# US 5,349,265 A · Synthetic diamond coated electrodes and filaments > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,265 A - Document ID: US5349265A - Status: Granted - Kind: A - Application number: 07/852,308 - Filed: 1992-03-16 - Granted: 1994-09-20 - Earliest claimed: 1990-03-16 - Inventors: Jerome H. Lemelson - Web page: https://patentgrep.com/patent/US5349265A ## CPC - B24D 18/00: Manufacture of grinding tools {or other grinding devices}, e.g. wheels, not otherwise provided for - B23D 61/185: {Saw wires; Saw cables; Twisted saw strips} - B28D 1/12: Saw-blades {or saw-discs} specially adapted for working stone {(B28D1/041 takes precedence)} - C04B 35/80: Fibres, filaments, whiskers, platelets, or the like - C23C 28/32: {including at least one pure metallic layer} - C23C 28/34: {including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates} - E21B 10/46: characterised by wear resisting parts, e.g. diamond inserts - B24D: TOOLS FOR GRINDING, BUFFING OR SHARPENING (abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls B24B31/14; honing tools B24B33/08; lapping tools B24B37/11) - B23D: PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR (making toothed gears or the like B23F; cutting metal by applying heat locally B23K; arrangements for copying or controlling B23Q) - B28D: WORKING STONE OR STONE-LIKE MATERIALS - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract Structures in electrodes such as filaments for electric lamps and the like are subject to heat corrosion and/or erosion or evaporation during use. The electrodes are coated with synthetic diamond which serves to protect the operating or exposed portion or portions of the electrodes from corrosion and/or erosion. Where the electrode is a filament employed to generate and emit radiation including light energy for illumination, the coating is thin enough to be transmissive of the light energy generated when the electrode is electrically energized. Similarly if the electrode is used in the generation of an arc or electron beam, the synthetic diamond coating serves to protect the core material of the electrode from erosion and/or corrosion while permitting the radiant energy to be transmitted therethrough. If the electrode is a filament in a light bulb, the side wall and end wall thereof heated to incandescense are coated with such protective light transmitting material. In a modified form, the entire electrode is made of carbon. ## Claims ### Claim 1 An electrical device comprising: a) a support, b) a filament having a metal core portion, c) a light transmitting envelope secured to said support and forming a closure therewith, d) input means for electrical energy secured to said support and connected to said filament, e) said metal core portion of said filament being coated with a synthetic diamond material which is operable to protect the metal of said filament from heat corrosion during the resistance heating of said filament when electrical energy is conducted to said input means and to said metal of said filament. ### Claim 2 (depends on 1) A device in accordance with claim 1 wherein said synthetic diamond material is coated on the entire surface of said metal core portion of said filament which is exposed to the enclosed volume defined by said assembled envelope and said support. ### Claim 3 (depends on 2) A device in accordance with claim 2 wherein said filament is made of tungsten and said synthetic diamond material is operable to prevent the tungsten of said filament from evaporating and failing due to the loss of atoms of tungsten when resistively heated by electrical energy passed therethrough. ### Claim 4 (depends on 1) A device in accordance with claim 1 wherein said filament is made of copper. ### Claim 5 (depends on 1) A device in accordance with claim 1 in the form of an incandescent lamp wherein said filament is operable to glow and discharge light energy when electrically energized with electrical energy passed therethrough from said input means, said coating of synthetic diamond material serving to protect the metal of said filament from heat corrosion destruction when it is resistively heated as a result of electrical energy passing therethrough during the electrical energizing of said device, said coating of synthetic diamond being transmissive of light energy generated during the glow discharge of the metal of said filament. ### Claim 6 (depends on 1) A device in accordance with claim 1 wherein the metal of said filament is operable when electrical energy is passed therethrough from said input means to generate radiant energy, said coating of synthetic diamond material operable to receive and transmit therethrough to the volume defined by said envelope at least part of the radiant energy generated when electrical energy is passed through said filament. ### Claim 7 (depends on 1) A device in accordance with claim 1 wherein said synthetic diamond material is formed in situ on the entire outer surface of said filament exposed volume defined by said envelope and said support as a coating having a thickness in the range