MXPA01008557A - Grinding wheel - Google Patents

Abstract

A cylindrical, abrasive grinding wheel (10) having a cylindrical abrasive region (12) with an abrasive surface (18) at an outer circular band thereof. The abrasive region includes layers (26) of abrasive particles. The layers (26) of abrasive particles can be tilted with respect to an axis of rotation (23) of the grinding wheel or they can be arranged such that grooving in the grinding wheel and a workpiece ground by the grinding wheel can be reduced. Alternatively, the abrasive region can be formed from a plurality of abrasive segments each having layers of abrasive particles. The layers of abrasive particles can be staggered in the direction of the axis of rotation from one segment to another. This can also reduce grooving in the grinding wheel and workpieces.

Description

MUELA RECTIFIERING Technical Field The present invention relates generally to abrasive or superabrasive tools. In particular, the present invention relates to a rotating grinding wheel having an abrasive or superabrasive surface.

Background of the Invention Certain types of workpieces (glass and plastic lenses, stone, concrete, and ceramics, for example) can be advantageously shaped using grinding tools, such as a grinding wheel or disc, which have an abrasive working surface, particularly a superabrasive work surface, a superabrasive surface is also an abrasive surface but has a greater abrasiveness. The work surface of the grinding tool may be composed of an abrasive band around the outer circumference of the wheel or disc. The work surface usually includes particles of an abrasive or super hard material, such as diamond, Ref.132466 cubic boron nitride, or boron suboxide surrounded by a bonding material and / or sandwiched in a metal matrix. It is these abrasive particles that act primarily to cut or grind a work piece when it is brought into contact with a rotating work surface of the tool for grinding. It is already known to form grinding or cutting wheels comprising segments of abrasive material. The abrasive segments can be formed by mixing the abrasive particles such as diamonds and metal powder and / or other binding material or filler in a mold, and pressure molding the mixture at an elevated temperature. The formation of abrasive segments in this manner, however, can create areas that have high concentrations of hard or abrasive particles and areas that have low concentrations of abrasive particles in the segment. In addition, the concentration of the abrasive particles on an abrasive surface affects the grinding characteristics of the grinding wheel for grinding such as the grinding wheel's wear speed and the speed of grinding. As such, non-uniform or randomly varying concentrations of abrasive particles can cause unstable cutting or grinding operation. Also, the formation of abrasive segments in this manner can be relatively expensive because a relatively high number of abrasive particles are used. To reduce the problems associated with non-uniform or randomly varying concentrations of the abrasive particles, it is already known to form abrasive segments in which the concentrations of the abrasive particles vary in an orderly or methodical manner. For example, the abrasive segments can be formed having flat, substantially parallel layers of the abrasive particles separated by regions of the bonding material. The abrasive material having such layers of the abrasive particles is described, for example, in U.S. Pat. No. 5,620,489, issued April 15, 1997 to Tselesin, entitled Method for Making Powder Preform and Abrasive Articles Made Therefrom; U.S. Pat. No. 5,049,165, issued September 17, 1991 to Tselesin entitled Composite Material; and Japanese Patent Publication Open to the Public J.P. Hei 3-161278 by Tanno Yoshiyuki, published on July 11, 1991, for Diamond Saw Blade ("Yoshiyuki"). Yoshiyuki describes a saw blade for cutting stone, concrete, and / or fire resistant material. The saw blade is formed from abrasive segments having flat layers of abrasive particles. The layers of abrasive particles are aligned with a direction of rotation of the saw blade in such a way that the cut in a workpiece forms notches, as can be seen in Figure 3 of Yoshiyuki. Such notches are formed because the areas of the material bonded between the planes of the abrasive particles wear out faster than the areas of the planes of the abrasive particles. Nevertheless, for some applications of a grinding tool, the wear of the notches is undesirable or unacceptable. In some cases, it is specifically desirable to be able to produce a rounded, smooth edge on a workpiece. For example, a type of grinding wheel, known as a grinding wheel with a cylindrical insert impregnated with diamond dust, is generally used to grind the edges of glass vessels or sheets to remove the sharp edges of the glass and leave the rounded edges free of ruptures that could cause the glass to break. The production of notches in the rounded edge could be undesirable. In addition to the foregoing, an improvement is desired over the generally practiced methods of assembling the grinding wheels. Typically, the assembly of a grinding wheel includes a process of either brazing or sintering to bond the abrasive material to the support plate (s). These processes can be disadvantaged for a number of reasons. For example, the brazing of an abrasive layer to an aluminum support plate (a preferred material due to its light weight) can be difficult to effect due to the presence of aluminum oxide on the surface of the support plate which inhibits the wetting of the material for welding with brass. Sintering is unfavorable generally due to the prolonged period of time and the high temperature required. In addition, both sintering and brassizing are incomptable with non-metallic (for example, polymeric) support plates. In view of these disadvantages, an improved method of bonding the abrasive layer to the support plate (s) in a grinding wheel is desirable.

Brief Description of the Invention In accordance with the present invention, a grinding wheel exhibits an abrasive surface having an ordered concentration of the abrasive particles to advantageously produce stable grinding results. But also, the abrasive surface of the wheel is able to produce a smooth edge on a work piece. In some cases, the edge produced on a workpiece can also be rounded. The present invention includes a cylindrical abrasive grinding wheel, which is rotatable about an axis of rotation. A substantially cylindrical region of the abrasive material having an abrasive surface on an outer peripheral surface thereof is formed from a plurality of layers of abrasive particles. Each layer of the abrasive particles extends in at least one circumferential direction and a radial direction of the cylindrical region of the abrasive material. By extending the layers in a radial direction, when an edge of a layer of the abrasive particle is worn by the use of the wheel, a fresh or new edge will be advantageously exposed. However, when a wheel having a shaped or profiled edge is used, the edge may have to be reprofiled when it is worn down. One aspect of the invention is characterized by the layers of the abrasive particles which are arranged or distributed on the abrasive surface in such a way that any circular path defined by an intersection of a plane perpendicular to the axis of rotation of the grinding wheel and a full circumference of the abrasive surface will intersect at least one of the plurality of layers of the abrasive particles. Another aspect of the invention may be characterized by the layers of the abrasive particles that are inclined with respect to the axis of rotation of the grinding wheel to form an angle of between 0 degrees and 180 degrees, exclusive therewith. In this way, when the grinding wheel is rotated through a 360 degree rotation, an exposed edge of a single abrasive particle layer will be swept or traversed over an axial distance wider than the width of the exposed edge of the particle layer. abrasive If the layers of the abrasive particles are inclined with respect to the axis of rotation in such a way that the width of the axial distances over which each layer of abrasive particles overlap or is in the sweep, then the grooving on the surface of a Workpiece can be reduced and preferably eliminated. Still another aspect of the invention can be characterized in that the grinding wheel is formed from a plurality of abrasive segments each including the layers of the abrasive particles. The layers of the abrasive particles are staggered in an axial direction from one segment to the other. In this way, the exposed edges of the layers of abrasive particles will be traversed or swept through a larger portion of an axial thickness of the abrasive surface. This can also reduce grooving on a work surface. In some embodiments, it may be feasible to reduce grooving with segments whose abrasive particles are not layered but spaced at random. Yet another aspect of the invention can be characterized by the grinding wheel including a layer of a metal bonding abrasive which is adhesively bonded to at least one support plate. When used herein the term "adhesive" refers to a polymeric organic material capable of retaining solid materials together by means of surface fixation. When used herein, the term "metal bonding abrasive" refers to an abrasive material comprising a plurality of abrasive particles distributed end to end of a metal bonding material. Abrasive particles can be randomly distributed (ie, random or non-uniform variable concentrations) from beginning to end of the metallic bonding material or the concentration of the abrasive particles may vary in a methodical or orderly manner (eg, flat, substantially parallel layers, of the abrasive particles separated by regions of the metallic bonding material). The layer of the metallic bonding abrasive may comprise a single mass or more than one mass. In a preferred embodiment, a plurality of discrete metallic bonding abrasive segments are circumferentially spaced between two support plates and adhesively bonded to the support plates by a structural adhesive which is interposed between the abrasive segments and the support plates .

Brief Description of the Drawings Figure 1 is a perspective view of an abrasive grinding wheel, having an inclined abrasive surface according to the present invention. Figure 2 is a cross-sectional view of the grinding wheel shown in Figure 1 taken along line 2-2 of the section of Figure 1. Figure 3 is a front view of the grinding wheel shown in Figure 1. Figure 1 illustrating the layers of the abrasive particles in an abrasive region thereof. Figure 4 is a partial cross-sectional side view of an abrasive grinding wheel, grinding a work piece illustrating how the layers of the abrasive particles between the bonding regions on the abrasive surface of the grinding wheel can cause grooving of the grinding wheel. the grinding wheel and the work piece. Figure 5a is a partial front view of a sheet of abrasive material which can be used to make the grinding wheel shown in Figure 1, which shows the abrasive particles and the layers of abrasive particles for purposes of illustration. Figure 5b is a partial front view of the grinding wheel shown in Figure 1 showing the layers of exaggerated abrasive particles for purposes of illustration and inclined with respect to an axis of rotation of the grinding wheel. Figure 6 is a perspective view of a laminated block from which the grinding wheel shown in Figure 1 can be formed. Figure 7 is a top view of a laminated sheet from which an abrasive region can be formed. of the grinding wheel shown in Figure 1. Figure 8 is an exploded front view of an example of a laminated sheet such as that shown in Figure 7. Figure 9 is a top view of a first embodiment of the porous material which it can be used to manufacture the laminated sheet shown in Figure 7. Figure 10 is a top view of a second embodiment of the porous material which can be used to manufacture the laminated sheet shown in Figure 7. Figure 11 is a view in perspective of a second embodiment of an abrasive grinding wheel, which includes abrasive segments having layers of abrasive particles according to the present invention. Figure 12 is a cross-sectional view of the grinding wheel shown in Figure 11 taken along line 12-12 of the section of Figure 11. Figure 13 is a cross-sectional view of the grinding wheel shown. in Figure 12, taken along line 13-13 of the section of Figure 12. Figure 14 is a cross-sectional view of the grinding wheel shown in Figure 12, taken along line 14. -14 of the section of Figure 12. Figure 15 is a cross-sectional view, taken along the same line of the section as Figure 12, of another embodiment of a grinding wheel according to the present invention. Figure 16 is a cross-sectional view of the grinding wheel shown in Figure 15 taken along line 16-16 of Figure 15. Figure 17 is a front view of the grinding wheel shown in Figure 11 which shows abrasive particles and layers of exaggerated abrasive particles for illustration purposes. Figure 18 is a front view of a third embodiment of an abrasive grinding wheel, including the stacked abrasive segments according to the present invention. Figure 19 is a cross-sectional view of the grinding wheel shown in Figure 18 taken along line 19-19 of the section of Figure 18. Figure 20 is a front view of another embodiment of the grinding wheel. abrasive, according to the present invention, having an abrasive surface with a variation of the axial position of the layers of abrasive particles. Figure 21 is a perspective view of a spacer which can be used to manufacture the grinding wheel shown in Figure 20. Figure 22 is a front view of another embodiment of an abrasive grinding wheel., according to the present invention having an abrasive surface formed of abrasive segments. Figure 23 is a front view of another embodiment of an abrasive grinding wheel, according to the present invention, having an abrasive layer which is adhesively bonded to the support plates. Figure 24 is a front view of another embodiment of an abrasive grinding wheel, according to the present invention, having an abrasive layer which was formed from a plurality of abrasive segments which are adhesively bonded to the backing plates . Figure 25a is a front view of another embodiment of an abrasive grinding wheel, according to the present invention having an abrasive layer that was formed from a plurality of abrasive segments which are adhesively bonded to the support plates. Figure 25b is a view of the assembly or assembly of the embodiment of Figure 25a.

