Output shaft rotation restriction structure of hand-held machine tool

Abstract

A output shaft rotation restriction structure of a hand-held machine tool having a shell, a drive shaft in the shell, and an output shaft in the shell, perpendicular to the drive shaft, provided with a grinding piece, and in linkage with the drive shaft via a steering gear set; two sides of the hand-held machine tool may be defined according to an extension line of the drive shaft. The output shaft rotation restriction structure includes a mounting hole on the shell, specifically, one of the two sides of the hand-held machine tool, a restriction hole on the output shaft and facing the mounting hole, and a rotation restriction group including a holder in the mounting hole, a restriction plug on the holder, and a spring, the restriction plug being forced into the restriction hole to interfere with the rotation of the output shaft.

What is claimed is: 
     
         1 . An output shaft rotation restriction structure of a hand-held machine tool, the hand-held machine tool comprising a shell, a drive assembly disposed in the shell, a drive shaft disposed in the shell and driven by the drive assembly, and an output shaft disposed in the shell and perpendicular to the drive shaft in an extension direction thereof, wherein the output shaft is provided with a grinding piece, connected to the drive shaft via a steering gear set, and driven by the drive shaft, and wherein two sides of the hand-held machine tool is defined on the basis of an extension line of the drive shaft; the output shaft rotation restriction structure comprising:
 a mounting hole provided on the shell and positioned on one of the two sides of the hand-held machine tool,   a restriction hole provided on the output shaft and facing the mounting hole, and   a rotation restriction group including a holder disposed in the mounting hole, a restriction plug disposed on the holder and exposed outside the shell, and a spring disposed in the holder and provides the restriction plug with a restoring force, wherein the restriction plug is inserted into the restriction hole to restrict rotation of the output shaft when the restriction plug is forced to move towards the output shaft.   
     
     
         2 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 1 , wherein the restriction hole extends through the output shaft. 
     
     
         3 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 1 , wherein the restriction hole is deviated from a center of the output shaft. 
     
     
         4 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 3 , wherein the holder includes a first opening for the restriction plug to insert in and a second opening coaxial with the first opening for the restriction plug to extend out. 
     
     
         5 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 4 , wherein the restriction plug includes an operation part exposed outside the shell, a connection part extending from the operation part and disposed in the holder, and a restriction part extending from the connection part and extending out of the second opening, wherein the connection part includes a convex rib abutting against a periphery of the first opening to prevent the restriction plug falling off from the holder. 
     
     
         6 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 5 , wherein a size of the restriction part is smaller than a size of the connection part. 
     
     
         7 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 6 , wherein the connection part includes a stage difference connection surface adjacent to the restriction part, and a guide inclined surface connecting the stage difference connection surface and extending in an opposite direction from the restriction part. 
     
     
         8 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 7 , wherein one side of the convex rib facing the restriction part is connected to the guide inclined surface without stage difference. 
     
     
         9 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 4 , wherein the holder is a tubular structure. 
     
     
         10 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 9 , wherein the holder includes a first thread provided on an outer surface of the holder, and the mounting hole includes a second thread fitting the first thread. 
     
     
         11 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 10 , wherein the holder includes a first portion inserted into the shell and a second portion exposed outside the shell, and the first thread is disposed on the first portion. 
     
     
         12 . The output shaft rotation restriction structure of the hand-held machine tool according to  claim 11 , wherein a cross-section of the holder at the second portion is polygonal.