US2273763A - Incandescible cathode - Google Patents

Incandescible cathode Download PDF

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Publication number
US2273763A
US2273763A US370538A US37053840A US2273763A US 2273763 A US2273763 A US 2273763A US 370538 A US370538 A US 370538A US 37053840 A US37053840 A US 37053840A US 2273763 A US2273763 A US 2273763A
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US
United States
Prior art keywords
core
wire
cathode
electron
substance
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
US370538A
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English (en)
Inventor
Reerink Engbert Harmen
Willigen Paul Christiaan V Der
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.)
Hartford National Bank and Trust Co
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Hartford National Bank and Trust 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
Priority to NL48681D priority Critical patent/NL48681C/xx
Priority to NL43688D priority patent/NL43688C/xx
Priority to DEN37489D priority patent/DE708896C/de
Priority to GB4785/35A priority patent/GB433520A/en
Priority to US16486A priority patent/US2273762A/en
Priority claimed from US16486A external-priority patent/US2273762A/en
Priority to FR788959D priority patent/FR788959A/fr
Application filed by Hartford National Bank and Trust Co filed Critical Hartford National Bank and Trust Co
Priority to US370538A priority patent/US2273763A/en
Application granted granted Critical
Publication of US2273763A publication Critical patent/US2273763A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • 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
    • H01J1/15—Cathodes heated directly by an electric current

Definitions

  • the present invention relates to activated incandescible cathodes of high electron emitting capacity and which are particularly adapted for use in large capacity fion discharge tubes.
  • ion discharge tube as used herein, is to be understood to mean a discharge tube having a gaseous filling which may be either a gas or a vapor, or a mixture of gases and/or vapors, and in which the discharge current is carried primarily by the ionized gaseous filling.
  • the present invention provides a novel construction for a cathode of high electron-emit ting capacity, which is comparatively simple and inexpensive, and which gives highly satisfactory allround results.
  • the desired results are obtained by winding around a metal core, preferably made of refractory material, a plurality of thin metal wires to form around the core a structure in which a comparatively large 1 mass and large area of highly electron-emissive substance surrounds the core and is securely retained by the turns and/or layers of the thin wire.
  • a very large emitting surface can be provided on the cathode with an ample sup- .ply of emissive substance, which substance at the same time firmly adheres to the cathode.
  • a cathode comprising a refractory core around which is helically wound a coated thin wire.
  • This construction comprises a wire core of a highly refractory material and surrounded by turns of a single thin wire of the same or different material, and coated with emissive substance; the wire forming a single layer on the core.
  • the purpose of this prior art construction was to provide a structure to which the electron-emitting substance firmly adheres.
  • the thin helical wire was comparatively closely wound 370,538. In Germany and the electron-emitting surface compared to that of a simple coated wire was not materially increased, nor was the quantity of electronemitting substance that could be held on the cathode.
  • the thin wire is wound in a plurality of layers, or a plurality of wires are wound on top of each other.
  • the capillary slots or interspaces produced in this construction and filled with electron-emissive substance are particularly important in the case of ion-discharge tubes, as in such tubes the gas or vapor ions neutralize the negative space charge of the incandescent cathode and thus the emitting particles located even at considerable depths of the slots and recesses can participate in the electron emission. Furthermore, the amount of emittingsubstance can be greatly increased and an ample supply thereof is provided.
  • Thuscathodes constructed according to the invention can be built for very high current carrying capacities,
  • the core wire itself may and preferably does form a helix, whereas the thin helically-wound wire surrounding the core can be applied thereto to form a plurality of layers which may be spaced in various manners.
  • Fig. l is an enlarged view of part of a core wire surrounded in accordance with the invention by two layers of wire constituting superimposed helices.
  • Fig. 2 is a side view of a cathode structure constructed in accordance with Fig. 1.
  • Fig. 3 is an enlarged cross-section through a portion of the cathode of Fig. 2.
  • Fig. 4 is an ion discharge tube using a cathode in accordance with the invention.
  • the wires 4 and 5 are preferably wound in opposite directions on the core I to form reverse helices,
  • the core I with the wires 4 and 5 thereon form thus a cathode as shown in Fig. 2.
  • the advantage in winding successive layers in opposite directions is due to the fact that the oppositely-directed stresses in the coils provides for a better grip upon the core wire.
  • Such arrangement of the windings also further increases the structures holding capacity for the electronemissive substance and prevents the turns from falling between turns of the preceding layer, as would be the case if successive layers were Wound in the Harborrection.
  • the layers are preferably wound with a pitch greater than is the diameter of the wire, whereby the holding capacity of the cathode is greatly increased. As a rule it is advantageous to make the pitch at least twice as large as is the diameter of the wire.
  • Fig. 3 is a greatly nlarged sectional View of a portion of the cathode shown in Fig. 2 whereby it will be noted that the electron-emissive substance 3 forms around the core a massive layer within which are embedded the wires 4 and 5; thus the electron-emitting substance is mechanically well secured to the core and in intimate electrical contact therewith, whereas a very large amount of electron-emitting substance is provided and a large active surface obtained.
  • Fig. 4 is an ion discharge tube yielding a double phase current rectified current of 6 amps.
  • a discharge vessel I4 contains an incandescent cathode l5 according to the invention.
  • the electrodes are connected to conductors I1 leading to four prongs IQ of a cap l8.
  • the discharge vessel contains a gasfilling of .7 mm. xenon.
  • the use of nickel introduces some diswire surrounding same, may be made of a refractory metal, for example tungsten, which is provided with a nickel plating.
  • one or more parts of the cathode structure may be provided with a nickel layer. whereas other parts may at the same time not be provided with nickel layers. Similarly some of. the parts, instead of being of a refractory metal coated with nickel, may be entirely of nickel.
  • An incandescible cathode comprising a metal core-wire, a plurality of helically-wound wires surrounding said core-wire and spaced from each other to form interspaces, and a highly electronemissive substance carried by said wires, and at least partly filling said interspaces.
  • An incandescible cath'ode structure comprising a metal core-wire, a plurality of helically wound thin wires forming superimposed spaced layers around said core-wire, adjacent layers of said thin wires being wound in opposite directions, and a highly electron-emissive substance carried by said structure and at least partly filling the space between said layers.
  • An incandescible cathode structure comprising a metal core, a plurality of helicallywound metal wires surrounding said core and spaced from each other to form interspaces, said wires being wound with a pitch which is larger than the diameter of the wire, and a highly electron-emissive substance carried by said structure and at least partly filling said interspaces.
  • An incandescible cathode structure comprising a metal core, a plurality of helically-wound metal wires surrounding said core and spaced from each other to form interspaces, said wires being wound with a pitch at least twice the diameter of the Wire, and a highly electron-emissive substance carried by said structure, and at least partly filling said interspaces.
  • An incandescible cathode comprising a metal core-wire, a helical metal sub-wire-structure surrounding said core-wire in contacting relationship to form a plurality of winding layers separated by interspaces, at least one of said layers being formed of nickel wire, and a highly electron-emissive substance carried by said structure and at least partly filling said interspaces.

