GB707285A - Improvements in or relating to electron emitting cathodes - Google Patents

Improvements in or relating to electron emitting cathodes

Info

Publication number
GB707285A
GB707285A GB30137/52A GB3013752A GB707285A GB 707285 A GB707285 A GB 707285A GB 30137/52 A GB30137/52 A GB 30137/52A GB 3013752 A GB3013752 A GB 3013752A GB 707285 A GB707285 A GB 707285A
Authority
GB
United Kingdom
Prior art keywords
tungsten
plate
spraying
mixture
porous
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
GB30137/52A
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.)
Thales SA
Original Assignee
CSF Compagnie Generale de Telegraphie sans Fil SA
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 CSF Compagnie Generale de Telegraphie sans Fil SA filed Critical CSF Compagnie Generale de Telegraphie sans Fil SA
Publication of GB707285A publication Critical patent/GB707285A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus 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
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microwave Tubes (AREA)
  • Coating By Spraying Or Casting (AREA)
  • Solid Thermionic Cathode (AREA)

Abstract

707,285. Making electron emitting cathodes. COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. Nov. 27, 1952 [Dec. 5, 1951], No. 30137/52. Classes 83 (2) and 83 (4). [Also in Group XI] Building up parts of articles by spraying.-A method of manufacturing an electron emitting cathode comprising a mixture of emitting oxides enclosed behind a layer of porous metal is characterized in that the porous layer is obtained by spraying finely divided fused metal on to a mould which is subsequently removed. A rod 1 of tungsten is fed through the central passage 2 of an oxyacetylene blow pipe comprising two conical frustrums 2<SP>1</SP> and 3. Oxygen is fed through the central passage 2 and acetylene through the annular passage 4 formed by the frustrums 2<SP>1</SP>, 3 and the combustion of the mixture fuses the tungsten rod. This finely divided fused metal is entrained by compressed air, nitrogen or a mixture of nitrogen and hydrogen, emerging from an annular passage 5 formed between the frustrum 3 and an outer conical frustrum 6. The body of the cathode which is placed 10-30 cms. away from the blow pipe, comprises a molybdenum or tantalum cylinder 7 having a flange 8 and an aluminium disc 9 which seals the end of the cylinder. The tungsten is deposited on the disc 9 and forms a porous plate 10. A tungsten grid 11 may be provided to strengthen the plate. The finished plate is polished and the aluminium disc removed by treating with hydrochloric acid. A layer 14 of a mixture of finely divided barium and strontium oxides is now provided against the tungsten plate the layer being supported by the closed end of a hollow cylinder 12 of tungsten, molybdenum or tantalum in which is mounted a heating element 13 to complete the cathode structure. Alternatively the metal rod may be heated by a propane-oxygen blow pipe or an electric arc. The surface of the porous tungsten plate may be of spherical cap-shape if desired as shown in Fig. 3. A cylindrical cathode for magnetron or like tubes is made by spraying tungsten on a revolving cylindrical mould the successive operations aftet spraying being as previously described
GB30137/52A 1951-12-05 1952-11-27 Improvements in or relating to electron emitting cathodes Expired GB707285A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR1046165T 1951-12-05

Publications (1)

Publication Number Publication Date
GB707285A true GB707285A (en) 1954-04-14

Family

ID=9592108

Family Applications (1)

Application Number Title Priority Date Filing Date
GB30137/52A Expired GB707285A (en) 1951-12-05 1952-11-27 Improvements in or relating to electron emitting cathodes

Country Status (3)

Country Link
BE (1) BE515811A (en)
FR (1) FR1046165A (en)
GB (1) GB707285A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4976644A (en) * 1988-11-12 1990-12-11 Samsung Electron Devices Co., Ltd. Manufacturing method for dispenser cathode for an electron gun

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1024171B (en) * 1953-12-16 1958-02-13 Siemens Ag Process for the production of cathode bodies for electrical discharge vessels
DE1144404B (en) * 1959-06-23 1963-02-28 Philips Nv Cathode for an electrical discharge tube

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4976644A (en) * 1988-11-12 1990-12-11 Samsung Electron Devices Co., Ltd. Manufacturing method for dispenser cathode for an electron gun

Also Published As

Publication number Publication date
FR1046165A (en) 1953-12-03
BE515811A (en)

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