US3325281A - Method of producing sintered electrodes - Google Patents

Method of producing sintered electrodes Download PDF

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Publication number
US3325281A
US3325281A US469165A US46916565A US3325281A US 3325281 A US3325281 A US 3325281A US 469165 A US469165 A US 469165A US 46916565 A US46916565 A US 46916565A US 3325281 A US3325281 A US 3325281A
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United States
Prior art keywords
mass
electrodes
electrode
activation
mixture
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Expired - Lifetime
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US469165A
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English (en)
Inventor
Ebhardt Horst
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Andritz Hydro GmbH Austria
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Andritz Hydro GmbH Austria
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/067—Main electrodes for low-pressure discharge lamps
    • H01J61/0675—Main electrodes for low-pressure discharge lamps characterised by the material of the electrode
    • H01J61/0677—Main electrodes for low-pressure discharge lamps characterised by the material of the electrode characterised by the electron emissive material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/04—Electrodes; Screens
    • H01J17/06—Cathodes
    • H01J17/066—Cold cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/067—Main electrodes for low-pressure discharge lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
    • H01J9/042—Manufacture, activation of the emissive part
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0064—Tubes with cold main electrodes (including cold cathodes)
    • H01J2893/0065—Electrode systems
    • H01J2893/0066—Construction, material, support, protection and temperature regulation of electrodes; Electrode cups

