Grinding wheel

Abstract

A cylindrical, abrasive grinding wheel having a cylindrical abrasive region with an abrasive surface at an outer circular band thereof. The abrasive region includes layers of abrasive particles. The layers of abrasive particles can be tilted with respect to an axis of rotation of the grinding wheel or they can 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.

What is claimed is:  
     
         1 . An abrasive grinding wheel that can be rotated about an axis of rotation, the abrasive grinding wheel comprising: 
 a means for defining an axis of rotation of the abrasive grinding wheel;    a substantially cylindrical region of abrasive material having a circumferentially extending abrasive surface at a peripheral band thereof and formed from a plurality of layers of abrasive particles, each layer of abrasive particles extending along at least a portion of the circumference of the abrasive surface and in a radial direction of the substantially cylindrical region of abrasive material from the abrasive surface toward 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 abrasive particles.    
     
     
         2 . The abrasive grinding wheel of  claim 1  wherein the plurality of layers of abrasive particles are substantially planar and parallel to one another.  
     
     
         3 . The abrasive grinding wheel of  claim 1  including a first support plate and a second support plate, and wherein the region of abrasive material is sandwiched between the first support plate and the second support plate.  
     
     
         4 . The abrasive grinding wheel of  claim 3  wherein the abrasive material is bonded to the first and the second support plates with an adhesive.  
     
     
         5 . The abrasive grinding wheel of  claim 3  wherein a plane substantially parallel with the layers of abrasive particles forms an angle of between 0 degrees and 180 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel.  
     
     
         6 . The abrasive grinding wheel of  claim 5  wherein the region of abrasive material includes a first surface and a second surface which is substantially parallel to the first surface, and wherein both the first surface and the second surface are tilted at an angle of between 0 degrees and 90 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel.  
     
     
         7 . The abrasive grinding wheel of  claim 1  wherein at least a first layer of abrasive particles of the plurality of layers of abrasive particles extends along the abrasive surface such that at least one path defined by the intersection of a plane perpendicular to the axis of rotation and the abrasive surface will intersect the first layer of abrasive particles in at least three locations.  
     
     
         8 . The abrasive grinding wheel of  claim 1  further including: 
 first and second support plates forming outer axial surfaces of the grinding wheel; and  
 a plurality of discrete abrasive segments circumferentially spaced between the first and second support plates to form the region of abrasive material, each abrasive segment having a plurality of layers of abrasive particles.  
 
     
     
         9 . The abrasive grinding wheel of  claim 8  wherein the abrasive segments are bonded to the first and the second support plates with an adhesive.  
     
     
         10 . The abrasive grinding wheel of  claim 8  wherein at least one of the plurality of layers of abrasive particles in at least one of the plurality of abrasive segments are offset in an axial direction from at least one of the plurality of layers of abrasive particles in at least one other of the plurality of abrasive segments.  
     
     
         11 . The abrasive grinding wheel of  claim 10  wherein the plurality of layers of abrasive particles in each of the plurality of abrasive segments is oriented to extend substantially perpendicular to the axis of rotation of the abrasive grinding wheel.  
     
     
         12 . The abrasive grinding wheel of  claim 10  wherein at least one of the plurality of layers of abrasive particles in each of the plurality of abrasive segments is separated from an adjacent layer of abrasive particles in a same segment by a separation distance perpendicular to each layer of abrasive particles and further wherein at least one separation distance in at least one of the plurality of abrasive segments is different from at least one separation distance in at least one other of the plurality of abrasive segments.  
     
     
         13 . The abrasive grinding wheel of  claim 8  further including: 
 at least one opening provided in the abrasive surface;  
 a first channel positioned radially interior to the abrasive surface and in fluid communication with the opening;  
 a second channel opening to the interior of the abrasive grinding wheel and located in a center 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 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.  
 