Detailed description Figure 1 is a perspective view of the grinding or cutting wheel 10 having an abrasive perimeter surface according to the present invention. The grinding wheel 10 is of a substantially cylindrical shape and includes an abrasive region 12 sandwiched or interposed preferably between a first support plate 14 and a second support plate 16. An external abrasive surface 18 of the abrasive region 12 is a substantially cylindrical band the which extends around a portion of the circumferential surface 24 of the wheel 10. The wheel 10 includes a hole 20 in the center thereof, which passes completely through the wheel 10. The hole 20 is to allow the wheel 10 is mounted to a rotating sh(not shown) to rotate wheel 10 around it. Accordingly, a rotary shpositioned through the hole 20 could extend along the axis of rotation 23 of the wheel 10. Alternatively, the axis of rotation can be defined by the longitudinally aligned portions of the sh fixed within the planes 14. and 16. It is also contemplated to fix the wheel 10 to a rotating sh by fixing a substantially circular mounting plate (not shown) having a central axis (not shown) to the wheel by means of the mounting holes 9. It is going to understand, however, that the mounting holes 9 are not necessary. By rotating the wheel 10 on or by means of a rotating sh a workpiece can be maintained or retained against the circumferential surface 24 of the wheel 10 so that it is subjected to abrasion by the abrasive surface 18 so that the workpiece can be shaped, polished, or cut appropriately. The support plates 14 and 16 are substantially rigid and are preferably formed of steel, but could also be made of bronze, aluminum, or any other suitably rigid material. The support plates 14 and 16 can be formed from a sintered or non-sintered powder material. At least one of these plates may comprise non-abrasive particles or may comprise some abrasive particles of concentration and / or smaller in size than the abrasive region 12. Plates 14 and 16 have external surfaces 14a and 16a respectively, which are preferably perpendicular to the surface. rotation axis 23 of the disk 10. The plates 14 and 16 also have internal surfaces 14b and 16b respectively. As shown in Figure 3, which is a front view of the wheel 10, the internal surfaces 14b and 16b are preferably substantially parallel to each other but inclined to form an angle? With a plane perpendicular to the axis of rotation 23. It is to be understood, however, and as described more fully below, that it is also within the scope of the present invention to have non-parallel layers of the abrasive particles, the layers which may not be parallel but which follow the contours of any adjacent layer. It is also contemplated that the internal surfaces 14b and 16b may be perpendicular to the axis of rotation 23 instead of being inclined. The abrasive region 12 is preferably substantially cylindrical having an upper surface 31 and a lower surface 33 which are substantially parallel to each other and also preferably inclined at an angle? with a plane perpendicular to the axis of rotation 23. In this way, the abrasive region 12 can be supported between the support plates 14 and 16 at the angle? with respect to a plane perpendicular to the axis of rotation 23 of the wheel 10. Because the upper surface 14a of the plate 14 and the lower surface 16a of the plate 16 can be substantially perpendicular to the axis of rotation 23, the surfaces 31 and 33 can they be tilted at an angle? with respect to surfaces 14a and 16a. It is to be understood that support plates 14 and 16 are optional. To facilitate the rotation of a grinding wheel formed without the support plates 14 and 16, a rotating shaft can be fixed directly to the upper and lower surfaces 31 and 33, respectively. As shown in Figure 2, which is a sectional view of the wheel 10 taken along the line 2-2 of Figure 1, the abrasive region 12 is annular, extending radially inwardly from the surface 24 towards the center of the wheel 10. In this way, when the external abrasive surface 18 is worn out by use, the additional abrasive surface is exposed, thus extending the useful life of the wheel 10. In the embodiment shown in Figure 2, the The abrasive region 12 extends through the entire radial distance between the circumferential surface 24 and the hole 20. It is also contemplated, however, that the abrasive region 12 extends radially through only the portion of the region between the surface 24. and the hole 20.

The abrasive region 12 contains particles of abrasive or hard material including, but not limited to, superabrasives such as diamond, cubic boron nitride, boron carbide, boron suboxide, and other abrasive particles such as silicon carbide, tungsten carbide, titanium carbide, and chromium boride suspended in a matrix of filler or bonding material. As shown in Figure 3, according to the present invention, the abrasive particles can be arranged in substantially flat parallel layers 26, in the abrasive region 12 with the regions of the bonding material 28 between the layers 26 of the abrasive particles. The layers of the abrasive particles 26 can define a plane which extends in a radial and circumferential direction in the wheel 10. As shown in Figure 3, which is a front view of the wheel 10, the abrasive surface 18 can be formed to cut through the layers 26 of the abrasive particles, represented by the shaded lines. In this way, the edges of the layers of abrasive particles 26 can be exposed on the abrasive surface 18. Also, the edges of the regions of the bonding material 28 are exposed on the surface 18. The exposure of the edges of the layers 26 on the surface 18 affects the shape, the wear profile, or the surface morphology of the surface 18 when the tool 10 is used. It also affects the profile of a surface of a workpiece which has been polished using the tool 10. This is because the regions of the bonding material 28 will wear out more quickly and cut a work piece less effectively than the layers of the abrasive particles 26. Figure 4 is a side view illustrating the wear profile of a grinding wheel 310 and a work piece 308 that has been subjected to abrasion by means of it. The grinding wheel 310 has the abrasive region 312 which can be sandwiched between the support plates 314 and 316. The abrasive region 312 includes the layers of abrasive particles 326 separated by the regions of the bonding material 328. The edges of the layers 326 are aligned in a plane perpendicular to the axis of rotation 323 of the wheel 310, and each edge of the layer 326 extends continuously around the perimeter of the wheel 310. As shown, the grinding of the edge of the work piece 308 using the wheel 310, can lead to grooving in the abrasive region 312. The raised sites of the grooves in the abrasive region 312 are present at the edges of the layers of abrasive particles 326 and the low sites occur in the regions of the bonded material 328. As it is shown, this grooving can be imitated or copied on the surface of the work piece 308 which is being polished because the edges of the layers of the abrasive particles s 326 will remove material from the work piece faster than the surrounding regions of the bonding material 328. However, as noted in the background section, it is generally desirable to produce a smooth surface on a workpiece surface. For example, glass manufacturers for automobiles and furniture use grinding wheels with a cylindrical tube with diamond powder to polish or rectify the edges of the glass that will be smooth and relatively free of defects. Therefore, to reduce grooving or other surface anomalies in a workpiece, as shown in Figure 3, the layers of the abrasive particles 26 can be tilted at an angle? in a plane perpendicular to the axis of rotation 23. The angle? it is preferably between 0 degrees and 180 degrees, exclusive. The layers of abrasive particles 26 are preferably sufficiently inclined such that any path or path 32 defined by the intersection of a plane perpendicular to the axis of rotation of the wheel 10 and a complete circumference of the abrasive surface 18 will intersect or strike a blow. cutting through at least one layer of abrasive particles 26. Thus, the entire surface of a workpiece rectified by the wheel 10 can be ground or polished to substantially the same speed and a smaller amount of notches or other anomalies are formed due to a region of the surface being ground or polished only by the bonding material or, alternatively, a disproportionately large amount of abrasive particles. The minimum angle? Mln to which the abrasive region 12 must be inclined with respect to a plane perpendicular to the axis of rotation of the grindstone 10 so that any route or path 32 to strike a shear through at least one layer of particles abrasive 26, depends on the size of the particles used in the formation of the abrasive region 12, the diameter of the grinding wheel 10, and the thickness of the regions of the bonding material 28 between the layers of »The abrasive particles 26. Figures 5a and 5b show schematic illustrations of the partial views of an abrasive material of the type from which the wheel 10 can be formed. Two abrasive particles 34 and 36 are in the layers of adjacent abrasive particles 26a and 26b, respectively, represented by the shaded lines. Figure 5a shows a schematic view of the cylindrical abrasive region 12 before being inclined in the wheel 10 to illustrate a method for the determination of Qm n. The particles 34 and 36 are diametrically opposed to each other through a diameter of the wheel 10. Thus, the particles 34 and 36 are at a distance from each other which would be equal to the diameter D of the abrasive region 12. The layers of the abrasive particles 26a and 26b are at a distance t from each other. An abrasive particle has a diameter d. Therefore, the angle? P? N is given by the equation: min = arctan (d + t / D) For example, for a wheel with a diameter of 10.16 cm (4 inches) (D = 4 inches) that has a separation between the adjacent particle layers of 0.127 cm (0.05 inches) (t = 0.05 inches) and the diameter of the abrasive particle of 0.0254 cm (0.01 inches) (d = 0.01 inches), the angle? M? N is approximately 0.86 degrees. Figure 5b shows a schematic illustration of the wheel 10 after the cylindrical abrasive region 12 has been inclined through the angle min min and sandwiched between the support plates 14 and 16. Although the above equation gives a minimum angle of inclination m For the abrasive region 12 to generally ensure that a route 32 will intersect an edge of a layer of abrasive particles, it is also within the scope of the present invention to tilt the abrasive region 12 to an angle? greater than? mn. It is also considered to tilt the abrasive region 12 to a smaller angle than that given by min, however, if an angle of inclination is used? smaller than? m ± n, a path 32 defined by the intersection of a plane perpendicular to the axis of rotation 23 and a circumference of the abrasive region 12 may not intersect an edge of a layer of abrasive particles. The above description with respect to the angle? Mn assumes that the same diameter d of the abrasive particles is used throughout the abrasive region 12 and that the spacing t between the layers of the adjacent abrasive particles is substantially the same throughout the abrasive region 12. It is within the scope of the present invention, however, to use abrasive particles of different diameter and different spacings between the adjacent layers of the abrasive particles. However, the above equation for the angle min min is usable if the largest separation between the layers of the adjacent abrasive particles is used for the t separation. In addition, the above equation for? Min only applies if the layers of the abrasive particles in the abrasive region are substantially planar and parallel to each other. Figure 6 shows one embodiment of a method of manufacturing the wheel 10 and Figures 7 and 8 show a laminated sheet 51 of the abrasive material having layers of abrasive particles therein. A method of manufacturing the laminated sheet 51 of the abrasive material is detailed below. It is to be understood that the blade 51 may be formed preferably as described below prior to carrying out the steps of assembling the grinding wheel 10. As shown in Figure 6, the blade 51 is applied with the first outer plate 53 and the second external plate 55 to form the rectangular block 56. This block 56 can then be sintered under pressure. In general, this sintering step is carried out at temperatures between approximately 480 ° C and 1600 ° C, at pressures as high as 100 to 550 kg / cm2, and with residence times from about 5 minutes to 1 hour. Block 56 can then be cut, as shown with interrupted lines, by a laser beam, a water jet, an EDM (electric discharge mechanism), electronic plasma beam, scissors, blades, dies, or other known method, to form the wheel 10. The hole 20 can be cut, as is shown with interrupted lines, using the same method or another either before or after cutting the wheel 10 from block 56. It should be understood that the shape of block 56 and / or sheet 51 is not limited to the rectangular shape but it can be of any form including the round one, with or without an internal opening which can also be of any form.

