Fixing device for rotary blade

Abstract

A fixing device for fixing a rotary blade to a spindle in a bench circular saw, for example, has a structure in which it is difficult to achieve structural compactification in radial size. Therefore, there has been a problem of sacrificing an inclination angle and a cutting depth of the rotary blade. Provided is a fixing device free from such problems owing to employment of a structure which can be easily compactified in a radial direction. Cam portions are provided on respective surfaces opposite to each other of an intermediate flange and an outer flange so as to mesh with each other. The cam portions slide with each other with a rotational force imparted to the rotary blade so that the rotational force is converted into a displacement in a direction of an axis of the intermediate flange and is applied in a direction of clamping the rotary blade.

1 . A device for fixing a rotary blade to a rotation fixing portion of a rotatable spindle, comprising:
 an inner flange and an outer flange fixing the rotary blade to the rotation fixing portion with respect to the rotation by clamping the rotary blade from both sides thereof; and   a fixing flange producing, with respect to the inner flange and the outer flange, a clamping force against the rotary blade in a direction of an axis of the spindle by tightening a fixing screw portion into an end surface of the rotation fixing portion;   wherein the fixing device further comprises:   an intermediate flange interposed between the rotary blade and the outer flange;   a cam meshing portion provided between the intermediate flange and the outer flange paired therewith, the cam meshing portion being constituted by meshing of cam portions varying in height in the direction of the axis of the spindle;   a member serving as the outer flange and paired with the intermediate flange so as to constitute the cam meshing portion, fixed to the rotation fixing portion with respect to the rotation; and   by rotational resistance imparted to the rotary blade, the intermediate flange is rotated relative to the member paired with the intermediate flange for constituting the cam meshing portion, so that an axial force in the direction of the axis of the spindle is produced in the cam meshing portion.   
   
   
       2 . The fixing device according to  claim 1 , wherein:
 the fixing device is provided with the inner flange fixed to the rotation fixing portion with respect to the rotation and contacting with an end portion of the rotation fixing portion so as to be restricted in displacement in the direction of the axis of the spindle;   the intermediate flange clamps the rotary blade between the intermediate flange and the inner flange and rotatable relative to the rotation fixing portion; the outer flange clamping the intermediate flange between the outer flange and the rotary blade and fixed to the rotation fixing portion with respect to the rotation;   the fixing flange clamping the outer flange between the fixing flange and the intermediate flange and threadably coupled immovably in the direction of the axis of the spindle by tightening the fixing thread portion into the end surface of the rotation fixing portion;   the cam meshing portion is provided between the intermediate flange and the outer flange; and   a relative rotational force relative to the outer flange, which is imparted to the intermediate flange via the rotary blade, is converted via the cam meshing portion into a pressing force of the intermediate flange in the direction of the axis of the spindle against the rotary blade.   
   
   
       3 . The fixing device according to  claim 2 , wherein frictional resistance in a rotational direction of the intermediate flange relative to the rotary blade is set to be higher than sliding resistance of the cam portions. 
   
   
       4 . The fixing device according to  claim 2 , wherein a friction reducing means is interposed between the rotary blade and the inner flange, for reducing frictional resistance in a rotational direction of the inner flange against to the rotary blade in comparison with the frictional resistance in the rotational direction of the intermediate flange against the rotary blade. 
   
   
       5 . The fixing device according to  claim 2 , wherein the inner flange is rotatably attached to the rotation fixing portion of the spindle. 
   
   
       6 . The fixing device according to  claim 2 , wherein:
 a cover is attached between the intermediate flange and the outer flange so as to cover peripheries thereof;   the cover is imparted with an elastic force in the rotational direction and is engaged with the intermediate flange and the outer flange in the rotational direction; and   regarding a position of the intermediate flange in the rotational direction relative to the outer flange, biasing is made toward an initial position at which the cam portions of the intermediate flange and the cam portions of the outer flange mesh most deeply with each other.   
   
   
       7 . The fixing device according to  claim 2 , wherein, regarding a position of the intermediate flange in the rotational direction relative to the spindle, an initial position biasing means is interposed between the intermediate flange and the rotation fixing portion of the spindle, for biasing toward an initial position at which the cam portions of the intermediate flange and the cam portions of the outer flange mesh most deeply with each other. 
   
