GB648955A - Improvements in electron-emitting electrodes for electric discharge tubes - Google Patents

Improvements in electron-emitting electrodes for electric discharge tubes

Info

Publication number
GB648955A
GB648955A GB1265746A GB1265746A GB648955A GB 648955 A GB648955 A GB 648955A GB 1265746 A GB1265746 A GB 1265746A GB 1265746 A GB1265746 A GB 1265746A GB 648955 A GB648955 A GB 648955A
Authority
GB
United Kingdom
Prior art keywords
per cent
tungsten
thorium
mixture
group
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
GB1265746A
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
Koninklijke Philips 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
Priority to NL249958X priority Critical
Application filed by Koninklijke Philips NV filed Critical Koninklijke Philips NV
Publication of GB648955A publication Critical patent/GB648955A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00Gas-discharge or vapour-discharge lamps
    • H01J61/02Details
    • H01J61/04Electrodes; Screens; Shields
    • H01J61/06Main electrodes
    • H01J61/067Main electrodes for low-pressure discharge lamps
    • H01J61/0675Main electrodes for low-pressure discharge lamps characterised by the material of the electrode
    • H01J61/0677Main electrodes for low-pressure discharge lamps characterised by the material of the electrode characterised by the electron emissive material
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00Details 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
    • H01J1/02Main electrodes
    • H01J1/13Solid thermionic cathodes
    • H01J1/14Solid thermionic cathodes characterised by the material

Abstract

648,955. Cathode materials and processing. PHILIPS LAMPS, Ltd. April 26, 1946, No. 12657. Convention date, March 21, 1942. [Class 39 (i)] A thermionic cathode consists of or is coated with an electron emissive material comprising at least one ingredient from each of groups A, B and C, group A containing tungsten and molybdenum, group B containing thorium, tantalum, hafnium and zirconium, and group C containing barium, calcium and strontium oxide, and the percentage by weight of the element or elements from group B is above 10 per cent and preferably above 20 per cent. In a modification, a quantity of thorium oxide may be included as part of the percentage allocated to group C. The material may be used to coat a conductive core either of a directly or indirectly heated cathode or may be pressed and sintered to form a cathode body. In the latter case the body is placed on or in a holder in, say, a high pressure mercury vapour discharge tube. The invention is also applicable to other gas- or vapour-filled discharge tubes, e.g. gas discharge lamps, and also to high vacuum discharge tubes. A number of examples are given : (i) a pressed and sintered body of 65 per cent tungsten, 25 per cent thorium, 10 per cent of a mixture of the alkaline earth oxides in group C; (ii) a pressed and sintered body of 10 per cent thoria, 10 per cent barium and calcium oxides, 10 per cent tantalum, 15 per cent hafnium, 5 per cent zirconium, 50 per cent tungsten and/or molybdenum ; (iii) 90 gms. of a mixture of 75 parts tungsten to 25 parts of thorium are mixed with 10 gms. of a mixture of barium, strontium and calcium carbonate. The mixture so formed is made into a paste with a 10 per cent solution of nitro-cellulose in ethyl glycol as binder, and the paste is pressed through a die to give small cylinders 3-4 mm. long and 2 mm. in diameter. The cylinders are mounted on a current supply wire of diameter 500Á, and heated and sintered to convert the carbonates into oxides; (iv) 80 gms. tungsten, 20 gms. of thorium, and 18 gms. of a mixture of barium, strontium and calcium carbonate is mixed with 45 c.cs. of butyl acetate having 1.8 per cent nitro-cellulose dissolved therein, and the mixture is ground in a ball mill for 24 hours. The core consisting of a straight tungsten wire carrying a helix of tungsten is immersed in the resulting paste, dried, and the treatment is repeated two or three times. The cathode thus obtained is then sintered and sealed'into the lamp. Specifications 237,270, 334,460, [both in Class 39 (i)], and 536,221 are referred to. The Specification as open to inspection under Sect. 91 states that alkali metal oxides may be used instead of alkaline earth oxides. Those metallic constituents which have a work function less than that of molybdenum, e.g. thorium, hafnium, tantalum, or iron, are present in the proportion of at least 1 per cent, preferably more than 10 per cent or more than 20 per cent. The tungsten or molybdenum may be replaced partly or wholly by tantalum, nickel, or zirconium. This subject-matter does not appear in the Specification as accepted.
GB1265746A 1942-03-21 1946-04-26 Improvements in electron-emitting electrodes for electric discharge tubes Expired GB648955A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
NL249958X 1942-03-21

Publications (1)

Publication Number Publication Date
GB648955A true GB648955A (en) 1951-01-17

Family

ID=19781041

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1265746A Expired GB648955A (en) 1942-03-21 1946-04-26 Improvements in electron-emitting electrodes for electric discharge tubes

Country Status (5)

Country Link
US (1) US2488731A (en)
BE (1) BE450151A (en)
CH (1) CH249958A (en)
FR (1) FR892748A (en)
GB (1) GB648955A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0010742A1 (en) * 1978-11-06 1980-05-14 Westinghouse Electric Corporation H.I.D. lamp electrode comprising barium-calcium niobate or tantalate

