US3906275A - Electric lamp with electrolysis preventing apparatus - Google Patents

Electric lamp with electrolysis preventing apparatus Download PDF

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Publication number
US3906275A
US3906275A US463738A US46373874A US3906275A US 3906275 A US3906275 A US 3906275A US 463738 A US463738 A US 463738A US 46373874 A US46373874 A US 46373874A US 3906275 A US3906275 A US 3906275A
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US
United States
Prior art keywords
lamp
pinch
screening element
conductors
current lead
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
US463738A
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English (en)
Inventor
Raymond Francois Spiessens
Rop Walter Jan Roza Adolf De
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
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US Philips Corp
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Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
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Publication of US3906275A publication Critical patent/US3906275A/en
Anticipated expiration legal-status Critical
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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/56—One or more circuit elements structurally associated with the lamp
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • 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
    • H01J61/366—Seals for leading-in conductors
    • H01J61/368—Pinched seals or analogous seals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/54—Igniting arrangements, e.g. promoting ionisation for starting
    • H01J61/545—Igniting arrangements, e.g. promoting ionisation for starting using an auxiliary electrode inside the vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/38—Seals for leading-in conductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/40—Leading-in conductors

Definitions

  • Trifari 5 7 1 ABSTRACT An electric lamp having a lamp envelope transmitting radiation which is sealed in a vacuum-tight manner at least one end by means of a pinch in which at least two current lead-through conductors are sealed. An electric voltage comprising a direct voltage component is present between these conductors during operation of the lamp. A metal scrreming element is placed in the pinch between the two current leadthrough conductors. The screening element is connected to the current lead-through conductor which has as an average a negative potential relative to the other current 1ead-through conductor during operation so that the drawbacks of electrolysis phenomena in the pinch are eliminated.
  • the invention relates to an electric lamp having a lamp envelope transmitting radiation and being sealed in a vacuum-tight manner at at least one end by means of a pinch in which at least two current lead-through conductors are sealed.
  • the invention relates to a dischargelamp provided with a first and a second main electrode between which the discharge isieffected during operation and an auxiliary electrode arianged in the vicinity of the first main electrode, the current lead-through conductors for the first main electrode and for the auxiliary electrode being sealed in a pinch.
  • gas discharge lamps for example, in highpressuremercury vapour discharge lamps which in addition to mercury comprise one or more metal halides.
  • These lamps generally have a hard glass or quartz glass discharge tube as a lamp envelope which is closed at both ends by a pinch.
  • a main electrode is placed within the discharge tube at each end which electrode is passed to the exterior by means of a current lead through conductor sealed in the adjacent pinch.
  • these lead-through conductors are at least partly formed as thin molybdenum foils.
  • An auxiliary electrode may be arranged in the vicinity of one of the main electrodes in such lamps, which auxiliary electrode is passed to the exterior by means' of a current lead-through conductor sealed in the adjacent pinch and comprising a molybdenum foil and which outside the lamp is connected through a resistor to the other main electrode.
  • This auxiliary electrode serves to facilitate the ignition of the lamp.
  • an electric voltage is present between the auxiliary electrode and the adjacent rnain electrode, which voltage contains such a direct voltage component that the auxiliary electrode has an average negative potential relative to the main electrode.
  • the said direct voltage component is a result of the fact that the main electrode more easily emits electrons than the auxiliary electrode.
  • Electrolysis in the pinch of a lamp and the attendant difficulties are found to occur also in electric incandescent lamps, for example, halogen lamps which are intended for direct voltage operation and in which the two current lead-through conductors are sealed in one pinch.
  • the invention provides electric lamps provided with simple means with which the drawback of the abovedescribed phenomenon of electrolysis can at least largely be obviated.
  • the invention is based on the recognition of the fact that it is not necessary to entirely prevent the occurrence of electrolysis in the pinch of a lamp so as to avoid the above-mentioned drawbacks of this electrolysis.
  • An electric lamp according to the invention has alamp envelope transmitting radiation and is sealed in a vacuum-tight manner at at least one end by means of a pinch in which at least two current lead-through conductors are sealed between which conductors an electric voltage is present during operation of the lamp which voltage comprises a direct voltage component and is characterized in that a metal screening element is placed in the pinch between the two current leadthrough conductors, the screening element not intersecting the internal surface of the lamp envelope and being connected to the current lead-through conductor which at an average has a negative potential relative to the other current lead-through conductor.
