished dimension by way of the outer annular band 5. If desired the diamond particles in the band 6 may have a mesh of approximately 400. The matrix of the band 6 is preferably the same as that of the outer band 5. The outer side face of the inner band constitutes the cutting face of such band. .The central and inner marginal portions of the cutting face of the inner band are fiat as shown in Figures 2 and 3. They are outwardly offset with respect to the inner edge of the cutting face of the outer band 5 and extends at true right angles to the axis of the wheel body 4. The outer marginal portion of the cutting face of the inner band I is formed so that it is frusto-conical and flares in the direction of the wheel body. It extends at substantially a 7 angle with respect to a plane at right angles to the axiaof the wheel body and. joins and forms a continuation of the inner marginal portion of the cutting face of the outer band 5. Said outer marginal portion of the cutting face of the inner band is normally nonfunctioning in connection with use of the inner band. By reason of the fact that the outer marginal portion of the cutting face of the inner band is frusto-conical and is arranged as hereinbefore pointed out the normal possibility of the tip of the tool being moved into contact with the coarse mesh diamonds of the outer band while it is being given its final or mirror finish by the inner band is effectively eliminated regardless of any. wearing on the part of the cutting face of the inner band. In other words, the frusto-conical contour of the outer marginal portion of the cutting face of the inner band serves in connection with wear of the cutting face of the inner band, to prevent the coarse diamond particles in the inner marginal portion of the cutting face of the inner band becoming so exposed that the tool tip in connection with acquisition of its final or mirror finish is likely to be brought into contact with such diamonds and thereby acquire a rough finish The frusto conical outer marginal portion of the cutting face of the inner band is of such depth that it fulfills its intended purpose up to the point of maximum wearing on the part of the inner band. The inner band 6, with the exception of its outer marginal portion, is preferably of uniform thickness throughout and is fixedly mounted on the wheel body as the result of the matrix thereof being bonded to the adjacent portion of the outer side face of the body of the wheel. The fine mesh diamond particles are provided in the inner annular band 6 inasmuch as such particles will produce the desired final or mirror finish without the necessity of being rotated at a surface speed as great as that of the coarse mesh diamond particles.

cutting tool the tip of the tool, after being rough ground by way of a silicon carbide grinding who 31- which may be at the other end of the shaft s, is placed against the cutting face of the outer annular band 5 while the wheel is driven by the shaft. The tip of the tool is held in place against the outer band until it is ground to a finished or predetermined dimension. After the tip of the tool is ground by thelouter band 5 it is placed against the cutting face of the inner band 6 in order to provide it with a final or mirror finish. By reason of the fact thatthe outer marginal portion of the cutting face of the inner band is frusto-conical there is no likelihood of the tip of the tool being ground by the inner band being brought into engagement with the coarse mesh diamond particles of the outer band and thereby acquiring a rough finish. v

The herein described abrasive wheel effectively and efficiently fulfills its intended purpose and is capable of being produced at a comparatively low cost.

Whereas the inner and outer bands have been described as embodying diamond particles it is to be understood that they may be provided with abrasive particles other than diamond particles.

' It is also to be understood that the invention is not to be restricted to the details set forth since these may be modified within the scope of the appended claims without departing from the spirit and scope of the invention.

Having thus described the invention what we claim as new and desire to secure by Letters Paten is:

i. As a new article of manufacture, an abrasive wheel adapted to grind the tips of cutting tools and comprising a rigid disc-like body provided with means whereby it may be connected to a power driven shaft so that its axis is in alignment with the axis of the shaft, an inner annular band mounted fixedly on one side face of the body, embodying abrasive particles of fine mesh, having the central and inner marginal portions of its outer side face forming the normal grinding surface for the inner band and preformed so that they are coplanar and flat, and having the outer marginal portion of its said outer side face extending at an obtuse angle to the central and inner marginal portion of said outer side face and arranged so that it is inclined outwards towards the body, and an outer annular band mounted fixedly on said one side face of the body in concentric relation with the inner band, embodying abrasive particles of coarse mesh, and having its outer side face extending in the direction, and forming a continuation, of, the outer marginal portion of the outer side face of the inner band.

2. As a new article of manufacture, an abrasive wheel adapted to grind the tips of cutting tools and comprising a rigid disc-like body provided with means whereby it may be connected to a power driven shaft so that its axis is in alignment with the axis of the shaft, a concentric inner annular band mounted fixedly on one side face of the body, embodying abrasive particles of fine mesh, having the central and inner marginal portions of its outer side face forming the normal grinding surface of the inner band and preformed so that they are coplanar and fiat and extend at right angles to the axis of the body, and having the outer marginal portion of its said outer side face extending at an obtuse angle to the central and inner marginal portion of said outer side face and arranged so that it is inclined outwards towards the body, and an outer annular band mounted fixedly on said one side face of the body in concentric and abutting relation with the inner band, embodying abrasive particles of coarse mesh, and having its outer side face extending in the direction of, joined to, and forming a continuation of, the outer marginal portion of the outer side face of the inner band.

3. As a new article of manufacture, an abrasive wheel adapted to grind the tips of cutting tools and comprising a rigid disc-like body provided with means whereby it may be connected to a power provided with means whereby it may be connected to a power driven shaft so that its axis is in alignment with the axis of the shaft, an

6 inner annular band mounted fixedly on one side face of the body, embodying abrasive particles of a certain mesh, having the central and inner marginal portions of its outer side face forming the normal grinding surface of the inner band and preformed so that they are coplanar, and having the outer marginal portion of its outer side face extending at an obtuse angle with respect to said central and inner marginal portions and also of its side face and arranged so that it is inclined outwards towards the body, and an outer annular band mounted fixedly on said one side face of the body in concentric and abutting relation with the inner band, embodying abrasive particles of different mesh and having its outer side face extending in the direction of, joined to, and forming a continuation of, the outer marginal portion of the outer face of the inner band.

4. As a new article of manufacture, an abrasive wheel adapted to grind the tips of cutting tools and comprising a rigid disc-like body provided with means whereby it may be connected to a power driven shaft so that its axis is in alignment with the axis of the shaft, a first annular band mounted fixedly on one side face: of the body, embodying abrasive particles of a certain mesh, having the central and one marginal portion of its outer side face forming the normal grinding surface of the first band and preformed so that they are coplanar, and having the other marginal portion of its outer side face extending at an obtuse angle with respect to said central and one marginal portions of its outer side face and arranged so that it is inchned outwards towards the body, and a second annular band mounted fixedly on said one side face of the body in concentric and abutting relation with the first band, embodying abrasive particles of a different mesh and having its outer side face extending in the direction of, joined to, and formin a continuation of, the said outenmarginal portion of the outer side face of the first band.

LEOPOLD H. METZGER. VINCENT JOHN FANTOZZI.

REFERENCES CITED The following references are of record the file of this patent:

UNITED STATES PATENTS

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