Definitions

  • the invention relates to a method of producing sintered electrodes, particularly for low pressure vapor discharge tubes which are activated with peroxide sand/or oxides of the alkaline-earth metals, if desired with iron, tantalum, tungsten, zirconium, molybdenum, or the like, by applying the mixture under a pressure ranging from 1000 to 2000 kg./cm. into the body of said electrode and heating the activated mass until a splattering of an insubstantial portion of the activation mass occurs.
  • the invention relates to sintered electrodes for electrical glow discharge lamps in which a metal powder is intimately mixed with an activating substance consisting of a peroxide or oxide of an alkaline earth metal and subsequently heated.
  • Prior known low pressure vapor discharge tubes as a rule have electrodes which possess an incandescent coil but although these occupy but little space they are subject, among other numerous disadvantages, to heavy wear.
  • the useful life of these known low pressure vapor discharge tubes is relatively short, being in the neighborhood of at the utmost about 5,000 burning hours.
  • Vapor discharge tubes are also known in which the electrodes are provided in the shape of cup electrodes which have an activation layer whose emitting substances contain oxides of the metals calcium, strontium or barrum.
  • the prior known electrodes of the type described above were made by the method in which the activation composition, as the part emitting electrons, was pressed in the form of a compact body, somewhat in the form of a pill, under high pressure into or on to a more or less cylindrical, annular or hemispherical elec trode body.
  • a powder of iron, tantalum, tungsten, zirconium, molybdenum, or the like is intimately mixed by mechanical means with peroxides and/ or oxides of the alkaline-earth metals and the mixture inserted into an electrode body, specifically a metal cup, in such a manner that the activation mass is in conductive connection with the electrode wire, whereupon the activation mass is forced under pressure into the electrode body and is thereafter heated, for example with the aid of a high frequency generator, until a Slight explosion occurs; the explosive pressure is so guided in one direction that only an inconsiderable part of the activation mass spurts out of the electrode body and the visible part of the activation mass exhibits after the sintering, a porous and rough surface.
  • the activation mass shows at the moment of explosion a tendency to escape in the direction of least resistance. Owing to the fact that the activation mass spreads out in this direction, the visible part of said mass exhibits a rough and porous surface, which in consequence of its consistency and character substantially facilitates the formation of a discharge glow point, whereby the cathode drop is notably reduced.
  • the original mixture advantageously consists, in a manner known per se, either of iron, tungsten, zirconium, molybdenum or the like in powder form, which is simply but very thoroughly mixed with barium oxide, or else the mixture is made up of zirconium, tantalum or tungsten and peroxide or of barium oxide and of carbonyl iron and tantalum powder.
  • the mixture advantageously consists of two parts of oxides or peroxides of alkaline-earth metals, particularly barium peroxide or oxide, and one part of metal powder, particularly iron powder, with an allowance of Especially good results have been found when the pulverulent activation mass is pressed into the electrode body under a pressure of about 1,000 to 2,000 kg./cm. and the pressed-in mass is heated to produce the explosion.
  • a further advantageous development of the invention consists in that the electrodes are fused into a glass body, particularly a glass cylinder, and subsequently tempered at a maximum temperature of 450 C.
  • the electrodes produced by the method of the invention exhibit an extremely high endurance and can be loaded with current intensities of to 180 milliamperes.
  • the endurance is moreover unaffected by switching frequency.
  • FIGURE 1 shows schematically a low pressure vapor discharge tube with cup electrodes made in accordance with the invention, with part of the tube broken away,
  • FIGURE 2 shows in a similar manner a low pressure vapor discharge tube with attachments for receiving the electrodes
  • FIGURES 3 to 6 show different cup-shaped forms of electrodes
  • FIGURE 7 shows an especially advantageous annular form of electrode in section along the line VIIVII in FIGURE 8, and
  • FIGURE 8 shows the same form of electrode in plan view, while FIGURES 9 to 13 show further forms of electrodes.
  • the electrodes 2 are arranged in the tube 1 coaxially therewith.
  • the electrodes 2 are in this case cup electrodes constructed in the form of cylindrical pots provided with bottoms in which the activation layer as the part emitting electrons is arranged in the form of a compact body 3'.
  • the electrodes 2 are provided with connection pins or wires 4 leading from the inside of the tube to the outside.
  • the layer of luminous substance can, in this case extend practically from one end of the tube 1 to the other, so that a tube of this kind, in which the electrodes 2 are arranged at a short distance from its ends is luminous throughout its whole length during operation.
  • FIGURE 1 If it is desired to produce long luminous bands Without any dark gaps, a number of tubes as in FIGURE 1 can be arranged end to end in series.
  • a more suitable solution is represented by the low pressure luminous tube shown in FIGURE 2, in which at the ends of the tube 1, at right-angles to the longitudinal extension thereof, short tubular attachments are arranged in which the electrodes 2 are housed.
  • electrodes 2 are provided such as are shown in detail in FIGURES 7 and 8.
  • the end faces of the tube 1 are made fiat in order that, with the layer of luminous substance extending throughout the'entire length of the tube, there is practically no break in the continuity of the luminous band when a number of the tubes are placed end to end in a row.
  • FIGURE 3 shows a cylindrical cup electrode which in itself may have any desired shape of cross-section.
  • the mixture of composition 3 emitting electrons is disposed at the bottom of a metal beaker 6 provided with a lead-in 4. It is clear that in the carrying out of the method according to the invention with the form of cup electrode 6 shown in the figure the explosive pressure will be directed towards the open end of the cup and only an inconsiderable portion of the activation mass can spurt out of the cup.
  • FIGURE 4 illustrates a funnel-shaped cup, the mass 3 emitting electrons being accommodated in the tip of the funnel-shaped cup, which is likewise equipped With a lead-in 4.
  • This cup too, can be made circular, rectangular, or the like.
  • FIGURE 5 shows a cup shaped like a hollow ball, and FIGURE 6 one shaped like a cap.
  • FIG- URES 7 and 8 An especially useful electrode is illustrated in FIG- URES 7 and 8.
  • the electron-emitting mass 3 is laced between two cylinders 7 and 8 which are arranged one within the other and the diameters of which differ only slightly, thus leaving a comparatively narrow space for the electron-emitting mass 3.
  • support 9 is suflicient, which may have any desired shape.
  • the ring formed by the electron-emitting mass 3 can also have a polygonal shape, for example be rectangular.
  • FIGURE 9 shows an annular electrode, similar to the electrode according to FIGURES 7 and 8 but having in this case a support 9 of, for example, insulatlating material and current lead-in 10 in the form of a wire.
  • FIGURES 10 and 11 illustrate an example of an electrode which is made up of a few walls 11 extending in parallel which constitute a plurality of chambers filled with the mass 3 emitting electrons, FIGURE 10 being a plan view and FIGURE 11 a side view of this embodiment.
  • FIGURE 12 Another electrode suitable for the method of the invention is seen in FIGURES 12 and 13, FIGURE 12 being a section along the line XIII-XIII in FIGURE 13.
  • the cup provided with the wall 7 and containing the electron-emitting mass 3 in its bottom, is surrounded by a wall 8.
  • a disc, a bar, a ring, etc. can be used to carry the electron-emitting mass 3.
  • any other geometrical figure can be chosen.
  • the metal powder is a member selected from the group consisting of iron, tungsten, zirconium and molybdenum power, and the oxidizing substance is barium oxide.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Discharge Lamp (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Powder Metallurgy (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
US469165A 1964-07-08 1965-07-02 Method of producing sintered electrodes Expired - Lifetime US3325281A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT586464A AT247460B (de) 1964-07-08 1964-07-08 Verfahren zur Herstellung von gesinterten Elektroden