Depending on the design, the grinding wheel 10 may have an abrasive region 12 thick or axially thin. The abrasive region 12 can then be mounted on a core, such as a metallic core or composite. The core can be integrated with the abrasive region 12 by any available means that include but are not limited to fixing and mechanical tension / expansion, brassizing, welding, adhesion, sintering and forging. To extract the wheel 10 out of the blade 51, it is advantageous to use cutting machines with a cutting means characterized in that it is capable of moving in 3 to 5 degrees of freedom. For example, a laser beam or a water jet that has nozzles which can move in 5 degrees of freedom. The first and second outer plates 53 and 55, respectively, may be formed of steel, aluminum, bronze, resin, or other substantially rigid material by the known methods. In the forming plates 53 and 55, the inner surface 53a of the first plate 53 is preferably angled at an angle? with respect to the external surface 53b thereof and the internal surface 55a of the second plate 55 is preferably angled at an angle? with respect to the external surface 55b thereof.

Alternatively, the annular abrasive region can be cut from one sheet of the abrasive material prior to sintering the first support plate 14 and the second support plate 16 therewith. The first support plate 14 and the second support plate 16 can also be formed prior to sintering. The annular abrasive region can then be laminated with support plates 14 and 16 and sintered under pressure to form a grinding wheel according to the present invention. A second alternative method for the formation of a grinding wheel having an inclined abrasive region according to the present invention includes the formation of an upper plate and a lower plate each having internal and external parallel surfaces. The sheet 51 can be walled and then sintered between the upper and lower plates. A hole with which the grinding wheel is mounted on a rotating shaft can then be formed at a different angle of 90 degrees with the inner and outer surfaces of the upper and lower plates. The grinding wheel could be optionally edged while mounted. A third alternative method for the formation of a grinding wheel according to the present invention includes the formation of an abrasive region from the sheet 51 in which the layers of the abrasive particles are at an angle of between 0 degrees and 180 degrees, exclusive , with the upper and lower surfaces substantially parallel to the abrasive region. Such an abrasive region can be formed by cutting the abrasive region of a sheet such as the sheet 51 using the cuts that are at an angle of between 0 degrees and 180 degrees with an upper or lower face of the sheet 51. The abrasive region can be sandwiched preferably between the upper and lower support plates each having substantially parallel inner and outer surfaces. Preferably, an orifice can be formed through the support plates and the abrasive region substantially perpendicular to the upper and lower surfaces of the abrasive region. In this way, a rotating shaft placed through the hole leads to the grinding wheel having an abrasive region with the layers of the abrasive particles that are at an angle of between 0 degrees and 180 degrees, exclusive, with respect to a perpendicular plane to an axis of rotation of the grinding wheel. After the formation of the grinding wheel 10 using any of the methods described above, the abrasive surface 18 can be sharpened using known processes to reduce or bend it with respect to the remainder of the outer perimeter 24 of the grinding wheel 10., as shown in Figure 1. It is also contemplated to sharpen the wheel 10 so that it has other forms of the abrasive surface 18 that a specific application may require. Examples include convex, concave, and more complicated surfaces such as a "gola or heel". Another method of making the wheel 10 having a concave, convex surface, or other abrasive surface 18 is by extracting several rings or ridges from the sheet 51 having varying diameters and then stacking the rings. For example to manufacture a wheel having a concave abrasive surface, the rings having variable external diameters can be extracted from the sheet 51. The rings can then be stacked on a core so that the resulting wheel has the desired concave shape. A method of fabricating the sheet 51 having substantially parallel layers of the abrasive particles is fully described in U.S. Patent Application. Copendent Serial No. 08 / 882,434 filed June 25, 1997, entitled "Superabrasive Cutting Surface", currently assigned to the assignee of the present invention. Figure 7 is a top view of the laminate sheet 51. In the embodiment of Figure 7, the laminate sheet 51 is square with a front edge 37 and a side edge 38. However, other shapes of the laminate sheet 51 are also within the scope of the present invention. The sheet 51 is composed of a plurality of thickening layers. Each thickening layer preferably includes a layer of a bonding material and a layer of abrasive particles. Each thickening layer of the sheet 51 can also include a layer of a porous material and / or an adhesive substrate. Figure 8 is an exploded front view of the front edge 37 of the sheet 51 showing the stacking of the thickening layers which can be used in the manufacture of the sheet 51. For the purposes of illustration in the embodiment of Figure 8, the sheet 51 is composed of only three thickening layers 40, 42, and 44. However, the sheet 51 may be composed of a different number of thickening layers and is preferably composed of from 2 to 10,000 layers. Each thickening layer 40, 42, and 44 includes a layer of bonding material 50, 52, and 54, respectively; a layer of porous material 60, 62, and 64, respectively; and a layer of abrasive particles 70, 72, and 74, respectively, comprising the abrasive particles 90. Each layer of thickening 40, 42, and 44 may also include the adhesive layers 80, 82, and 84, respectively, placed on a face of the porous material layers 60, 62, and 64, respectively, and each has at least one face which includes a pressure sensitive adhesive. The adhesive face of the adhesive layers 80, 82, and 84 is placed against the porous layers 60, 62, and 64, respectively. In this way, when the abrasive particles 90 of the layers of the abrasive particles 70, 72, and 74 are placed in the openings of the porous layers 60, 62, and 64, respectively, the abrasive particles 90 adhere to the adhesive layers. 80, 82, and 84 in such a way that the abrasive particles 90 are retained in the openings of the porous layers 60, 62, and 64. It should be understood that the porous layers mentioned above can be selected, for example, from materials of the type mesh (for example, woven and non-woven mesh materials, metallic and non-metallic mesh materials), materials deposited with steam, powder or powder-fiber materials, and crude tablets, any of which include pores or openings distributed in all the material. It should also be understood that the order or placement of the various layers may be different from that shown. The porous layer can be separated or removed from the adhesive layer after the abrasive particles have been received by the adhesive layer. The use of adhesive substrates to retain the abrasive particles to be used in a sintering process is described in U.S. Pat. No. 5,380,390 to Tselesin and U.S. Pat. No. 5,620,489 to Tselesin and U.S. Patent Application. Serial No. 08 / 728,169, filed October 9, 1996. The thickening layers 40, 42, and 44 are compressed together by an upper die 84 and a lower die 85 to form the sintered laminate sheet 51. As noted previously, sintering processes suitable for the present invention are already known in the art and are described, for example, in US Pat. No. 5,620,489, by Tselesin. Although Figure 8 shows a layer of single bonding material for each thickening layer 40, 42, and 44, it is also contemplated to include 2 or more tie layers for each thickening layer 40, 42, and 44. To perform the above manufacturing process, the joining material that makes up the layers of the bonding material 50, 52 and 54 can be any sinterable material with the layers of the abrasive particles 70, 72, and 74 and is preferably an easily deformable flexible material, Soft (SEDF) manufacturing which is known in the art and is described in US Pat. No. 5,620,489. Such SEDF can be formed by forming a paste or suspension of the powder or bonding material such as tungsten carbide particles or cobalt particles, and a binder composition that includes a cement such as a rubber cement and a diluent such as rubber cement thinner. The abrasive particles can also be included in the paste or suspension but this is not necessary. A substrate is formed from the paste or suspension and is solidified and cured at room temperature or with heat to evaporate the volatile components of the agglutination phase. The SEDF used in the embodiment shown in Figure 5 to form the layers of the bonding material 50, 52, and 54 may include methyl ethyl ketone: toluene, polyvinyl butyral, polyethylene glycol, and dioctyl phthalate as a binder and a mixture of copper, iron, nickel , tin, chromium, boron, silicon, tungsten carbide, titanium, cobalt, and phosphorus as a material of the binding matrix. Certain of the solvents will be removed by drying after application while the remaining organic substances will be removed by burning during sintering. An example of an exact composition of a SEDF that can be used with the present invention is described later in the Examples. Components for the composition of such SEDF are available from several suppliers including: Sulzer Metco, Inc., of Troy, MI; All-Chemie, Ltd. from Mount Pleasant, SC; Transmet Corp., of Columbus, OH; Valimet, Inc., of Stockton, CA; CSM Industries of Cleveland, OH; Engelhard Corp. de Séneca, SC; Kulite Tungsten Corp. of East Rutherford, NJ; Sinterloy, Inc., of Selon Mills, OH; Scientific Alloys Corp. of Clifton, NJ; Chemalloy Company, Inc., Bryn Mawr, PA; SCM Metal Products of Research Triangle Park, NC; F.W. Winter & Co. Inc., of Camden, NJ; GFS Chemicals Inc. of Powell, OH; Aremco Products of Ossining, NY; Eagle Alloys Corp. of Cape Coral, FL; Fusion, Inc. of Cleveland, OH; Goodfellow, Corp. of Berwyn, PA; Wall Colmonoy of Madison Hts, MI; and Alloy Metals, Inc. of Troy, MI. It should also be noted that not always the joining layer forming the sheet 36 needs to be of the same composition; it is contemplated that one or more layers of the binding material could have different compositions. The porous material can be virtually any material since the material is substantially porous (about 30% up to 99.5% porosity) and preferably comprises a plurality of openings spaced not at random. Suitable materials are mesh, woven or non-woven, metallic or organic materials, such as copper, bronze, zinc, steel, or nickel mesh materials, or fiber meshes (e.g., carbon or graphite). Particularly suitable for use with the present invention are stainless steel wire meshes, expanded metal materials, and organic materials of the low melting temperature mesh type. In the embodiment shown in Figure 8, a mesh is formed from a first set of parallel wires crossed perpendicularly with a second set of parallel wires to form the porous layers 60, 62, and 64. The exact dimensions of a mesh of Stainless steel wire which can be used with the present invention are described later in the Example. As shown in Figure 9, which is a top view of a single porous layer 60 of the sheet 51 having the abrasive particles 90 placed thereon, a first set of parallel wires 61 can be placed parallel with the front edge 37 of the sheet 51 and the second set of the parallel wires 69 can be placed parallel to the side edge 38. However, as shown in Figure 10 it is also possible to angle the porous layer in such a way that the sets of the parallel wires 61 and 69 are at an angle of about 45 degrees with the front edge 37 and the side edge 38. It is also contemplated to form the sheets 51 having some layers using the configuration of Figure 10 and some layers using the configuration of Figure 9. The abrasive particles 90 can be formed of any relatively hard substance including superabrasive particles such as diamond, cubic boron nitride, subox boron, boron carbide, silicon carbide and / or mixtures thereof.

