Patent ID: 7461648

Claim:
An apparatus for cutting a multiplicity of thin wafers from at least two similar blocks, the apparatus comprising a supply reel to supply cutting wire, an upper pair of parallel spaced roller guides having a multiplicity of circumferential grooves on surfaces thereof, a lower pair of parallel spaced roller guides having a multiplicity of circumferential grooves on surfaces thereof that are similar to the multiplicity of circumferential grooves on surfaces of the upper pair of parallel spaced roller guides and spaced apart from the upper pair of roller guides in a plane generally parallel to and spaced apart from a plane defined by the axes of the upper pair of roller guides, a collection reel, means for driving the cutting wire rapidly from the supply reel to the collection reel, wherein the cutting wire from the supply reel is arranged to pass around successive grooves along the roller guides from near the supply reel to near the collection reel to from a four sided continuous web of cutting wire along the length of the roller guides, and means for moving the blocks through the web of cutting wire between the pairs of roller guides in a direction generally perpendicular to the axes of the roller guides, so that the blocks are cut into wafers by the action of the moving cutting wire, wherein part way along the roller guides, the cutting wire is diverted around at least two pulley wheels to remove the cutting wire from the web after it has passed over a roller guide at a predetermined point, and to reintroduce the cutting wire into the web via a subsequent roller guide at a point laterally displaced from the point at which the cutting wire left the web, so that there is a gap in the web of cutting wire which divides the web into two separate sections, and no cutting action can occur in that gap.