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US3673454A - Electric incandescent lamp with an improved pinch seal - Google Patents

Electric incandescent lamp with an improved pinch seal Download PDF

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Publication number
US3673454A
US3673454A US84775A US3673454DA US3673454A US 3673454 A US3673454 A US 3673454A US 84775 A US84775 A US 84775A US 3673454D A US3673454D A US 3673454DA US 3673454 A US3673454 A US 3673454A
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United States
Prior art keywords
lamp
foil
vanadium
molybdenum
pinch seal
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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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US84775A
Inventor
Victor Rosallie Notelteirs
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US Philips Corp
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US Philips Corp
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Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01KELECTRIC INCANDESCENT LAMPS
    • H01K1/00Details
    • H01K1/38Seals for leading-in conductors
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C27/00Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
    • C22C27/02Alloys based on vanadium, niobium, or tantalum
    • C22C27/025Alloys based on vanadium, niobium, or tantalum alloys based on vanadium
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T403/00Joints and connections
    • Y10T403/47Molded joint

Definitions

  • the invention relates to an electric incandescent lamp having a quartz bulb provided with at least one pinch in which current conductors formed by a thin foil portion of molybdenum connected at both ends to wire-shaped conductors are sealed at least by the thin foil portion.
  • lamps of this kind are employed in copying apparatus, in which in operation the lamps are regularly switched on and off for a few seconds over a fairly long period of time, cracking of the pinch material often occurs. ln most cases this means that the lamp can no-longer be used.
  • the pinch temperature remains, in operation, below about 300 C, that is to say below the temperature at which molybdenum oxidizes in air. Cracking of the pinch material is therefore not due to stesses produced by oxidation of the molybdenum but has to be attributed to a locally excessively high current density in the metal parts in the pinch, particularly in the junction between the wire-shaped conductor and the thin foil portion of molybdenum. At this junction very high temperatures may occur. Owing to unequal expansions of the pinch materials stresses occur which may give rise to cracking of the pinch.
  • the invention has for its object to provide a lamp structure in which this phenomenon is avoided.
  • a lamp in which this detrimental effect does not occur is characterized in that the wire-shaped conductor located outside the bulb is welded to the molybdenum foil with the interposition of a foil of vanadium or a vanadium alloy.
  • the foil of vanadium or a vanadium alloy may have a thickness lying between and 50 p.
  • Suitable vanadium alloys are alloys of vanadium with about 0.1 to about 10 percent of molybdenum, tungsten, zirconium or hafnium.
  • the use of the intermediate vanadium foil provides a reduction of the transitional resistance at the weld.
  • FIG. 1 is an enlarged cross sectional view of the pinch of a lamp embodying the invention and FIG. 2 shows one embodiment of the lamp in accordance with the invention, the invention will now be described more fully.
  • reference numeral 1 designates the quartz bulb of a halogen incandescent lamp; the bulb 1 has a pinch 2, in which a strip of a molybdenum foil 3 is sealed. At one end this strip 3 is welded to a current conductor 4, which in turn is fastened to the tungsten helix 5. At the other end the molybdenum foil 3 is fastened to the current conductor 6, by means of which the lamp can be connected to a current source. The current conductor 6 is welded to the molybdenum strip 3 with the interposition of a foil 7 of vanadium.
  • FIG. 2 shows a so-called copying lamp.
  • the numerals in the Figure have the same meaning as in FIG. 1, 8 designates helical stays for the tungsten helix 5.
  • the foil 3 has a length of 9 mms, a width of 4 mms and a maximum thickness of 35 p.
  • the conductor 6 of molybdenum has a diameter of 0.6 mm.
  • An electric incandescent lamp comprising a quartz bulb provided with at least one pinch seal; at least two current conductors included within said seal, each of said current conductors including a thin for] portion of molybdenum connected at one end to an internal wire-type conductor and at the other end to an external wire-type conductor, said foil portion being within said pinch seal; and a foil of vanadium being interposed between the external wire conductor and said molybdenum foil, said molybdenum foil being welded to the external conductor with said vanadium foil so interposed.
  • the lamp of claim 2 wherein the interposed foil consists of a vanadium alloy containing 0.1 to 10 percent of molybdenum, tungsten, zirconium or hafnium.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)

Abstract

An electric incandescent lamp, having a quartz bulb provided with at least one pinch seal, has substantially reduced cracking of the pinch seal during operation of the lamp by the interposition of a foil of vanadium or vanadium alloy between the usual thin foil molybdenum connection to the wire-type current conductors of the lamp.