of 0.00001" to 0.001". ### Claim 8 An electrical device comprising: a) a housing defined by a support and a light transmitting wall portion defining an enclosure with said support, b) an electrode secured to said support and having a core made of electrically conducting material, said electrode core being operable to be resistively heated and generate radiant energy when electrical energy is passed therethrough, c) a synthetic diamond material coating said core of said electrode, d) input means for electrical energy secured to said support and connected to said core to permit electrical energy received thereby to be passed to said core, e) said synthetic diamond material being operable to receive and transmit said radiant energy from said core to the volume defined by said enclosure and through said light transmitting wall portion of said housing, f) said coating of said synthetic diamond material also serving to protect said core from corrosion and evaporation of the material thereof during the electrical energization of said electrical device. ### Claim 9 (depends on 8) An electrical device in accordance with claim 8 wherein said synthetic diamond material coating said core has a uniform thickness about said core in the range of 0.00001" to 0.005". ### Claim 10 (depends on 8) A device in accordance with claim 8 wherein said synthetic diamond material coating said core has a thickness less than 0.001". ### Claim 11 (depends on 8) An electrical device in accordance with claim 8 wherein said electrode is in the shape of a single filament and is formed of metal selected from the group of metals including tungsten, copper, aluminum, titanium and alloys thereof. ### Claim 12 (depends on 8) An electrical device in accordance with claim 8 having at least part of one of said input means secured to said support exposed to the atmosphere, said exposed portion of said input means being coated with synthetic diamond material to protect said input means against atmospheric corrosion and arcing erosion. ### Claim 13 An electrode for use in an electrical device comprises a core made of electrically conducting material and a coating of synthetic diamond material surrounding a select portion of said core leaving the remainder of said core void of synthetic diamond coating material in order to facilitate the discharge of an electrical arc therefrom, a support, and an electrically conducting input means supported by said support and connected to said core for conducting electrical energy to said core, at least part of said input means being coated with synthetic diamond material. ### Claim 14 An electrical device comprising in combination: a) a support, b) a plurality of electrical terminal means supported by said support, c) a thin sheet-like envelope secured to said support and defining an enclosed volume void of air, d) electrical insulating material secured to said support e) a plurality of metal filament supports secured to said support and said insulating material which insulates the filament supports from each other, said electrical terminal means being respectively electrically connected to respective said filament supports, f) said electrical terminal means extending into the air evacuated volume defined by the assembly of said envelope and said support, g) a length of resistence filament material supported by said metal filament supports, h) a layer of synthetic diamond material secured to and defining a protective coating on said length of resistance filament material, i) said synthetic diamond material being transparent to radiant energy generated when said length of resistence filament material is electrically energized and being operable to protect said length of resistance filament material from erosion and heat corrosion. ### Claim 15 (depends on 14) An electrical device in accordance with claim 14 wherein select portions of said metal filament supports are coated with synthetic diamond material. ### Claim 16 (depends on 14) An electrical device in accordance with claim 14 wherein said envelope is a thin walled glass bulb, the entire portions of said metal filament supports and the length of resistance filament material supported thereby which are exposed to radiation generated when said filament is electrically energized being coated with said synthetic diamond material. ### Claim 17 (depends on 14) An electrical device in accordance with claim 14 wherein said metal filament supports are made of short lengths of metal wire. ### Claim 18 (depends on 14) An electrical device in accordance with claim 14 wherein said length of resistance filament material has a conducting core selected from the group of materials including tungsten, titatnium, copper, nickle, chromium, vanadium, aluminum and alloys thereof as well as high strength carbon having a diameter less than 0.08" and wherein said layer of synthetic diamond material serves to strength said length of resistance filament material and prevent its failure due to shocks and flexure of said length of resistance filament material during handling and use of said device.