US2673277A - Incandescible cathode and method of making the same - Google Patents

Incandescible cathode and method of making the same Download PDF

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Publication number
US2673277A
US2673277A US191341A US19134150A US2673277A US 2673277 A US2673277 A US 2673277A US 191341 A US191341 A US 191341A US 19134150 A US19134150 A US 19134150A US 2673277 A US2673277 A US 2673277A
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United States
Prior art keywords
members
cathode
cavity
making
porous
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Expired - Lifetime
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US191341A
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English (en)
Inventor
Lemmens Hendrikus Johannes
Jansen Marinus Jacobus
Zaat Josephus Arnold Bernardus
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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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
    • H01J1/28—Dispenser-type cathodes, e.g. L-cathode
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
    • Y10T428/12063—Nonparticulate metal component
    • Y10T428/1209—Plural particulate metal components

Definitions

  • the invention is more particularly concerned with incandescible cathodes of the type in which the electron-emissive material is provided within the cavity of a body having a porous wall p0r-
  • the porous wall portion is made of sintered refractory material such as tungsten, molybdenum, tantalum, hafnium, or niobium and the pores of this body form the largest apertures for the egress of the electron emissive material.
  • This butt-welding method consists in placing the porous wall portion against the body in such a way that they contact along a rim and form a cavity for the emissive material. Then a pressure is exerted so that both pieces are in good electrical contact all along the rim and a heavy electric current of short duration is passed through this contact. Preferably a condenser discharge is used for generating the current.
  • the cathode body is provided with the electron emissive material and the porous wall portion of refractory material is put in place with its surface abutting the adjacent surface portion of the cathode body which is of refractory material such as molybdenum, tantalum or niobium.
  • numeral I designates a small cylindrical cap of a porous refractory material such as tungsten butt-welded to a hollow refractory metal member 3 at the circular edge 5 to form a cavity containing emissive material for example alkaline earth metal compounds.
  • a heating coil 4 is positioned in the hollow member 3.
  • Figure 2 shows a structure similar to that of Fig. l in which the cavity containing the emissive compounds 2 is formed by a fiat place 6 of a porous refractory material, butt-welded at edge E to the extending peripheral portion 'I of a cylindrical refractory metal member 23 having a cup shaped surface 24.
  • the cup shaped nature of the body 23 facilitates assembly of the cathode for the butt-welding operation.
  • Figure 3 is a modification of Figure 2 and in which the cupshaped body 8 of molybdenum of other refractory material containing emissive compounds 2 and mounted on a hollow refractory metal member 9 is sealed by a fiat porous plate member 6 welded thereto at edge 5.
  • a large area of surface contact between bodies 8 and 9 facilitates the transmission of heat to the emissive compound 2 from the coil d in the body 9.
  • Figure 4 shows an embodiment of the invention in which a cavity containing emissive compounds 2 is formed by an outer cylindrical body l0 of porous refractory material andan inner cylindrical refractory metal member ll having centric cylinders I3 of porous refractory material and I4 of refractory metal, the inner cylinder I4 having end portions I5 expanded in the direction of the outer cylinder I3 and welded thereto at outer edges 5.
  • the heating coil is positioned along the axis of the concentric cylinders I4 and passes through the ends thereof.
  • the cathode in Figure 6 is similar to that of Figure 5 the seal of the cavity however being affected in this structure by ring members I6 butt welded to the concentriccylinders I3 and I4 at edges 5 and 25.
  • the cylinder I3 of porous refractory material surrounding the emissive material 2 has butt welded to each of its ends a hollow refractory metal member 3 enclosing a heating coil 4.
  • Such a structure assists in the achievement of uniform -heating and is particularly advantageous in cases where the cylinder I3 is required Ato be elongated.
  • the cathode 'body of Figure 9 has improved uniform-'heating characteristics over that of the structure of Figure 7 achieved by a pin-like extension of the refractory metal member I'I.
  • the extension I8 is positioned in the body I in direct contact with the emissive material 2.
  • a cylindrical capl I of porous refractory material contains a supply of emissive material 2 insulated from a heating coil 4 by a coating of material on the coil.
  • the cap I is sealed by a plate I9 of refractory material butt welded to the cap at edge 5.
  • the capv I9 is provided with apertures through which the leads of the heating coil 4 pass in electrically insulating relation being tightly sealed to the plate I9- at the edges of the apertures by an insulating material such as thorium oxide.
  • the cathode of Figure 11 is adapted for direct heating of the body I3 of porous refractory material which surrounds the emissive material 2 and is sealed by refractory metal plates 2
  • Fig. 12 the cathode parts 3 and 1 are clamped against each other by means of the arms 23 and 21 of the welding apparatus.
  • the emissive material 2 is present in the cavity formed by ⁇ the depression 24 .
  • the arm 26 extends within the skirt 23 and on the upper arm 21 a pressure of -about 20 kilograms is exerted when thediameter of 6 is about 3 mm.
  • the upper arm 27 is hinged in an insulating block 28 against which arm 26 is secured.
  • ⁇ A welding transformer 29 is connected with a secondary winding 30 to arms 2G and 21.
  • may be connected to a battery 32 of condensers by switch 33 which in the other position connects the battery 32 to a rectifier 34.
  • the battery 32 of about 1000 pf. is charged to about 550 volts. In this way a satisfactory tight seal between the porous Wall body B and the 4 cathode body 1 is obtained.
  • the term buttwelded join as employed in the claims is delined ⁇ as a joint between two metal member formed by bringing the metal members into abutting relationship to establish physical contact between the ends of the metal members, applying longitudinal pressure to both metal members and passing Van electrical current through the two members to fuse the ends of the members into a homogeneous metal structure.
  • a method of making a thermionic cathode comprising the steps of placing Within an open cavity of a member of refractory metal a supply of alkaline earth compound subject to deteriorationby heat, placing over the opening of the cavity a member of sintered refractory metal fhaving a porous portion, and locally heating abutting surface portions of said members by pressing said members together while passing through the connection between the membersY an electrical current of such intensity and duration as to form a fused joint without deleteriously affecting the alkaline earth compounds.
  • a method of making a thermionic cathode comprising the steps of placing within an open cavity of a member of refractory metal a supply of alkaline earth compounds subject to deterioration by heat, placing over the opening of the cavity a sintered tungsten member having a porous portion, and locally heating abutting surface portions of said members by pressing said members together while passing through the' connection between the members a condenser current discharge of such intensity and duration as to form a fused joint Without deleteriously affecting the alkaline earth compounds.
  • a method of making a thermionic cathode comprising the step of placing within an open cavity of a member of refractory metal a supply of alkaline earth compounds subject to deterioration by heat, placing over the opening of the cavity a sintered tungsten member having a porous portion, and locally heating abutting surface portions of said members by pressing said members together with a pressure of about 20 kgms. while passing through the connection between the members a condenser discharge of such intensity and duration as to form a fused joint without deleteriously aecting the alkaline earth compounds.

