US2477279A - Electrical discharge device - Google Patents

Electrical discharge device Download PDF

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Publication number
US2477279A
US2477279A US696114A US69611446A US2477279A US 2477279 A US2477279 A US 2477279A US 696114 A US696114 A US 696114A US 69611446 A US69611446 A US 69611446A US 2477279 A US2477279 A US 2477279A
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United States
Prior art keywords
metal
electrode
electrodes
discharge
zirconium
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Expired - Lifetime
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US696114A
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English (en)
Inventor
Jr William T Anderson
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Hanovia Chemical and Manufacturing Co
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Hanovia Chemical and Manufacturing Co
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Publication date
Application filed by Hanovia Chemical and Manufacturing Co filed Critical Hanovia Chemical and Manufacturing Co
Priority to US696114A priority Critical patent/US2477279A/en
Priority to GB7463/49A priority patent/GB671352A/en
Priority to NL145671A priority patent/NL76362C/xx
Priority to FR983782D priority patent/FR983782A/fr
Priority to DEP38258D priority patent/DE819430C/de
Priority to CH278760D priority patent/CH278760A/de
Application granted granted Critical
Publication of US2477279A publication Critical patent/US2477279A/en
Anticipated expiration legal-status Critical
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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
    • H01J61/073—Main electrodes for high-pressure discharge lamps
    • H01J61/0735—Main electrodes for high-pressure discharge lamps characterised by the material of the electrode
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/24—Means for obtaining or maintaining the desired pressure within the vessel
    • H01J61/26—Means for absorbing or adsorbing gas, e.g. by gettering; Means for preventing blackening of the envelope
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/922—Static electricity metal bleed-off metallic stock
    • Y10S428/9335—Product by special process
    • Y10S428/939—Molten or fused coating
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12333—Helical or with helical component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12632—Four or more distinct components with alternate recurrence of each type component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12812—Diverse refractory group metal-base components: alternative to or next to each other

