Method, apparatus, and tools for precision polishing of lenses and lens molds

Abstract

A tool, apparatus, and method for polishing objects having a wide variety of materials and shapes including precision optical surfaces, injection mold inserts, and thin film coating dies. The tool has an inflatable bladder contained within an abrasive surface. The bladder may be inflated using a variety of fluids having a range of physical properties. The apparatus comprises a multi-axis computer controlled machine to which the tool is attached.

1 . A polishing tool comprising 
 a) a mandrel having a shank at a proximal end thereof, and at a flange at a distal end thereof;    b) a bladder sealably engaged with said flange of said mandrel, defining a cavity contained between said flange and an inner surface of said bladder; and    c) a passageway disposed within said mandrel between said cavity and the exterior of said mandrel.    
   
   
       2 . The polishing tool as recited in  claim 1 , wherein said bladder comprises a first lip, said flange of said mandrel comprises a first groove, and said first lip is disposed and held within said first groove.  
   
   
       3 . The polishing tool as recited in  claim 2 , further comprising a washer engaged with said bladder, and a nut in contact with said washer and threadedly engaged with said mandrel.  
   
   
       4 . The polishing tool as recited in  claim 2 , wherein said passageway further comprises an axial bore having a first end in communication with the exterior of said mandrel.  
   
   
       5 . The polishing tool as recited in  claim 4 , wherein said cavity contains a liquid.  
   
   
       6 . The polishing tool as recited in  claim 5 , wherein said liquid is a viscous liquid.  
   
   
       7 . The polishing tool as recited in  claim 4 , wherein said passageway further comprises a radial bore in communication with said cavity and with said axial bore.  
   
   
       8 . The polishing tool as recited in  claim 7 , wherein said bladder comprises a second lip, said flange of said mandrel comprises a second groove, and said second lip is disposed and held within said second groove.  
   
   
       9 . The polishing tool as recited in  claim 8 , further comprising an inflation device disposed within said axial bore.  
   
   
       10 . The polishing tool as recited in  claim 4  wherein said bladder is dome shaped.  
   
   
       11 . The polishing tool as recited in  claim 4  wherein said bladder is cone shaped.  
   
   
       12 . The polishing tool as recited in  claim 2 , further comprising a polishing foil disposed on at least a portion of the exterior surface of said bladder.  
   
   
       13 . The polishing tool as recited in  claim 12 , wherein said polishing foil further comprises a first abrasive ring.  
   
   
       14 . The polishing tool as recited in  claim 12 , wherein said polishing foil further comprises a polishing ring assembly comprising a backer ring disposed on said portion of said exterior surface of said bladder, and an abrasive ring disposed on the exterior surface of said backer ring.  
   
   
       15 . The polishing tool as recited in  claim 14 , wherein said backer ring consists essentially of poly(ethylene terephthalate).  
   
   
       16 . The polishing tool as recited in  claim 14 , wherein said abrasive ring is impregnated with abrasive particles selected from the group consisting of ceria, alumina, silica, diamond, and mixtures thereof.  
   
   
       17 . An apparatus for polishing objects comprising: 
 a) a first linear slide movable along a first axis, disposed upon a base;    b) a first rotatable spindle engaged with said first linear slide, said first rotatable spindle further comprising a first chuck, and said first rotatable spindle aligned with said first axis;    c) a second linear slide movable along a second axis, engaged with said first linear slide, with said second axis disposed orthogonally to said first axis;    d) a second rotatable spindle engaged with said second linear slide, said second rotatable spindle further comprising a second chuck; and    e) a polishing tool engaged with said second chuck of said second rotatable spindle, said polishing tool comprising a mandrel having a shank at a proximal end thereof, and at a flange at a distal end thereof; a bladder sealably engaged with said flange of said mandrel, defining a cavity contained between said flange and an inner surface of said bladder, and a passageway disposed within said mandrel between said cavity and the exterior of said mandrel.    
   
   
       18 . The apparatus as recited in  claim 17 , further comprising a third linear slide movable along a third axis, engaged with said first linear slide, and engaged with said second linear slide, with said third axis disposed orthogonally to said first axis and said second axis.  
   
   
       19 . The apparatus as recited in  claim 18 , wherein said second rotatable spindle is rotatable about an axis parallel to said third axis.  
   
   
       20 . The apparatus as recited in  claim 17 , further comprising a computer in control of said first linear slide, said second linear slide, said first rotatable spindle, and said second rotatable spindle.  
   
   
       21 . The apparatus as recited in  claim 17  further comprising a fluid delivery system comprised of a reservoir, a pump, and a fluid conduit directed at said bladder of said polishing tool.  
   
   
       22 . The apparatus as recited in  claim 17  further comprising a toolchanger.  
   
   
       23 . The apparatus as recited in  claim 17 , further comprising means to deliver a pressurized fluid to said passageway of said polishing tool.  
   
   
       24 . A method of polishing a surface of an object using a machine tool apparatus comprising a polishing tool comprised of a mandrel having a shank at a proximal end thereof, and at a flange at a distal end thereof; a bladder sealably engaged with said flange of said mandrel, defining a cavity contained between said flange and an inner surface of said bladder; and a passageway disposed within said mandrel between said cavity and the exterior of said mandrel, comprising the steps of: 
 a) preparing said polishing tool for said polishing of objects;    b) preparing and programming said machine tool for said polishing of objects;    c) executing a first polishing cycle with said machine tool apparatus, wherein said polishing tool is in contact with said surface of said object; and    d) measuring said surface of said object.    
   
   
       25 . The method as recited in  claim 24 , after said measuring of said surface of said object, further comprising the steps of reprogramming said machine tool, and executing a second polishing cycle with said machine tool apparatus.  
   
   
       26 . The method as recited in  claim 24 , wherein said step of preparing and programming said machine tool for said polishing of objects comprises the steps of: 
 a) installing said polishing tool in said machine tool;    b) entering polishing tool data into a controller of said machine tool;    c) engaging said object having a surface to be polished with said machine tool;    d) entering data on said object into said controller of said machine tool;    e) analyzing a spot size function of said polishing tool on said object;    f) programming said controller of said machine tool; and    g) calculating the deterministic path of said polishing tool on said surface of said object.    
   
   
       27 . The method as recited in  claim 26 , wherein said deterministic path comprises a zigzag motion.  
   
   
       28 . The method as recited in  claim 26 , wherein said deterministic path comprises an orbital motion.  
   
   
       29 . The method as recited in  claim 26 , wherein said deterministic path comprises an elliptical motion.