Device for polishing an optical surface of optical lenses, polishing machine and method for polishing

Abstract

A device for polishing an optical surface of lenses, a connecting element for being fitted on a polishing machine on one end of the device, and a polishing wheel on another end, the polishing wheel having an axially disposed drive shaft running radially to a longitudinal center axis of a spindle, the device having a crown or bevel gear by which the polishing wheel is drivable via the drive shaft by a rotary spindle part, the crown or bevel gear formed by a cogwheel disposed on one end of the drive shaft and by a crown or bevel wheel rotatably mounted on a fixed bearing sleeve running coaxially to the spindle of the polishing machine, an additional toothing on an outer circumference of the crown or bevel wheel for driving the polishing wheel via the drive shaft via a toothed wheel driven by a separate drive motor.

1 . A device ( 1 ) for polishing an optical surface ( 2 ) of optical lenses ( 3 ), comprising a connecting element ( 5 ) for being fitted on a polishing machine ( 4 ) being provided on one end of the device ( 1 ), and a polishing wheel ( 11 ) being disposed on another end of the device ( 1 ), said polishing wheel ( 11 ) having an axially disposed drive shaft ( 15 ) running radially to a longitudinal center axis ( 14 ) of a spindle ( 9 ) of the polishing machine ( 4 ), and the device ( 1 ) having a crown gear or a bevel gear ( 18 ) by which the polishing wheel ( 11 ) is drivable via the drive shaft ( 15 ) by a rotary part ( 8 ) of the spindle ( 9 ) of the polishing machine ( 4 ), wherein the crown or bevel gear ( 18 ) is formed by a cogwheel ( 19 ) disposed on one end of the drive shaft ( 15 ) and by a crown or bevel wheel ( 23 ) rotatably mounted on a fixed bearing sleeve ( 21 ) of the device ( 1 ), said bearing sleeve ( 21 ) running coaxially to the spindle ( 9 ) of the polishing machine ( 4 ), an additional toothing ( 25 ) being provided on an outer circumference ( 24 ) of the crown or bevel wheel ( 23 ), the polishing wheel ( 11 ) being drivable via the drive shaft ( 15 ) by means of said toothing ( 25 ) via a toothed wheel ( 28 ) driven by a separate drive motor ( 26 ). 
     
     
         2 . The device according to  claim 1 , wherein, on an end of the connecting element ( 5 ) directed at the polishing machine ( 4 ), the connecting element ( 5 ) has a bearing pin ( 6 ) which is receivable and mounted by a clamping system ( 7 ) of the rotary part ( 8 ) of the spindle ( 9 ) of the polishing machine ( 4 ), and that a mounting frame ( 13 ) for receiving and supporting the polishing wheel ( 11 ) is provided on an end of the connecting element ( 5 ) facing away from the polishing machine ( 4 ). 
     
     
         3 . The device according to  claim 2 , wherein the clamping system ( 7 ) is a hydraulic expansion chuck. 
     
     
         4 . The device according to  claim 2 , wherein the drive shaft ( 15 ) of the polishing wheel ( 11 ) is mounted on lateral legs ( 16 ) of the U-shaped mounting frame ( 13 ). 
     
     
         5 . The device according to  claim 2 , wherein the drive shaft ( 15 ) protrudes over one side of the mounting frame ( 13 ), the cogwheel ( 19 ) being mounted on the protruding part ( 20 ) of the drive shaft ( 15 ). 
     
     
         6 . The device according to  claim 2 , wherein the polishing wheel ( 11 ) is mounted between the two lateral legs ( 16 ) of the mounting frame ( 13 ) so as to have low backlash. 
     
     
         7 . The device according to  claim 1 , wherein the outer circumference of the polishing wheel ( 11 ) has an elastic rubber coating ( 10 ). 
     
     
         8 . The device according to  claim 7 , wherein the outer circumference of the elastic rubber coating ( 10 ) has a convex surface. 
     
     
         9 . The device according to  claim 1 , wherein the bearing sleeve ( 21 ) has a retaining element ( 29 ) for the drive motor ( 26 ), in or on which the drive motor ( 26 ) with its longitudinal center axis ( 27 ) is disposed parallel to the longitudinal center axis ( 14 ) of the spindle ( 9 ) of the polishing machine ( 4 ). 
     
     
         10 . A polishing machine ( 4 ) for polishing an optical surface ( 2 ) of optical lenses ( 3 ) using a device ( 1 ) according to  claim 1 . 
     
     
         11 . A method for polishing an optical surface ( 2 ) of optical lenses ( 3 ) using a device ( 1 ) according to the  claim 1  or a polishing machine ( 4 ), comprising the following steps:
 a. Positioning the polishing wheel ( 11 ) with its elastic rubber coating ( 10 ) on the surface ( 2 ) of the lens ( 3 ); 
 b. Rotating the spindle ( 9 ) of the polishing machine ( 4 ) around its longitudinal center axis ( 14 ) while the crown or bevel wheel ( 23 ) is blocked while simultaneously rotating the polishing wheel ( 11 ) around the longitudinal center axis ( 14 ) of the spindle ( 9 ) of the polishing machine ( 4 ) and the longitudinal center axis ( 31 ) of the drive shaft ( 15 ), the cogwheel ( 19 ) rolling on the blocked crown or bevel wheel ( 23 ) at a constant transmission ratio; 
 c. Changing the transmission ratio between the crown or bevel wheel ( 23 ) and the cogwheel ( 19 ) while simultaneously changing the speed or changing the rotating direction of the polishing wheel ( 11 ) by operating the drive motor ( 26 ). 
 
     
     
         12 . The method according to  claim 11 , wherein the rotating direction of the drive motor ( 26 ) is switched, the speed of the polishing wheel ( 11 ) being changed. 
     
     
         13 . The method according to  claim 11 , wherein the speed of the drive motor ( 26 ) is changed.