Definitions

  • FIG. 2 FIG. 3
  • This invention relates to electrical discharge devices and is concerned in particular with metal vapor discharge devices
  • High pressure metal vapor electric arc devices comprise a discharge envelope constructed of fused quartz or high melting point glass, having an ionizable filling of metal vapor, and an inert gas, .e. g. argon, and a pair of cooperating incandescent electrodes, at least one ofwhich is an activated electrode.
  • the inert gas serves as a starting gas adapted to give an initial discharge on imposition of an electrical potential on the electrodes sufiicient to ionize the gas
  • the metal vapor serves to carry the arc discharge and is at a pressure such that the voltage consumption of the arc discharge is increased to at least double the voltage consumption of the discharge in the first moment after starting the discharge.
  • Such devices are more particularly described'in Germer U. S. Letters Patent No. 2,202,199.
  • the pressure of the metal vapor in such devices may thus amount to from about one-fourth of an atmosphere to several atmospheres and more, e. 3. about one atmosphere.
  • the efiiciency and life of metal vapor discharge devices depend in a considerable measure on the efliciency and life of the incandescent electrodes. It has, therefore, been aprlncipal object of the art to produce sturdy electrodes which do not disintegrate under the bombardment to which they are subjected by the current-carrying particles of the arc, principally by the positive gas ions.
  • Many types of activated electrodes have, therefore, been developed as part of such high pressure metal vapor are devices, such, for example, as electrodes of coiled wires orthe like, e. g. in the form of a helix, of high melting metal, such as tungsten, combined in one form or another with highly emissive substances, e. g. barium, thorium or the like.
  • the purity of the inert gas of the ionizable filling is another important factor with respect to the usefulness of the discharge device.
  • the electrical potential at which thesedevices will start depends in part on such purity.
  • getters such as barium or phosphorus
  • getters such as barium or phosphorus
  • the oxygen then reacts with the leads and supports of the electrode to form metal oxide coatings which evaporate during the operation of the device and on deposition blacken the walls of the device, thus impairing the transmission of the visible and invisible radiations through the wall of the envelope.
  • Positive nitrogen ions rapidly attack the electrode metal, e. g. tungsten, and the activation material, thus causing a decrease in the electron emission from such electrodes with resultant premature shortening of the useful life of the electrodes and therewith of the discharge device.
  • Fig. 1 represents a cross-sectional view of an electrical discharge device with a pair of cooperating solid incandescent electrodes
  • Fig. 2 represents an elevational perspective view, on an enlarged scale, of one embodiment of the electrode according to the invention
  • Fig. 3 is a sectional view on the line A--A of Fig. 2,
  • Fig. 4 represents a sectional view like that of Fig. 3, but of a slightly different form of such embodiment
  • Fig. 5 represents an elevational sectional view of another embodiment of the electrode according to the invention.
  • Fig. 6 is a sectional view on the line BB of Fig. 5.
  • the electrical discharge device comprises the customary structural and operative elements of such devices, such as a discharge envelope of high fusing radiation transmitting material such as quartz or high silica content glass, an ionizable filling of inert starting gas, e. g. argon or noun or the like, and a discharge carrying metal vapor, e. g. vapor of mercury, cadmium, sodium, rubidium, arsenic or the like, electrical accessories such as energizing circuit, ballast etc., and so forth, and is characterized by the provision of at least one incandescent electrode according to this invention.
  • a discharge envelope of high fusing radiation transmitting material such as quartz or high silica content glass
  • an ionizable filling of inert starting gas e. g. argon or noun or the like
  • a discharge carrying metal vapor e. g. vapor of mercury, cadmium, sodium, rubidium, arsenic or the like
  • electrical accessories such as
  • Fig. 1 a customary discharge envelope I, e. g. of fused quartz, of elongated tubular shape with cooperating incandescent electrodes 2 and 3, spaced apart at opposite ends of the discharge envelope supported by lead-in conductors 4 and 5 sealed through the discharge envelope.
  • I e. g. of fused quartz, of elongated tubular shape with cooperating incandescent electrodes 2 and 3, spaced apart at opposite ends of the discharge envelope supported by lead-in conductors 4 and 5 sealed through the discharge envelope.
  • the incandescent electrodes 2 and 3 consist of a composite body comprising on the one hand a high temperature resistant metal, e. g. tungsten. molybdenum or the like, or in some cases even nickel, iron or the like, as one member thereof, and on the other hand a metal of the group consisting of titanium, zirconium and hafnium. as another member thereof.
  • the two members of this composite body are juxtaposed and are then subjected to a heat treatment to produce fusion thereof at at least part of the area of contact.
  • the juxtaposition of the members of the composite body constituting the incandescent electrode according to this invention may be accomplished in any suitable manner.
  • Figs. 2 and 3 of the drawings I have illustrated one particularly effective way of achieving the desired result.
  • the electrode structure is in the form of a helical coil 6, each coil consisting of a stranded wire, one or more strands I consisting of high temperature resistant metal, e. g. tungsten, (indicated in Fig. 3 in light cross section) and one or more strands 8 consisting of metal of the group titanium, zirconium and hafnium, e. g. zirconium, (indicated in Fig. 3 in heavy cross section).
  • Fig. 4 I have shown another very effective electrode structure, comprising a stranded wire 9 of tungsten or other heat resistant metal having wound around it a helically arranged wire or ribbon ii! of metal of the group titanium, zirconium Fig.
  • the disks, or washers may have any suitable thickness, e. g. about 0.004 inch.
  • Other structures adapted to produce close juxtaposition of the two members of the composite body may be used, c. g. cones, cups, tubes or the like.
  • The'in'candescent electrode of the invention emits a copious flow of electrons.
  • the electron emission emanates primarily from the fused junction of the two members of the composite body. Once the fused junction has been produced, ionization of the gaseous filling of the discharge device occurs on application of an electrical potential even when the electrodes are in an unheated condition and the gaseous discharge is quickly converted into a metal vapor arc.
  • the production of the fused junction, at at least part of the area of contact, of the two members of the composite body may be accomplished in any desired manner by the application of heat.
  • the fusion may be produced either as a special heating step, during or after the manufacture of the electrode structure, or as part of the heating occurring after scaling in of the electrodes during the evacuation of the discharge envelope.
  • the fusion should take place by melting of the metal of the group titanium, zirconium and hafnium to the high temperature resistant metal, without melting of such high temperature resistant metal, so that in the preferred embodiment of the invention the temperature resistant metal has a melting point in excess of that of the other member.
