Random orbital sanding tool

Abstract

A random orbital sanding tool includes a power motor, a driving spindle connected to the power motor, an eccentric block connected to the driving spindle, a tool holder disposed on the eccentric block, and a sanding pad connected to the tool holder and indirectly driven by the power motor. The random orbital sanding tool includes a friction ring disposed on the tool holder, the friction ring contacts a surface of the eccentric block facing the sanding pad, the friction ring stops rotation of the tool holder and the sanding pad by a friction force exerting on the surface of the eccentric block when the power motor stops operation, the friction ring includes a base part protruding into a gap between the tool holder and the eccentric block, a sleeve part diverged and extended from the base part.

What is claimed is: 
     
         1 . A random orbital sanding tool, comprising a power motor, a driving spindle connected to the power motor, an eccentric block connected to the driving spindle, a tool holder disposed on the eccentric block, and a sanding pad connected to the tool holder and indirectly driven by the power motor, wherein the random orbital sanding tool comprises a friction ring disposed on the tool holder, the friction ring contacts a surface of the eccentric block facing the sanding pad, the friction ring stops rotation of the tool holder and the sanding pad by a friction force exerting on the surface of the eccentric block when the power motor stops operation; the friction ring comprises a base part protruding into a gap between the tool holder and the eccentric block, a sleeve part diverged and extended from the base part, and a friction part connected to the base part and constantly in contact with the surface of the eccentric block. 
     
     
         2 . The random orbital sanding tool as claimed in  claim 1 , wherein the eccentric block comprises an accommodating slot provided for disposal of the tool holder therein, and the friction part is in constant contact with an edge of a slot opening of the accommodating slot. 
     
     
         3 . The random orbital sanding tool as claimed in  claim 2 , wherein a level height of the friction part in a free state is higher than that of the base part. 
     
     
         4 . The random orbital sanding tool as claimed in  claim 3 , wherein the friction part extends obliquely toward the eccentric block. 
     
     
         5 . The random orbital sanding tool as claimed in  claim 4 , wherein a level height of a bottom edge of the friction ring is higher than that of the tool holder. 
     
     
         6 . The random orbital sanding tool as claimed in  claim 4 , wherein the friction ring is made of rubber. 
     
     
         7 . The random orbital sanding tool as claimed in  claim 3 , wherein the friction part is disc-shaped. 
     
     
         8 . The random orbital sanding tool as claimed in  claim 1 , wherein the friction ring is recessed at a junction between the base part and the friction part. 
     
     
         9 . The random orbital sanding tool as claimed in  claim 1 , wherein the friction ring comprises a ring inner space, and a shape of the ring inner space in the base part is different from that in the sleeve part. 
     
     
         10 . The random orbital sanding tool as claimed in  claim 1 , wherein a level height of a bottom edge of the friction ring is higher than that of the tool holder. 
     
     
         11 . The random orbital sanding tool as claimed in  claim 1 , wherein the friction part is formed by a plurality of columns connected to the base part and disposed at intervals, respectively. 
     
     
         12 . The random orbital sanding tool as claimed in  claim 11 , wherein bottom edges of the plurality of columns are connected to the sleeve part. 
     
     
         13 . The random orbital sanding tool as claimed in  claim 11 , wherein each of the plurality of columns is one of the following: cylinder and polygonal column. 
     
     
         14 . The random orbital sanding tool as claimed in  claim 11 , wherein a level height of a bottom edge of the friction ring is higher than that of the tool holder. 
     
     
         15 . The random orbital sanding tool as claimed in  claim 11 , wherein the friction ring is made of rubber.