Preferably diamonds of a diameter and a shape such as those which fit or fit into the holes of the porous material are used as the abrasive particles 90. It is also contemplated to use abrasive particles which are slightly larger than the holes of the porous material and / or the particles that are sufficiently small such that a plurality of particles will adapt or fit into the holes of the porous material. The adhesive layers 80, 82, and 84 can be formed from a material having a tack quality sufficient to retain the at least temporary abrasive particles such as a flexible substrate having a pressure sensitive adhesive thereon. Such substrates having adhesives are well known in the art. The adhesive should be able to retain the abrasive particles during the preparation, and preferably should be free of the burning ash during the sintering step. An example of a usable adhesive is a pressure sensitive adhesive commonly referred to as a Book Tape # 895 available from the Minnesota Mining and Manufacturing Company (St. Paul, MN). Another embodiment of the present invention is shown in Figures 11-17. Like elements are labeled with similar numbers in all Figures 11-17. Figure 11 shows a grinding wheel 110 having a first support plates 114, a second support plate 116 and an abrasive region 112 sandwiched between them. The grinding wheel 110 is generally cylindrical and has a hole 120 that passes through an upper and lower face thereof. Similarly to the wheel 10, the wheel 110, by means of the hole 120, can be mounted on a rotating shaft (not shown) and rotated about the axis of rotation 123. The abrasive region 112 has a substantially cylindrical abrasive surface 118 that it extends around a surface 124 of the perimeter of the wheel 110. Unlike the abrasive region 12 of the wheel 10, the upper surface 131 and the lower surface 133 of the abrasive region 112 are illustrated being substantially aligned with a plane which is substantially perpendicular to the of rotation 123 of the grinding wheel 110. The abrasive region 112 is composed of the abrasive segments 113 which may have parallel layers 126, substantially flat, of the abrasive particles, shown in Figure 11 by the shaded lines. However, it is also within the scope of the present invention to have non-parallel layers or layers which can not be parallel but follow the contours of any adjacent layer. The abrasive segments 113 are spaced circumferentially around the perimeter of the wheel 110 and are supported between the first support plate 114 and the second support plate 116. With the provision of plural discrete abrasive segments 113, the voids 119 may advantageously exist between the adjacent • abrasive segments 113. As shown in Figure 11, the recesses 119 are substantially rectangular and extend between the upper and lower surfaces 131 and 133, respectively, at a different angle of 90 degrees from them. The segments 113 and the recesses 119 must be arranged so that before a workpiece loses contact with a first segment 113 during grinding, it comes into contact with an adjacent segment 113. This can advantageously reduce the noise or "rattling" generated by the grinding of a workpiece against the grinding wheel 110. It is also contemplated, however, that the gaps or voids 119 extend between the upper and lower surfaces 131 and 133, respectively, at an angle of substantially 90 degrees with respect to them. As shown in Figure 12, which is a sectional view of the wheel 110 taken along the line of section 12-12 of Figure 11, the wheel 110 has radial distribution channels 117. As shown in Figures 13 and 14, which are sectional views of the wheel 110 taken along the lines of section 13-13 and 14-14, respectively, of Figure 12, the radial distribution channels 117 are formed of channels or ducts 127 and 129 generally U-shaped cut into support plates 114 and 116, respectively. The radial distribution channels 117 preferably extend from a circular distribution channel 121 near the center of the wheel 110 radially outwardly to a circumferential distribution channel 125. The circular channel 121 is preferably formed in the support plates 114 and 116 a from ducts 127 and 129 generally U-shaped so that they extend around an inner circumferential edge 111 of the wheel 110. The circumferential distribution channel 125 passes radially under or in the internal part of the abrasive segments 113. A lubricant, such as water, it can be fed under pressure into the circular distribution channel 121 to pass through the radial distribution channels 117 and into the circumferential distribution channel 125. The lubricant is then forced through the holes 119 between the segments 113 for lubricating the abrasive surface 118 during grinding. Alternatively, as shown in Figures 11 and 12, the segments 113 may include the openings 130 which place the perimeter of the wheel 110 in fluid communication with the distribution channel 125 and through which the lubricant may be supplied to the abrasive surface 118 during grinding. The openings 130 can be of one of several shapes including circular, square, polygonal, or any other shape. Each opening 130 may taper from end to end of the thickness of the segment 113. The wheel 110 may include the openings 130 with or without the holes 119. Either with or without the openings 130, the wheel 110 may be used with a mill fed with water in the center. The use of a lubricant on the grinding surface 118 during grinding or grinding can increase the life of the grinding wheel 110 and improve the finishing of the work piece. Although the modality shown in Figure 12 includes 4 channels of radial distribution 117, it is also within the scope of the present invention to include a larger or smaller amount than the 4 channels 117. The distribution channels 121, 117 and 125 are formed from the ducts 127 and 129 generally U-shaped, machined or otherwise formed on the inner surfaces of the plates 114 and 116, respectively. When plates 114 and 116 are mounted on top of one another, conduits 127 and 129 are aligned to form channels 121, 117 and 125.

