Worktool

Abstract

A worktool comprises a principal drive shaft with a sun gear attached thereto. At least two planetary gears are distributed about the circumference of the sun gear at substantially equal angular separation. A carriage constrains the planetary gears such that they maintain their angular separation about the axis of the principal drive shaft. Each planetary gear has an eccentric axis in addition to its rotational axis constrained by the carriage, such that each planetary gear can drive, in use, a rotating work-piece engaging surface around the respective eccentric axis. There may be a phase difference of 2π/n radians (n being an integer equal to the number of planetary gears) between any two eccentric axes.

1 . A worktool comprising: 
 a principal drive shaft with a sun gear attached thereto; 
 at least two planetary gears distributed about the circumference of the sun gear at substantially equal angular separation; and  
 a carriage for constraining the planetary gears such that they maintain their angular separation about the axis of the principal drive shaft,  
   wherein: 
 each planetary gear has an eccentric axis in addition to its rotational axis constrained by the carriage, such that each planetary gear can drive, in use, a platen around the respective eccentric axis.  
   
     
     
         2 . The worktool of  claim 1 , wherein the phase difference between any two eccentric axes is to be 2π/n radians, wherein n equals the number of planetary gears and is an integer value greater than 1.  
     
     
         3 . The worktool of  claim 1 , arranged to be a polisher.  
     
     
         4 . The worktool of  claim 1 , arranged to be a sander.  
     
     
         5 . The worktool of  claim 1 , wherein the principal drive shaft is connected to a motor.  
     
     
         6 . The worktool of  claim 1 , wherein the platens can rotate freely.  
     
     
         7 . The worktool of  claim 1 , wherein the platens are partially rotationally constrained.  
     
     
         8 . A worktool comprising: 
 a principal drive shaft with a sun gear attached thereto; 
 at least two planetary gears distributed about the circumference of the sun gear at substantially equal angular separation; and  
 a carriage for constraining the planetary gears such that they maintain their angular separation about the axis of the principal drive shaft,  
   wherein: 
 each planetary gear has an eccentric axis in addition to its rotational axis constrained by the carriage, such that each planetary gear can drive, in use, a platen around the respective eccentric axis, and wherein the phase difference between any two eccentric axes is to be 2π/n radians, wherein n equals the number of planetary gears and is an integer value greater than 1.