US3450924A - Sealing means for refractory ceramic discharge device envelopes - Google Patents

Sealing means for refractory ceramic discharge device envelopes Download PDF

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Publication number
US3450924A
US3450924A US640528A US3450924DA US3450924A US 3450924 A US3450924 A US 3450924A US 640528 A US640528 A US 640528A US 3450924D A US3450924D A US 3450924DA US 3450924 A US3450924 A US 3450924A
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United States
Prior art keywords
ceramic
discharge device
refractory metal
arc tube
arc
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Expired - Lifetime
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US640528A
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English (en)
Inventor
William J Knochel
Francis C M Lin
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Philips North America LLC
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Westinghouse Electric Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/36—Seals between parts of vessels; Seals for leading-in conductors; Leading-in conductors

Definitions

  • a ceramic discharge device including a polycrystalline alumina, tubular envelope hermetically sealed at each end by a refractory metal or refractory ceramic closure member.
  • An axially extending electrode is mounted interiorly of each closure member and a lead-in conductor is electrically connected to said electrode through said closure member.
  • the closure members sealing oif the ends of the envelope have a generally frustoconically-shaped interior surface tapering from a larger diameter adjacent the arc sustaining electrode to a smaller diameter adjacent the electrode mount thereby reducing the volume of the area behind the electrodes.
  • This invention relates to ceramic discharge devices and more particularly to the improved construction of a ceramic arc tube for high temperature discharge la'mps.
  • Another object of the present invention is to reduce the temperature encountered by the hermetic seals employed to seal olf the arc tube.
  • a further object of the present invention is to provide a ceramic discharge device in which the temperature of the arc can be increased through structural configuration of the device to improve the color and efficiency of the lamp.
  • a hermetically sealed ceramic discharge device including a tubular light transmitting ceramic envelope sealed at each end by a closure means which carries a discharge sustaining electrode secured centrally on the interior surface of each of the closure means and lead-in conductors electrically connected to each of the electrodes through said closure means and in which the closure means includes a conically shaped interior surface tapering from a larger diameter adjacent the interiorly extending end of the adjacent electrode to a smaller diameter adjacent the other end of the electrode.
  • FIG. 1 is a sectional view of the ends of a ceramic arc tube constructed in accordance with the present invention
  • FIG. 2 is a sectional view of the tubulation end of another embodiment of a ceramic discharge lamp constructed in accordance with the present invention
  • FIG. 3 is a sectional View of yet another embodiment of the present invention similar to FIG. 2;
  • FIGS. 4 and 5 are sectional views of the tubulation ends of ceramic discharge devices illustrating still further embodiments of the present invention.
  • FIG. 6- is a sectional view of the ends of a ceramic discharge device illustrating a still further embodiment of the present invention.
  • FIGS. 7 and S illustrate, in cross section, still further embodiments which the ends of the arc tube may take in accordance with the present invention.
  • the main tubular body member is generally hermetically sealed with a closure member in the form of a refractory metal or refractory oxide cap or disc at each end.
  • the cap or disc generally has mounted on its interior surface an arc sustaining elec-- trode with a lead-in conductor in the form of a refractory metal strip or refractory metal tubulation secured to or through the external side of the end cap or disc in electrical connection with the electrodelIn the conventional ceramic arc tube the internal volume of the hermetically sealed chamber is of a uniform diameter from the internal surface of one closure member to the other.
  • the internal diameter of the portion of the enclosed volume is substantially decreased in the area of the arc tube between the electrode ⁇ and its adjacent closure member.
  • refractory metal cones 14 preferably of tantalum are secured within each end of the ceramic arc tube 12 by means of a suitable sealing composition at 16.
  • a suitable sealing composition at 16 preferably of tantalum