As shown in Figure 13, to feed a lubricant in the circular distribution channel 121, the wheel 110 is mounted on the spindle 190. The spindle 190 includes the projection 191, the longitudinal distribution channel 193, and the distribution channel. transverse 192. The wheel 110 rests on the projection 191 so that the transverse distribution channel 192 is aligned with the circular distribution channel 121 and is in fluid communication therewith. The longitudinal distribution channel 193 intersects the transverse distribution channel 192 and is in fluid communication therewith. The longitudinal channel 193 opens at one end of the spindle 190 in the coupling sleeve 194. The coupling sleeve 194 allows the spindle 190 to be connected to the water supply discharge pipe 195 in such a way that the spindle 190 can rotate around of the rotation shaft 123 on the discharge tube 195, and the longitudinal channel 193 may be in sealed fluid communication with the inner channel 196 of the discharge tube 195. Such sealed connections are known in the art. The spindle 190 can rotate with the wheel 110 in such a way that the lubricant can be fed through the inner channel 196, through the longitudinal channel 193, into the transverse channel 192 and into the circular distribution channel 121. It is also contemplated that the wheel 110 rotates with respect to the spindle 190. The spindle 190 can be formed of steel or other rigid material and the distribution channels 192 and 193 can be formed therethrough by drilling or other known methods. An alternative method of feeding the liquid lubricant through the distribution channels in a grinding wheel according to the present inventions is shown in Figures 15 and 16. Figure 15 is a top section view, taken along the same line of the section as the sectional view of the grinding wheel 110 shown in Figure 12, of a grinding wheel 410 according to the present invention. Similarly to the grinding wheel 110, the grinding wheel 410 includes the abrasive segments 413 arranged around a perimeter thereof, a circumferential distribution channel 425 extending radially below or inside the abrasive segments 413, and radial distribution channels 417 in fluid communication with the circumferential distribution channel 425. However, the grinding wheel 410 includes the circular distribution channel 421 which is open along the upper face 431 of the grindstone 410. As shown in FIG. shown in Figure 16, which is a sectional view of the wheel 410 taken along the line of section 16-16 of Figure 15, the circular distribution channel 421 is in fluid communication with the channels of radial distribution 417. As such, the liquid lubricant can be fed into the circular distribution channel 421 by means of a stationary discharge tube 495 while that the wheel 410 is rotated by the spindle or the rotating shaft 490 and is fed into the distribution channels 417, through the circumferential distribution channel 425 and through the recesses 419 and / or the openings (not shown) in the segments 413 to lubricate the abrasive surface of the wheel 410. The wheel 410 can be manufactured in substantially the same manner as the wheel 110. Now directing attention to the wheel 110, as noted above, the abrasive region 112 can be formed from the abrasive segments 113 having the layers 126 of the abrasive particles. Preferably, the layers 126 are substantially planar and parallel, but this is not necessary. In addition, the layers of the abrasive particles 126 may be arranged to be in a plane perpendicular to the axis of rotation. As shown in Figure 17, which is a partial front view of the wheel 110 having the abrasive particles 134 and the layers of the abrasive particles 126a, 126b, and 126c exaggerated for purposes of illustration, the layers of the abrasive particles 126a, 126b, and 126c are shown in a plane substantially perpendicular to the axis of rotation 123. However, to ensure smooth and complete abrasion, the layers 126a , 126b, and 126c are offset in an axial direction (the direction of the axis of rotation 123) between a segment 113 to another segment 113. That is, the layers 126 are not aligned circumferentially from a segment 113 to an adjacent segment 113. it is within the scope of the present invention, however, not to axially displace the layers of abrasive particles 126 between the adjacent segments, but instead, for example, between each second or third segment. All that is necessary is that the layers of abrasive particles 126 are displaced axially in some segment or segments around the perimeter of the wheel 110. Because the layers of the abrasive particles 126 are not aligned circumferentially, none is a region of the joined material 128 between the layers 126. Accordingly, when a workpiece is ground against the abrasive surface 118, the probability that some portion or portions of the surface of the workpiece being polished will contact only the regions of the workpiece. bonding material 128 or only with the layers of the abrasive particles 126, is reduced and can be minimized. This reduces the likelihood that notches or other surface anomalies will be formed on the surface of the workpiece that is polished or ground and facilitates the formation of a smooth surface on the work surface. An explanation of how the segments of the circumferentially misaligned abrasive particles 113 in the wheel 110 can facilitate grinding a smooth surface onto a workpiece can be made with reference to Figure 17. Figure 17 is a front, exaggerated, schematic view for purposes of illustration, of three segments 113a, 113b, and 113c having the layers of the abrasive particles 126a, 126b, and 126c, respectively, and the regions of the bonding material 128a, 128b, and 128c, respectively. In the schematic illustration of Figure 17, the axial height 169 of the abrasive region 112 is approximately six times the diameter 168 of the abrasive particles (or the thickness of the layers of the abrasive particles) that make up the layers of the abrasive particles 126a , 126b, and 126c. The separation 167 between the layers of the abrasive particles is shown to be about twice the diameter 168. The segment 113a is formed and placed in the wheel 110 such that one of the two layers of the abrasive particles 126a provides a lower surface 133 of the abrasive region 118. The bonding material provides an upper surface 131 of the abrasive region 118 and extends axially to the layer of abrasive particles 126a closest to the top surface 131. The segment 113b is formed and placed in the wheel 110 in such a way that one of the two layers of abrasive particles 126b is spaced at a distance 179 from the lower surface 133 of the abrasive region 118. The distance 179 is preferably approximately equal to the diameter of the abrasive particle 168 The joining material fills the region between the lower surface 133 and the layer of abrasive particles 126b closest to the surface bottom 133. The bonding material also fills the region between the top surface 131 and the abrasive particle layer 126b closest to the top surface 131. The segment 113c is formed and placed in the wheel 110 such that one of the two layers of abrasive particles 126c define the upper surface 131 of the abrasive region 118. The bonding material fills the region between the bottom surface 133 and the layer of the abrasive particles 126c closest to the bottom surface 133. For ease of illustration, in the embodiment shown in Figure 17, segments 113a, 113b and 113c each include only two layers of abrasive particles 126a, 126b, and 126c, respectively. However, it is within the scope of the present invention to include more than two layers of abrasive particles per segment. In addition, the thickness of each layer of abrasive particles and / or the diameter of the abrasive particles used can vary between the segments and within the segments. By scaling the layers of the abrasive particles 126a, 126b and 126c as shown in Figure 17, any route 132 defined by the intersection of a plane perpendicular to the axis of rotation 123 and a total circumference of the abrasive region 118 will intersect a layer of particles. abrasive 126 of at least one abrasive segment 113. This means that substantially all of a surface of a workpiece in contact with the abrasive surface 118 such as the wheel 110 being rotated, will intersect a layer of abrasive particles 126a, 126b, or 126c. As noted above, this facilitates the formation of a smooth edge or surface on a workpiece. The sequence of layers of staggered abrasive particles does not need to be as shown. It is only important to carry out the smooth abrasion of a surface of the workpiece, the axial distance of the abrasive surface 118 must include at least one layer of the abrasive particles to cover the axial distance. Due to manufacturing variations, the precise control of the thickness of the layers of the abrasive particles 126 and the region of the bonding material 128, and the alignment thereof, can be difficult. Accordingly, the formation of the wheel 110 in a precise manner as shown in Figure 17 may be difficult to achieve. As such, the layers of abrasive particles 126a, 126b, and 126c can be formed thicker to better facilitate overlapping them between the segments. Additionally, the wheel 110 is preferably formed from more than three segments and can be formed with as many segments as can be accommodated around the perimeter of the wheel 110. This creates a larger number of abrasive edges of the abrasive layers 126 so that a work piece passes crosswise in a single rotation of the wheel 110. The segments 113 can be extracted, ie cut, from the laminated sheet 51 as shown with interrupted lines in Figure 7. The laminated sheet 51 it must be at least partially sintered, and preferably completely sintered, prior to any extraction. The first and second support plates 114 and 116, respectively, are solid and can be formed from steel, resin, or other substantially rigid material as is known in the art. The conduits 127 and 129 can be machined, molded, or otherwise formed into plates 114 and 116, respectively, as is known. The opening 121 can be formed in the plate 114 by drilling or other known method. The segments 113 are then stacked between plates 114 and 116 and brass, or preferably sintered therewith under pressure. When segments 113 are stacked with support plates 114 and 116, conduit 127 in support plate 114 is axially aligned with conduit 129 in support plate 116 to form channels 117 and 125, as shown in FIGS. Figures 12, 13, and 14. The segments 113 can also be secured by means of adhesives, brass, solder (including laser beam welding) or other known means between the plates 114 and 116. It should be noted that if the segments 113 are sintered with the plates 114 and 116, this sintering process can be additionally with respect to the sintering process, detailed above, used to form the sheet 51 from which the segments 113 can be cut. The hole 120 can be formed by drilling or by another known process either before or after the sintering plates 114 and 116 with the segments 113. To form the segments 113 having different distances between the ca From the abrasive particles, such as the segments 113a, 113b, and 113c shown in Figure 17, the segments can be cut from the different laminated sheets having different distances between the layers 126. Also, in some cases such as the segments 113a and 113c, the segments are substantially the same as each other, but are inverted in the wheel 110. Consequently, it was considered to form such segments from the same sheet and to invert one or the other before the final assembly of the segments with the plates 114 and 116. For forming the laminated sheets such as the sheet 51 but having different distances between the layers of the abrasive particles, a larger or smaller amount of the layers, of the layers of the bonding material such as the layers 50 , 52, or 54 shown in Figure 8, they can be placed between the layers of the abrasive particles before sintering to form a sheet such as the sheet 51. The number of layers of the binding material required to produce a given distance between the layers of the abrasive particles can be determined empirically It is also within the scope of the present invention to form the wheel 110 having abrasive segments, such as the abrasive segments 113, wherein the layers of the abrasive particles are at an angle of between 0 degrees and 180 degrees with a plane perpendicular to the axis of the abrasive. rotation of the grinding wheel 110. What is important is that the abrasive surface 118, when rotated about the axis of rotation 123, will sweep an edge of a layer of abrasive particles 116 through an axial distance greater than the axial thickness of the grinding wheel. edge at any given point. It is to be understood that the segmented design of the wheel 110 can also be formed with the abrasive segments such as the segments 113, with the abrasive particles randomly distributed therein as described in the Background of the Invention section. Although segments such as segments 113 having randomly distributed particles may lack the advantages of the segments 113 having the layers of the abrasive particles, to form a wheel such as the wheel 110 using the segments having the particles distributed to the randomly, they could still allow the liquid lubricant to be distributed to the grinding surface of the grinding wheel during grinding using a grinding wheel having channels such as channels 117, 121, and 125. Figure 18 shows an alternative embodiment of the present invention. The elements in Figure 18 functionally similar to those of Figures 1 and 2 are shown with like numbers increased by 200. Figure 18 shows the wheel 210 having the stacked abrasive segments 213a and 213b between the upper and lower support plates 214 and 216, respectively. By stacking the abrasive segments 213a and 213b, a grinding wheel coarser axially can be formed. However, stacking segments 213a and 213b thus can cause notches 247 to be formed therebetween. To reduce the likelihood that the notches 247 form an embossed edge in a workpiece, the segments 213a and 213b may be stacked, with the narrow segments 213a alternating positions with the thicker segments 213b between the circumferentially adjacent segments. In this way the notches 247 are stacked in an axial direction around the circumference of the abrasive surface 218. By axially stacking the notches 247, the probability that the notches contact a workpiece for complete rotation of the wheel 210 is reduced, thus decreasing the likelihood of the formation of an embossed edge on a surface of the workpiece. The wheel 210 can be manufactured in substantially the same manner as the wheel 110. Figure 19 is a sectional view of the wheel 210 taken along line 19-19 of Figure 18. Figure 19 shows a possible configuration for vertically stacking the abrasive segments 213a and 213b. As shown, the abrasive segments 213a and 213b are grooved together. The joint grooving of the abrasive segments 213a and 213b as shown, has the advantage of providing a more secure attachment of the segments 213a and 213b to support the plates 214 and 216. It is also contemplated that the abrasive segments 213a and 213b are slotted together in any other configuration. It is also contemplated that the segments 213a and 213b join only in a butt joint without any of the grooves. Figure 20 is a front view of another embodiment of a grinding wheel according to the present invention. In the modality of Figure 20, the wheel 510 includes an abrasive region 512 preferably sandwiched between a first support plate 514 and a second support plate 516, but this is not necessary. The abrasive region 512 includes an outer abrasive surface 518 which may be a substantially cylindrical band extending around the perimeter of the abrasive grinding wheel 510. The grinding wheel 510 has a rotation axis 523. In a similar manner to the abrasive region 12 of the wheel 10, the abrasive region 512 is composed of layers of hard or abrasive particles 526, represented by the shaded lines, surrounded by the regions of the bonding material 528. However, the layers of the abrasive particles 526 are not substantially planar, instead they can be configured to have an exposed edge similar to a sinusoidal shape along the abrasive surface 518. In this way, the abrasive surface 518, when rotated about the axis of rotation 523, will sweep an edge of a layer of abrasive particles 526 through an axial distance greater than the axial thickness of the edge at any given point on the bord and. Also, at least one route defined by the intersection of a plane perpendicular to the axis of rotation and the abrasive surface will intersect at least one layer of the abrasive particles in at least three locations. Further, in the embodiment shown in Figure 20, the distance in the axial direction between two layers of adjacent abrasive particles may remain substantially constant around the perimeter of the wheel 510, but is not necessary. Additionally, the peaks of any first edge of the abrasive particle layer may extend to an axial point level with or above the ducts or channels of another edge of the layers of abrasive particles adjacent to and above the first edge of the abrasive particle layer . In this way, any route defined by the intersection of a plane perpendicular to the axis of rotation of the wheel 510 and a complete circumference of the abrasive region 512 will intersect or give a cutting stroke on at least one layer of abrasive particles 526. it contemplated that the layers of the abrasive particles 526 have edges which form other configurations such as sawtooth-shaped waves or irregular soft waves. To form the wheel 510 having the edges of the layer of abrasive particles 526 which are corrugated in a waveform as shown in Figure 20, the layers comprising the abrasive region 512, which are the tie layers 50- 54, the layers of the hard or abrasive particles 70-74, and if desired, the layers of the porous material 60-64 and the adhesive layers 80-84, are preferably stacked and sintered in a single sintering step with the plates of support 514 and 516. Such a sintering process can be substantially the same sintering process as that used to form the laminated sheet 51, however, the support plates 514 and 516 could be applied up and down, respectively, of the layers that they form the abrasive region 512. However, the support plates 514 and 516 do not need to have angled inner faces with respect to a plane parallel to the axis of rotation 523 of the grindstone 10. Also, to create the corrugations, the eartips spacer 597 are preferably circumferentially spaced between the layers forming the abrasive region 512 and the first support 514 and between the layers forming the abrasive region 512 and the second support plate 516. The position of the spacers 597 that are adjacent to the first Support plate 514 can be circumferentially displaced from the position of lbs spacers 597 that are adjacent to second support plate 516. One embodiment of spacers 597 is shown in the perspective view in Figure 21. As shown, the spacer 597 is preferably tapered and wedge-shaped having a front face 597a and a tail or tapering end 597b. Only the front face 597a is visible in Figure 20. The spacers 597 can be formed of any substantially rigid material such as steel, aluminum, or bronze. Because the layers of the abrasive region 512 are each flexible, each layer can be formed to pass smoothly or under the spacers 597 in such a way that when the layers of the material forming the abrasive region 512 are sandwiched with the spacers 597 between the support plates 514 and 516, the undulations of sinusoidal shape are formed in the layers of the material forming the abrasive region 512, including the layers of the abrasive particles 526. It is also contemplated to form the spacers 597 in other configurations such as rectangular, prism-shaped, cylindrical, or semi-cylindrical. After sintering, the wheel 510 can be mounted on a rotating shaft in substantially the same manner as the wheel 10.