     
     
         14 . The abrasive grinding wheel of  claim 8  wherein an abrasive segment that extends over a circumferential portion of the abrasive surface is made up of plural axial segments that are stacked adjacent to one another in the axial direction of the grinding wheel and supplied between the first and second support plates.  
     
     
         15 . The abrasive grinding wheel of  claim 8  wherein at least a first abrasive particle layer of the plurality if abrasive particle layers in at least one abrasive segment of the plurality of abrasive segments intersects in at least two locations a path defined by the intersection of a plane perpendicular to the axis of rotation and the abrasive surface.  
     
     
         16 . The abrasive grinding wheel of  claim 1  wherein the abrasive surface includes a grinding profile which is convex.  
     
     
         17 . The abrasive grinding wheel of  claim 1  wherein the abrasive surface includes a grinding profile which is concave.  
     
     
         18 . An abrasive grinding wheel for connection to a rotary tool so that the abrasive grinding wheel can be rotated about an axis of rotation, comprising: 
 a means for defining an axis of rotation of the abrasive grinding wheel;    a substantially cylindrical abrasive region having layers of abrasive particles, each layer of abrasive particles extending along at least a portion of the circumference of the abrasive surface and in at least a radial direction of the substantially cylindrical region of abrasive material, and wherein the plurality of layers of abrasive particles form an angle of between 0 degrees and 180 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel.    
     
     
         19 . The abrasive grinding wheel of  claim 18  wherein the abrasive region includes a first surface and a second surface, both the first surface and the second surface being substantially parallel to the plurality of layers of abrasive particles, both the first and second surfaces further being tilted at an angle of between 0 degrees and 90 degrees, exclusive, with the axis of rotation of the abrasive grinding wheel.  
     
     
         20 . The abrasive grinding wheel of  claim 19  including a first support plate and a second support plate, and wherein the region of abrasive material is sandwiched between the first support plate and the second support plate.  
     
     
         21 . The abrasive grinding wheel of  claim 20  wherein the region of abrasive material comprises a single laminated block.  
     
     
         22 . An abrasive grinding wheel that can be rotated about an axis of rotation, comprising: 
 a means for defining an axis of rotation of said abrasive grinding wheel;    a first support plate;    a second support plate; and    a substantially cylindrical region of abrasive material sandwiched between the upper support plate and the lower support plate and formed from a plurality of discrete abrasive segments, each of the plurality of abrasive segments having a plurality of layers of abrasive particles extending along at least a portion of the circumference of an abrasive surface;    wherein at least one of the plurality of layers of abrasive particles in at least one of the plurality of abrasive segments are 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 other of the plurality of abrasive segments.    
     
     
         23 . The abrasive grinding wheel of  claim 22  wherein each of the plurality of layers of abrasive particles in each of the plurality of abrasive segments is oriented to extend substantially perpendicular to the axis of rotation of the abrasive grinding wheel.  
     
     
         24 . The abrasive grinding wheel of  claim 22  further including: 
 at least one opening provided in the abrasive surface of the grinding wheel;  
 a first channel positioned radially interior to the plurality of abrasive segments and in fluid communication with the opening;  
 a second channel opening to the interior of the abrasive grinding wheel and located in a center 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 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 rotation of the grinding wheel.  
 
     
     
         25 . The abrasive grinding wheel of  claim 22  wherein an abrasive segment that extends over a circumferential portion of the abrasive surface is made up of plural axial segments that are stacked adjacent to one another in the axial direction of the grinding wheel and supplied between the first and second support plates.  
     
     
         26 . A method of fabricating a grinding wheel for rotating about an axis of rotation, comprising the steps of: 
 providing a sheet of abrasive material comprising a plurality of abrasive particle layers;    shaping the sheet of abrasive material into a substantially cylindrical grinding wheel having a substantially cylindrical abrasive region, wherein the layer of 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 abrasive material from the abrasive surface towards a center of the grinding wheel;    defining an axis of rotation for the grinding wheel so that the layers of abrasive particles are at an angle of between 0 degrees and 180 degrees, exclusive with the axis of rotation.    
     