  • sealing compositions may be used effectively, where reference to sealing compositions are made throughout this application it is preferable that the sealing compositions ⁇ described in the copending application Ser. No. 562,016, led June 30, 1966', by Richard B. Grekila, Shih Ming Ho, William J. Knochel and Francis C. M. Lin and owned by the present assignee, are preferable.
  • These sealing compositions in general comprise CaO and A1203 in nearly eutectic proportions plus selective additives oxides.
  • the area between the refractory metal cones 14 and the Walls of the tubular envelope 12 are then filled with a mixture of aluminum oxide powder and amyl acetate or alternatively a preformed ceramic plug 18.
  • An end cap or disc 20 is then sealed by means of the above referred to sealing compositions to the aluminum oxide fill and the polycrystalline alumina envelope as indicated at 22.
  • the end cap or disc 20 preferably carries at ⁇ one end a refractory metal exhaust and fill tubulation 24 brazed thereto and extending therethrough on which is mounted a discharge sustaining electrode 26.
  • the other end of the arc tube may be sealed off identically with tubulati-on 24 or as illustrated on the right-hand side of FIG.
  • a refractory metal disc preferably of niobium having welded thereto a second discharge 4sustaining electrode 26 on the interior surface and a refractory metal lead-in conductor 28, preferably in the form of a tantalum strap, welded to the outer surface thereof.
  • the sealed configuration with its conical refractory metal interior surface with a large diameter to small diameter ratio of about 2:1 substantially reduces the enclosed area behind each of the electrodes thus reducing cold spot temperatures. Additionally the surface of the tantalum cone reflects radiation back to the arc which also assists in raising the arc temperature to thereby produce better c-olor particularly in the red and increased lamp efficiencies of from l to 20%. Not the least of the advantages of the present construction is the fact that the seals at 22 are substantially insulated from the high temperatures of the arc, which reduction in seal temperature contributes -greatly to the life of the lamp.
  • a preformed ceramic plug 30 is sealed to the ends and along the interior surface of the arc tube 12 by means of the above described sealing compositions as for example at 32.
  • the same sealing compositions are employed to seal refractory metal tubulation 24 with its associated electrode 26 through a central bore in the preformed ceramic plug 30 as for example at 34.
  • this embodiment provides an extended seal area 32 to ensure a good hermetic seal at each end of the arc tube 12.
  • the -other end ⁇ of the arc tube may be sealed off similarly with refractory metal tubulation or alternatively have sealed lthrough a substantially smaller central opening a single lead-in conductor electrode combination.
  • FIG. 3 is quite similar to that of FIG. 2 but has as an addition an extension 36 to ceramic plug 30.
  • a niobium end cap 37 is secured by the previously referred to sealing compositions to the end of the extension 36 in order that a titanium or zirconium braze can be employed at 38 to seal the electrode carrying exhaust and fill tubulation 24 to the plug closure member.
  • This configuration provides for even greater insulation of the seal from the high temperature arc while providing for metal to 4'met-al sealing to the tubulation or lead-in conductor.
  • FIG. 4 combines the advantages of the FIG. 1 and FIG. 2 embodiments by eliminating the requirement for a metallic end disc or cap while still having the reective characteristics of a refractory metal interior surface on the conical insert.
  • a refractory metal, preferably tantalum, cone 14 is sealed within the end of the arc tube and a ceramic cylinder having a complementary tapered conical interior surface inserted within the end of the arc tube to fill the gap between the refractory metal cone and the interior surface of the arc tube body member 12.
  • both the refractory metal cone and the ceramic cylinder are sealed to the interior wall of the arc tube by the sealing composition at 32 and the seal is completed by the application of a titanium braze at 42 to the refractory metal tubulation 24.
  • FIG. 5 embodiment is substantially identical with the FIG. 4 embodiment except that the ceramic cylinder 40 is replaced with a packing material, preferably quartz Wool, 44 which provides additional insulation between the high temperature internal arc tube area and the sealing compositions 32.
  • a packing material preferably quartz Wool
  • a double walled cup 46 of refractory metal such as for example tantalum or niobium has a conical inner Wall ⁇ 48 the inner surface of which operates as described in the preceding embodiments.