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  • Solid Thermionic Cathode (AREA)
  • Powder Metallurgy (AREA)
US191341A 1949-10-25 1950-10-21 Incandescible cathode and method of making the same Expired - Lifetime US2673277A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL292225X 1949-10-25

Publications (1)

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US2673277A true US2673277A (en) 1954-03-23

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Country Status (6)

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US (1) US2673277A (it)
BE (1) BE498869A (it)
CH (1) CH292225A (it)
DE (1) DE837273C (it)
FR (1) FR1026424A (it)
GB (1) GB675456A (it)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2798182A (en) * 1951-07-12 1957-07-02 Siemens Ag Dispenser cathode having heater embedded in densely sintered receptacle wall
US2808531A (en) * 1952-03-24 1957-10-01 Siemens Ag Cathode for electrical discharge tubes
US2814754A (en) * 1952-08-28 1957-11-26 Raytheon Mfg Co Indirectly-heated cathodes
US2830218A (en) * 1953-09-24 1958-04-08 Gen Electric Dispenser cathodes and methods of making them
US2869017A (en) * 1956-10-24 1959-01-13 Philips Corp Thermionic dispenser cathode
US2895070A (en) * 1955-08-23 1959-07-14 Philips Corp Thermionic cathode
US2902621A (en) * 1953-03-04 1959-09-01 Egyesuelt Izzolampa Supply cathode
US2902620A (en) * 1953-03-04 1959-09-01 Egyesuelt Izzolampa Supply cathode
US2912611A (en) * 1953-08-14 1959-11-10 Int Standard Electric Corp Thermionic cathodes
US2913812A (en) * 1954-06-16 1959-11-24 Csf Manufacture of sintered cathodes
US2988666A (en) * 1953-12-22 1961-06-13 Philips Corp Cylindrical dispenser cathode for magnetrons
US3010826A (en) * 1951-03-22 1961-11-28 Philips Corp Method of making dispenser type cathodes
US4299627A (en) * 1978-09-11 1981-11-10 Toyota Jidosha Kogyo Kabushiki Kaisha Method of manufacturing oxygen sensing element
US4310775A (en) * 1978-09-27 1982-01-12 Siemens Aktiengesellschaft Dispenser cathode, particularly a metal capillary cathode
EP0272881A2 (en) * 1986-12-19 1988-06-29 Kabushiki Kaisha Toshiba Indirectly heated cathode structure for electron tubes
US5128584A (en) * 1990-03-13 1992-07-07 Samsung Electron Devices Co., Ltd. Impregnated cathode