Description

United States Patent Notelteirs [151 3,673,454 [451 June 27, 1972 1 ELECTRIC INCANDESCENT LAlVIP WITH AN IMPROVED PINCH SEAL Victor Rosallie Notelteirs, Emmasingel, Eindhoven, Netherlands U.S. Philips Corporation, New York, NY.
Oct. 28, 1970 inventor:
Assignee:
Filed:
Appl. No.:
[30] Foreign Application Priority Data Nov. 1 1969 Netherlands ..6916499 US. Cl .L ..3l3/332, l74/50.6l, l74/50.64, 287/l89.36 D, 313/331 Int. Cl. .1101 j 5/52 Field of Search ..l74/50.6l, 50.64; 287/l89.365; 313/331, 332
[56] References Cited UNITED STATES PATENTS 3,420,944 1/1969 Holcomb ..313/222 X 3,487,536 1/1970 Goldstein ..287/l89 365X Primary Examiner.lohn Kominski Att0rney-F rank R. Trifari ABSTRACT 3 Claims, 2 Drawing figures PATENTEuJum I972 3. 673 .454
INVENTOR.
VICTOR R. NOTELTEIRS AGENT ELECTRIC INCANDESCENT LAMP WITH AN IMPROVED PlNCl-l SEAL The invention relates to an electric incandescent lamp having a quartz bulb provided with at least one pinch in which current conductors formed by a thin foil portion of molybdenum connected at both ends to wire-shaped conductors are sealed at least by the thin foil portion.
When lamps of this kind are employed in copying apparatus, in which in operation the lamps are regularly switched on and off for a few seconds over a fairly long period of time, cracking of the pinch material often occurs. ln most cases this means that the lamp can no-longer be used.
With lamps of this kind the pinch temperature remains, in operation, below about 300 C, that is to say below the temperature at which molybdenum oxidizes in air. Cracking of the pinch material is therefore not due to stesses produced by oxidation of the molybdenum but has to be attributed to a locally excessively high current density in the metal parts in the pinch, particularly in the junction between the wire-shaped conductor and the thin foil portion of molybdenum. At this junction very high temperatures may occur. Owing to unequal expansions of the pinch materials stresses occur which may give rise to cracking of the pinch.
The invention has for its object to provide a lamp structure in which this phenomenon is avoided.
According to the invention a lamp in which this detrimental effect does not occur is characterized in that the wire-shaped conductor located outside the bulb is welded to the molybdenum foil with the interposition of a foil of vanadium or a vanadium alloy.
The foil of vanadium or a vanadium alloy may have a thickness lying between and 50 p. Suitable vanadium alloys are alloys of vanadium with about 0.1 to about 10 percent of molybdenum, tungsten, zirconium or hafnium.
The use of the intermediate vanadium foil provides a reduction of the transitional resistance at the weld.
This phenomenon might be accounted for by the fact that the oxide skin at the surface of the areas to be welded dissolves in the intermediate foil so that it can no longer give rise to locally high transitional resistances.
With reference to the accompanying drawing, in which FIG. 1 is an enlarged cross sectional view of the pinch of a lamp embodying the invention and FIG. 2 shows one embodiment of the lamp in accordance with the invention, the invention will now be described more fully.
Referring to FIG. 1, reference numeral 1 designates the quartz bulb of a halogen incandescent lamp; the bulb 1 has a pinch 2, in which a strip of a molybdenum foil 3 is sealed. At one end this strip 3 is welded to a current conductor 4, which in turn is fastened to the tungsten helix 5. At the other end the molybdenum foil 3 is fastened to the current conductor 6, by means of which the lamp can be connected to a current source. The current conductor 6 is welded to the molybdenum strip 3 with the interposition of a foil 7 of vanadium.
FIG. 2 shows a so-called copying lamp. The numerals in the Figure have the same meaning as in FIG. 1, 8 designates helical stays for the tungsten helix 5. The foil 3 has a length of 9 mms, a width of 4 mms and a maximum thickness of 35 p. The conductor 6 of molybdenum has a diameter of 0.6 mm.
With a lamp of the kind shown suitable for a voltage of 230 V and a load of 1,500 W the pinch temperature rises to about C, when this lamp is switched on for 3 seconds and switched off for 12 seconds over a longer period of time. If no particular precautions are taken, about 30 percent of the lamps will show cracking of the pinch before the lamp has been switched on and off 50,000 times.
If a foil of vanadium or a vanadium alloy of a thickness of 10 p. is arranged between the molybdenum strip and the conductor 6 no defects of the said kind occur any longer.
What is claimed is:
1. An electric incandescent lamp comprising a quartz bulb provided with at least one pinch seal; at least two current conductors included within said seal, each of said current conductors including a thin for] portion of molybdenum connected at one end to an internal wire-type conductor and at the other end to an external wire-type conductor, said foil portion being within said pinch seal; and a foil of vanadium being interposed between the external wire conductor and said molybdenum foil, said molybdenum foil being welded to the external conductor with said vanadium foil so interposed.
2. The lamp according to claim 1 wherein said interposed foil is of a vanadium alloy.
3. The lamp of claim 2 wherein the interposed foil consists of a vanadium alloy containing 0.1 to 10 percent of molybdenum, tungsten, zirconium or hafnium.