Publications (1)

Publication Number Publication Date
US3325281A true US3325281A (en) 1967-06-13

Family

ID=3580368

Family Applications (1)

Application Number Title Priority Date Filing Date
US469165A Expired - Lifetime US3325281A (en) 1964-07-08 1965-07-02 Method of producing sintered electrodes

Country Status (11)

Country Link
US (1) US3325281A (enrdf_load_stackoverflow)
AT (1) AT247460B (enrdf_load_stackoverflow)
BE (1) BE666308A (enrdf_load_stackoverflow)
CH (1) CH449117A (enrdf_load_stackoverflow)
DE (2) DE1120016B (enrdf_load_stackoverflow)
DK (1) DK111333B (enrdf_load_stackoverflow)
ES (1) ES314933A1 (enrdf_load_stackoverflow)
FR (1) FR1456547A (enrdf_load_stackoverflow)
GB (1) GB1119224A (enrdf_load_stackoverflow)
NL (1) NL148435B (enrdf_load_stackoverflow)
SE (1) SE308760B (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3458913A (en) * 1966-04-19 1969-08-05 Siemens Ag Supply cathode for electrical discharge vessels and method for its production
US4135286A (en) * 1977-12-22 1979-01-23 United Technologies Corporation Sputtering target fabrication method
DE3232802A1 (de) * 1982-09-03 1984-03-08 Alfred Prof. Dr.-Ing. 7830 Emmendingen Walz Verfahren und vorrichtung zum erzeugen ultravioletter strahlung
US4710344A (en) * 1983-10-07 1987-12-01 Union Carbide Corporation Method of forming a getter assembly
US4822312A (en) * 1983-12-05 1989-04-18 Gte Products Corporation Electrode for high intensity discharge lamps
EP0584858A1 (en) * 1992-08-10 1994-03-02 Koninklijke Philips Electronics N.V. Low pressure discharge lamp having sintered "cold cathode" discharge electrodes

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1120016B (de) * 1964-07-08 1961-12-21 Elger 1 Alpenlaendisches Unter Nicht geheizte Elektrode, insbesondere fuer Niederspannungsleuchtstofflampen, sowie Lampe mit solchen Elektroden
NL6411355A (enrdf_load_stackoverflow) * 1964-09-30 1966-03-31
DE19616408A1 (de) * 1996-04-24 1997-10-30 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Elektrode für Entladungslampen

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2117636A (en) * 1934-03-24 1938-05-17 Gerald B Tjoflat Thermionic electrode
US2175345A (en) * 1935-07-12 1939-10-10 Gen Electric Electric gaseous discharge device
US2753615A (en) * 1951-06-08 1956-07-10 Ets Claude Paz & Silva Emissive electrode for electric discharge apparatus
US2953443A (en) * 1957-02-11 1960-09-20 Alloyd Engineering Lab Inc Chemical heating composition, heating unit containing the same and method of manufacture