  • a metal screening element is incorporated in the pinch between the two current lead-through conductors.
  • the screening element is connected to the current lead-through conductor which during operation, possibly as an average in time, has a negative potential relative to the other current leadthrough conductor.
  • the screening element will have the same negative potential relative to the other current lead-through conductor. In this manner the electrical field resulting from the direct voltage component between the two current leadthrough conductors will be displaced for the greater part to the region in the pinch between the positive current lead-through conductor and the screening element.
  • the negative current lead-through conductor is screened in an effective manner from the electrical field resulting in electrolysis by the screening element located between this conductor and the positive current lead-through conductor.
  • Such a gas discharge lamp according to the invention has a discharge space enclosed by the lamp envelope, which space comprises a gas filling and is provided with a first and a second main electrode between which the discharge takes place during operation and furthermore with an auxiliary electrode arranged in the vicinity of the first main electrode in which the current lead-through conductor for the first main electrode and the current leadthrough conductor for the auxiliary electrode are sealed in a pinch, which conductors are substantially co-planar and comprise a foil mainly consisting of molybdenum and is characterized in that the metal screening element is placed in the pinch between the foils and substantially in the plane determined by the foils and that the screening element has the same potential as the auxiliary electrode during operation.
  • the gas discharge lamps according to the invention have an auxiliary electrode which, as described in the preamble, may be connected outside the lamp through a resistor to a main electrode and which serves to ignite the lamp easily.
  • the auxiliary electrode has a negative potential during operation relative to the main electrode.
  • the phenomena of electrolysis which conse quently might occur on the auxiliary electrode are prevented according to the invention by a metal screening element located between the current lead throughconductors in the pinch. These conductors are substantially co-planar and the screening element is in the same plane.
  • the screening element is connected to the current lead-through conductor for the auxiliary electrode in such a manner that this screening element assumes the same potential as the auxiliary electrode.
  • This construction according to the invention provides a very satisfactory screening of the current lead through conductor for the auxiliary electrode because the said conductor for the auxiliary electrode is substantially entirely screened by the screening element as viewed from the current lead-through conductor for the main electrode.
  • the screening element may be, for example, a foil mainly consisting of molybdenum.
  • a wire of high melting point metal is preferably used, for example, tungsten, molybdenum or tantalum as a screening element. Such a wire-shaped screening element yields optimum results.
  • the invention is preferably used in high-pressure mercury vapour discharge lamps which in addition to mercury also comprise a rare gas as a starter gas.
  • mercury vapour discharge lamps which in addition to mercury also comprise a rare gas as a starter gas.
  • the phenomenon of electrolysis may be very disturbing especially when the lamps are intended for the horizontal operating condition where the auxiliary electrode is located below the main electrode.
  • Such high-pressure mercury vapour discharge lamps according to the invention are especially preferred which in addition to mercury and a rare gas comprise at least one metal halide.
  • a halidecontaining lamps is provided with an alkali metal halide the phenomena of electrolysis may be very serious because alkali metal may penetrate the material of the pinch from the discharge space and may cause an increase of a number of charge carriers and consequently an increase of the electrolysis current.
  • the invention may likewise be used to great advantage in electric incandescent lamps, for example, in halogen lamps which are intended for direct voltage operation and are provided with a filament body located within the lamp envelope which body can be connected to a direct voltage source by means of two current lead-through conductors sealed in one pinch.
  • the said current lead-through conductors are then substantially co-planar and comprise a foil mainly consistin g'of molybdenum.
  • electrolysis in the pinch of such an incandescent lamp is prevented by a metal screening element placed in the pinch between the foils and substantially in the plane determined by the foils. The screening element is then connected to the negative terminal of the voltage source during operation of the lamp.
  • FIG. 1 shows a metal halide-containing high-pressure mercury vapour discharge lamp according to the invention
  • FIG. 2 is a cross-sectional of an embodiment of a pinch construction and screening element for use in a lamp according to the invention.
  • FIG. 3 shows an incandescent lamp according to the invention.
  • l is the quartz glass discharge tube of a high-pressure mercury vapour discharge lamp according to the invention.
  • the main electrodes 2 and 3 con sisting of tungsten spirals secured to tungsten current lead-through conductors 4 and 5 are present at the ends of the tube 1. These conductors 4 and 5 are passed in a vacuum-tight manner through the pinches 6 and 7, respectively.
  • the vacuum-tight seal is obtained by forming part of the conductors 4 and 5 as molybdenum foils 8 and 9, respectively.
  • An auxiliary electrode 10 consisting of a tungsten pin is placed in the vicinity of the main electrode 2.
  • the auxiliary electrode 10 is passed in a vacuum-tight manner through the pinch 6 by means of a current lead-through conductor 1 1 comprising a molybdenum foil 12.