  • the radial flange 49 of the cup extends from the outer wall 47 and to the ceramic body member 12 as illustrated at 50 by the above described sealing compositions or the radial flange 49 may be turned over and the entire surf-ace of the body member 12 which contacts the cup member 46 sealed thereto by the sealing com-positions as indicated at 50 ⁇ in FIG. 7.
  • the tantalum tubulation may then Ibe sealed to a central bore in the double walled cup member 46 by a zirconium or titanium braze as illustrated at 52. If one of the ends is desired to be sealed without exhaust and fill tubulation the central bore in the cone shaped cup is eliminated and a -discharge sustaining electrode 26 may be welded directly to the interior surface of the cone and a lead-in conductor 28 welded to the exterior surface centrally thereof.
  • a refractory metal plug 56 may be inserted into the tubulation 24.
  • the actual seal area is again comparatively remote from the hot arc chamber and the inner wall with its internal conical surface is free to expand and contract during temperature changes incident to starting and stopping the lamp and hence additionally reduces any strains which might act upon the seal areas.
  • FIG. 8 embodiment is somewhat similar to the embodiments of FtIGS. 6 and 7.
  • a cup shaped refractory metal member of niobium or tantalum 58 is sealed into the end of the arc tube 12 by one of the preferred sealing compositions as illustrated at 60 while a refractory metal tubulation 24 with its associated discharge sustaining electrode 26 is sealed into an aperture in the bottom of the cup shaped member by means of a zirconium or titanium braze as illustrated at 62.
  • the materials employed are substantially reduced, the expansion and contraction characteristics are retained to a limited extent and the volume of the area behind each of the discharge sustaining electrodes is slightly reduced.
  • closure members for ceramic discharge devices described in the foregoing ⁇ paragraphs considerably reduce the area of the arc sustaining volume behind each of the electrodes, substantially insulates the seal areas from the hot arc sustaining enclosed volume to reduce seal tempeartures and provides for the reflection of radiation directed at the ends of the arc tube back into the arc to improve the temperature of the arc and hence create better color and efficiency in the lamp.
  • light outputs have been increased from about lumens per watt to as high as 120l lumens per watt with the present end closure construction while at the same time color rendition, particularly of the reds, has been signticantly improved.
  • a hermetically sealed ceramic discharge device comprising:
  • closure means hermetically sealing otf each end of said ceramic envelope
  • electrode means including a discharge sustaining electrode secured centrally on an interior surface of each of said closure means and extending substantially axially of said envelope;
  • a hermetically sealed ceramic discharge device according to claim 1 wherein said closure means is a ceramic plug.
  • a hermetically sealed ceramic discharge device 1 wherein the conically shaped interior surface of said closure member is a refractory metal.
  • a hermetically sealed ceramic discharge device according to claim 2 wherein the conically shaped interior surface of said ceramic plug is a refractory metal.
  • a hermetically sealed ceramic discharge device according to claim 4 wherein said refractory metal on the interior surface of said ceramic plug is tantalum.
  • a hermetically sealed ceramic discharge device according to claim 1 wherein said closure means comprises a double walled refractory metal cup with one of said walls sealed to said envelope and the other of said walls forming said conically shaped interior surface.
  • a ceramic discharge device comprising:
  • closure means sealing olf each end of said ceramic envelope, said closure means having a cone shaped interior surface extending about an axis coextensive with the axis of said tubular envelope with the largest diameter of said cone shaped surface nearest the longitudinal middle of said envelope;
  • discharge sustaining means including an electrode and a lead-in conductor secured to each of said closure means, said electrode extending internally of said envelope with at least a portion thereof lying within said cone shaped surface, and said lead-in conductor extending externally of said sealed envelope.
  • a discharge device includes a cylindrical ceramic plug having an outer diameter substantially equal to the internal diameter of said envelope and an internal bore forming said cone shaped surface.
  • a discharge device wherein said internal bore is covered by a thin walled refractory metal cone.
  • a ceramic discharge device comprises a double walled refractory metal cup with one of said walls sealed to said envelope and the other of said walls forming said cone shaped interior surface.

