US3567982A - Electron discharge device anode fin having heat distortion preventive means incorporated therein - Google Patents

Electron discharge device anode fin having heat distortion preventive means incorporated therein Download PDF

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Publication number
US3567982A
US3567982A US786185A US3567982DA US3567982A US 3567982 A US3567982 A US 3567982A US 786185 A US786185 A US 786185A US 3567982D A US3567982D A US 3567982DA US 3567982 A US3567982 A US 3567982A
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United States
Prior art keywords
fin
anode
heat distortion
preventive means
cathode
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
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US786185A
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English (en)
Inventor
Cyril Droppa
Charles C Hendrickson
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GTE Sylvania Inc
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Sylvania Electric Products Inc
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Publication date
Application filed by Sylvania Electric Products Inc filed Critical Sylvania Electric Products Inc
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Publication of US3567982A publication Critical patent/US3567982A/en
Assigned to NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP. reassignment NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP. ASSIGNS ITS ENTIRE RIGHT TITLE AND INTEREST, UNDER SAID PATENTS AND APPLICATIONS, SUBJECT TO CONDITIONS AND LICENSES EXISTING AS OF JANUARY 21, 1981. (SEE DOCUMENT FOR DETAILS). Assignors: GTE PRODUCTS CORPORATION A DE CORP.
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Expired - Lifetime legal-status Critical Current

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    • 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
    • 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
    • H01J2893/0013—Sealed electrodes

Definitions

  • the leading edges of the fins which extend close to the cathode, are subject to very high current densities and consequently very high temperatures.
  • the high temperatures cause the fin material to expand along the leading edge thereof.
  • the repeated expansion and contraction that occurs during the operating life of the tube, for example, in a television receiver, causes the material to stretch, and the leading edge of the fin to become permanently deformed. This deformation may appear as a side-to-side rippled effect along the edge or may even produce a twisting action which exposes the side of the fin to the cathode of the tube.
  • the tube characteristics are adversely affected.
  • the anode or plate current decreases, and the screen grid current increases, thus decreasing the plate to screen current ratio.
  • the inefiicient operation that results therefrom further raises tube temperatures and makes the tube susceptible to control grid and screen grid emission and their associated problems.
  • This chain of events has a detrimental effect on overall tube performance, reliability, and life expectancy.
  • these effects are manifested in a decrease in the width of the scan and a reduction in the high voltage to the picture tube. If the fin distortion becomes severe enough, it may cause the fin to short out to either the beam plate or the screen grid, thus rendering the tube inoperative.
  • FIG. 1 there is shown an electron discharge device 10 of a type known as a beam power tube and used, for example, as a horizontal deflection amplifier in television receivers.
  • the device 10 is comprised of a glass envelope 12 and an electrode cage 14 which is positioned between a pair of supporting micas 16, only one of which is shown.
  • the electrode cage comprises a cathode 18 having an electron emissive material 20 thereon, a control grid 22, a screen grid 24, a beam-confining plate 26, and an anode 28 having anode fin 30 projecting inwardly of the cage toward the cathode.
  • heat-radiating wings 32 may be attached to the fin 30 or to some other suitable location on the anode 28.
  • the anode or plate 28 is comprised of halves 34 and 36 having, respectively, end walls 38 and 40. Oppositely disposed sidewalls 42 and 44 project from end wall 38 and are formed to provide outwardly extending longitudinal joining flanges 46 and 48 at the portion thereof remote from end wall 38.
  • oppositely disposed sidewalls 50 and 52 project from end wall 40 and are formed to provide outwardly extending longitudinal joining flanges 54 and 56 at the portion thereof remote from end wall 40.
  • Anode fins 30 are fixedly positioned between pairs of the joining flanges so that their leading edges 58 project inwardly toward the cathode.
  • the fins 30 may be comprised of a substantially U-shaped, double thickness of material, as shown in FIG. 1, as two spaced-apart, parallel members of single thickness, as shown in FIG. 2, or as a single thickness of material.
  • the invention disclosed herein is equally adaptable to any of the above-described fin designs.
  • the anode 28 and fins 30 for this type of tube are generally fabricated from high expansion alloys; i.e., alloys having a coefficient of expansion in the neighborhood of 20 X 10"/ C/in.
  • high expansion alloys i.e., alloys having a coefficient of expansion in the neighborhood of 20 X 10"/ C/in.
  • a plate fin 1.75 inches long would experience an expansion of .021 inches at 600 C. This, however, is true for a fin that is at a uniform temperature and that is free to expand in all directions without hindrance.
  • the plate fin has a very pronounced temperature gradient along the leading edge and also from the edge back to the main portion of the plate.
  • the back of the fin is staked tightly to the main plate structure and is not free to expand. It is these conditions that produce such severe'deformation and buckling of the fins.
  • the material from which the plate and fin are fabricated is bimetallic; for example, copper-cored nickel or aluminum-coated steel.
  • This material is bimetallic; for example, copper-cored nickel or aluminum-coated steel.
  • the unequal temperature distribution over the surface of the fin together with the bimetallic effect of the dissimilar layers produces severe stresses in the fin. These stresses and the bimetallic effect cause the fin to bend in a sideways direction. After repeated heating and cooling with the consequent application of stress, the material crystallizes and becomes permanently deformed and will not return to its original shape.
  • the heat distortion preventive means 60 in the instant concept, take the form of expansion openings 62.
  • these openings 62 are configured as substantially V-shaped notches 64. They are three in number, substantially equally spaced-apart in the embodiment shown, but this number may vary depending upon the length of the fin.
  • FIG. 4 the openings are provided in the form of rectangular slots 66, spaced as in the embodiment described above.
  • FIG. 5 is shown the locking tabs 68 which lock the rear portion of the fins 30 to the flanges on the anode halves.
  • the expansion openings 62 in the leading edges of the fins 30 allow controlled expansion thereof during operation without undesirable stresses being applied and the consequent buckling thereof which was so detrimental to prior art devices.
  • either the fins 30 and the main portion of the anode 28 or both may be provided with laterally extending reinforcing beads 70.
  • both the fins and anode are provided with the beads 70, they should be aligned, as is shown in FIG. 5. Also, the beads on the fins should be equally spaced between the expansion openings.
  • the heat distortion preventive means greatly enhance the operating characteristics of the device.
  • the anode fin is far more durable than prior art tins and the device itself has an increased life expectancy with greater stability of operating characteristics over the life thereof.
  • an electron discharge device having a cathode and at least one grid; an anode surrounding said cathode and said grid; and a fin formed to project inwardly of said anode to a point closer to said cathode than any part of said anode, the improvement comprising: heat distortion preventive means incorporated in said fin.
  • said heat distortion preventive means comprises a plurality of expansion openings formed in the edge of said fin facing said cathode.