     
         27 . The method of  claim 26  wherein the step of providing the sheet of abrasive material further comprises forming the sheet of abrasive material by: 
 interleaving a plurality of layers of abrasive particles with a plurality of layers of bond material; and  
 sintering the plurality of layers of abrasive particles with the plurality of layers of bond material to form the sheet of abrasive material.  
 
     
     
         28 . The method of  claim 26  further including the step of fixedly securing the sheet of abrasive material between a first support plate and a second support plate by sintering the sheet of abrasive material between the first support plate and the second support plate.  
     
     
         29 . The method of  claim 26  further including the step of fixedly securing the sheet of abrasive material between a first support plate and a second support plate by adhesively bonding the sheet of abrasive material to the first support plate and the second support plate.  
     
     
         30 . A method of fabricating an abrasive grinding wheel for rotating about an axis of rotation, comprising the steps of: 
 providing a plurality of abrasive segments each having a plurality of layers of abrasive particles forming an abrasive surface, the layers of abrasive particles extending along at least a portion of the circumference of the abrasive grinding wheel;    circumferentially spacing the plurality of abrasive segments between a first support plate and a second support plate;    fixedly securing the plurality of abrasive segments between the first support plate and the second support plate such that at least one of the plurality of layers of abrasive particles in at least one of the plurality of abrasive segments is staggered in the direction of the axis of rotation of the grinding wheel from at least one of the plurality of layers of abrasive particles in at least one other of the plurality of abrasive segments.    
     
     
         31 . The method of  claim 30  wherein the step of fixedly securing the plurality of abrasive segments between the first support plate and the second support plate comprises bonding the plurality of abrasive segments to the first and the second support plates with an adhesive.  
     
     
         32 . The method of  claim 30  including wherein the step of providing a plurality of abrasive segments includes forming the plurality of abrasive segments by: 
 forming at least a first sheet of abrasive material having a plurality of layers of abrasive particles; and  
 cutting the plurality of abrasive segments from the first laminated sheet.  
 
     
     
         33 . The method of  claim 32  wherein the step of forming at least a first sheet of abrasive material includes: 
 interleaving a plurality of layers of abrasive particles with a plurality of layers of bond material;  
 sintering the plurality of layers of abrasive particles with the plurality of layers of bond material to form the laminated sheet.  
 
     
     
         34 . A method of fabricating a grinding wheel comprising the steps of: 
 interleaving a plurality of layers of abrasive particles with a plurality of layers of bond material;    placing the plurality of layers of abrasive particles and plurality of layers of bond material between a first support plate and a second support plate;    spacing a plurality of spacers between the plurality of layers of abrasive particles and plurality of layer of bond material and the first support plate;    spacing a plurality of spacers between the plurality of layers of abrasive particles and plurality of layer of bond material and the second support plate; and    sintering the plurality of layers of abrasive particles, the plurality of layers of bond material, the spacers and the first and second support plates under pressure to form the grinding wheel such that the spacers cause the plurality of layers of abrasive particles undulate in a wave-like pattern.    
     
     
         35 . An abrasive grinding wheel comprising: 
 a perimeter edge having an abrasive surface;    at least one opening provided in the abrasive surface;    a first channel positioned radially interior to the abrasive surface and in fluid communication with the opening;    a second channel opening to the interior of the abrasive grinding wheel and located in a center 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 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.    
     
     
         36 . The abrasive grinding wheel of  claim 35  further including a first circular surface and a second circular surface opposed to the first circular surface and wherein the second channel includes an opening on the first circular surface to allow liquid lubricant to be provided to the second channel via the opening.  
     
     
         37 . The abrasive grinding wheel of  claim 36  further including a central bore wherein the second channel includes an opening to the central bore to allow liquid lubricant to be provided to the second channel via the opening.  
     