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  • Vessels And Coating Films For Discharge Lamps (AREA)
US640528A 1967-05-23 1967-05-23 Sealing means for refractory ceramic discharge device envelopes Expired - Lifetime US3450924A (en)

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US64052867A 1967-05-23 1967-05-23

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US (1) US3450924A (xx)
BE (1) BE715443A (xx)
DE (1) DE1764299C3 (xx)
FR (1) FR1563563A (xx)
GB (1) GB1178091A (xx)
NL (1) NL6807165A (xx)

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3604972A (en) * 1970-02-25 1971-09-14 Us Army Metal vapor lamp with alkali metal reservoir means
US3657588A (en) * 1970-01-19 1972-04-18 Varian Associates Envelope structure for high intensity three electrode arc lamps incorporating heat shielding means
US3716743A (en) * 1969-08-29 1973-02-13 Matsushita Electronics Corp High-pressure metal-vapor discharge tube
US3731133A (en) * 1972-01-07 1973-05-01 Varian Associates High-intensity arc lamp
JPS4929338B1 (xx) * 1970-02-04 1974-08-03
US3832589A (en) * 1972-03-01 1974-08-27 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh High-pressure metal vapor discharge lamps, particularly sodium vapor lamps with hermetic seal
US3872341A (en) * 1974-03-04 1975-03-18 Westinghouse Electric Corp Electrode support element for ceramic discharge lamp
US3876895A (en) * 1969-07-07 1975-04-08 Gen Electric Selective spectral output metal halide lamp
US3886392A (en) * 1974-02-25 1975-05-27 Gte Sylvania Inc Method of sealing alumina arc tube
US3907949A (en) * 1970-10-27 1975-09-23 Westinghouse Electric Corp Method of making tubular polycrystalline oxide body with tapered ends
US3930176A (en) * 1974-02-14 1975-12-30 Xenon Corp Inner electrode-support seal for a gaseous discharge flashtube
JPS511641Y1 (xx) * 1970-12-30 1976-01-19
JPS5145278U (xx) * 1974-09-30 1976-04-03
US3974410A (en) * 1975-04-04 1976-08-10 General Electric Company Alumina ceramic lamp having enhanced heat conduction to the amalgam pool
US3984719A (en) * 1975-05-15 1976-10-05 Ilc Technology, Inc. Internally sealed lamp
US4147952A (en) * 1974-12-12 1979-04-03 Gte Sylvania Incorporated Method of sealing alumina arc tube
US4198586A (en) * 1977-04-15 1980-04-15 U.S. Philips Corporation High pressure metal vapor discharge lamp and seal structure therefor
US4203050A (en) * 1977-07-28 1980-05-13 Heimann Gmbh Gas discharge lamp and method
DE3016892A1 (de) * 1979-05-07 1980-11-20 Westinghouse Electric Corp Entladungsrohr fuer hochdrucknatriumentladungslampen
US4277715A (en) * 1976-11-02 1981-07-07 U.S. Philips Corporation Electric gas discharge lamp
US6362568B1 (en) * 1998-12-14 2002-03-26 Corning Incorporated Electrode assembly and discharge lamp comprising the same
EP1220295A2 (en) * 2000-12-12 2002-07-03 Toshiba Lighting & Technology Corporation High pressure discharge lamp, high pressure discharge lamp lighting apparatus and luminaire therefor
US6570328B1 (en) * 1999-09-06 2003-05-27 Koninklijke Philips Electronics N.V. Electric lamp with feedthrough comprising a gauze
US20060033438A1 (en) * 2002-11-25 2006-02-16 Koninklijke Philips Electronics N.V. Coated ceramic discharge vessel for improved gas tightness
US20060071597A1 (en) * 2002-11-25 2006-04-06 Koninklijke Philips Electronics N.V. Crevice-less end closure member comprising a feed-through
US20070048402A1 (en) * 2001-02-09 2007-03-01 Matsushita Electric Industrial Co., Ltd. Method for manufacturing arc tube body and core used in the method
US11116043B2 (en) * 2019-12-09 2021-09-07 Arizona Board Of Regents On Behalf Of Arizona State University High temperature heater lamp

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6037645A (ja) * 1983-08-10 1985-02-27 Toshiba Corp 金属蒸気放電灯
DE3829729A1 (de) * 1988-09-01 1990-03-15 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Hochdruckentladungslampe

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1570041A (en) * 1923-03-12 1926-01-19 Adolph W Gast Electrode for high-frequency generators
US3363133A (en) * 1966-02-28 1968-01-09 Sylvania Electric Prod Electric discharge device having polycrystalline alumina end caps
US3363134A (en) * 1965-12-08 1968-01-09 Gen Electric Arc discharge lamp having polycrystalline ceramic arc tube
US3385463A (en) * 1965-03-11 1968-05-28 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Alkali metal vapor lamp

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1570041A (en) * 1923-03-12 1926-01-19 Adolph W Gast Electrode for high-frequency generators
US3385463A (en) * 1965-03-11 1968-05-28 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Alkali metal vapor lamp
US3363134A (en) * 1965-12-08 1968-01-09 Gen Electric Arc discharge lamp having polycrystalline ceramic arc tube
US3363133A (en) * 1966-02-28 1968-01-09 Sylvania Electric Prod Electric discharge device having polycrystalline alumina end caps

