A prototype machine to cut stone by diamond wire

Diamond wire is widely used for stone cutting; it is typically employed to extract a block in quarry and to square the block in machining company. Therefore, many are the unsolved technological problems yet, such as the high costs of the diamond wire, the frequent break of the diamond wire during cutting and so on. The present work shows an innovative prototype machine to cut by a diamond wire by overcoming those technological limits. The developed machine has a bridge frame among which two pulleys move the diamond wire as regards the stone block according with the feed speed. The diamond wire moves on the two pulleys too by a cutting speed. A tensile force is applied to the wire that twists it during the contact with the stone, instead of keeping it along a straight direction parallel to the foundation of the machine. The twisting of the diamond wire makes the use of the wire itself more productive and safer, since the wear of each single bead during cutting is uniform. Moreover, the resulting specific pressure acts on each bead along the arc of contact with the cut block and increases along the cutting direction from the entrance to the exit of the contact with the stone. The increasing of the specific pressure causes a bending of the diamond wire during the contact with the stone. The developed prototype was provided by a sensory system to measure both the cutting power and the tensile force of the diamond wire during some experimental tests. In this way it was possible to verify the functionality of the prototype plant and, in the same time, to evaluate the productivity of the implemented cutting process.