US1875106A - Discharge tube having an indirectly heated cathode - Google Patents

Discharge tube having an indirectly heated cathode Download PDF

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Publication number
US1875106A
US1875106A US495806A US49580630A US1875106A US 1875106 A US1875106 A US 1875106A US 495806 A US495806 A US 495806A US 49580630 A US49580630 A US 49580630A US 1875106 A US1875106 A US 1875106A
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United States
Prior art keywords
cathode
passages
indirectly heated
discharge tube
heated cathode
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Expired - Lifetime
Application number
US495806A
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English (en)
Inventor
Mulder Johannes Gysber Wilhelm
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.)
RCA Corp
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RCA Corp
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Filing date
Publication date
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Publication of US1875106A publication Critical patent/US1875106A/en
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    • 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
    • H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment

Definitions

  • This invention relates to discharge tubes having an indirectly heated cathode.
  • cathodes Indirectly heated cathodes are known in which the heating element is freely mounted within a metal envelope constituting the cathode proper, the envelope itself consisting of an emitting material or being coated with an emitting substance. Furthermore, cathodes are known in which a body made of insulating material is provided with passages in which a filament is laid, or in which the plastic in sulating material is kneaded around the filament so as to surround it entirely, and subsequently hardened. Furthermore, the outer side of this insulating body is provided with the cathode proper, consisting, for example, of a metal case which is coated with barium oxide.
  • I such as, for example, cathodes of the type as are frequently used in rectifiers for great current intensities.
  • cathodes of the type as are frequently used in rectifiers for great current intensities.
  • the cathode of a body made of conducting material, which is provided with a plurality of passages in which heating wires are arranged which are electrically insulated from the conducting body.
  • the emitting surface of this body will be very quickly and uniformly heated due to the 'great conducting capacity of the metal.
  • theconducting body is provided With'an accidented surface, to which a substance having a highly electron emitting capacity is applied.
  • the body is shaped as a hollow cylinder, whose annular end surfaces are connected by passages through which the heating wires are slipped.
  • the inner wall of thecylinder is coated with a substance having a highly electron emitting capacity.
  • a helically wound wire which is laid on the inner or outer surface of the metal cylinder.
  • the heating wires may be insulated from the conducting body by means of tubes made of steatite which are placed in the bores ofthis body.
  • Fig. 1 is a perspective view of an indirectly heated cathode according to the invention.
  • Fig. 2 is a longitudinal section of this cathode.
  • Fig. 3 is a cross section of the cathode
  • Fig. 4 shows the cathode mounted in a rectifying tube having two anodes.
  • passages 2 are provided in a hollow cylindrical body 1 consisting of conducting material, for example, nickel.
  • conducting material for example, nickel.
  • both end surfaces of the cylinder are connected.
  • tubes 8 of insulating, highly refractory material, for example, steatite are provided in the passages. Through these successive tubes one single heating wire 4 is led back and forth.
  • the inner wall of the cylinder is coated with a layer 5 of a highly electron-emitting substance consisting, for example, of one or more of the oxides, carbides, or silicates of barium, strontium, ceasium, rubidium, and so forth.
  • a layer 5 of a highly electron-emitting substance consisting, for example, of one or more of the oxides, carbides, or silicates of barium, strontium, ceasium, rubidium, and so forth.
  • the inner 1 wallof the cylinder is roughened, so that the emitting layer adheres better thereto. This inight be also obtained by providing the surface-to which the emitting layer is applied with a helically wound wire.
  • cathode 1 is mounted on two supporti'ng wires6 and 7, the latter serving at the same time as pole wire.
  • the current is supplied to the heating wire through the. leading-in wir'esfS and 9; Forclearness"sakej," y these wires are only partly represented on the drawing.
  • Near theends-of the cathode two anodes 10 and llare arranged which are supported by thewires 12'and 13 servingatvthe same time as leading-in wires;
  • An electron discharge device comprising a sealedenvelope encloslng an anode and a cathode comprising a tubular conducting body having a plurality of passages extend- 'ing' atubular metal body having in its wall a plurality of passages eXten-ding-longitudt ing through said body between its annular end surfaces, and an'insulated heater wire in said passages.
  • An electron emitting cathode compris- I ing a tubular'conducting body having in its wall a plurality of passages symmetrically disposed about and'parallel to the longitudie nal axis of-saidbody andextending from one end of said bodyto the other, heater'wires in 7 said passages, refractory insulation between said heater wires and said body,and an elect tron emitting layer on the inner wall of said body.
  • An electron emitting cathode comprising a tubular conducting body, an electron emitting layer on the inner wall of said body, and a plurality of insulated heated wires embedded in said body and symmetrically dis V posed about and parallel to the longitudinal axis of said body.
  • An electron emitting cathode comprising

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  • Solid Thermionic Cathode (AREA)
  • Discharge Lamp (AREA)
US495806A 1930-01-22 1930-11-15 Discharge tube having an indirectly heated cathode Expired - Lifetime US1875106A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL362627X 1930-01-22

Publications (1)

Publication Number Publication Date
US1875106A true US1875106A (en) 1932-08-30

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ID=19785436

Family Applications (1)

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US495806A Expired - Lifetime US1875106A (en) 1930-01-22 1930-11-15 Discharge tube having an indirectly heated cathode

Country Status (5)

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US (1) US1875106A (en(2012))
DE (1) DE625602C (en(2012))
FR (1) FR708235A (en(2012))
GB (1) GB362627A (en(2012))
NL (1) NL28875C (en(2012))

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2456579A (en) * 1942-10-30 1948-12-14 Rca Corp Electron discharge device for ultra high frequencies

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB810202A (en) * 1955-06-10 1959-03-11 Vickers Electrical Co Ltd Improvements relating to thermionic cathodes for electron discharge devices

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2456579A (en) * 1942-10-30 1948-12-14 Rca Corp Electron discharge device for ultra high frequencies

Also Published As

Publication number Publication date
NL28875C (en(2012))
FR708235A (fr) 1931-07-21
GB362627A (en) 1931-12-10
DE625602C (de) 1936-02-12

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