Figure 22 is a front view of still another embodiment of an abrasive grinding wheel, according to the present invention. In the embodiment of Figure 22, the wheel 610 includes an abrasive region 612 preferably sandwiched between a first support plate 614 and a second support plate 616. The abrasive region 612 includes an external abrasive surface 618 which can be a substantially cylindrical extending around the perimeter of the abrasive grinding wheel 610. The grinding wheel 610 has a rotation axis 623. Similar to the abrasive region 512 of the grinding wheel 510, the abrasive region 612 is composed of layers of hard or abrasive particles 626, represented by shaded lines, surrounded by the regions of the bonding material 628. In addition, the edges of the layers of abrasive particles 626 are corrugated in a sinusoidal-like manner as are the edges of the abrasive particle layers 526 that at least one edge of a layer of abrasive particles intersects in at least two locations of at least one route defined by the in Tersection of a plane perpendicular to the axis of rotation and the abrasive surface. However, the abrasive region 612 is formed of abrasive segments 613 similar to the abrasive segments 113 of the wheel 110. Each segment 613 has layers of abrasive particles 626 which curl or curl into a sinusoidal-like shape. In addition, similarly to the wheel 510, the peaks of any first edge of the abrasive particle layer will extend at an axially point level with or above the ducts or channels of another edge of the abrasive particle layer adjacent to and above the surface. First edge of the layer of abrasive particles. Accordingly, similarly to the wheel 510, any route defined by the intersection of a plane perpendicular to the axis of rotation of the wheel 510 and a complete circumference of the abrasive region 512 will intersect or strike a sharp blow on at least one layer of abrasive particles 526. It is also contemplated that the layers of abrasive particles 626 have edges which form other configurations such as sawtooth-shaped waves or irregular soft waves. The grinding wheel 610 can be formed substantially in the same way as the grinding wheel 110 with the exception that when a laminated sheet is formed such as the sheet 51 from which the segments 613 are cut, the spacers 697, which are substantially the same as the spacers 597, are placed between the layers forming the laminated sheet and the upper die, such as the die 84, and between the layers forming the laminated sheet and a lower die, such as the die 85. The spacers 697 are circumferentially spaced in a circular configuration similar to the spacers used to form the wheel 510. Also, the spacers 697 adjacent the upper die are offset circumferentially with respect to the spacers adjacent the lower die. The layers used to form the laminated sheet are then sintered together with the spacers. The abrasive segments 613 can then be cut from the resultant laminated sheet as shown in Figure 7. The present invention also provides abrasive grinding wheels and a method for manufacturing abrasive grinding wheels in which the abrasive layer is adhesively bonded to one or more abrasive grinding wheels. more support plates. Various embodiments of the adhesively bonded grinding wheels are shown in Figures 23-25. Similar elements are labeled with similar numbers in all Figures 23-25. Referring now to Figure 23, there is shown a first embodiment of a grinding wheel for abrasive grinding, adhesively bonded. The grinding wheel 710 includes the first support plate 714 (having the internal main surface 714a and the external main surface 714b), the second support plate 716 (having the internal main surface 716a and the external main surface 716b), the metal bond abrasive layer 712 (having the first major surface 712a and the second major surface 712b), the first adhesive layer 715, and the second adhesive layer 717. The metal bond abrasive layer 712 is a simple (ie, continuous) mass of a metallic bonding abrasive and is interposed between the first adhesive layer 715 and the second adhesive layer 717. The first adhesive layer 715 joins the first major surface 712a of the abrasive layer 712 to the internal main surface 714a of the first support plate 714. Similarly, the second adhesive layer 717 joins the second major surface 712b of the abrasive layer 712 to the inner main surface 716a of the second support plate 716. The grinding wheel 710 is generally cylindrical and has the hole 720 passing through an upper face and in ferior of it. The wheel 710, by means of the hole 720, can be mounted on a rotary shaft (not shown) and rotated about the axis of rotation 273. It is also contemplated to fix the wheel 710 to a rotating shaft by attaching a mounting plate (not shown) having a central axis (not shown) to the wheel using the mounting holes 709. It will be understood, however, that the 709 assembly jobs are not necessary. By rotating the wheel 710 on or by a rotating shaft, a workpiece can be retained against the abrasive surface 718 of the wheel 710 so that the workpiece can be shaped, polished, or cut. The metal bond abrasive layer 712 has a substantially cylindrical abrasive surface 718 that extends around the perimeter surface of the wheel 710. The abrasive surface 718 can have any desired rectification profile. In a preferred embodiment, the grinding profile of the abrasive surface 718 is concave, which allows the grinding wheel 710 to impart a rounded edge to the workpiece. The metal bond abrasive layer 712 may have ordered layers (e.g., flat layers, sinusoidal layers) of the abrasive particles as described herein or the abrasive layer may have the abrasive particles randomly distributed from start to finish of the metal bonding material . In Figure 23, the abrasive layer 712 is shown having the abrasive particles 724 randomly distributed from start to finish of the bonding material 726. The abrasive particles 724 can be formed from any relatively hard substance including superabrasive particles such as diamond, cubic boron nitride, boron suboxide, boron carbide, silicon carbide and mixtures thereof. Referring now to Figure 24, there is shown a second embodiment of an adhesively bonded grinding wheel of the present invention. The grinding wheel 810 includes the first support plate 814 (having the internal main surface 814a and 'the external main surface 814b), the second support plate 816 (having the internal main surface 816a and the external main surface 816b), the metal bond abrasive layer 812, the first adhesive layer 815, and the second adhesive layer 817. Similarly to the wheel 710, the wheel 810 by means of the hole 820 and the optional mounting holes 809 can be mounted on a spindle rotary (not shown) and rotated about the axis of rotation 823. The metal bond abrasive layer 812 is composed of a plurality of discrete metal bond abrasive segments 813 which are circumferentially spaced around the perimeter of the wheel 810. abrasive segments 813 each have a first major surface 813a and a second major surface 813b. The metal bond abrasive segments 813 are interposed between the first adhesive layer 815 and the second adhesive layer 817. The first adhesive layer 815 joins the first major surfaces 813a of the metal bond abrasive segments 813 to the internal major surface 814a of the first support plate 814. Similarly, the second adhesive layer 817 joins the second major surfaces 813b of the metal bond abrasive segments 813 to the internal main surface 816a of the second support plate 816. The metal bond abrasive layer 812 may have ordered layers (e.g. parallel, substantially planar, or sinusoidal layers) of the randomly distributed abrasive particles or abrasive particles (see for example, Figure 23). It is also within the scope of the present invention to include both the abrasive segments having the ordered layers of the abrasive particles and the abrasive segments having the abrasive particles randomly distributed in the same grinding wheel. In Figure 24, the abrasive segments 813 are shown having the abrasive particles 824 distributed throughout the bonding material in the substantially flat parallel layers 828 (shown with shaded lines in Figure 24). Referring now to Figures 25a and 25b, a third embodiment of the adhesively bonded grinding wheel of the present invention is shown. The grinding wheel 910 includes the first support plate 914 (having the inner main surface 914a and the outer main layer 914b), the second support plate 916 (having the inner major surface 916a and the outer major surface 916b), the abrasive layer 912, the first adhesive layer 915, and the second adhesive layer 917. Similarly to the wheel 710, the wheel 910 by means of the hole 920 and the optional mounting holes 909 can be mounted on a rotating shaft (not shown) and rotated about the axis of rotation 923 As shown in Figure 25b, the first support plate 914 includes the axially extending surface 930. The second support plate 916 has the circular opening 922 which is in correspondence with the first support plate 914 on the axially extending surface 930. The abrasive layer 912 is comprised of a plurality of metal bond abrasive segments 913 which are circumferentially spaced around the perimeter of the grinding wheel 910. The abrasive segments 913 each have a first major surface 913a and a second major surface 913b. The metal bond abrasive segments 913 are interposed between the first adhesive layer 915 and the second adhesive layer 917. The first adhesive layer 915 joins the first major surfaces 913a of the metal bond abrasive segments 913 to the internal major surface 914a of the first support plate 914. Similarly, the second adhesive layer 917 joins the second major surfaces 913b of the metal bond abrasive segments 913 to the internal major surface 916a of the second support plate 916. Optionally, the adhesive can be applied to the axial surface 930 for further bonding the metal bond abrasive segments 913 to the first support plate 914. The metal bond abrasive segments 913 may have ordered layers (e.g., parallel, substantially flat layers, or sinusoidal layers) of abrasive particles or abrasive particles distributed randomly. It is also within the scope of the invention to include both the abrasive segments having ordered layers of the abrasive particles and the abrasive segments having abrasive particles randomly distributed in the same grinding wheel. In Figures 25a and 25b, the abrasive layer 912 is shown having the abrasive particles 924 randomly distributed throughout the bonding material 926. The adhesives suitable for bonding the abrasive layer to the support plate (s) they include those adhesives which have sufficient strength to bond the abrasive layer to the support plate (s) under the typical conditions of use for a grinding wheel. That is, the adhesive must retain or hold the abrasive layer against the forces generated during the abrasion operation. Primarily, this includes the shear force (s) generated by the rotation of the grinding wheel about its axis and the shear force (s) generated by the contact between the abrasive layer and the shear layer. Workpiece. A preferred class of adhesives can be described as the structural adhesives because they are capable of forming a bond between two materials wherein the bond has a high shear strength and a high peel strength. Examples of the types of adhesives which may be suitable include single-part thermosetting adhesives, two-part thermosetting adhesives (for example, two-part epoxies), acrylics, urethanes, pressure sensitive adhesives , hot melt adhesives, adhesives for curing in wet conditions, and the like. Such adhesives can be provided as liquids, solids, powders, pastes, films, and can be reactive, dried, thermally cured mixtures and the like. The adhesive can be applied over the entire contact area between the metal bond abrasive layer and the backing plate (s) or the adhesive can only be applied to a portion of the contact area. It should be understood that the selection of a suitable adhesive for the bonding of the metallic bonding abrasive layer to the support plate (s) may depend on factors such as the diameter of the grinding wheel., the mass of the abrasive layer or the abrasive segments, the surface area of the adhesive, the rotary speed of the grinding wheel to grind. For example, when the maximum rotational speed of the sharpening wheel is increased, the strength of the adhesive bond must be increased to counteract the shear force (s) (eg, centripetal force) acting on the layer abrasive Similarly, when the bonding area between the adhesive layer and the support plate is reduced, the strength of the adhesive bond must be increased to counteract the increased unit force (s). Similarly, it must be recognized that changes in the diameter of the wheel require changes in the adhesive force to hold the wheel together. As an example, for a 15.24 cm (6 inch) grinding wheel with segments that have a mass of 0.05 kg (0.110 pounds) and a joint area of 12.90 cm2 (2 square inches), an adhesive shear strength is required from approximately 2.95 kg / cm2 (42 psi) to approximately 3000 rpm and an adhesive shear strength of approximately 11.82 kg / cm2 (168 psi) is required at approximately 6000 rpm. Following the same procedure as above, for a 25.4 cm (10 inch) grinding wheel with segments that have a mass of 0.05 kg (0.110 pounds) and a joint area of 12.90 cm2 (2 square inches), an adhesive shear strength of approximately 4.92 kg / cm2 (70 psi) is required at approximately 3000 rpm and an adhesive shear strength of approximately 19.63 kg / cm2 (279 psi) is required at approximately 6000 rpm. Typically, it is desirable to exceed, preferably substantially exceed, the adhesive shear strength required. For this purpose, preferred adhesives can be described as structural adhesives because they form adhesive bonds for load bearing and high strength (e.g., high shear and shear strength). Suitable adhesives typically provide a shear strength of at least about 6.89 MPa (1000 psi), preferably at least about 10.34 MPa (1500 psi), more preferably at least about 13. 7 MPa (2000 psi), and even more preferably at least about 27.58 MPa (4000 psi). A particularly suitable class of adhesives are thermosetting structural adhesives which are cured or hardened with heating to provide a structural bond. A commercially available thermosetting structural adhesive is available under the registered designation "SCOTCH-WELD" and is identified as the AF-30 Structural Adhesive Film. (commercially available from Minnesota Mining and Manufacturing Company, St. Paul, MN). Another suitable structural adhesive is an epoxy-acrylic adhesive identified as Structural Bonding Tape 9244 (commercially available from Minnesota Mining and Manufacturing Company, St. Paul, MN). Support plates suitable for use in the adhesively bonded abrasive grinding wheels of the present invention can be made of any substantially rigid material. Preferably, the support plates are made of metal, for example, of steel, aluminum, brass, or titanium. More preferably, the support plates are made of aluminum to reduce the total weight of the grinding wheel. The support plates made of polymeric materials and polymeric materials reinforced with fiber can also be used. It should be recognized that the selected adhesives, although dependent on the strength properties required for this application, are also selected based on the surface material that is bonded. The adhesives used to bond the abrasive bodies to the steel support plates may be different from those selected for bonding to the aluminum support plates. The joining of the metal bonding abrasive segments to the support plate can be improved by treating the surface of the support plate (s) and / or the metal bonding abrasive layer prior to bonding. adhesive Surface treatment techniques include, for example, conditioning the abrasive surface (for example, sand blasting), solvent cleaning, base or acid treatment, and chemical priming. A suitable chemical primer is commercially available under the "First EC1660" registered designation (available from Minnesota Mining and Manufacturing Company, St. Paul, MN). The joint can also be improved by axially compressing the grinding wheel assembly (e.g., using a platen press) while the adhesive is cured. In the case of thermosetting adhesives, it may be desirable to heat the platen press to cure the adhesive under compression.

