US3806754A - Electric discharge tube comprising a mesh grid - Google Patents

Electric discharge tube comprising a mesh grid Download PDF

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Publication number
US3806754A
US3806754A US00329235A US32923573A US3806754A US 3806754 A US3806754 A US 3806754A US 00329235 A US00329235 A US 00329235A US 32923573 A US32923573 A US 32923573A US 3806754 A US3806754 A US 3806754A
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US
United States
Prior art keywords
grid
wire elements
wires
electric discharge
discharge tube
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
US00329235A
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English (en)
Inventor
K Hinkel
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.)
US Philips Corp
Original Assignee
US Philips Corp
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 US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3806754A publication Critical patent/US3806754A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H01J19/28—Non-electron-emitting electrodes; Screens
    • H01J19/38—Control electrodes, e.g. grid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0015—Non-sealed electrodes
    • H01J2893/0017—Cylindrical, helical or annular grids

Definitions

  • the invention relates to an electric discharge tube comprising one or more cylindrical grids which are constructed from wires of molybdenum or a different metal having a high melting point, which wires are wound according to left and according to right helical lines and extend on either side along a same cylinder surface and welded together at the intersections.
  • Such a grid is known by the name of mesh grid and in known from the US. Pat. No. 2.795.726. Grids construct'ed in this manner which are often used as control electrodes in tubes having a high output power, maintain in general a sufficient mechanical stability in normal operating conditions. However, the temperatures to which the grid is subjected during operation of the tube are not an absolute measure of the required mechanical stability of the grid. The grid must also capable of withstanding extremely high temperatures during the manufacture. It is known, for example, from German Patent Specification 1,051,991 to check the thermal electron emission of such a grid occurring at high temperature by covering the wires of the grid with a thin layer of zirconium carbide which itself is covered again with a thin layer of platinum or gold. The zirconium carbide is provided on the grid wires in a furnace and under a neutral atmosphere by sintering at a temperature of approximately 2000C. It has been found,
  • the mesh grid according to the invention comprises in addition to the thin wires of approximately the same cross-section a few thicker wires which are incorporated in the grid according to the same pattern and which, as regards position, are regularly distributed on the circumference of the grid.
  • the mechanically reinforced grid is furthermore known from German Patent Specification No. 1,108,814.
  • This specification also relates to a wirewound grid.
  • Some of the supporting wires which in this case are equally thick or even thinner than the original grid wire are added to the grid longitudinally and others according to turns having a larger pitch than that of the grid wire, so as to shift the resonant frequency of the grid to higher frequencies.
  • the reinforcement wires are provided according to the same pattern as the grid wires.
  • the original grid pattern is not disturbed, while in addition a particularly effective reinforcement of the grid is obtained.
  • the contribution of the reinforcement wires to the rigidity of the grid is optimum if both the grid wires and the reinforcement wires enclose an angle of substantially 45 with the longitudinal axis of the grid.
  • the invention is used in particular in mesh grids having an axial length of more than 200 mm.
  • the diameter of the thick wires is from one-and-a-half to three times the diameter of the thin wires, the number of thick wires being from five to fifteen times smaller than the number of thin wires.
  • the grid comprises, for example 46 wires I wound according to left helical lines and, for example, 46 wires 2 wound according to right helical lines.
  • the length of the grid is, e.g., 276 mm, the diameter is, e.g.,
  • the pitch at which the molybdenum wires are wound is, e.g., 261 mm.
  • the wires are welded together.
  • the grid comprises, in addition to wires 1 having a diameter of, e.g., 0.325 mm, a few wires 4 which have a diameter of, e.g., 0.6 mm and likewise consist of molybdenum.
  • the arrangement of said thick wires 4 is such that between two successive thick wires 4 wound in the same sense alternatively, 10 or 1] thin wires, for example, are present.
  • An electric discharge tube including at least one cylindrical grid, said grid comprising first and second sets of wire elements of high melting point metal, said wire elements of said first and second sets extending along substantially the same cylindrical surface and forming respectively left and right helices, said wire elements being welded together at their intersecting places, said first and second sets individually comprising both relatively thin said wire elements and relatively thick said wire elements interspersed among said relatively thin wire elements.

Landscapes

  • Solid Thermionic Cathode (AREA)
  • Electrostatic Separation (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Gas-Filled Discharge Tubes (AREA)
US00329235A 1972-02-05 1973-02-02 Electric discharge tube comprising a mesh grid Expired - Lifetime US3806754A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7201534A NL7201534A (fr) 1972-02-05 1972-02-05

Publications (1)

Publication Number Publication Date
US3806754A true US3806754A (en) 1974-04-23

Family

ID=19815300

Family Applications (1)

Application Number Title Priority Date Filing Date
US00329235A Expired - Lifetime US3806754A (en) 1972-02-05 1973-02-02 Electric discharge tube comprising a mesh grid

Country Status (8)

Country Link
US (1) US3806754A (fr)
JP (1) JPS4889674A (fr)
CA (1) CA975418A (fr)
CH (1) CH552282A (fr)
DE (1) DE2303776C3 (fr)
FR (1) FR2170208B1 (fr)
GB (1) GB1368542A (fr)
NL (1) NL7201534A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3976909A (en) * 1975-07-11 1976-08-24 Rca Corporation Wire mesh cathode

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2277148A (en) * 1941-01-30 1942-03-24 Bell Telephone Labor Inc Electrode for electron discharge devices
US2882436A (en) * 1955-04-02 1959-04-14 Philips Corp Electric discharge tube and cathode therefor
US3172002A (en) * 1960-11-21 1965-03-02 Rca Corp Cathode mount and method of fabrication

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4329650Y1 (fr) * 1965-11-15 1968-12-05

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2277148A (en) * 1941-01-30 1942-03-24 Bell Telephone Labor Inc Electrode for electron discharge devices
US2882436A (en) * 1955-04-02 1959-04-14 Philips Corp Electric discharge tube and cathode therefor
US3172002A (en) * 1960-11-21 1965-03-02 Rca Corp Cathode mount and method of fabrication

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3976909A (en) * 1975-07-11 1976-08-24 Rca Corporation Wire mesh cathode

Also Published As

Publication number Publication date
FR2170208B1 (fr) 1977-08-26
CA975418A (en) 1975-09-30
DE2303776A1 (de) 1973-08-09
JPS4889674A (fr) 1973-11-22
NL7201534A (fr) 1973-08-07
DE2303776B2 (de) 1977-12-15
GB1368542A (en) 1974-09-25
FR2170208A1 (fr) 1973-09-14
CH552282A (de) 1974-07-31
DE2303776C3 (de) 1978-08-10

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