US1777253A - Oxide cathode - Google Patents

Oxide cathode Download PDF

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Publication number
US1777253A
US1777253A US171051A US17105127A US1777253A US 1777253 A US1777253 A US 1777253A US 171051 A US171051 A US 171051A US 17105127 A US17105127 A US 17105127A US 1777253 A US1777253 A US 1777253A
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US
United States
Prior art keywords
wire
core
oxide
platinum
cathode
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 - Lifetime
Application number
US171051A
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English (en)
Inventor
Bruijnes Johannes
Hoeven Jacob Van Der
Oosterhuis Ekko
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
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 Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Application granted granted Critical
Publication of US1777253A publication Critical patent/US1777253A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/13—Solid thermionic cathodes
    • H01J1/14—Solid thermionic cathodes characterised by the material

Definitions

  • rlheincandescent cathode according ⁇ - to the invention has a core of highly refractory e@ metal, preferably a poor conductor of heat,
  • an element selected from .the lefthand members of Group Vl of the periodic system between atomic numbers lil and 75 for example, in the form of a wire be used for the core a metal wire which is preferably coated with alkaline earth oxide, being then wound on the said core so as to be in electrical Contact therewith.
  • a metal wire which is preferably coated with alkaline earth oxide, being then wound on the said core so as to be in electrical Contact therewith.
  • platinum or a platinum alloy is used for the winding wire.
  • a stretched core wire l made, for example, of tungsten or molybdenum has helically wound onit a wire 2.
  • turns of the latter wire may be adjacent each other, as shown in the drawing but also they may be wound quite well so as to heslightl spaced apart,it ⁇ this should he desirable or any reason, forexample, in view or" the steepness of the discharge tube for which the cathode is intended.V
  • the wire 2 which is preferably lmade oi platinum or a platinum alloy (forexample platinum-rhodium) isv coated with a lm of a Y substance of high emission capacity, for example barium oxide.
  • rlfhis oxide may be applied to the wire 2 in one of the ways known for this purpose, for example, by first coating the wire with copper, oxidizing the copper and precipitating metallic barium on the copper oxide. The barium reduces the copper in the-presence of heat and by additional heat the reduced'copper is evaporated,
  • the wire 2 may be coated with copper and oxidized before it is wound on the core l andonly then the barium may be precipitated.
  • the core wire 1T extends on both sides outside the ends of the wire spiral 2 and the ends of the wire 2 are secured to the said protruding ends of the core wire 1, which ,are finally attached to leads 3 and 4 which serve tosupply the current and which are secured in a knownman# ner to the glass pinch of a lamp toot.
  • the core wire with the emission wire wound on it in continuous len ths, to divide it into portions of the required length and to set the said portions tightly between the leads.
  • the example illustrated has, however, the advantage that the temperature will he substantially uniform all along the emitting surface by reason of the comparatively poor conduction of heat on the part of the free ends of the core wire l.
  • the incandescent cathode is used in a discharge talee comprising one or more auxiliary electrodes9 the so-called steepness is flunced.
  • An incandescent cathode comprising a core of highly refractory metal, a metal wire helically wound on the said core so as to be in electrical contact therewith, and a sub'- stance of high electron emitting capacity applied to said wire.
  • An incandescent cathode comprising a ap lie and a substance of high electron emitting core consisting of at least one of t e metals tungsten and molybdenum, a platinum Wire helically wound on the core so as to be in electrical contact therewith, and a substance of high electron emitting capacity comprisin g an alkaline earth oxide applied to said wire.
  • An incandescent cathode comprising a core consisting of an element of the left hand members of Group VI of the periodic system between atomic numbers 41 and 75, a metal wire helically wound on the core so as to be in electrical contact therewith, and a substance of high electron emitting capacity comprising an alkaline earth oxide applied to said wire.
  • An incandescent cathode comprising a core consisting of an element of the left hand members of Group VI of the periodic system between atomic numbers 41 and 75, a metal wire comprising platinum helically wound on the core so as to be in electrical contact therewith, and a substance of high electron emitting capacity comprising an alkaline earth oxide applied to said Wire.
  • An incandescent cathode comprising a core consisting of an element/of the left hand members of Group VI of the periodic system between atomic numbers 41 and 75, a platinum wire helicall wound on the core so as to be in electrica contact therewith, and a substance of high electron emitting capacity comprising an alkaline earth oxide to-said wire.

Landscapes

  • Solid Thermionic Cathode (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
US171051A 1926-04-06 1927-02-25 Oxide cathode Expired - Lifetime US1777253A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL1777253X 1926-04-06

Publications (1)

Publication Number Publication Date
US1777253A true US1777253A (en) 1930-09-30

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ID=19873084

Family Applications (1)

Application Number Title Priority Date Filing Date
US171051A Expired - Lifetime US1777253A (en) 1926-04-06 1927-02-25 Oxide cathode

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US (1) US1777253A (en))
BE (1) BE340880A (en))
DE (1) DE665414C (en))
NL (1) NL19436C (en))

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2505909A (en) * 1948-02-26 1950-05-02 Bishop H Russell Cathode-ray tube with oxide coated cathode
US2629065A (en) * 1948-05-14 1953-02-17 Westinghouse Electric Corp Overwound filament
US2848635A (en) * 1954-11-16 1958-08-19 Vacuum Electronic Engineering Ionization gauges
US3312856A (en) * 1963-03-26 1967-04-04 Gen Electric Rhenium supported metallic boride cathode emitters

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2505909A (en) * 1948-02-26 1950-05-02 Bishop H Russell Cathode-ray tube with oxide coated cathode
US2629065A (en) * 1948-05-14 1953-02-17 Westinghouse Electric Corp Overwound filament
US2848635A (en) * 1954-11-16 1958-08-19 Vacuum Electronic Engineering Ionization gauges
US3312856A (en) * 1963-03-26 1967-04-04 Gen Electric Rhenium supported metallic boride cathode emitters

Also Published As

Publication number Publication date
DE665414C (de) 1938-09-24
NL19436C (en))
BE340880A (en))

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