Examples Example 1: The following procedure was used to form an abrasive wheel according to the present invention. Two steel plates were machined in such a way that the total dimensions of the plates were 25.4 cm by 25.4 cm by 0.476 cm thick (10 inches by 10 inches by 3/16 of an inch thick) with a lateral taper of 0.150 degrees . Between these two steel plates (on the tapered side and on the opposite side), 34 alternating layers of the metal tape and shaped diamond cut into 10-inch nominal squares are aligned. The layers of the metal tape consisted of a 1: 1 ratio of bronze to cobalt, with the addition of a small amount of brass at low temperature, and a small amount of organic substances clumps together to allow the tape to be manageable. The composition of the suspension used to manufacture the metallic tape layer was specifically as shown in the diagram below, the values represent the percentage by weight of the substance. 38.28 - cobalt 38.28 - bronze 2.38 - nickel 0.195 - chromium 0.195 ~ phosphorus 17.74 - 1.5 / 1 MEK / toluene 1.387 - polyvinyl butyral 0.527 - polyethylene glycol having a molecular weight of approximately 200 0.877 ~ dioctyl phthalate 0.132 - corn oil.

These tapes were cast so that the density of the area was approximately 0.15 grams / cm2 (1 gram / inch2) when they were dried. To form the layers of diamond abrasive particles, a pressure sensitive adhesive commercially available from the Minnesota Mining and Manufacturing Company (St. Paul, MN) under the registered designation of the "SCOTCH" adhesive tape, was placed on one side of the an open mesh screen having apertures of approximately 107 μm, 165 apertures per 6.45 cm2 (1 square inch), and made of 0.48 mm diameter stainless steel wire. The approximately 170/200 mesh diamond abrasive particles were dropped onto the mesh openings in a 20.32 cm (8 inch) radial ring configuration so that the diamonds would adhere to the belt. This led to diamond particles occupying most of the screen openings. Once the radial configuration of the diamonds was applied, a small weight of the steel introduced was used for filling in the entire remaining exposed area. The sieves, filled with abrasive particles, and the flexible sheets of the metallic powder were stacked together to form a laminar compound. After the stratification of the metallic tape and the abrasive layers between the plates, the part was sintered as shown in the following table: Once the final part had cooled, the 25.4 cm by 25.4 cm plate was machined to extract the diamond abrasive region in the shape of a round wheel. This wheel was balanced, rectified and revived up to the final diameter of 20.32 cm (8 inches) in diameter. The appropriate mounting holes were also introduced. Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.

Example 2 The following procedure was used to form an abrasive wheel according to the present invention. Fifty-five alternative layers of the metallic tape and diamond shaped abrasive cut into nominal 5-inch squares were stacked and aligned. These layers were then compacted cold to produce an untreated or raw structure, ready for sintering. The layers of the metal belt consisted of iron / copper diamond hardening powders, with the addition of a small amount of low temperature brass, and binders with a small amount of organic substances to allow the belt to be manageable. The composition of the suspension used to manufacture the metallic tape layer was specifically as shown in the diagram below, the values represent the percentage by weight of the substance. copper 33.7 iron 27.5 nickel 7.87 tin 3.41 chromium 2.43 boron 0.34 silica 0.44 tungsten carbide 9.38 cobalt 0.67 phosphorus 0.17 Methyl Et .il Cetone 12.6 Polivini .1 butyral 0.89 Santicizer 1601 0.62 Santicizer 160 is commercially available from Solutia Inc., St. Louis MO .

These tapes were cast so that the density of the area was on average 0.1 grams / cm2 (0.65 grams / inch2) when they were dry. To form the layers of diamond abrasive particles, a pressure sensitive adhesive commercially available from Minnesota Mining and Manufacturing (St. Paul, MN) under the registered designation of "SCOTCH" adhesive tape designated as Book Tape # 845 was placed on one side of an open mesh screen having apertures of approximately 107 μm, 165 apertures per 6.45 cm2 (165 apertures per square inch), and made from 0.48 mm diameter stainless steel wire. The approximately 200/300 mesh diamond abrasive particles were dropped onto the screen in such a way that one diamond was in each opening of the 5-inch square layer. This led to diamond particles occupying most of the screen openings. The sieves, filled with the abrasive particles, and the flexible sheets of the metallic powder were stacked one on top of the other to form a laminar compound. After stratification of the metal tape and the abrasive layers between the plates, the part was sintered as shown in the following table.