   
       8 . (canceled) 
   
   
       9 . (canceled) 
   
   
       10 . A device for fixing a rotary blade to a rotation fixing portion of a rotatable spindle, comprising:
 an inner flange and an outer flange fixing the rotary blade to the rotation fixing portion with respect to the rotation by clamping the rotary blade from both sides thereof; and   a fixing flange producing, with respect to the inner flange and the outer flange, a clamping force against the rotary blade in a direction of an axis of the spindle by tightening a fixing screw portion into an end surface of the rotation fixing portion;   wherein the fixing device further comprises:   an intermediate flange interposed between the rotary blade and the inner flange;   a cam meshing portion provided between the intermediate flange and the inner flange paired therewith, the cam meshing portion being constituted by meshing of cam portions varying in height in the direction of the axis of the spindle;   a member serving as the inner flange and paired with the intermediate flange so as to constitute the cam meshing portion, fixed to the rotation fixing portion with respect to the rotation; and   by rotational resistance imparted to the rotary blade, the intermediate flange is rotated relative to the member paired with the intermediate flange for constituting the cam meshing portion, so that an axial force in the direction of the axis of the spindle is produced in the cam meshing portion.   
   
   
       11 . The fixing device according to  claim 10 , wherein:
 the inner flange is fixed to the rotation fixing portion with respect to the rotation and contacting with an end portion of the rotation fixing portion so as to be restricted in displacement in the direction of the axis of the spindle;   the intermediate flange is clamped between the inner flange and the rotary blade and is allowed to be rotated relative to the rotation fixing portion;   the outer flange clamps the rotary blade between the outer flange and the intermediate flange and fixed to the rotation fixing portion with respect to the rotation;   the fixing flange clamps the outer flange between the fixing flange and the rotary blade and threadably coupled immovably in the direction of the axis of the spindle by tightening the fixing thread portion into the end surface of the rotation fixing portion;   the cam meshing portion is provided between the inner flange and the intermediate flange; and   a relative rotational force relative to the inner flange, which is imparted to the intermediate flange via the rotary blade, is converted via the cam meshing portion into a pressing force of the intermediate flange in the direction of the axis of the spindle against the rotary blade.   
   
   
       12 . The fixing device according to  claim 11 , wherein frictional resistance in a rotational direction of the intermediate flange relative to the rotary blade is set to be higher than sliding resistance of the cam portions. 
   
   
       13 . The fixing device according to  claim 11 , wherein, regarding a position of the intermediate flange in the rotational direction relative to the spindle, an initial position biasing means is interposed between the intermediate flange and the rotation fixing portion of the spindle, for biasing toward an initial position at which the cam portions of the intermediate flange and the cam portions of the inner flange mesh most deeply with each other. 
   
   
       14 . A device for fixing a rotary blade to a rotation fixing portion of a rotatable spindle, comprising:
 an inner flange fixed to the rotation fixing portion with respect to the rotation and contacting with an end portion of the rotation fixing portion so as to be restricted in displacement in the direction of the axis of the spindle;   an inner intermediate flange clamped between the inner flange and the rotary blade and allowed to be rotated relative to the rotation fixing portion;   an outer intermediate flange clamping the rotary blade between the outer intermediate flange and the inner intermediate flange and allowed to be rotated relative to the rotation fixing portion;   an outer flange clamping the outer intermediate flange between the outer flange and the rotary blade and fixed to the rotation fixing portion with respect to the rotation;   a fixing flange clamping the outer flange between the fixing flange and the outer intermediate flange and threadably coupled immovably in the direction of the axis of the spindle by tightening the fixing thread portion into the end surface of the rotation fixing portion; and   cam meshing portions varying in height in the direction of the axis of the spindle mesh with each other, respectively provided between the inner flange and the inner intermediate flange and between the outer flange and the outer intermediate flange,   wherein relative rotational forces relative to the inner flange and the outer flange, which are imparted to the inner intermediate flange and the outer intermediate flange via the rotary blade, are converted via the cam meshing portions constituted by the two sets of the cam portions into pressing forces of the inner intermediate flange and the outer intermediate flange in the direction of the axis of the spindle against the rotary blade.   
   
   
       15 . The fixing device according to  claim 14 , wherein frictional resistance in a rotational direction of the outer intermediate flange relative to the rotary blade is set to be higher than sliding resistance of the cam portions provided between the outer flange and the outer intermediate flange. 
   
   
       16 . The fixing device according to  claim 14 , wherein:
 a cover is attached between the outer intermediate flange and the outer flange so as to cover peripheries thereof;   the cover is imparted with an elastic force in the rotational direction and is engaged with the outer intermediate flange and the outer flange in the rotational direction; and   regarding a position of the outer intermediate flange in the rotational direction relative to the outer flange, biasing is made toward an initial position at which the cam portions of the outer intermediate flange and the cam portions of the outer flange mesh most deeply with each other.   
   
   
       17 . The fixing device according to  claim 14 , wherein, regarding a position of the outer intermediate flange in the rotational direction relative to the spindle, an initial position biasing means is interposed between the outer intermediate flange and the rotation fixing portion of the spindle, for biasing toward an initial position at which the cam portions of the outer intermediate flange and the cam portions of the outer flange mesh most deeply with each other.