WO2007052201A2 - An electric lamp - Google Patents

An electric lamp Download PDF

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Publication number
WO2007052201A2
WO2007052201A2 PCT/IB2006/053970 IB2006053970W WO2007052201A2 WO 2007052201 A2 WO2007052201 A2 WO 2007052201A2 IB 2006053970 W IB2006053970 W IB 2006053970W WO 2007052201 A2 WO2007052201 A2 WO 2007052201A2
Authority
WO
WIPO (PCT)
Prior art keywords
end piece
mould
metal foil
electric lamp
gas
Prior art date
Application number
PCT/IB2006/053970
Other languages
French (fr)
Other versions
WO2007052201A3 (en
Inventor
Hans Galenkamp
Jacobus L. J. Ruigrok
Johannes A. Zaat
Wilfried Kohlmann
Original Assignee
Koninklijke Philips Electronics N.V.
Philips Intellectual Property & Standards Gmbh
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 Koninklijke Philips Electronics N.V., Philips Intellectual Property & Standards Gmbh filed Critical Koninklijke Philips Electronics N.V.
Publication of WO2007052201A2 publication Critical patent/WO2007052201A2/en
Publication of WO2007052201A3 publication Critical patent/WO2007052201A3/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/36—Seals between parts of vessel, e.g. between stem and envelope
    • 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
    • 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
    • H01J61/361—Seals between parts of vessel
    • H01J61/363—End-disc seals or plug seals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/24—Manufacture or joining of vessels, leading-in conductors or bases
    • H01J9/32—Sealing leading-in conductors
    • H01J9/323—Sealing leading-in conductors into a discharge lamp or a gas-filled discharge device