  • the tube 1 is suspended in a glass outer envelope 13 by means of metal strips 14 and .15 which clamp about the pinches 6 and 7 and are secured to the supporting terminals or current supply members 16 and 17, respectively.
  • These supporting terminals 16 and 17 also serve as current supply members for the electrodes 2 and 3 and are passed in a vacuumtight manner through the outer envelope 13 and are connected to the contacts of the lamp cap 18.
  • the auxiliary electrode 10 facing the main electrode 2 is connected outside the discharge tube 1 through a resistor 19 to the current supply conductor 17 for the main electrode 3.
  • a screening element 20 is sealed in the pinch between the current lead-through conductors 1 1, l2 and 4, 8 of auxiliary electrode 10 and main electrode 2.
  • This element 20 consists of a tungsten wire and is located in the plane of the molybdenum foils 8 and 12.
  • the wire 20 extends in the pinch 6 up to a distance of approximately 2 mm from the internal surface of the discharge tube 1 and is connected outside the lamp to the current supply conductor 21 for the auxiliary electrode 10.
  • the discharge tube 1 is provided with a quantity of mercury completely evaporating during operation of the lamp and furthermore with the iodides of sodium, thallium and indium. Furthermore a quantity of rare gas is introduced as an ignition gas into the tube 1.
  • the distance between the electrodes 2 and 3 is approximately 40 mm.
  • the lamp has a power of 400 W during operation.
  • FIG. 2 shows a preferred embodiment in a crosssection of a pinch construction and a screening element for a lamp according to the invention.
  • the reference numeral 120 denotes the quartz glass pinch body which changes over to the quartz glass wall 121 of the lamp.
  • the pinch 120 has an elevation 22 projecting within the lamp.
  • a screening element 23 which extends into the elevation 22 is sealed in the pinch.
  • the element 23 consisting of a tungsten wire extends in the pinch in the direction of the inner surface 24 of the lamp wall up to beyond those parts of the portions 25 and 26 of the current lead-through conductors 25, 27, 29 and 26, 28, 30 which are located within the pinch.
  • the screening element 23 is connected outside the lamp to the current lead-through conductor 25, 27, 29 which assumes a negative potential during operation of the lamp relative to the lead-through conductor 26, 28, 30.
  • the reference numeral 30 denotes the wall of a halogen incandescent lamp according to the invention.
  • the lamp is sealed by a pinch 31 through which the current lead-through conductors 32, 34, 36 and 33, 35, 37 are passed in a vacuum-tight manner. These conductors provide for the current supply of the filament body 38 consisting of a tungsten spiral.
  • the lamp is intended for direct voltage operation and the conductor 33 is connected to the negative terminal and the conductor 32 is connected to the positive terminal of a voltage source. Electrolysis phenomena on the negative current lead-through conductor 33, 35, 37 particularly on the molybdenum foil 35 are prevented by the tungsten wire screening element 39 sealed in the pinch 31.
  • the element 39 is connected outside the pinch 31 to the negative current lead-through conductor 33.
  • An electric lamp for use with an associated electric power supply which comprises: a radiation transmitting lamp envelope, means for sealing in a vacuum-tight manner at one end of said envelope, said means including a pinch, at least two current lead-through conductors extending through said pinch in sealed relation said lead-through conductors having an electric voltage comprising a direct voltage component being present between said conductors during operation of the lamp from the associated electric power supply, a metal screening element disposed in the pinch between the two current lead-through conductors, said screening element not intersecting the internal surface of the lamp envelope and being connected to the current lead-through conductor which at an average has a negative pontential relative to the other current leadthrough conductor during operation.
  • said lamp is a gas discharge lamp having a gas-filled discharge space surrounded by said lamp envelope, said lamp including a first and a second main electrode between which a discharge is effected during operation, said lamp further including an auxiliary electrode arranged in the vicinity of said first main electrode, said lead-through conductors being connected to said first electrode and said auxiliary electrode respectively, said conductors being disposed in substantially co-planar relationship and comprising a foil primarily consisting of molybdenum, said metal screening element being disposed in the pinch between the foils and substantially in the plane determined by said foils, and means for maintaining said screening element at the same potential as said auxiliary electrode during lamp operation.
  • a lamp as claimed in claim 6 wherein said lamp is a high-pressure mercury vapour discharge lamp in which mercury and a rare gas as an ignition gas are disposed in said discharge space.
  • a high-pressure mercury vapour discharge lamp as claimed in claim 7 in which at least one metal halide is disposed in said discharge space.
  • a lamp as claimed in claim 8 wherein said halide is an alkali metal halide.
  • a lamp as claimed in claim 1 said lamp being an incandescent lamp for use with an associated direct voltage supply, and having a filament body disposed within said lamp envelope, said current lead-through conductors sealed in one pinch and being substantially co-planar and comprising a foil primarily consisting of molybdenum, said metal screening element being disposed in the pinch between the foils and substantially in the plane determined by the foils, and said screening element being connected to the negative terminal of the associated direct voltage source during lamp operatlOl'l.