     
         38 . An abrasive grinding wheel that can be rotated about an axis of rotation, the abrasive grinding wheel comprising: 
 a means for defining an axis of rotation of the abrasive grinding wheel;    a substantially cylindrical region of metal bond abrasive material having a circumferentially extending abrasive surface; and    at least one support plate;    wherein the region of metal bond abrasive material is bonded to the support plate with an adhesive.    
     
     
         39 . The abrasive grinding wheel of  claim 38  wherein the region of 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.  
     
     
         40 . The abrasive grinding wheel of  claim 38  including a first and a second support plate the first and second plates forming the outer axial surface of the grinding wheel wherein the region of abrasive material is interposed between the first support plate and the second support plate and wherein the region of abrasive material is bonded to the first and the second support plate by an adhesive.  
     
     
         41 . The abrasive grinding wheel of  claim 38  wherein the adhesive is a thermosetting adhesive.  
     
     
         42 . The abrasive grinding wheel of  claim 38  wherein the adhesive has a shear strength of at least about 1000 psi.  
     
     
         43 . The abrasive grinding wheel of  claim 38  wherein the adhesive has a shear strength of at least about 1500 psi.  
     
     
         44 . The abrasive grinding wheel of  claim 38  wherein the abrasive particles are selected from the group consisting of diamond, cubic boron nitride, boron suboxide, and combinations thereof.  
     
     
         45 . The abrasive grinding wheel of  claim 38  wherein the metal bond abrasive material comprises a plurality of abrasive particles randomly distributed in a metal bond material.  
     
     
         46 . The abrasive grinding wheel of  claim 38  wherein the metal bond abrasive material comprises a plurality of abrasive particles which are present in substantially planar, parallel layers.  
     
     
         47 . The abrasive grinding wheel of  claim 38  wherein the support plate is made of steel, aluminum, brass, titanium, polymer, fiber reinforced polymer, or a combination thereof.  
     
     
         48 . An abrasive grinding wheel that can be rotated about an axis of rotation, comprising: 
 a 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 metal bond abrasive material formed from a plurality of discrete abrasive segments interposed between the first support plate and the second support plate and bonded to the first and the second support plate with an adhesive.    
     
     
         49 . A method of making an abrasive grinding wheel for rotating about an axis of rotation, comprising the steps of: 
 (i) providing a first support plate having an inner and an outer major surface;    (ii) providing a second support plate having an inner and an outer major surface;    (iii) providing a region of metal bond abrasive having a first and a second major surface;    (iv) circumferentially spacing the region of metal bond abrasive between the inner major surface of the first support plate and the inner major surface of the second support plate, wherein a first layer of adhesive is interposed between the inner major surface of the first support plate and the first major surfaces of the metal bond abrasive layer, and wherein a second layer of adhesive is interposed between the inner major surface of the second support plate and the second major surfaces of the metal bond abrasive layer; and    (v) curing the first and the second layers of adhesive to provide an abrasive grinding wheel having a circumferentially extending abrasive surface.    
     
     
         50 . The method of  claim 49  wherein the region of metal bond abrasive material is formed from a plurality of discrete abrasive segments which are circumferentially spaced at the periphery of the support plates.  
     
     
         51 . The method of  claim 49  wherein the adhesive is a thermosetting adhesive.  
     
     
         52 . The method of  claim 49  wherein the adhesive has a shear strength of at least about 1000 psi.  
     
     
         53 . The method of  claim 49  wherein the adhesive has a shear strength of at least about 1500 psi.  
     
     
         54 . The method of  claim 49  wherein the metal bond abrasive material comprises a plurality of abrasive particles randomly distributed in a metal bond material.  
     
     
         55 . The method of  claim 49  wherein the metal bond abrasive material comprises a plurality of abrasive particles which are present in substantially planar, parallel layers.  
     
     
         56 . The method of  claim 49  wherein the support plate is made of steel, aluminum, brass, titanium, polymer, fiber reinforced polymer, or a combination thereof.