Claims (2)

  1. 2. The lamp according to claim 1 wherein said interposed foil is of a vanadium alloy.
  2. 3. The lamp of claim 2 wherein the interposed foil consists of a vanadium alloy containing 0.1 to 10 percent of molybdenum, tungsten, zirconium or hafnium.
US84775A 1969-11-01 1970-10-28 Electric incandescent lamp with an improved pinch seal Expired - Lifetime US3673454A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6916499A NL6916499A (en) 1969-11-01 1969-11-01

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US3673454A true US3673454A (en) 1972-06-27

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US84775A Expired - Lifetime US3673454A (en) 1969-11-01 1970-10-28 Electric incandescent lamp with an improved pinch seal

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BE (1) BE758332A (en)
DE (1) DE2050693A1 (en)
FR (1) FR2071859A5 (en)
NL (1) NL6916499A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4038579A (en) * 1973-01-11 1977-07-26 U.S. Philips Corporation Solder joint connection between lead-in conductor and electrode
US5264756A (en) * 1991-12-26 1993-11-23 Gte Products Corporation Small volume, high wattage press sealed lamp
US20040183467A1 (en) * 2003-03-21 2004-09-23 Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen Mbh Dielectric barrier discharge lamp with pinch seal

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL183794B (en) * 1979-02-26 Philips Nv HIGH PRESSURE MERCURY DISCHARGE LAMP.

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3420944A (en) * 1966-09-02 1969-01-07 Gen Electric Lead-in conductor for electrical devices
US3487536A (en) * 1966-02-24 1970-01-06 Teledyne Inc Method of forming a high temperature ceramic-to-metal seal

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3487536A (en) * 1966-02-24 1970-01-06 Teledyne Inc Method of forming a high temperature ceramic-to-metal seal
US3420944A (en) * 1966-09-02 1969-01-07 Gen Electric Lead-in conductor for electrical devices

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4038579A (en) * 1973-01-11 1977-07-26 U.S. Philips Corporation Solder joint connection between lead-in conductor and electrode
US5264756A (en) * 1991-12-26 1993-11-23 Gte Products Corporation Small volume, high wattage press sealed lamp
US20040183467A1 (en) * 2003-03-21 2004-09-23 Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen Mbh Dielectric barrier discharge lamp with pinch seal
US7106003B2 (en) * 2003-03-21 2006-09-12 Patent-Treuhand-Gesellschaft Fuer Elektrische Gluehlampen Mbh Dielectric barrier discharge lamp with pinch seal

Also Published As

Publication number Publication date
DE2050693A1 (en) 1971-05-19
FR2071859A5 (en) 1971-09-17
BE758332A (en) 1971-04-30
NL6916499A (en) 1971-05-04

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