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3876895A (en) * 1969-07-07 1975-04-08 Gen Electric Selective spectral output metal halide lamp
US3716743A (en) * 1969-08-29 1973-02-13 Matsushita Electronics Corp High-pressure metal-vapor discharge tube
US3657588A (en) * 1970-01-19 1972-04-18 Varian Associates Envelope structure for high intensity three electrode arc lamps incorporating heat shielding means
JPS4929338B1 (xx) * 1970-02-04 1974-08-03
US3604972A (en) * 1970-02-25 1971-09-14 Us Army Metal vapor lamp with alkali metal reservoir means
US3907949A (en) * 1970-10-27 1975-09-23 Westinghouse Electric Corp Method of making tubular polycrystalline oxide body with tapered ends
JPS511641Y1 (xx) * 1970-12-30 1976-01-19
US3731133A (en) * 1972-01-07 1973-05-01 Varian Associates High-intensity arc lamp
US3832589A (en) * 1972-03-01 1974-08-27 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh High-pressure metal vapor discharge lamps, particularly sodium vapor lamps with hermetic seal
US3930176A (en) * 1974-02-14 1975-12-30 Xenon Corp Inner electrode-support seal for a gaseous discharge flashtube
US3886392A (en) * 1974-02-25 1975-05-27 Gte Sylvania Inc Method of sealing alumina arc tube
US3872341A (en) * 1974-03-04 1975-03-18 Westinghouse Electric Corp Electrode support element for ceramic discharge lamp
JPS5444469Y2 (xx) * 1974-09-30 1979-12-20
JPS5145278U (xx) * 1974-09-30 1976-04-03
US4147952A (en) * 1974-12-12 1979-04-03 Gte Sylvania Incorporated Method of sealing alumina arc tube
US3974410A (en) * 1975-04-04 1976-08-10 General Electric Company Alumina ceramic lamp having enhanced heat conduction to the amalgam pool
US3984719A (en) * 1975-05-15 1976-10-05 Ilc Technology, Inc. Internally sealed lamp
US4277715A (en) * 1976-11-02 1981-07-07 U.S. Philips Corporation Electric gas discharge lamp
US4198586A (en) * 1977-04-15 1980-04-15 U.S. Philips Corporation High pressure metal vapor discharge lamp and seal structure therefor
US4203050A (en) * 1977-07-28 1980-05-13 Heimann Gmbh Gas discharge lamp and method
DE3016892A1 (de) * 1979-05-07 1980-11-20 Westinghouse Electric Corp Entladungsrohr fuer hochdrucknatriumentladungslampen
US6362568B1 (en) * 1998-12-14 2002-03-26 Corning Incorporated Electrode assembly and discharge lamp comprising the same
US6570328B1 (en) * 1999-09-06 2003-05-27 Koninklijke Philips Electronics N.V. Electric lamp with feedthrough comprising a gauze
EP1220295A2 (en) * 2000-12-12 2002-07-03 Toshiba Lighting & Technology Corporation High pressure discharge lamp, high pressure discharge lamp lighting apparatus and luminaire therefor
EP1220295A3 (en) * 2000-12-12 2003-12-03 Toshiba Lighting & Technology Corporation High pressure discharge lamp, high pressure discharge lamp lighting apparatus and luminaire therefor
US20070048402A1 (en) * 2001-02-09 2007-03-01 Matsushita Electric Industrial Co., Ltd. Method for manufacturing arc tube body and core used in the method
US20060033438A1 (en) * 2002-11-25 2006-02-16 Koninklijke Philips Electronics N.V. Coated ceramic discharge vessel for improved gas tightness
US20060071597A1 (en) * 2002-11-25 2006-04-06 Koninklijke Philips Electronics N.V. Crevice-less end closure member comprising a feed-through
US7247990B2 (en) * 2002-11-25 2007-07-24 Koninklijke Philips Electronics, N.V. Crevice-less end closure member comprising a feed-through
US11116043B2 (en) * 2019-12-09 2021-09-07 Arizona Board Of Regents On Behalf Of Arizona State University High temperature heater lamp
US11477855B2 (en) 2019-12-09 2022-10-18 Arizona Board Of Regents On Behalf Of Arizona State University High temperature heater lamp

Also Published As

Publication number Publication date
BE715443A (xx) 1968-10-16
DE1764299C3 (de) 1978-03-23
NL6807165A (xx) 1968-11-25
FR1563563A (xx) 1969-04-11
GB1178091A (en) 1970-01-14
DE1764299B2 (de) 1977-07-14
DE1764299A1 (de) 1971-06-16

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Owner name: NORTH AMERICAN PHILIPS ELECTRIC CORP.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION;REEL/FRAME:004113/0393

Effective date: 19830316