Once the final part had cooled, the metal bonding abrasive was converted into arc-shaped metal bond abrasive segments by means of a cut with an abrasive water jet. These abrasive metal bond segments were then attached to two aluminum support plates using a structural adhesive. The support plates and the segments were cleaned and treated to provide a suitable surface for the joint. In the case of the aluminum support plates, the bonding surfaces were cleaned with MEK, etched, and primed. The acid etching of the aluminum support plates comprised several steps. First, the support plates were immersed in an alkaline wash for 10 minutes at 88 ° C. The alkaline wash was comprised of approximately 260.1 - 317.9 grams (9-11 ounces) per 3,785 liters (one gallon) of Oakite 164 (commercially available from Oakite Products, Inc., Berkeley Hgts., NJ). After a complete rinse with water, the plates were etched with acid for 10 minutes at 71 ° C in a mixture of sulfuric acid. After rinsing with water, the support plates are allowed to air dry for 10 minutes on an inclined support and then dried in an oven for an additional 10 minutes at 71 ° C. Surface priming was effected by brushing a thin layer of the EC1660 primer (commercially available from the Minnesota Mining and Manufacturing Company, St. Paul, MN) on the bonding surfaces. The primer was allowed to dry in accordance with the conditions recommended by the manufacturer. In the case of the metallic bonding abrasive segments, the bonding surfaces were treated with a sandblast, washed with a solvent with methyl ethyl ketone, and surface-primed. The sandblasting process was carried out using 80-degree aluminum oxide at a pressure of approximately 4.22 kg / cm2 (60 psi). Surface priming was carried out by brushing a thin layer of the EC1660 primer over the bonding surfaces. The primer was allowed to dry in accordance with the conditions recommended by the manufacturer. After the surface preparation was supplemented, a 0.0254 cm (10 mils) layer of a structural adhesive (commercially available from Minnesota Mining and Manufacturing Company, St. Paul, MN under the registered designation "AF30" was placed on the first bonding surface of the support plate The abrasive segments attached to a metal, in the shape of an arch, were then placed on the adhesive surface creating a cylindrical region of the abrasive around the center of the support plate. A second layer of structural adhesive of the same type A second aluminum support plate was then placed on the second layer of the structural adhesive whereby a grinding wheel assembly is formed (see, Figure 25b). It was then placed in a hot platen press to cure the thermosetting adhesive to form the joints between the seconds. abrasives and support plates. The assembly of the wheel was then heated from 38 ° C to 177 ° C at a rate of 5.6 ° C / minute under a constant pressure of 689 KPa. After the retention at 177 ° C for one hour, the assembly of the grinding wheel was cooled to room temperature under the same applied pressure. The abrasive grinding wheel was balanced, rectified and revived up to the final diameter of 20.32 cm (8 inches). Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (45)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. An abrasive grinding wheel that can be rotated about an axis of rotation, the abrasive grinding wheel is characterized in that it comprises: a means to define a rotation axis of the abrasive grinding wheel; a first support plate; a second support plate; a substantially cylindrical region of abrasive material sandwiched between the first support plate and the second support plate and attached to the first and second support plates with an adhesive and having an abrasive surface extending circumferentially in a peripheral band thereof , wherein the abrasive material comprises a plurality of layers of abrasive particles, each layer of the abrasive particles extends along at least a portion of the circumference of the abrasive surface and in a radial direction of the substantially cylindrical region of the material abrasive from the abrasive surface towards the axis of rotation; and wherein any circular path defined by an intersection of a plane perpendicular to the axis of rotation of the abrasive grinding wheel and a complete circumference of the abrasive surface will intersect at least one of the plurality of layers of the abrasive particles.
2. 2. The abrasive grinding wheel according to claim 1, characterized in that the plurality of the layers of the abrasive particles are substantially planar and parallel to each other.
3. 3. The abrasive grinding wheel according to claim 1, characterized in that a plane substantially parallel with the layers of the abrasive particles forms an angle of between 0 degrees and 180 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel.
4. The abrasive grinding wheel according to claim 3, characterized in that the region of the abrasive material includes a first surface and a second surface which is substantially parallel to the first surface, and wherein both the first and the second surface are inclined at an angle between 0 degrees and 90 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel.
5. The abrasive grinding wheel according to claim 1, characterized in that at least one first layer of the abrasive particles of the plurality of the layers of the abrasive particles extends along the abrasive surface in such a way that at least one The route defined by the intersection of a plane perpendicular to the axis of rotation and the abrasive surface will intersect the first layer of the abrasive particles in at least three locations.
6. The abrasive grinding wheel according to claim 1, characterized in that it further includes: a plurality of discrete abrasive segments spaced circumferentially between the first and second support plates to form the region of the abrasive material, each abrasive segment having a plurality of layers of the abrasive particles.
7. The abrasive grinding wheel according to claim 6, characterized in that at least one of the plurality of particles in at least one of the plurality of the abrasive segments is offset in an axial direction from at least one of the plurality of the abrasive segments. layers of the abrasive particles in at least one of the plurality of the abrasive segments.
8. The abrasive grinding wheel according to claim 7, characterized in that the plurality of the layers of the abrasive particles in each of the plurality of the abrasive segments are oriented to extend substantially perpendicular to the axis of rotation of the grinding wheel abrasive
9. 9. The abrasive grinding wheel according to claim 7, characterized because at least one of the plurality of layers of the abrasive particles in each of the plurality of the abrasive segments is separated from an adjacent layer of the abrasive particles in the same segment by a separation distance perpendicular to each layer of the particles abrasives and further wherein at least one separation distance in at least one of the plurality of the abrasive segments is different from at least one separation distance in at least one of the plurality of the abrasive segments.
10. 10. The abrasive grinding wheel according to claim 6, characterized in that it also includes: at least one opening provided in the abrasive surface; a first channel positioned internally radially with respect to the abrasive surface and in fluid communication with the opening; a second channel that opens towards the interior of the abrasive grinding wheel and located in a central region thereof; and at least one radial channel extending from the second channel of the abrasive grinding wheel to the first channel and in fluid communication with both the first channel and the second channel; so that a liquid lubricant provided under pressure to the first channel can pass through the radial channel, into the circular channel and through the opening to lubricate the abrasive surface of the grinding wheel during rotation of the grinding wheel.
11. The abrasive grinding wheel according to claim 6, characterized in that an abrasive segment extending over a circumferential portion of the abrasive surface is composed of a plurality of axial segments that are stacked adjacent to each other in the axial direction of the grinding wheel. grinding and supplied between the first and second support plates.
12. The abrasive grinding wheel according to claim 6, characterized in that at least a first layer of abrasive particles of the plurality, if the layers of the abrasive particles in at least one abrasive segment of the plurality of abrasive segments intersect in at least one two locations a route defined by the intersection of a plane perpendicular to the axis of rotation and the abrasive surface.
13. 13. The abrasive grinding wheel according to claim 1, characterized in that the abrasive surface includes a rectification profile which is convex.
14. 14. The abrasive grinding wheel according to claim 1, characterized in that the abrasive surface includes a grinding profile which is concave.
15. 15. An abrasive grinding wheel for connection to a rotary tool so that the abrasive grinding wheel can be rotated about an axis of rotation, characterized in that it comprises: means for defining an axis of rotation of the abrasive grinding wheel; a first support plate; a second support plate; a substantially cylindrical abrasive region of abrasive material comprising a plurality of layers of the abrasive particles, each layer of the abrasive particles extending along at least a portion of the circumference of the abrasive surface and in at least one radial direction of the abrasive. the substantially cylindrical region of the abrasive material, and wherein the plurality of the layers of the abrasive particles form an angle of between 0 degrees and 180 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel, wherein the abrasive region substantially Cylindrical is sandwiched between the first support plate and the second support plate and attached to the first support plate and the second support plate with an adhesive.
16. The abrasive grinding wheel according to claim 15, characterized in that the abrasive region includes a first surface and a second surface, both the first surface and the second surface are substantially parallel with respect to the plurality of the layers of the abrasive particles , both the first and the second surfaces are further inclined at an angle of between 0 degrees and 90 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel.
17. 17. The abrasive grinding wheel according to claim 15, characterized in that the region of the abrasive material comprises a single laminated block.
18. 18. An abrasive grinding wheel that can be rotated about an axis of rotation, characterized in that it comprises: means for defining an axis of rotation of the abrasive grinding wheel; a first support plate; a second support plate; and a substantially cylindrical region of the abrasive material sandwiched between the first support plate and the second support plate and formed from a plurality of the discrete abrasive segments, each of the plurality of the abrasive segments having a plurality of layers of the abrasive segments. abrasive particles extending along at least a portion of the circumference of an abrasive surface, and each of the plurality of abrasive segments is attached to the first and second support plates with an adhesive; wherein at least one of the plurality of layers of abrasive particles in at least one of the plurality of abrasive segments is offset in a direction of the axis of rotation from at least one of the plurality of layers of abrasive particles in at least one of the plurality of the abrasive segments.
19. The abrasive grinding wheel according to claim 18, characterized in that each of the plurality of layers of the abrasive particles in each of the plurality of the abrasive segments is oriented to extend substantially perpendicular to the axis of rotation of the grinding wheel. abrasive grinding machine 20.
20. The abrasive grinding wheel according to claim 18, characterized in that it further includes: at least one opening provided in the abrasive surface of the grinding wheel; a first channel positioned radially inside with respect to the plurality of the abrasive segments and in fluid communication with the opening; a second channel that opens into the abrasive grinding wheel and located in a central region of the same; and at least one radial channel extending from the second channel of the abrasive grinding wheel to the first channel and in fluid communication with the first channel and the second channel; so that a liquid lubricant provided under pressure to the first channel can pass through the radial channel, into the second channel and through the opening to lubricate the abrasive surface during the rotation of the grinding wheel.
21. The abrasive grinding wheel according to claim 18, characterized in that an abrasive segment extending over a circumferential portion of the abrasive surface is composed of plural axial segments that are stacked adjacent to each other in the axial direction of the grinding wheel and supplied between the first and second support plates.
22. 22. A method of manufacturing a grinding wheel to rotate about an axis of rotation, characterized in that it comprises the steps of: providing a sheet of abrasive material comprising a plurality of layers of abrasive particles; forming the sheet of the abrasive material into a substantially cylindrical grinding wheel having a substantially cylindrical abrasive region, wherein the layer of the abrasive particles extends along at least a portion of the circumference of the abrasive surface and in a radial direction from the substantially cylindrical region of the abrasive material from the abrasive surface towards a center of the grinding wheel; securely securing the sheet of the abrasive material between a first support plate and a second support plate by the adhesive bonding of the sheet of the abrasive material to the first support plate and the second support plate; define an axis of rotation for the grinding wheel so that the layers of the abrasive particles are at an angle of between 0 degrees and 180 degrees, exclusive with the axis of rotation.
23. The method according to claim 22, characterized in that the passage of the provision of the sheet of the abrasive material further comprises the formation of the sheet of the abrasive material by: the intercalation of a plurality of layers of the abrasive particles with a plurality of the layers of the bonding material; and sintering the plurality of the layers of the abrasive particles with the plurality of the layers of the bonding material to form the sheet of the abrasive material.
24. 24. A method of manufacturing an abrasive grinding wheel to rotate about an axis of rotation, characterized in that it comprises the steps of: providing a plurality of the abrasive segments each having a plurality of layers of the abrasive particles forming a abrasive surface, the layers of the abrasive particles extend along at least a portion of the circumference of the abrasive grinding wheel; circumferentially spacing the plurality of the abrasive segments between a first support plate and a second support plate; joining the plurality of abrasive segments to the first and second support plates with an adhesive such that at least one of the plurality of layers of abrasive particles in at least one of the plurality of abrasive segments is stepped in the direction of the axis of rotation of the grinding wheel from at least one of the plurality of layers of the abrasive particles in at least one of the plurality of the abrasive segments.
25. 25. The method according to claim 24, characterized in that the step of providing a plurality of the abrasive segments includes the formation of the plurality of the abrasive segments by: the formation of at least a first sheet of the abrasive material having a plurality of layers of the abrasive particles; and cutting the plurality of the abrasive segments from the first laminated sheet.
26. The method according to claim 25, characterized in that the step of forming at least a first sheet of the abrasive material includes: sandwiching a plurality of layers of the abrasive particles with a plurality of the layers of the bonding material; sintering the plurality of the layers of the abrasive particles with the plurality of the layers of the joining material to form the laminated sheet.
27. 27. An abrasive grinding wheel that can be rotated about an axis of rotation, the abrasive grinding wheel is characterized in that it comprises: means for defining an axis of rotation of the abrasive grinding wheel; a substantially cylindrical region of the metal bond abrasive material having a circumferentially extending abrasive surface; and at least one support plate; wherein the region of the metal bond abrasive material is bonded to the backing plate with an adhesive.
28. 28. The abrasive grinding wheel according to claim 27, characterized in that the region of the abrasive material is formed from a plurality of discrete abrasive segments which are circumferentially spaced at the periphery of the grinding wheel to provide the circumferentially extending abrasive surface.
29. 29. The abrasive grinding wheel according to claim 27, characterized in that it includes a first and a second support plates, the first and second support plates form the external axial surface of the grinding wheel where the region of the abrasive material is interposed between the first support plate and the second support plate and wherein the region of the abrasive material is attached to the first and second support plates by an adhesive.
30. 30. The abrasive grinding wheel according to claim 22, characterized in that the adhesive is a thermosetting adhesive.
31. 31. The abrasive grinding wheel according to claim 27, characterized in that the adhesive has a shear strength of at least about 70.37 kg / cm2 (1000 psi).
32. 32. The abrasive grinding wheel according to claim 27, characterized in that the adhesive has a shear strength of at least about 105.55 kg / cm2 (1500 psi).
33. 33. The abrasive grinding wheel according to claim 27, characterized in that the abrasive particles are selected from the group consisting of diamond, cubic boron nitride, boron suboxide, and combinations thereof.
34. 34. The abrasive grinding wheel according to claim 27, characterized in that the metallic bonding abrasive material comprises a plurality of abrasive particles randomly distributed in a metallic bonding material.
35. 35. The abrasive grinding wheel according to claim 27, characterized in that the metallic bonding abrasive material comprises a plurality of abrasive particles which are present in parallel layers, substantially flat.
36. 36. The abrasive grinding wheel according to claim 27, characterized in that the support plate is made of steel, aluminum, bronze, titanium, polymer, fiber reinforced polymer, or a combination thereof.
37. 37. An abrasive grinding wheel that can be rotated about an axis of rotation, characterized in that it comprises: means for defining an axis of rotation of the abrasive grinding wheel; a first support plate; a second support plate; a substantially cylindrical region of the metallic bonding abrasive material formed from a plurality of the discrete abrasive segments interposed between the first support plate and the second support plate and attached to the first and second support plates with an adhesive.
38. 38. A method of manufacturing an abrasive grinding wheel to rotate about an axis of rotation, characterized in that it comprises the steps of: (i) providing a first support plate having an internal and an external major surface; (ii) providing a second support plate having an internal and an external major surface; (iii) providing a region of the metal bonding abrasive having a first and a second major surface; (iv) circumferentially spacing the region of the metal bonding abrasive between the internal main surface of the first support plate and the internal main surface of the second support plate, wherein a first layer of the adhesive is interposed between the internal main surface of the first support plate and the first major surfaces of the metal bonding abrasive layer, and wherein a second layer of the adhesive is interposed between the internal main surface of the second support plate and the second major surfaces of the bonding abrasive layer metal; and (v) curing the first and second layers of the adhesive to provide an abrasive grinding wheel having a circumferentially extending abrasive surface.
39. 39. The method according to claim 38, characterized in that the region of the metallic bonding abrasive material is formed from a plurality of discrete abrasive segments which are circumferentially spaced at the periphery of the support plates.
40. 40. The method according to claim 38, characterized in that the adhesive is a thermosetting adhesive.
41. 41. The method according to claim 38, characterized in that the adhesive has a shear strength of at least about 70.37 kg / cm2 (1000 psi).
42. 42. The method of compliance with the claim 38, characterized in that the adhesive has a shear strength of at least about 105.55 kg / cm2 (1500 psi).
43. 43. The method according to claim 38, characterized in that the metallic bonding abrasive material comprises a plurality of abrasive particles randomly distributed in a metallic bonding material.
44. 44. The method according to claim 38, characterized in that the metallic bonding abrasive material comprises a plurality of abrasive particles which are present in parallel, substantially planar layers.
45. 45. The method according to claim 38, characterized in that the support plate is composed of steel, aluminum, brass, titanium, polymer, fiber reinforced polymer, or a combination thereof.