  • the high electron emissivity of the electrode of the invention is contingent on the heat treatment and the provision of the fused contact or junction area. Prior to the heat treatment, the electron emissivity is extremely low but once the fusion junction is produced the electrodes are adapted to emit a copious flow of electrons on application of an electrical potential.
  • the composite electrode at the fusion junction has a work function lower than that of either component and, therefore, an electron emissivity higher than that of either component.
  • the fusion area is produced by the fusion of one metal only. while the other metal remains solid, preferably by fusion of the metal of the group consisting of titanium. zirconium and hafnium.
  • the metal vapor is preferably derived from a small quantity of the vaporizable metal and the vapor is at'such pressure duringdzhe operation of the device that the voltage consumption of the arc discharge is increased to at least double the voltage consumption of the discharge in the first moment after starting the discharge and, furthermore, all the vaporizable metal is preferably in the vapor phase during operation of the device so that the vapor density is maintained at a constant value.
  • the electrodes of the invention may be of socalled "self-heating" type, i. e. are operative on application of the electrical potential and without preheating and are admirably suited for use in connection with single in-leads, as shown in the drawings, although they may be used also in connection with double in-leads permitting, if desired, preheating of the electrode by resistance heating.
  • Titanium, zirconium and hafnium are extremely stable in air at lower temperatures, such as temperatures below 200 0., because of a thin sealing layer of oxide formed on the surface.
  • the operating temperature of the electrical discharge device in excess of 900 (2., these metals have, however, in such'discharge devices a very high solubility for oxygen, nitrogen and certain other undesirable impurities but not for the rare gases or the metal vapor.
  • the electrode thus binds, by absorption within its body, the undesirable gaseous impurities, with the result that the arcing potential of the discharge device is decreased and the impurities can not react with the tungstenor other like metal of the electrode.
  • Group -IV of the periodic system also includes thorium but while electrodes of tungsten and the like and thorium constitute activated electrodes as such they are not characterized by the essential feature of the electrodes of this invention in that they do not in the, operation of the discharge device dissolve oxygen and nitrogen or the like to any appreciable extent and the thorium does not, as do titanium, zirconium and hafnium, protect the. tungsten or the like from positive ion bombardment by these gaseous impurities.
  • the composite electrode of the invention is constructed preferably in such manner that the member comprising the heat resistant metal, e. g. one or more metals such as tungsten, molybdenum or the like, constitutes the major portion of the composite body and the member comprising metal of the group titanium, zirconium and hafnium constitutes the minor portion of the composite body, so that after the heat treatment the electrode of the invention exhibits a surface of heat resistant metal as well as a surface of the metal of the group titanium, zirconium and hafnium, thus avoiding a structure wherein, for instance, the zirconium substantially overflows and smothers the tungsten in itsentirety.
  • the zirconium substantially overflows and smothers the tungsten in itsentirety.
  • the incandescent electrode of the invention thus possesses great electron emission efficiency and withstands disintegration even in high pressure metal vapor arc lamps to a greater extent than has been achieved heretofore. It furthermore, promptly and continuously, during the life of the device in which it is embodied, dissolves oxygen, nitrogen and other undesirable gaseous impurities, thereby protecting the body of the electrode from destructive ionic gas bombardment and maintaining the lowest attainable breakdown voltage of the inert gas filling throughout the life of the device. Electrical discharge devices embodying such electrodes are thus easier to manufacture, are more eflicient in their operation and maintain their efliciency for longer periods of time than heretofore.
  • the electrode of the invention may also include in its composite body other elementswhlch may be desired.
  • the electrode may thus include other activation materials, e. g., barium,
  • strontium or other highly electron emissive substance orsubstances either in the form of a metal or a compound thereof, e. g. in the latter hafnium.
  • efiective electrodes according to the invention are those composed of tungsten or molybdenum or both as one member and zirconium as the other member, whereas in other devices, e. g. rectiflers, electrodes of iron or the like with zirconium or titanium orhafnium are quite useful.
  • electrodes of the invention make unnecsary the employment .of extreme precautions to avoid contamination of the'rare gas prior to and during the filling of the discharge device as has been necessary in the case of other incandescent 4 electrodes as heretofore known.
  • the avoidance of premature disintegration of the electrodes also eliminates the undersirable deposition of sputtered particles of the electrode on the wall of the discharge envelope, a deposition which otherwise interferes with the transmission of the radiations other activation material will decrease the work function of the electrode still further, so that, where desired, the size of the electrode may thus be decreased, with resultant lower wattage loss and other benefits.
  • the zirconium, titanium or hafnium member will protect such other activation material against easy vaporization, due to alloying of the two highly emissive substances with each other.
  • the other activation material i. e. the activation material dissimilar to titanium, zirconium and hafnium, may therefore be present in the electrode either as a separate element or,
  • Such alloyed form being produced either initially or' during the operation of the device.
  • v I may thus provide for instance an electrode in which the metal of the group titanium, zirconium and hafnium is alloyed with such other, dissimilar, activation of which consists of heat resistant metal and at least one strand of which consists of metal of the group consisting of titanium, zirconium and hafnium, said strands being fused together at at least part of the area of contact thereof to form a low work function fusion area.
  • An incandescent electrode comprising a plurality of superimposed disks, said disks consisting alternately of a heat resistant metal and a metal taken from the group consisting of titanium, zircomum and hafnium, said disksbeing fused to- 1 a gather along at least part 0! the areas of contact to form a low work function fusion area.
  • An incandescent electrode comprising I;
  • the following references are of record in the composite'body of at least one member of heat file of this patent: resistant metal and at least one member of metal rm taken from the group consisting of titanium, 811'- U STATES PATENTS conium and hafnium, said members being in Number N me Date closely juxtaposed conditioned fused together at 3,241,345 Gustin et a1.
  • May 6, 1941 at least part of the area of contact to form a low 2,241,362 Gustin e a1 M y 1 work function fusion area
  • said electrode also 10 embodying an activation material comprising a FOREIGN PATENTS highly electron emissive substance other than Number Country Date titanium, zirconium or hafnium. 467,248 Great Britain Sept. 6, 1935 WILLIAM T. ANDERSON, Ja.

