# US 5,195,410 A · Cutting brittle materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,195,410 A - Document ID: US5195410A - Status: Granted - Kind: A - Application number: 07/349,455 - Filed: 1989-05-08 - Granted: 1993-03-23 - Earliest claimed: 1988-05-10 - Assignees: Sra Developments Limited - Inventors: Michael J. R. Young - Web page: https://patentgrep.com/patent/US5195410A ## CPC - B26D 7/086: {by vibrating, e.g. ultrasonically} - B06B 3/00: Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency - B28D 1/26: by impact tools, e.g. by chisels or other tools having a cutting edge (portable percussive tools B25D) - B28D 5/047: {by ultrasonic cutting (using abrading substances or abrading tools subjected to a bouncing action by ultrasonic energy B24B1/04)} - Y10S 83/956: Ultrasonic - Y10T 83/04: Processes - Y10T 83/97: Miscellaneous - Y10T 225/10: Methods - B26D: CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING (for growing crops or plants A01D, A01G; for fodder or straw A01F; for bulk butter A01J; for dough A21C; slaughtering A22B; for tobacco, cigars or cigarettes A24; marking-out, perforating or making buttonholes A41H25/00; manufacturing footwear A43D; brushmaking A46D; surgery A61B; disintegrating, mincing or shredding in general B02C; cutting wire, making pins or nails B21F, B21G; of the kind used formetal B23; cutting by abrasive fluid jets B24C5/02; hand-held cutting tools B26B; perforating, cutting-out, stamping-out or punching, or severing by means other than cutting B26F; for wood B27; for stone B28D; working of plastics or substances in a plastic state B29; making boxes, cartons, envelopes or bags, of paper or similarly worked materials, e.g. metal foil, B31B; article or web delivery apparatus incorporating cutting or line-perforating devices B65H35/00; for leather or upholstery B68, C14B; for glass C03B; making matches C06F; for peat C10F; for sugar C13B45/00; for textile materials D06H; civil engineering, building, mining, see Section E; for light guides G02B6/25; cutting processed photographic material G03D15/04) - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) - B28D: WORKING STONE OR STONE-LIKE MATERIALS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A method of cutting a brittle workpiece comprises applying to the surface of the workpiece a pointed tool, applying high frequency vibrations in a longitudinal direction to the tool, and moving the tool along a line to be cut of the workpiece while applying substantially steady longitudinally directed pressure to the tool. Stress is thereby applied to the workpiece as a combination of short impulses and steady direct stress and the breaking stress of the material would be attained coincident with the peak oscillatory stress. Crack propagation would therefore proceed by a series of stepwise fractures induced by successive cyclic stress peaks, resulting ultimately in the separation of the workpiece into two pieces. An apparatus for carrying out the method comprises a piezoelectric ceramic transducer to generate ultrasonic vibrations, a tip to be applied to the workpiece and having a hardness greater than that of the workpiece, with a tuned horn or the like being utilized to convey the ultrasonic vibrational energy to the tip. ## Claims ### Claim 1 The method of cutting a workpiece of brittle material into two pieces along a predetermined line comprising producing a micro crack in said material by applying directly and alone to the surface of the workpiece at a point on said line the pointed end of a tool, applying high frequency vibrations in a longitudinal direction to the tool while applying substantially steady longitudinal directed pressure from the tool to the workpiece until said micro crack occurs, moving said tool along said line to propagate micro cracks in said workpiece along the length of the line, and then breaking said workpiece along said line into two pieces. ### Claim 2 (depends on 1) A method as claimed in claim 1, wherein the vibrations applied to the tool are of a frequency in the region of 8 to 35 kHz. ### Claim 3 (depends on 2) A method as claimed in claim 2, wherein the brittle workpiece is a ceramic tile and the frequency is in the region of 30 kHz. ### Claim 4 (depends on 2) A method as claimed in claim 2, wherein the brittle workpiece is a concrete product and the frequency is in the region of 10 kHz. ### Claim 5 (depends on 1) A method as claimed in claim 1, wherein the high frequency vibrations applied to the tool are derived from ultrasonic vibrations of a piezoceramic transducer.