US2245394A - Hermetic seal - Google Patents

Hermetic seal Download PDF

Info

Publication number
US2245394A
US2245394A US376228A US37622841A US2245394A US 2245394 A US2245394 A US 2245394A US 376228 A US376228 A US 376228A US 37622841 A US37622841 A US 37622841A US 2245394 A US2245394 A US 2245394A
Authority
US
United States
Prior art keywords
envelope
quartz
strip
seal
conductor
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
US376228A
Other languages
English (en)
Inventor
Victor J Francis
Kettlewell Eric
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Application granted granted Critical
Publication of US2245394A publication Critical patent/US2245394A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/32—Seals for leading-in conductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/20—Seals between parts of vessels
    • H01J5/22—Vacuum-tight joints between parts of vessel
    • H01J5/24—Vacuum-tight joints between parts of vessel between insulating parts of vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0033—Vacuum connection techniques applicable to discharge tubes and lamps
    • H01J2893/0037—Solid sealing members other than lamp bases
    • H01J2893/0038—Direct connection between two insulating elements, in particular via glass material
    • H01J2893/004—Quartz-to-quartz connection

Definitions

  • This invention relates to high pressure vapor electric discharge devices with envelopes of quartz or like material of the type in which at least one leading-in electrical conductor is introduced into the envelope by meansof an hermetic strip seal and in which, during full operation, the pressure exceeds'5 atm.
  • Material like quartz means any vitreous, highly siliceous material having a coeilflcient of expansion not greater than 1..” per C. measured under conditions such that the coeillcient of expansion of quartz is 0.55x 10- per C. -In what follows.
  • quartz will be used for brevity to mean quartz or like materia
  • a quartz tube is usually collapsed onto both the strip itself and a stouter conductor to which the end of the strip is attached. Since the quartz shrinks away from the stouter conductor when the seal cools, an annulus is left between the quartz and the conductor terminated by a sharp angle.
  • the device is made by sealing an I already prepared. strip seal into an aperture in the quartz envelope, an annulus is apt to be left between the quartzof the seal and the quartz of the envelope also terminated by a sharp angle.
  • We have found 'thatthe presence of these sharp angles leads to mechanical weakness of the envelope which is apt to burst when a high vapor pressure is developed within it during operation of the device.
  • the object of the invention is to avoid this diillculty and to increase the mechanical strength of such envelopes.
  • a quartz tube is collapsed onto an electrical conductor comprising a thin, foil-like'strip ill of molybdenum, for example, to which a stouter conductor I is fastened as by welding.
  • the conductor l consists of a wire or strip of refractory metal, such as molybdenum or tungsten, and is of such thickness that the quartz does not make an hermetic joint therewith as it does with the strip Ill.
  • seal element or plug thus formed has a gap 5 between the stout conductor 4 and the quartz element I.
  • the gap 5 is of appreciable depth and terminates in a sharp angle as shown in Fig. l of the drawing.
  • the pressure of the gaseous atmosphere in the envelope 3 is usually less than atmospheric pressure when the envelope 3 is, at room temperature and is 5 atmospheres and higher when the device is operating.
  • the high pressure exerts force of considerable magnitude in the gap 5 tending to burst the seal as'indicated by the arrows inFig. 1. Since the gap terminates in a sharp angle, as pointed out above, it is a point of mechanical weakness of the device.
  • the part of the quartz element l surrounding the gap 5 is mounted within the space defined by the envelope 3 where the force tending to burst the seal is opposed by force tending to compress it, as indicated by the arrows in 3.
  • the sharp angle between the quartz element l and the envelope 3 characteristic of prior devices is shown at I in Fig. 1 of the drawing.
  • This sharp angle is a weak part of the envelope 3 of the device which is strengthened by moving the quartz element I further into the envelope part 3 after these parts have been Joined by fusion and while the quartz is still plastic.
  • FIG. 2 shows the preferred position of the bulge 0' on the element I with respect to the angular opening about the conductor 4.
  • the completed seal is shown in Fig. 8.
  • FIG. 4 illustrates a complete discharge lamp having seals embodying the present invention.
  • Electrodes II are mounted on conductors l and are separated a few millimeters from each: other in the substantially spherical envelope 3.
  • the envelope ,3 has therein a starting gas, such as neon; at a pressure of about 5 mm. and a quantity.12 of vaporizable material, such as mercury,
  • the electrodes II are hollow, pointed, perforated metal shells, such as tungsten shells, con-- taining material of high electron emissivity characteristics, such as barium or strontium, or mixtures of such materials.
  • Fig. 4 of the drawing the hermetic fused joint between the quartzelement I of the plug and the metal strip Iii terminates in the-space defined by the envelope 3 and the gap between the quartz element I and the conductor 4 is within said space.
  • the lamp described above is a long-lived compact
  • An envelope for an. electric discharge device of the high pressure type said envelope having a perforated part consisting of a vitreous material misses which the characteristics of quartz, a plug of similar vitreous material fused into and hermetically sealing said envelope part, said plug extending from the interior to theexterior of said err-f velope, and an electrical conductor extending through said plug, saidconductor comprising a thin, foil-like strip of metal hermetically fused into and terminating in said plug at an apprecia.
  • said conductor comprising a thin. foil-like strip of metal hermetically fused into and terminating within said cylindrical member and a metal body connected to said strip in said cylindrical member and extending beyond said cylindrical member, said metal bodybeing incapable of making a hermetic Joint with said cylin cal member, said cylindrical member having an annular protuberance thereon between the ends of said metal strip for supporting said seal in said envelope and providing material for the formation of a rounded surface between said envelope and said cylindrical member when these eiements are combined by fusion;