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  • Vessels And Coating Films For Discharge Lamps (AREA)
US463738A 1973-05-04 1974-04-24 Electric lamp with electrolysis preventing apparatus Expired - Lifetime US3906275A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7306208A NL7306208A (enrdf_load_stackoverflow) 1973-05-04 1973-05-04

Publications (1)

Publication Number Publication Date
US3906275A true US3906275A (en) 1975-09-16

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ID=19818784

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Application Number Title Priority Date Filing Date
US463738A Expired - Lifetime US3906275A (en) 1973-05-04 1974-04-24 Electric lamp with electrolysis preventing apparatus

Country Status (6)

Country Link
US (1) US3906275A (enrdf_load_stackoverflow)
JP (1) JPS5027357A (enrdf_load_stackoverflow)
BE (1) BE814480A (enrdf_load_stackoverflow)
DE (1) DE2418890A1 (enrdf_load_stackoverflow)
FR (1) FR2228295B3 (enrdf_load_stackoverflow)
NL (1) NL7306208A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4876483A (en) * 1988-05-26 1989-10-24 Gte Products Corporation Arc lamp with surface arc resistant barrier
US5144192A (en) * 1990-08-02 1992-09-01 Patent Treuhand Gesellschaft Fur Elektrische Glunlampen M.B.H. High-pressure discharge lamp
US5193100A (en) * 1990-06-29 1993-03-09 Arthur Pfeiffer Vakuumtechnik Wetzlar Gmbh Apparatus for detecting gaseous discharge in vacuum furnaces
US5422535A (en) * 1992-10-12 1995-06-06 U.S. Philips Corporation Capped electric lamp
US20030117062A1 (en) * 2001-12-20 2003-06-26 Patent-Treuhand-Gesellschaft Fur Elektrisch Gluhlampen Mbh Compact low-pressure discharge lamp
US6988906B1 (en) * 2005-04-27 2006-01-24 Chuan-Ying Chen Fluorescent lamp tube seat

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1985028A (en) * 1929-12-13 1934-12-18 Siemens Ag Discharge device
US2329019A (en) * 1941-10-06 1943-09-07 Heintz & Kaufman Ltd Vitreous seal protector
US2454384A (en) * 1946-05-21 1948-11-23 Rca Corp Button stem for electron discharge devices
US2569848A (en) * 1950-05-31 1951-10-02 Eitel Mccullough Inc Electron tube seal structure
US3275885A (en) * 1965-04-07 1966-09-27 Gen Electric High pressure discharge lamp with electrolysis preventing means
US3668456A (en) * 1970-08-28 1972-06-06 Sylvania Electric Prod Lamp having improved press seal

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1985028A (en) * 1929-12-13 1934-12-18 Siemens Ag Discharge device
US2329019A (en) * 1941-10-06 1943-09-07 Heintz & Kaufman Ltd Vitreous seal protector
US2454384A (en) * 1946-05-21 1948-11-23 Rca Corp Button stem for electron discharge devices
US2569848A (en) * 1950-05-31 1951-10-02 Eitel Mccullough Inc Electron tube seal structure
US3275885A (en) * 1965-04-07 1966-09-27 Gen Electric High pressure discharge lamp with electrolysis preventing means
US3668456A (en) * 1970-08-28 1972-06-06 Sylvania Electric Prod Lamp having improved press seal

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4876483A (en) * 1988-05-26 1989-10-24 Gte Products Corporation Arc lamp with surface arc resistant barrier
US5193100A (en) * 1990-06-29 1993-03-09 Arthur Pfeiffer Vakuumtechnik Wetzlar Gmbh Apparatus for detecting gaseous discharge in vacuum furnaces
US5144192A (en) * 1990-08-02 1992-09-01 Patent Treuhand Gesellschaft Fur Elektrische Glunlampen M.B.H. High-pressure discharge lamp
US5422535A (en) * 1992-10-12 1995-06-06 U.S. Philips Corporation Capped electric lamp
US20030117062A1 (en) * 2001-12-20 2003-06-26 Patent-Treuhand-Gesellschaft Fur Elektrisch Gluhlampen Mbh Compact low-pressure discharge lamp
US6919671B2 (en) * 2001-12-20 2005-07-19 Patent-Treuhand-Gesellschaft Fur Elektrisch Gluhlampen Mbh Compact low-pressure discharge lamp
US6988906B1 (en) * 2005-04-27 2006-01-24 Chuan-Ying Chen Fluorescent lamp tube seat

Also Published As

Publication number Publication date
FR2228295B3 (enrdf_load_stackoverflow) 1977-03-04
BE814480A (fr) 1974-11-04
FR2228295A1 (enrdf_load_stackoverflow) 1974-11-29
DE2418890A1 (de) 1974-11-21
JPS5027357A (enrdf_load_stackoverflow) 1975-03-20
NL7306208A (enrdf_load_stackoverflow) 1974-11-06

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