DE492160C - Incandescent cathode for vacuum tubes, consisting of a hard-to-melt metal, e.g. B tungsten etc., with the addition of thoroxide, which is brought into a state of high specific emission by reducing agents such as carbon - Google Patents

Incandescent cathode for vacuum tubes, consisting of a hard-to-melt metal, e.g. B tungsten etc., with the addition of thoroxide, which is brought into a state of high specific emission by reducing agents such as carbon

Info

Publication number
DE492160C
DE492160C DEG57111D DEG0057111D DE492160C DE 492160 C DE492160 C DE 492160C DE G57111 D DEG57111 D DE G57111D DE G0057111 D DEG0057111 D DE G0057111D DE 492160 C DE492160 C DE 492160C
Authority
DE
Germany
Prior art keywords
carbon
thoroxide
hard
addition
high specific
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
DEG57111D
Other languages
German (de)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Application granted granted Critical
Publication of DE492160C publication Critical patent/DE492160C/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00Apparatus 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
    • H01J9/02Manufacture of electrodes or electrode systems
    • H01J9/04Manufacture of electrodes or electrode systems of thermionic cathodes
    • H01J9/042Manufacture, activation of the emissive part
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00Gas-filled discharge tubes with solid cathode
    • H01J17/02Details
    • H01J17/22Means for obtaining or maintaining the desired pressure within the tube
    • H01J17/24Means for absorbing or adsorbing gas, e.g. by gettering

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Discharge Lamp (AREA)

Description

Gegenstand der vorliegenden Erfindung ist eine Glühkathode für Vakuumröhren, die nach einem besonderen Verfahren hergestellt ist. Die Vorteile von Entladungsgefäßen, bei denen eine Elektrode Thorium oder eine Thoriumverbindung enthält, sind bekannt. Solche Elektroden bestehen aus einem feuerfesten leitenden Material, z. B. Wolfram, mit einem Zusatz von Thorerde. Es muß dabei die Glühkathode so bearbeitet werden, daß das aktive Material zum Schluß aus metallischem Thorium besteht oder zum mindesten aus einem niedrigeren Thoriumoxyd als Thorerde (ThO2). Es ist bereits bekannt, Thorrumkathoden mitüels Kohlenstoffs zu reduzieren. Die vorliegende Erfindung gründet sich darauf, den Kohlenstoff, abweichend von den bisher üblichen Verfahren, dem Kathodenmaterial bereits vor seiner Einführung in die Entladungsröhre, also zweckmäßig schon bei seiner Herstellung, zuzufügen. Kohle in einer thorisierten Kathode verhindert nicht nur die Wiederoxydation des aktiven Thoriums, sondern, was noch wesentlicher ist, sie reduziert Thorerde in einem aktiven Zustand. 2g Es hat sich ergeben, daß eine Kathode mit guter Elektronenemission dann erzielt wird, wenn etwa 3/4 ο/ο Thorerde und 2/3 Gewichtsprozent Kohle dem Fadenmaterial, z. B. Wolfram, zugeführt wird. Die Herstellung des thorisierten Fadens kann durch Bespritzen von Wolfram und Thorerde mit einem kohlehaltigen Bindemittel erfolgen.The present invention relates to a hot cathode for vacuum tubes, which is produced by a special process. The advantages of discharge vessels in which an electrode contains thorium or a thorium compound are known. Such electrodes are made of a refractory conductive material, e.g. B. tungsten, with an addition of thorer earth. The hot cathode must be processed in such a way that the active material ultimately consists of metallic thorium or at least a lower thorium oxide than thore earth (ThO 2 ). It is already known to reduce thoracic cathodes with carbon. The present invention is based on adding the carbon to the cathode material prior to its introduction into the discharge tube, that is to say expediently already during its manufacture, in a departure from the previously customary methods. Charcoal in a thorized cathode not only prevents reoxidation of the active thorium, but, more importantly, it reduces sulfur earth in an active state. 2 g It has been found that a cathode with good electron emission is obtained when about 3/4 ο / ο thoria and 2/3 weight percent carbon the thread material z,. B. tungsten is supplied. The thorised thread can be produced by spraying tungsten and thorn earth with a carbon-containing binding agent.