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
US376228A 1940-01-02 1941-01-27 Hermetic seal Expired - Lifetime US2245394A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2245394X 1940-01-02

Publications (1)

Publication Number Publication Date
US2245394A true US2245394A (en) 1941-06-10

Family

ID=10902138

Family Applications (1)

Application Number Title Priority Date Filing Date
US376228A Expired - Lifetime US2245394A (en) 1940-01-02 1941-01-27 Hermetic seal

Country Status (2)

Country Link
US (1) US2245394A (de)
BE (1) BE464275A (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2676197A (en) * 1950-11-17 1954-04-20 Bell Telephone Labor Inc Glass to metal seal for deep-sea electric cable
US3971352A (en) * 1974-02-06 1976-07-27 Ethyl Corporation Fuel induction system
US4171500A (en) * 1977-05-16 1979-10-16 U.S. Philips Corporation Electric lamp
US4202999A (en) * 1978-04-11 1980-05-13 General Electric Company Fused silica lamp envelope and seal
EP0206598A2 (de) * 1985-06-14 1986-12-30 Kabushiki Kaisha Toshiba Metallhalogenidbogenlampe
US5374872A (en) * 1992-11-13 1994-12-20 General Electric Company Means for supporting and sealing the lead structure of a lamp and method for making such lamp
US5598063A (en) * 1992-12-16 1997-01-28 General Electric Company Means for supporting and sealing the lead structure of a lamp

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2676197A (en) * 1950-11-17 1954-04-20 Bell Telephone Labor Inc Glass to metal seal for deep-sea electric cable
US3971352A (en) * 1974-02-06 1976-07-27 Ethyl Corporation Fuel induction system
US4171500A (en) * 1977-05-16 1979-10-16 U.S. Philips Corporation Electric lamp
US4202999A (en) * 1978-04-11 1980-05-13 General Electric Company Fused silica lamp envelope and seal
EP0206598A2 (de) * 1985-06-14 1986-12-30 Kabushiki Kaisha Toshiba Metallhalogenidbogenlampe
EP0206598A3 (en) * 1985-06-14 1988-12-14 Kabushiki Kaisha Toshiba Metal halide arc lamp
US5374872A (en) * 1992-11-13 1994-12-20 General Electric Company Means for supporting and sealing the lead structure of a lamp and method for making such lamp
US5598063A (en) * 1992-12-16 1997-01-28 General Electric Company Means for supporting and sealing the lead structure of a lamp

Also Published As

Publication number Publication date
BE464275A (de)

Similar Documents

Publication Publication Date Title
US2135661A (en) Gaseous electric discharge device
US4160930A (en) Electric discharge lamp with annular current conductor
US2245394A (en) Hermetic seal
US2177714A (en) Gaseous electric discharge lamp device
US3390296A (en) Electric discharge device having spaced electrodes sealed to opposite end of envelope
US2200939A (en) Gaseous electric discharge lamp device
US2682009A (en) Seal and method of fabrication
US4707636A (en) High pressure sodium vapor lamp with PCA arc tube and end closures
US2159794A (en) Electric lamp and similar devices
US2114869A (en) Quartz-to-metal seal
EP0160316B1 (de) Einseitig gesockelte Hochintensitätsentladungslampe und Herstellung
US4668204A (en) Single-ended high intensity discharge lamp and manufacture
US2829295A (en) Internally conductively coated lamp and method of manufacture
US2845557A (en) Arc tube mounting
US3515929A (en) Short arc lamp seal
US2409361A (en) Seal for electric lamps and similar devices
US2138224A (en) Method of sealing electrical conductors into vitreous envelopes
US3278778A (en) High-current seal for electric discharge lamp
US2814748A (en) Fluorescent lamp
US2451297A (en) Rugged gaseous discharge triodes
GB476488A (en) Improvements in the sealing of electric conductors into quartz envelopes
US2748309A (en) Gas or vapor discharge tube
US2518944A (en) Electric discharge device seal
US2598241A (en) Electric discharge device
US2848641A (en) Vapor electric lamp