Precision abrasive finishing apparatus

Abstract

A precision abrasive finishing apparatus comprising a base, preferably of granite and being ground to true flat; an abrasive lap capable of being vacuum-clamped against said base and having an abrasive material disposed on it upper, lapping surface; and vacuum clamping means. The abrasive material may be any conventional abrasive grit, such as aluminum oxide, silicon carbide, cubic boron nitride, or other material of suitable hardness, sharpness, friability, durability, inertness, and cost, but preferably is diamond.

1 . A precision abrasive lap for use with a conventional lapping table base having an upper and a lower surface, the invention comprising a precision shim having a perimeter, an upper surface to which an abrasive material is bonded, and a lower surface that enables said shim to be securely held against said upper base surface using vacuum clamping technology.  
     
     
         2 . The precision abrasive lap, as claimed in  claim 1 , wherein said lower shim surface is provided with air evaluation means within and near the perimeter of the shim  
     
     
         3 . The precision abrasive lap, as claimed in  claim 2 , wherein said air evacuation means is a channel that is milled into said lower shim surface.  
     
     
         4 . The precision abrasive lap, as claimed in  claim 1 , wherein said upper base surface is provided with air evaluation means such that said shim may be securely clamped to said upper base surface by means of vacuum clamping.  
     
     
         5 . The precision abrasive lap, as claimed in  claim 1 , further comprising a spacer having an upper surface and a lower surface disposed between said shim and said upper base surface and capable of securely holding said shim against said upper base surface by means of vacuum clamping.  
     
     
         6 . The precision abrasive lap, as claimed in  claim 5 , wherein air evaluation means are disposed within each of said upper and lower surfaces of said spacer.  
     
     
         7 . The precision abrasive lap, as claimed in  claim 5 , wherein said spacer is composed of materials capable of forming a vacuum seal selected from the group consisting of, elastomeric, rubber, polymeric, gel, metal, and ceramic.  
     
     
         8 . The precision abrasive lap, as claimed in  claim 1 , wherein said lower shim surface is provided with a plurality of protrusions that bias said lower shim surface away from said base surface such that air evacuation means are defined therebetween.  
     
     
         9 . The precision abrasive lap, as claimed in  claim 1 , wherein said abrasive material is diamond.  
     
     
         10 . A precision abrasive lap for use with conventional lapping table bases having a lapping surface, the invention comprising a plurality of precision shims, each having a perimeter, an upper surface to which an abrasive material is bonded and a lower surface that is capable of being securely held against the upper base surface using vacuum clamping technology.  
     
     
         11 . The precision abrasive lap, as claimed in  claim 8 , wherein said plurality of precision shims have a geometry that is conducive to coplanar arrangement.  
     
     
         12 . The precision abrasive lap, as claimed in  claim 9 , wherein said geometry is circular.  
     
     
         13 . The precision abrasive lap, as claimed in  claim 9 , wherein said geometry is polygonal.