Landscapes

  • Solid Thermionic Cathode (AREA)
  • Discharge Lamp (AREA)
  • Microwave Tubes (AREA)
US370538A 1934-04-17 1940-12-17 Incandescible cathode Expired - Lifetime US2273763A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
NL48681D NL48681C (fr) 1934-04-17
NL43688D NL43688C (fr) 1934-04-17
DEN37489D DE708896C (de) 1934-04-17 1934-12-02 Aktivierte Gluehkathode fuer Ionenentladungsroehren mit aus vorzugsweise hochschmelzendem Metall bestehendem, als Heizkoerper und Zufuehrungsleiter dienendem und zum Festhalten der emittierenden Stoffe mit duennen Metalldraehten bewickeltem Drahtkern
GB4785/35A GB433520A (en) 1934-04-17 1935-02-14 Improved incandescent cathode
US16486A US2273762A (en) 1934-04-17 1935-04-15 Incandescible cathode
FR788959D FR788959A (fr) 1934-04-17 1935-04-17 Cathode à incandescence activée
US370538A US2273763A (en) 1934-04-17 1940-12-17 Incandescible cathode

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE433520X 1934-04-17
US16486A US2273762A (en) 1934-04-17 1935-04-15 Incandescible cathode
US370538A US2273763A (en) 1934-04-17 1940-12-17 Incandescible cathode

Publications (1)

Publication Number Publication Date
US2273763A true US2273763A (en) 1942-02-17

Family

ID=32096462

Family Applications (1)

Application Number Title Priority Date Filing Date
US370538A Expired - Lifetime US2273763A (en) 1934-04-17 1940-12-17 Incandescible cathode

Country Status (4)

Country Link
US (1) US2273763A (fr)
FR (1) FR788959A (fr)
GB (1) GB433520A (fr)
NL (2) NL48681C (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2422469A (en) * 1945-07-09 1947-06-17 Edward A Coomes Electron emitting cathode
US2447038A (en) * 1945-10-31 1948-08-17 Raytheon Mfg Co Cathode structure

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL48805C (fr) * 1936-09-01

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2422469A (en) * 1945-07-09 1947-06-17 Edward A Coomes Electron emitting cathode
US2447038A (en) * 1945-10-31 1948-08-17 Raytheon Mfg Co Cathode structure

Also Published As

Publication number Publication date
NL43688C (fr)
NL48681C (fr)
GB433520A (en) 1935-08-15
FR788959A (fr) 1935-10-21

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