Tool for polishing conventional and free-form optical surfaces

Abstract

A tool for polishing optical surfaces including a rigid base having a spherical surface which carries a resilient cushion with a polishing face. The diameter of the rigid base is between 50 and 65 mm, the radius of curvature of the spherical surface is between 54 and 60 mm, the thickness of the resilient cushion is between 13 and 16 mm and the resistance to compression of the resilient cushion is substantially between 0.08 and 0.15 bar at 10% compression and substantially between 0.55 and 0.8 bar at 70% compression. The tool can be used for polishing an optical surface, particularly an ophthalmic lens, and more particularly a free-form lens.

1 - 10 . (canceled) 
     
     
         11 . A tool for polishing optical surfaces comprising: a rigid base which has a spherical surface which carries a resilient cushion which has a polishing face, wherein:
 the diameter of the rigid base is between 50 and 65 mm,   the radius of curvature of the spherical surface is between 54 and 60 mm,   the thickness of the resilient cushion is between 13 and 16 mm, and   the resistance to compression of the resilient cushion ( 12 ) is substantially between 0.08 and 0.15 bar at 10% compression and substantially between 0.55 and 0.8 bar at 70% compression.   
     
     
         12 . The tool according to  claim 11 , wherein the resistance to compression of the resilient cushion is substantially between 0.10 and 0.16 bar at 15% compression and between 0.20 and 0.30 bar at 50% compression. 
     
     
         13 . The tool according to  claim 11 , wherein the thickness of the resilient cushion is between 14 and 15 mm. 
     
     
         14 . The tool according to  claim 11 , wherein the radius of curvature of the spherical surface of the rigid base is between 54 and 56 mm. 
     
     
         15 . The tool according to  claim 11 , wherein the diameter of the rigid base is between 55 and 65 mm. 
     
     
         16 . The tool according to  claim 11 , wherein the resilient cushion is Eurocell 130™. 
     
     
         17 . The tool according to  claim 11 , wherein the polishing face of the resilient cushion is a separate polishing pad attached to said resilient cushion. 
     
     
         18 . The tool according to  claim 17 , wherein the polishing pad includes a top layer and a bottom layer, the top layer being a nap layer adapted to carry an abrasive slurry. 
     
     
         19 . The tool according to  claim 18 , wherein the bottom layer of the polishing pad is a polyurethane impregnated non-woven fabric. 
     
     
         20 . The use of the tool according to  claim 11  for polishing an optical surface. 
     
     
         21 . The use of the tool according to  claim 11  for polishing an ophthalmic lens. 
     
     
         22 . The use of the tool according to  claim 11  for polishing a free-form lens.