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  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
  • Plasma Technology (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
US696114A 1946-09-11 1946-09-11 Electrical discharge device Expired - Lifetime US2477279A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US696114A US2477279A (en) 1946-09-11 1946-09-11 Electrical discharge device
GB7463/49A GB671352A (en) 1946-09-11 1949-03-18 Improvements in or relating to electrical discharge devices
NL145671A NL76362C (de) 1946-09-11 1949-03-29
FR983782D FR983782A (fr) 1946-09-11 1949-03-29 Dispositif à décharge électronique
DEP38258D DE819430C (de) 1946-09-11 1949-03-30 Glueh-Elektrode
CH278760D CH278760A (de) 1946-09-11 1949-04-01 Glühelektrode.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US696114A US2477279A (en) 1946-09-11 1946-09-11 Electrical discharge device
GB7463/49A GB671352A (en) 1946-09-11 1949-03-18 Improvements in or relating to electrical discharge devices

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US2477279A true US2477279A (en) 1949-07-26

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US696114A Expired - Lifetime US2477279A (en) 1946-09-11 1946-09-11 Electrical discharge device

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US (1) US2477279A (de)
CH (1) CH278760A (de)
DE (1) DE819430C (de)
FR (1) FR983782A (de)
GB (1) GB671352A (de)
NL (1) NL76362C (de)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2663816A (en) * 1949-09-28 1953-12-22 Sylvania Electric Prod Electric discharge lamp
US2686274A (en) * 1949-05-20 1954-08-10 Gen Electric Thermionic cathode
US2737708A (en) * 1951-12-12 1956-03-13 Schwarzkopf Dev Co Production of electrical switch contact elements
US2784123A (en) * 1952-05-01 1957-03-05 Rca Corp Secondary electron emitter and process of preparing same
DE962461C (de) * 1950-12-18 1957-04-25 Dr Hermann E Krefft Gluehelektrode fuer elektrische Hochdruck- und Hoechstdruck-Entladungslampen
US2792621A (en) * 1953-08-19 1957-05-21 Mallory Sharon Titanium Corp Consumable titanium electrode
US2813921A (en) * 1954-05-10 1957-11-19 Rem Cru Titanium Inc Consumable electrode for melting of chemically reactive metals
US2874325A (en) * 1952-02-05 1959-02-17 Ets Claude Paz & Silva Electrode for electric discharge apparatus
US2875362A (en) * 1956-10-31 1959-02-24 Sylvania Electric Prod Beam collector
US2886737A (en) * 1949-11-11 1959-05-12 Fruengel Frank Quick-responsive spark gap device
US2911376A (en) * 1951-11-01 1959-11-03 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Activating material for electrodes in electric discharge devices
US2930918A (en) * 1957-10-16 1960-03-29 Gen Electric High damping twisted wire
US2982019A (en) * 1953-05-22 1961-05-02 Union Carbide Corp Method of protecting magnesium with a coating of titanium or zirconium
US2982017A (en) * 1953-05-22 1961-05-02 Union Carbide Corp Method of protecting magnesium with a coating of titanium
US3391303A (en) * 1965-01-25 1968-07-02 Lewis D. Hall Electronic vacuum pump including a sputter electrode
US3501617A (en) * 1967-11-24 1970-03-17 Chicago Bridge & Iron Co Apparatus for sublimating and evaporating metals
US3690043A (en) * 1968-11-25 1972-09-12 Bodo Futterer Electrofilter for gases
US4925741A (en) * 1989-06-08 1990-05-15 Composite Materials Technology, Inc. Getter wire
DE19757152A1 (de) * 1997-12-20 1999-07-01 Thomas Eggers Elektrode für Entladungslampen

