Spring-loaded contour following end effectors for lapping/polishing

Abstract

End effectors are provided for performing surface lapping using a robot. The end effectors allow orthogonal surface contact in order to maintain optimum pressure applied by the robot. One or more end effectors include a base, a plate, a lapping pad attached to the plate, and a pivot joint. The pivot joint allows the plate to pivot about two substantially orthogonal axes. The base is attached to an arm of a robot. The end effector includes a component for absorbing applied pressure, such as a spring-loaded shaft or a pneumatic shaft. In an aspect of the invention, the two axes are substantially parallel to the planar surface.

What is claimed is:  
     
         1 . A robotic system for lapping a surface, the robotic system comprising: 
 a robotic arm for applying pressure; and    a end effector unit including: 
 a base attached to the robotic arm;  
 a plate;  
 a lapping pad attached to the plate;  
 a pivot joint for allowing the plate to pivot about two orthogonal axes; and  
 a component for absorbing pressure applied to the end effector unit.  
   
     
     
         2 . The system of  claim 1 , wherein the component includes a spring-loaded shaft.  
     
     
         3 . The system of  claim 1 , wherein the component includes a pneumatic shaft.  
     
     
         4 . The system of  claim 3 , wherein the component further includes a pneumatic sensor for sensing pressure applied to the plate.  
     
     
         5 . The system of  claim 1 , wherein the two axes are substantially parallel to the planar surface.  
     
     
         6 . The system of  claim 5 , wherein the two axes are substantially orthogonal to a direction of the pressure applied to the robot.  
     
     
         7 . The system of  claim 5 , wherein the pivot joint includes a universal joint.  
     
     
         8 . The system of  claim 5 , wherein the pivot joint includes a gimbaled joint.  
     
     
         9 . The system of  claim 5 , wherein the pivot joint includes a needle bearing joint.  
     
     
         10 . The system of  claim 5 , wherein the pivot joint includes a ball and socket joint.  
     
     
         11 . The system of  claim 10 , wherein the ball and socket joint includes a half-ball and socket joint.  
     
     
         12 . The system of  claim 10 , wherein the ball and socket joint includes a crossed-pin ball and socket joint.  
     
     
         13 . A lapping end effector comprising: 
 a base;    a plate having a planar surface;    a lapping pad attachable to the planar surface of the plate; and    a pivot joint for allowing the plate to pivot about two axes, the pivot joint including a pressure absorbing component for absorbing a predetermined amount of pressure applied to the plate.    
     
     
         14 . The system of  claim 13 , wherein the pressure absorbing component includes a spring.  
     
     
         15 . The system of  claim 13 , wherein the two axes are substantially parallel to the planar surface.  
     
     
         16 . The system of  claim 15 , wherein the pivot joint includes a universal joint.  
     
     
         17 . The system of  claim 15 , wherein the pivot joint includes a hexagonal ball joint.  
     
     
         18 . The system of  claim 15 , wherein the pivot joint includes a crossed-pin ball and socket joint.  
     
     
         19 . A robotic system for lapping a surface, the robotic system comprising: 
 a robotic arm;    a support member coupled to the robotic arm; and    a plurality of end effector units including: 
 a base attached to the support member;  
 a plate having a planar surface;  
 a lapping pad attachable to the planar surface of the plate; and  
 a pivot joint for allowing the plate to pivot about two axes; and  
 one or more components for absorbing pressure applied to each end effector unit.  
   
     
     
         20 . The system of  claim 19 , wherein the one or more components include a spring-loaded shaft.  
     
     
         21 . The system of  claim 19 , wherein the one or more components include a pneumatic shaft.  
     
     
         22 . The system of  claim 19 , wherein the one or more components include a spring.  
     
     
         23 . A method for lapping a surface, the method comprising: 
 applying pressure by a robot between a lapping pad attached to a plate having a planar surface and the surface;    pivoting the plate to move about two axes, wherein the two axes are substantially parallel to the planar surface and the applied pressure is substantially orthogonal to the two axes; and    absorbing at least some of the applied pressure.