Brush-like Grindstone

Abstract

A brush-like grindstone ( 1 ) has threadlike grinding elements ( 2 ) each being a thread that is a collection of long inorganic fibers and is impregnated with resin and solidified. To grind work (W), the grindstone ( 1 ) is moved relative to the work (W) with the forward ends of the threadlike grinding elements ( 2 ) pressed against the work (W). In order to prevent the grinding elements ( 2 ) from breaking, each threadlike grinding element ( 2 ) is curved from its base end to its forward end with high hardness of the grinding elements ( 2 ) maintained. Also, the grinding elements ( 2 ) are formed in an elliptic or oblong cross-sectional shape whose minor axis is aligned with the direction of the curve. Therefore, the grinding elements ( 2 ) have extremely high rigidity in the direction perpendicular to the direction of the curve but they easily deform in the direction of the curve. Consequently, the grinding elements ( 2 ) softly engages the work (W) at their forward ends and, when excessive force acts on the elements ( 2 ), the brush-like grindstone ( 1 ) does not break because the elements ( 2 ) deform to absorb the force.

1 . A brush-like grindstone wherein a plurality of linear grinding materials are held in a holder, the linear grinding materials is obtained by impregnating an assemblage of long inorganic fiber filaments with a resin and hardening the resin, and an circumferential outer side surface of the holder is a circular circumferential surface, characterized in that:
 the long inorganic fibers are selected from alumina fibers, silicon carbide fibers, carbon fibers, silicon nitride fibers, and glass fibers, and   each of the plurality of linear grinding materials is curved in at least one location from its proximal end to its distal end.   
   
   
       2 . The brush-like grindstone according to  claim 1 , wherein each of the plurality of linear grinding materials is curved over the entire length thereof from the proximal end to the distal end. 
   
   
       3 . The brush-like grindstone according to  claim 1 , wherein each of the plurality of linear grinding materials extends radially from an outer circumferential side surface of the holder, and curves circumferentially in the same direction. 
   
   
       4 . The brush-like grindstone according to  claim 3 , wherein:
 a plurality of the holders are disposed in an axial direction of the holders, and   each of the plurality of linear grinding materials is held on each of the plurality of holders.   
   
   
       5 . The brush-like grindstone according to  claim 1 , wherein the plurality of linear grinding materials extend radially from an outer circumferential side surface of the holder, and curve toward one side in an axial direction of the holder. 
   
   
       6 . The brush-like grindstone according to  claim 5 , wherein
 a plurality of holders are disposed in the axial direction of the holders; and   the plurality of linear grinding materials are held in each of the plurality of holders.   
   
   
       7 . The brush-like grindstone according to  claim 1 , wherein
 two holders are disposed as a pair in an axial direction of the holders; and   the plurality of linear grinding materials extend radially from a circumferential surface of the two holders, and curve in a direction whereby the distal ends of the plurality of linear grinding materials held in the two holders are close to one another.   
   
   
       8 . The brush-like grindstone according to  claim 1 , wherein each of the plurality of linear grinding materials extends in an axial direction from an end surface of one side of the holder in the axial direction, and curves outwards from an inside of the end surface of the one side. 
   
   
       9 . The brush-like grindstone according to  claim 1 , wherein each of the plurality of linear grinding materials extends in an axial direction from an end surface of one side of the holder in the axial direction, and curves inwards from an outside of the end surface of the one side. 
   
   
       10 . The brush-like grindstone according to  claim 1 , wherein the plurality of linear grinding materials are held in the holder as a plurality of bundles. 
   
   
       11 . The brush-like grindstone according to  claim 1 , wherein the plurality of linear grinding materials are held along the entirety of the circumferential direction in a circumferential groove formed on an outer circumferential side surface or on an end surface of one side of the holder. 
   
   
       12 . The brush-like grindstone according to  claim 1 , wherein the plurality of linear grinding materials have an elliptical or oval cross section in which a minor axis faces a direction of curvature. 
   
   
       13 . The brush-like grindstone according to  claim 1 , wherein a drive shaft extends from the holder in an axial direction. 
   
   
       14 . (canceled)