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB467248A (en) * 1934-09-25 1937-06-14 British Thomson Houston Co Ltd Improvements in and relating to electric discharge devices
US2241362A (en) * 1940-03-01 1941-05-06 Westinghouse Electric & Mfg Co Electron emissive cathode
US2241345A (en) * 1938-06-24 1941-05-06 Westinghouse Electric & Mfg Co Electron emissive cathode

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB467248A (en) * 1934-09-25 1937-06-14 British Thomson Houston Co Ltd Improvements in and relating to electric discharge devices
US2241345A (en) * 1938-06-24 1941-05-06 Westinghouse Electric & Mfg Co Electron emissive cathode
US2241362A (en) * 1940-03-01 1941-05-06 Westinghouse Electric & Mfg Co Electron emissive cathode

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2686274A (en) * 1949-05-20 1954-08-10 Gen Electric Thermionic cathode
US2663816A (en) * 1949-09-28 1953-12-22 Sylvania Electric Prod Electric discharge lamp
US2886737A (en) * 1949-11-11 1959-05-12 Fruengel Frank Quick-responsive spark gap device
DE962461C (de) * 1950-12-18 1957-04-25 Dr Hermann E Krefft Gluehelektrode fuer elektrische Hochdruck- und Hoechstdruck-Entladungslampen
US2911376A (en) * 1951-11-01 1959-11-03 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Activating material for electrodes in electric discharge devices
US2737708A (en) * 1951-12-12 1956-03-13 Schwarzkopf Dev Co Production of electrical switch contact elements
US2874325A (en) * 1952-02-05 1959-02-17 Ets Claude Paz & Silva Electrode for electric discharge apparatus
US2784123A (en) * 1952-05-01 1957-03-05 Rca Corp Secondary electron emitter and process of preparing same
US2982017A (en) * 1953-05-22 1961-05-02 Union Carbide Corp Method of protecting magnesium with a coating of titanium
US2982019A (en) * 1953-05-22 1961-05-02 Union Carbide Corp Method of protecting magnesium with a coating of titanium or zirconium
US2792621A (en) * 1953-08-19 1957-05-21 Mallory Sharon Titanium Corp Consumable titanium electrode
US2813921A (en) * 1954-05-10 1957-11-19 Rem Cru Titanium Inc Consumable electrode for melting of chemically reactive metals
US2875362A (en) * 1956-10-31 1959-02-24 Sylvania Electric Prod Beam collector
US2930918A (en) * 1957-10-16 1960-03-29 Gen Electric High damping twisted wire
US3391303A (en) * 1965-01-25 1968-07-02 Lewis D. Hall Electronic vacuum pump including a sputter electrode
US3501617A (en) * 1967-11-24 1970-03-17 Chicago Bridge & Iron Co Apparatus for sublimating and evaporating metals
US3690043A (en) * 1968-11-25 1972-09-12 Bodo Futterer Electrofilter for gases
US4925741A (en) * 1989-06-08 1990-05-15 Composite Materials Technology, Inc. Getter wire
DE19757152A1 (de) * 1997-12-20 1999-07-01 Thomas Eggers Elektrode für Entladungslampen
US6437509B1 (en) 1997-12-20 2002-08-20 Thomas Eggers Electrode for discharge lamps
DE19757152C2 (de) * 1997-12-20 2002-10-31 Thomas Eggers Elektrode für Entladungslampen

Also Published As

Publication number Publication date
CH278760A (de) 1951-10-31
FR983782A (fr) 1951-06-27
DE819430C (de) 1951-10-31
GB671352A (en) 1952-04-30
NL76362C (de) 1954-11-15

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