Die vorliegende Erfindung stellt eine Vereinfachung der Fabrikation dar. Xach den bisher üblichen Verfahren wurde der Kohlenstoff dem Kathodenmaterial erst in den Entladungsröhren selbst zugeführt. Diese Methode hatte technisch verschiedene Schwierigkeiten und war außerdem kostspieliger als die Herstellung gemäß der Erfindung.The present invention represents a simplification of the fabrication. Xach the Up to now, the usual method, the carbon was added to the cathode material only in the discharge tubes self fed. This method had various technical difficulties and was also more expensive than that Manufacture according to the invention.

Claims (2)

Patentansprüche:Patent claims: i. Glühkathode für Vakuumröhren, bestehend aus einem schwer schmelzbareni. Hot cathode for vacuum tubes, consisting of a hard-to-melt Metall, z.B. Wolfram usw., mit Thoroxydzusatz*, welche durch reduzierende Mittel, wie. Kohlenstoff, in einen Zusatz hoher spezifischer Emission versetzt wird, dadurch gekennzeichnet, daß das reduzierende Mittel, z. B. Kohlenstoff, dem Glühfaden bereits vor seiner Einfügung in die Entladungsröhre zugefügt ist.Metal, e.g. tungsten, etc., with the addition of thoroxide *, which can be reduced by reducing agents, how. Carbon, is put in an additive of high specific emission, thereby characterized in that the reducing agent, e.g. B. carbon, the filament before its insertion into the Discharge tube is added. 2. Glühkathode nach Anspruch i, dadurch gekennzeichnet, daß sie ungefähr 3/4°/0 Thorerde
Kohle enthält.
2. thermionic cathode according to claim i, characterized in that it about 3/4 ° / 0 thoria
Contains coal.
und 2/3 Gewichtsprozentund 2/3 weight percent
DEG57111D 1921-08-11 1922-07-23 Incandescent cathode for vacuum tubes, consisting of a hard-to-melt metal, e.g. B tungsten etc., with the addition of thoroxide, which is brought into a state of high specific emission by reducing agents such as carbon Expired DE492160C (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US491634A US1529597A (en) 1921-08-11 1921-08-11 Electron-emitting device and method of preparation

Publications (1)

Publication Number Publication Date
DE492160C true DE492160C (en) 1930-02-19

Family

ID=23953025

Family Applications (1)

Application Number Title Priority Date Filing Date
DEG57111D Expired DE492160C (en) 1921-08-11 1922-07-23 Incandescent cathode for vacuum tubes, consisting of a hard-to-melt metal, e.g. B tungsten etc., with the addition of thoroxide, which is brought into a state of high specific emission by reducing agents such as carbon

Country Status (4)

Country Link
US (1) US1529597A (en)
DE (1) DE492160C (en)
FR (1) FR26734E (en)
GB (1) GB184446A (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2465864A (en) * 1943-06-22 1949-03-29 Westinghouse Electric Corp Automatic carbonization of filaments
US2459792A (en) * 1944-07-08 1949-01-25 Standard Telephones Cables Ltd Beam type electron discharge device
US2513114A (en) * 1944-10-19 1950-06-27 Atomic Energy Commission Liquid air trap
US2693546A (en) * 1948-07-10 1954-11-02 Eitel Mccullough Inc Electron emitter for electron tubes
US3290110A (en) * 1962-12-26 1966-12-06 Rca Corp Processing metal vapor tubes
US3656826A (en) * 1970-07-17 1972-04-18 Westinghouse Electric Corp Method for the preparation and handling of highly oxygen reactant materials

Also Published As

Publication number Publication date
FR26734E (en) 1924-03-06
US1529597A (en) 1925-03-10
GB184446A (en) 1924-01-15

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