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL97571C (it) * 1953-11-18
DE1021956B (de) * 1953-12-22 1958-01-02 Siemens Ag Verfahren zur Herstellung einer Kathode fuer elektrische Entladungsgefaesse

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2011121A (en) * 1934-06-06 1935-08-13 Smith Corp A O Method of making welded irregular shaped hollow articles
US2021119A (en) * 1934-06-22 1935-11-12 Mccord Radiator & Mfg Co Method of making pressure cartridges
US2121589A (en) * 1934-06-28 1938-06-21 Westinghouse Electric & Mfg Co Emissive incandescent cathode
US2131204A (en) * 1936-01-15 1938-09-27 Siemens Ag Indirectly heated thermionic cathode
US2354947A (en) * 1940-08-30 1944-08-01 Thompson Prod Inc Hollow head poppet valve
US2375808A (en) * 1943-02-16 1945-05-15 Samuel C Miller Electrode for luminous tubes
US2492619A (en) * 1948-01-02 1949-12-27 Sylvania Electric Prod Electrical discharge tube
US2506747A (en) * 1946-06-18 1950-05-09 Smith Roger Olof Device for the end welding of studs
US2543728A (en) * 1947-11-26 1951-02-27 Hartford Nat Bank & Trust Co Incandescible cathode

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2011121A (en) * 1934-06-06 1935-08-13 Smith Corp A O Method of making welded irregular shaped hollow articles
US2021119A (en) * 1934-06-22 1935-11-12 Mccord Radiator & Mfg Co Method of making pressure cartridges
US2121589A (en) * 1934-06-28 1938-06-21 Westinghouse Electric & Mfg Co Emissive incandescent cathode
US2131204A (en) * 1936-01-15 1938-09-27 Siemens Ag Indirectly heated thermionic cathode
US2354947A (en) * 1940-08-30 1944-08-01 Thompson Prod Inc Hollow head poppet valve
US2375808A (en) * 1943-02-16 1945-05-15 Samuel C Miller Electrode for luminous tubes
US2506747A (en) * 1946-06-18 1950-05-09 Smith Roger Olof Device for the end welding of studs
US2543728A (en) * 1947-11-26 1951-02-27 Hartford Nat Bank & Trust Co Incandescible cathode
US2492619A (en) * 1948-01-02 1949-12-27 Sylvania Electric Prod Electrical discharge tube

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3010826A (en) * 1951-03-22 1961-11-28 Philips Corp Method of making dispenser type cathodes
US2798182A (en) * 1951-07-12 1957-07-02 Siemens Ag Dispenser cathode having heater embedded in densely sintered receptacle wall
US2808531A (en) * 1952-03-24 1957-10-01 Siemens Ag Cathode for electrical discharge tubes
US2814754A (en) * 1952-08-28 1957-11-26 Raytheon Mfg Co Indirectly-heated cathodes
US2902621A (en) * 1953-03-04 1959-09-01 Egyesuelt Izzolampa Supply cathode
US2902620A (en) * 1953-03-04 1959-09-01 Egyesuelt Izzolampa Supply cathode
US2912611A (en) * 1953-08-14 1959-11-10 Int Standard Electric Corp Thermionic cathodes
US2830218A (en) * 1953-09-24 1958-04-08 Gen Electric Dispenser cathodes and methods of making them
US2988666A (en) * 1953-12-22 1961-06-13 Philips Corp Cylindrical dispenser cathode for magnetrons
US2913812A (en) * 1954-06-16 1959-11-24 Csf Manufacture of sintered cathodes
US2895070A (en) * 1955-08-23 1959-07-14 Philips Corp Thermionic cathode
US2869017A (en) * 1956-10-24 1959-01-13 Philips Corp Thermionic dispenser cathode
US4299627A (en) * 1978-09-11 1981-11-10 Toyota Jidosha Kogyo Kabushiki Kaisha Method of manufacturing oxygen sensing element
US4310775A (en) * 1978-09-27 1982-01-12 Siemens Aktiengesellschaft Dispenser cathode, particularly a metal capillary cathode
EP0272881A2 (en) * 1986-12-19 1988-06-29 Kabushiki Kaisha Toshiba Indirectly heated cathode structure for electron tubes
US4820954A (en) * 1986-12-19 1989-04-11 Kabushiki Kaisha Toshiba Indirectly heated cathode structure for electron tubes
EP0272881A3 (en) * 1986-12-19 1989-10-04 Kabushiki Kaisha Toshiba Indirectly heated cathode structure for electron tubes
US5128584A (en) * 1990-03-13 1992-07-07 Samsung Electron Devices Co., Ltd. Impregnated cathode

Also Published As

Publication number Publication date
GB675456A (en) 1952-07-09
BE498869A (it)
DE837273C (de) 1952-04-21
FR1026424A (fr) 1953-04-28
CH292225A (de) 1953-07-31

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