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2755199A (en) * 1951-02-19 1956-07-17 Kellogg M W Co Hard coated composite and method of forming
US2743400A (en) * 1951-05-29 1956-04-24 Fansteel Metallurgical Corp Electrolytic devices
US2941281A (en) * 1953-12-04 1960-06-21 Int Nickel Co Hot workable, heat resistant metal bodies
US2828254A (en) * 1954-01-05 1958-03-25 Vitro Corp Of America Method of forming a high friction element
US2830017A (en) * 1954-01-18 1958-04-08 Vitro Corp Of America Method of forming a sacrificial lubricating layer
US2861935A (en) * 1954-05-20 1958-11-25 Vitro Corp Of America Electrophoretic method of applying a lubricant coating
US2826541A (en) * 1954-06-15 1958-03-11 Vitro Corp Of America Method of making ceramic-clad metal structures
US2881512A (en) * 1954-06-16 1959-04-14 Cie Generale De Telegraphite S Composition for sintered barium cathodes
US3082516A (en) * 1957-12-03 1963-03-26 Union Carbide Corp Fabrication of metal shapes
US3075066A (en) * 1957-12-03 1963-01-22 Union Carbide Corp Article of manufacture and method of making same
US3088195A (en) * 1958-06-16 1963-05-07 Copperweld Steel Co Cladding with powdered metal to form bimetallic products
DE1180435B (en) * 1958-12-12 1964-10-29 Varta Ag A continuous process for the production of sintered frames for foil electrodes, in particular strip electrodes for electrical accumulators
US3197847A (en) * 1961-04-27 1965-08-03 Sylvania Electric Prod Clad materials and process of fabricating the same
US3352694A (en) * 1963-06-17 1967-11-14 Varian Associates Low temperature metallizing paint and method of making same
US3323924A (en) * 1964-03-27 1967-06-06 Varian Associates Low dielectric loss metallizing paint composition having a reduced sintering temperature
US3489554A (en) * 1969-03-13 1970-01-13 Sylvania Electric Prod Art of producing emitter-type electrode structures
US5041041A (en) * 1986-12-22 1991-08-20 Gte Products Corporation Method of fabricating a composite lamp filament

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1422019A (en) * 1913-01-17 1922-07-04 Yunck John Adam Alloy of refractory metals and process of forming same
AT91341B (en) * 1914-07-15 1923-02-26 Aeg Electrical discharge vessel for pure electron discharge.
US1997693A (en) * 1929-11-16 1935-04-16 Westinghouse Electric & Mfg Co Electrical discharge device
US2219590A (en) * 1937-01-21 1940-10-29 Henry E Fracker Multiunit tube
US2208920A (en) * 1939-06-03 1940-07-23 Rca Corp Cathode for electron discharge devices

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0010742A1 (en) * 1978-11-06 1980-05-14 Westinghouse Electric Corporation H.I.D. lamp electrode comprising barium-calcium niobate or tantalate

Also Published As

Publication number Publication date
US2488731A (en) 1949-11-22
FR892748A (en) 1944-05-17
CH249958A (en) 1947-07-31
BE450151A (en)

Similar Documents

Publication Publication Date Title
US3374386A (en) Field emission cathode having tungsten miller indices 100 plane coated with zirconium, hafnium or magnesium on oxygen binder
US3708710A (en) Discharge lamp thermoionic cathode containing emission material
GB734209A (en) Improvements in or relating to cathode bodies and electric discharge tubes comprising such cathode bodies
GB1190470A (en) A Rotating-Anode X-Ray Tube.
US3798492A (en) Emissive electrode
US2147447A (en) Glow cathode
US3121184A (en) Discharge lamp with cathode shields
US2198329A (en) Electric discharge tube
GB734311A (en) Improvements in or relating to cathodes for use in electric discharge tubes, tubes comprising such cathodes and methods of manufacturing such cathodes
US3969279A (en) Method of treating electron emissive cathodes
US3766423A (en) Integral emissive electrode
US2177705A (en) Electric lamp
US4843266A (en) Metal-halogen discharge lamp with conically shaped insulating elements in outer envelope
GB737668A (en) Tuning indicator valve of small dimension and a high sensitivity
US2501089A (en) Thermionic electron emitter
US2741717A (en) Dispenser type cathode having gettercoated parts
US2207174A (en) Electric discharge lamp
US2847605A (en) Electrode for fluorescent lamps
US2314134A (en) Gaseous discharge device
US4303846A (en) Sintered electrode in a discharge tube
US4275330A (en) Electric discharge lamp having a cathode with cesium metal oxide
US2806970A (en) Electron emission coatings and method of preparing air stabilized barium oxide
GB499570A (en) Improvements in and relating to electrodes for electric discharge devices and methodof making the same
US4152620A (en) High intensity vapor discharge lamp with sintering aids for electrode emission materials
US2488731A (en) Electron-emitting electrode for electric discharge tubes