Rotary tool

Abstract

The spindle has a lower end portion configured as an externally threaded portion and a flange portion protruding radially outward from the spindle above the externally threaded portion. The anti-loosening member is fitted around the spindle above the externally threaded portion. The flange portion has a lower surface having a first inclined surface that extends in the circumferential direction around the drive axis and is inclined downward toward the first direction. The anti-loosening member includes an annular base portion having a second inclined surface that slidably contacts the first inclined surface, and a peripheral wall portion that protrudes upward along the outer edge portion of the base portion, and abuts the side surface of the flange portion during the rotation of the spindle to receive the rotational driving force. The peripheral wall portion is provided only in a part of the outer edge portion of the base portion.

1 . A rotary tool, comprising:
 a spindle configured to be rotationally driven in a first direction around a drive axis that defines an up-down direction of the rotary tool, the spindle having a lower end portion configured as an externally threaded portion and a flange portion protruding in a radially outward direction of the spindle above the externally threaded portion;   an internally threaded member removably screwed onto the externally threaded portion; and   an anti-loosening member having an annular shape and fitted around the spindle above the externally threaded portion, the anti-loosening member being configured to (i) rotate integrally with the spindle when the spindle rotates in the first direction and (ii) restrict loosening of the internally threaded member by displacing downward while rotating in the first direction with respect to the spindle in response to stopping of rotation of the spindle,   wherein:   the flange portion has a lower surface having a first inclined surface that extends in a circumferential direction around the drive axis and is inclined downward toward the first direction,   the anti-loosening member comprises:
 (i) an annular base portion disposed below the flange portion and having a second inclined surface that slidably contacts the first inclined surface of the flange portion; and 
 (ii) a peripheral wall portion protruding upward along an outer edge portion of the base portion and configured to abut a side surface of the flange portion and receive rotational driving force when the spindle rotates, and 
   the peripheral wall portion is provided only on a part of the outer edge portion of the base portion.   
     
     
         2 . The rotary tool according to  claim 1 , wherein the base portion comprises a passage extending from a radially inward end to a radially outward end of the base portion below the flange portion. 
     
     
         3 . The rotary tool according to  claim 2 , wherein the passage is adjacent to an end of the second inclined surface, the end being opposite to the first direction in the circumferential direction. 
     
     
         4 . The rotary tool according to  claim 1 , wherein an upper end of the peripheral wall portion of the anti-loosening member is at a lower position than an upper end of the flange portion of the spindle in the up-down direction. 
     
     
         5 . The rotary tool according to  claim 4 , wherein the upper end of the peripheral wall portion is at a position the same as or below a center in the up-down direction of the flange portion. 
     
     
         6 . The rotary tool according to  claim 1 , wherein the peripheral wall portion comprises:
 a rotation transmission portion having a rotation transmission surface configured to receive the rotational driving force from the spindle; and   an extension portion (i) disposed radially outward of the flange portion and (ii) extending in a second direction, which is opposite to the first direction, from an end on the second direction side of the rotation transmission portion.   
     
     
         7 . The rotary tool according to  claim 6 , wherein:
 the peripheral wall portion further comprises a stopper portion having a stopper surface configured to abut the side surface of the flange portion to restrict rotation of the anti-loosening member when the anti-loosening member rotates in the first direction with respect to the spindle, and   the extension portion extends along the outer edge portion of the base portion from at least a virtual first plane containing the rotation transmission surface to a virtual second plane containing the stopper surface.   
     
     
         8 . The rotary tool according to  claim 6 , further comprising:
 an annular member removably disposed around the spindle between the anti-loosening member and the externally threaded portion,   wherein:   the annular member is configured to engage with the anti-loosening member and rotate integrally with the anti-loosening member,   a recess configured to engage with the annular member is formed in a lower portion of the rotation transmission portion of the base portion, and   the extension portion extends in the second direction beyond an end on the second direction side of the recess.   
     
     
         9 . The rotary tool according to  claim 1 , further comprising:
 an annular elastic body attached to an annular groove formed on an outer peripheral surface of the spindle,   wherein the anti-loosening member is held by the elastic body such that the anti-loosening member is (i) rotatable around the drive axis with respect to the spindle and (ii) movable in the up-down direction with respect to the spindle due to elastic deformation of the elastic body.   
     
     
         10 . The rotary tool according to  claim 1 , wherein an angle between a plane orthogonal to the drive axis and the first inclined surface is greater than a lead angle of a thread of the externally threaded portion. 
     
     
         11 . The rotary tool according to  claim 3 , wherein the peripheral wall portion comprises:
 a rotation transmission portion having a rotation transmission surface configured to receive the rotational driving force from the spindle; and   an extension portion (i) disposed radially outward of the flange portion and (ii) extending in a second direction, which is opposite to the first direction, from an end on the second direction side of the rotation transmission portion.   
     
     
         12 . The rotary tool according to  claim 11 , wherein
 the peripheral wall portion further comprises a stopper portion having a stopper surface configured to abut the side surface of the flange portion to restrict rotation of the anti-loosening member when the anti-loosening member rotates in the first direction with respect to the spindle, and   the extension portion extends along the outer edge portion of the base portion from at least a virtual first plane containing the rotation transmission surface to a virtual second plane containing the stopper surface.   
     
     
         13 . The rotary tool according to  claim 12 , further comprising
 an annular member removably disposed around the spindle between the anti-loosening member and the externally threaded portion,   wherein:   the annular member is configured to engage with the anti-loosening member and rotate integrally with the anti-loosening member,   a recess configured to engage with the annular member is formed in a lower portion of the rotation transmission portion of the base portion, and   the extension portion extends in the second direction beyond an end on the second direction side of the recess.   
     
     
         14 . The rotary tool according to  claim 5 , wherein the peripheral wall portion comprises:
 a rotation transmission portion having a rotation transmission surface configured to receive the rotational driving force from the spindle; and   an extension portion (i) disposed radially outward of the flange portion and (ii) extending in a second direction, which is opposite to the first direction, from an end on the second direction side of the rotation transmission portion.   
     
     
         15 . The rotary tool according to  claim 14 , wherein
 the peripheral wall portion further comprises a stopper portion having a stopper surface configured to abut the side surface of the flange portion to restrict rotation of the anti-loosening member when the anti-loosening member rotates in the first direction with respect to the spindle, and   the extension portion extends along the outer edge portion of the base portion from at least a virtual first plane containing the rotation transmission surface to a virtual second plane containing the stopper surface.   
     
     
         16 . The rotary tool according to  claim 15 , further comprising
 an annular member removably disposed around the spindle between the anti-loosening member and the externally threaded portion,   wherein:   the annular member is configured to engage with the anti-loosening member and rotate integrally with the anti-loosening member,   a recess configured to engage with the annular member is formed in a lower portion of the rotation transmission portion of the base portion, and   the extension portion extends in the second direction beyond an end on the second direction side of the recess.