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE838031C (de) * 1952-03-27 Loewe Opta Aktiengesellschaft, Berlin-Steglitz Entladungsgefäß, insbesondere Leuchtröhre
DE642722C (de) * 1931-12-19 1937-03-13 Claude Lumiere Sa Pour Les App Elektrische Gasentladungslampe mit Edelgas-, insbesondere Heliumgasfuellung, und positiver Saeulenentladung
DE637206C (de) * 1932-09-07 1936-10-23 Lon Ladislaus Von Kramolin Gas- oder dampfgefuellte elektrische Entladungslampe, insbesondere Hochdrucklampe, mit durch die Entladung geheizten Gluehelektroden
US2006081A (en) * 1934-03-02 1935-06-25 Hanovia Chemical & Mfg Co Electrode for vapor electric devices
FR50165E (fr) * 1938-11-26 1940-01-17 Perfectionnements apportés à la fabrication des tubes et lampes, à décharges électriques, sur les réseaux à basse tension, pour usages domestiques
DE917860C (de) * 1951-11-01 1954-09-13 Patra Patent Treuhand Aktivierungsmaterial fuer Elektroden von elektrischen Entladungsgefaessen
DE894289C (de) * 1951-12-12 1953-10-22 Neon Baecker Explosionssichere Leuchtstoffroehre
AT183479B (de) * 1953-03-07 1955-10-10 Joseph Carl Dr Pole Elektrode für Entladungsröhren
DE1686466U (de) * 1953-08-19 1954-11-04 Patra Patent Treuhand Kathode fuer elektrische entladungsblitzroehren.
DE1120016B (de) * 1964-07-08 1961-12-21 Elger 1 Alpenlaendisches Unter Nicht geheizte Elektrode, insbesondere fuer Niederspannungsleuchtstofflampen, sowie Lampe mit solchen Elektroden

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2117636A (en) * 1934-03-24 1938-05-17 Gerald B Tjoflat Thermionic electrode
US2175345A (en) * 1935-07-12 1939-10-10 Gen Electric Electric gaseous discharge device
US2753615A (en) * 1951-06-08 1956-07-10 Ets Claude Paz & Silva Emissive electrode for electric discharge apparatus
US2953443A (en) * 1957-02-11 1960-09-20 Alloyd Engineering Lab Inc Chemical heating composition, heating unit containing the same and method of manufacture

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3458913A (en) * 1966-04-19 1969-08-05 Siemens Ag Supply cathode for electrical discharge vessels and method for its production
US4135286A (en) * 1977-12-22 1979-01-23 United Technologies Corporation Sputtering target fabrication method
DE3232802A1 (de) * 1982-09-03 1984-03-08 Alfred Prof. Dr.-Ing. 7830 Emmendingen Walz Verfahren und vorrichtung zum erzeugen ultravioletter strahlung
US4710344A (en) * 1983-10-07 1987-12-01 Union Carbide Corporation Method of forming a getter assembly
US4822312A (en) * 1983-12-05 1989-04-18 Gte Products Corporation Electrode for high intensity discharge lamps
US5585694A (en) * 1990-12-04 1996-12-17 North American Philips Corporation Low pressure discharge lamp having sintered "cold cathode" discharge electrodes
EP0584858A1 (en) * 1992-08-10 1994-03-02 Koninklijke Philips Electronics N.V. Low pressure discharge lamp having sintered "cold cathode" discharge electrodes

Also Published As

Publication number Publication date
AT247460B (de) 1966-06-10
NL6508707A (enrdf_load_stackoverflow) 1966-01-10
ES314933A1 (es) 1966-02-01
NL148435B (nl) 1976-01-15
BE666308A (enrdf_load_stackoverflow) 1965-11-03
DE1225757B (de) 1966-09-29
CH449117A (de) 1967-12-31
DK111333B (da) 1968-07-29
SE308760B (enrdf_load_stackoverflow) 1969-02-24
FR1456547A (fr) 1966-07-08
GB1119224A (en) 1968-07-10
DE1120016B (de) 1961-12-21

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