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  • Lasers (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
US786185A 1968-12-23 1968-12-23 Electron discharge device anode fin having heat distortion preventive means incorporated therein Expired - Lifetime US3567982A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US78618568A 1968-12-23 1968-12-23

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US3567982A true US3567982A (en) 1971-03-02

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US (1) US3567982A (enrdf_load_stackoverflow)
GB (1) GB1259216A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3866076A (en) * 1972-12-29 1975-02-11 Philips Corp Electric discharge tube, comprising a highly loaded anode
USRE29390E (en) * 1972-12-29 1977-09-06 U.S. Philips Corporation Electric discharge tube, comprising a highly loaded anode
US4439684A (en) * 1980-05-16 1984-03-27 Kernforschungsanlage Julich Gesellschaft Mit Beschrankter Haftung Accelerating grid
US4779022A (en) * 1986-07-30 1988-10-18 Siemens Aktiengesellschaft Cooling structure for a screen grid electron tube such as a transmitter tetrode

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3866076A (en) * 1972-12-29 1975-02-11 Philips Corp Electric discharge tube, comprising a highly loaded anode
USRE29390E (en) * 1972-12-29 1977-09-06 U.S. Philips Corporation Electric discharge tube, comprising a highly loaded anode
US4439684A (en) * 1980-05-16 1984-03-27 Kernforschungsanlage Julich Gesellschaft Mit Beschrankter Haftung Accelerating grid
US4779022A (en) * 1986-07-30 1988-10-18 Siemens Aktiengesellschaft Cooling structure for a screen grid electron tube such as a transmitter tetrode

Also Published As

Publication number Publication date
GB1259216A (enrdf_load_stackoverflow) 1972-01-05

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AS Assignment

Owner name: NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP.,

Free format text: ASSIGNS ITS ENTIRE RIGHT TITLE AND INTEREST, UNDER SAID PATENTS AND APPLICATIONS, SUBJECT TO CONDITIONS AND LICENSES EXISTING AS OF JANUARY 21, 1981.;ASSIGNOR:GTE PRODUCTS CORPORATION A DE CORP.;REEL/FRAME:003992/0284

Effective date: 19810708

Owner name: NORTH AMERICAN PHILIPS CONSUMER ELECTRONICS CORP.

Free format text: ASSIGNS ITS ENTIRE RIGHT TITLE AND INTEREST, UNDER SAID PATENTS AND APPLICATIONS, SUBJECT TO CONDITIONS AND LICENSES EXISTING AS OF JANUARY 21, 1981.;ASSIGNOR:GTE PRODUCTS CORPORATION A DE CORP.;REEL/FRAME:003992/0284

Effective date: 19810708