Grinding device and grinding implement for said grinding device

Abstract

A grinding device has a support unit attached to a rotary shaft so as to be rotatable integrally with the rotary shaft, and a grinding element stacked on the support unit and having an uneven grinding surface formed by a plurality of abrasive grains. The support unit has, in a surface thereof, protruding surface portions to be brought into contact with a rear surface of the grinding element when in use, and recessed surface portions recessed from the protruding surface portions, alternately located in a circumferential direction. An engagement mechanism which makes an engagement at each of predetermined angular positions so as to retain the grinding element or the support unit moved by a predetermined angle in the circumferential direction, is provided between the support unit and the grinding element, between the rotary shaft and the grinding element, or between the rotary shaft and the support unit.

1 . A grinding device comprising:
 a support unit attached to a rotary shaft driven by a rotary drive unit, so as to be rotatable integrally with the rotary shaft; and   a grinding element stacked on the support unit and having an uneven grinding surface formed by a plurality of abrasive grains, wherein   the support unit has, in a surface thereof, protruding surface portions to be brought into contact with a rear surface of the grinding element when in use, and recessed surface portions recessed from the protruding surface portions, the protruding surface portions and recessed surface portions being alternately located in a circumferential direction, and   the grinding device also comprises an engagement mechanism which makes an engagement at each of predetermined angular positions so as to retain the grinding element or the support unit moved by a predetermined angle in the circumferential direction, the engagement mechanism being located between the support unit and the grinding element, between the rotary shaft and the grinding element, or between the rotary shaft and the support unit.   
     
     
         2 . The grinding device according to  claim 1 , wherein the engagement mechanism includes at least one engaging projection provided on one of the support unit and the grinding element, and a plurality of engaging holes provided in the other of the support unit and the grinding element at respective predetermined angular positions so as to be engageable with or disengageable from the engaging projections. 
     
     
         3 . The grinding device according to  claim 1 , wherein the engagement mechanism includes a ratchet gear constituting an internal gear attached to an inner circumferential surface of the grinding element or the support unit and having a predetermined pitch along the circumferential direction, and at least one ratchet pawl attached to the rotary shaft so as to be engaged with the ratchet gear. 
     
     
         4 . The grinding device according to  claim 1 , further comprising a displacement mechanism which moves the grinding element or the support unit by a predetermined angle in the circumferential direction in response to engaging action of the engagement mechanism. 
     
     
         5 . The grinding device according to  claim 4 , wherein
 the displacement mechanism includes a guide member provided on one of the grinding element and the support unit, and a displacement member attached to an outer circumference of the guide member so as to be movable in an axial direction along the guide member but be restricted from moving in the circumferential direction, and   the engagement mechanism includes at least one engaging pin provided on an outer circumferential surface of the displacement member so as to project outward in a radial direction, and an engaging groove formed on an entirety of the inner circumferential surface of the other of the grinding element and the support unit and including stepped portions each formed at a predetermined angular position.   
     
     
         6 . The grinding device according to  claim 4 , wherein
 the engagement mechanism includes a first face gear attached to one of the support unit and the grinding element and having a predetermined pitch along the circumferential direction, and a second face gear attached to the other of the support unit and the grinding element and having a pitch which allows the second face gear to mesh with the first face gear, along the circumferential direction,   the displacement mechanism includes a third face gear attached to an outer circumference of the second face gear so as to be movable in the axial direction but be restricted from moving in the circumferential direction, and having a pitch which allows the third face gear to mesh with the first face gear, along the circumferential direction, and   the third face gear has teeth deviated from the second face gear in the circumferential direction.   
     
     
         7 . A grinding implement to be attached, for use, to a base member which is attached to a rotary shaft driven by a rotary drive unit, so as to be rotatable integrally with the rotary shaft and which has an engaging projection on a surface thereof, the grinding implement comprising:
 a protrusion/recess-forming member attached to the base member and configured to form protruding surface portions and recessed surface portions recessed from the protruding surface portions, alternately located in a circumferential direction; and   a grinding element stacked on the protrusion/recess-forming member and having an uneven grinding surface formed by a plurality of abrasive grains, wherein   the protrusion/recess-forming member has an attachment hole to be engaged with the engaging projection so as to attach the protrusion/recess-forming member on the base member, and   the grinding element has a plurality of engaging holes each provided at a predetermined angular position so as to be engageable with or disengageable from the engaging projection.   
     
     
         8 . A grinding implement to be attached, for use, to a support unit which is attached to a rotary shaft driven by a rotary drive unit, so as to be rotatable integrally with the rotary shaft, and which has in a surface thereof protruding surface portions and recessed surface portions recessed from the protruding surface portions, the protruding surface portions and recessed surface portions being alternately located in a circumferential direction, the grinding implement comprising:
 a grinding element stacked on the support unit and having an uneven grinding surface formed by a plurality of abrasive grains; and   a guide member attached to a rear surface of the grinding element, wherein   the grinding element is attached to the support unit by inserting the guide member into an inner circumference of a displacement member provided on the support unit, so as to move by a predetermined angle in the circumferential direction with respect to the support unit in response to engaging action of a displacement mechanism included in the support unit.