Definitions

  • the present invention relates to an electric lamp comprising an outer bulb at least substantially made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass, wherein said outer bulb is provided at least at one end thereof with a gas-tight seal having at least one metal foil sealed therein, said metal foil having secured to it the end of a current supply wire projecting outside the lamp, as well as the end of a pole wire projecting inside the lamp.
  • the invention also refers to a process for manufacturing said electric lamp.
  • Such an electric lamp and such a manufacturing process are generally known. It is common practice to lead the current supply wires projecting outside the lamp to the exterior through the narrow limits of the seal formed by a flat pinch remote from the lamp space. Use is made of an elongated metal foil in the form of a strip embedded in the flat pinch, wherein the current supply wires and the pole wires are connected to the strip on opposing ends thereof.
  • the flat pinch has a relatively large size and therefore a comparatively large space must be available for such a lamp to be mounted in a car headlight, for example, viewed in the longitudinal direction of the lamp.
  • the shape of the flat pinch cannot be accurately controlled. As a result, the position of the pole wires inside the lamp cannot be accurately controlled either.
  • an electric lamp of the type mentioned in the introduction to the description is characterized in accordance with the invention in that said gas-tight seal is formed by a single end piece connected to the outer bulb in a gas-tight manner, wherein said single end piece is also made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass.
  • said single end piece is adhered to said outer bulb using an adhesive.
  • said single end piece is welded to said outer bulb.
  • said single end piece is soldered to said outer bulb using a soldering material.
  • both the outer bulb and the single end piece are made of hard glass, a ceramic material or quartz glass, that is a material having a very high melting temperature compared to soft glass, i.e. particularly with a melting temperature above 1200 0 C.
  • Said single end piece acts as a glass base for lamp elements inside the outer bulb.
  • the invention ensures that (i) the position of the pole wires inside the lamp can be accurately controlled, (ii) said single end piece can have a very compact form, (iii) said outer bulb may have any suitable form, (iv) multiple spaced-apart metal foils can be accurately positioned in said single end piece, and (v) an exhaust tube may not be necessary.
  • said single end piece with the metal foil sealed therein is connected to said outer bulb in an suitable gas environment, that is the electric lamp is filled with a suitable gas during or before attachment of said single end piece to said outer bulb.
  • Hard glass and quartz glass have a melting temperature of approximately 1400 0 C and 2200 0 C, respectively, while soft glass usually has a melting temperature below 1000 0 C.
  • said outer bulb and said single end piece are made of the same material having such a high melting temperature.
  • the electric lamp is provided at one end with a single end piece acting as a gas-tight seal having two spaced-apart metal foils sealed therein.
  • the electric lamp is provided at two opposing ends with a single end piece acting as a gas-tight seal having one metal foil sealed therein.
  • the electric lamp comprises a filament, wherein the ends of the filament bridge the remote ends of the pole wires.
  • the pole wires support electrodes or the pole wires serve as electrodes themselves in order to generate a discharge arc between them.
  • the present electric lamp comprises a discharge vessel surrounded by an envelope (e.g. said outer bulb) with clearance, wherein (outer ends of) said discharge vessel bridge the remote ends of the pole wires.
  • said metal foil comprises molybdenum.
  • the invention also refers to a process for manufacturing an electric lamp in accordance with the invention comprising the steps of providing at least one end thereof with a gas-tight seal having at least one metal foil sealed therein; securing said metal foil to the end of a current supply wire projecting outside the lamp, as well as to the end of a pole wire projecting inside the lamp; characterized in that said gas-tight seal is formed by a single end piece that is connected to the outer bulb in a gas-tight manner, said single end piece being made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass.
  • said end piece is made using a slip-casting technique.
  • a slip-casting process comprises the steps of providing a mould; positioning said metal foil into said mould; introducing a suspension comprising a material chosen from the group consisting of hard glass, a ceramic material and quartz glass into said mould; - drying the mould and said material provided therein at a drying temperature; removing said dried material from said mould; sintering said dried material at a sintering temperature.
  • a de-binding step is carried out before said sintering step in order to have (organic) solvents released.
  • said end piece is made using a sol-gel technique. More particularly, such a sol-gel process comprises the steps of providing a mould; - positioning said metal foil into said mould; introducing a sol-gel comprising a material chosen from the group consisting of hard glass, a ceramic material and quartz glass into said mould; drying the mould and said material provided therein at a drying temperature; removing said dried material from said mould; - sintering said dried material at a sintering temperature.
  • Figure 1 and Figure 2 are a schematic side view of an embodiment of the present lamp according to the prior art (seen on the flat side of the foil) and according to the invention (seen in perspective), respectively.
  • Figure 1 shows an inner bulb or discharge vessel 1 in the form of a cylinder of quartz glass of a discharge lamp according to the prior art.
  • electrodes 2,3 are provided on each end of the discharge vessel 1 , said electrodes 2,3 being sealed in a vacuum-tight manner through quartz glass pinches 6,7 (acting as seals) of the discharge vessel 1 by means of molybdenum foils 4,5.
  • the inner bulb or discharge vessel 1 is disposed inside a quartz outer bulb or envelope 8, so that an intermediate space 9 is present.
  • the molybdenum foils 4,5 are secured on one end thereof to a current supply wire 10 projecting outside the discharge vessel 1 and on the other end thereof to a pole wire 11 projecting inside the discharge vessel 1.
  • Figure 2 relates to an electric lamp having pole wires 11 supporting electrodes 12, wherein parts that correspond to those of Figure 1 are designated with the same reference numerals.
  • a quartz end piece 13 is melted onto said quartz outer bulb 8 in a gas-tight manner, using a laser.
  • Said end piece 13 with the molybdenum foils 4,5 sealed therein is made using a slip-casting or sol-gel technique.
  • a mould is provided for manufacturing said end piece 13, wherein said metal foils 4,5 are positioned into said mould.
  • a suspension (slip-casting) or a sol-gel (sol-gel technique) of quartz (with a melting temperature equal to or less than 2200 0 C) is introduced into said mould.
  • the mould and said quartz present therein are dried for approximately 1 hour at room temperature. Thereafter the mould and said quartz are dried for approximately 1 hour at a drying temperature of approximately 275°C so that solvents and binders may be removed into the ambient air. After the mould has been removed, said quartz is finally sintered for approximately 1 hour at a sintering temperature of approximately 1400 0 C.
  • said single end piece 13 with the molybdenum foils 4,5 is realized, being ready for use, that is ready to be attached to the outer bulb 8 with the help of a laser.
  • composition of the suspension and the sol-gel mentioned above is as follows. Suspension: ceramic pearls 600 gram, butylacetate 21.2 gram, nitrocellulose
  • Sol-gel sol-gel compositions can be found at the website www.solgel.com. It should be noted that the present invention is not restricted to the embodiments shown, but extends also to other variants within the scope of the appended claims.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)

Abstract

An electric lamp comprising an outer bulb at least substantially made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass, wherein said outer bulb is provided at least at one end thereof with a gas-tight seal having at least one metal foil sealed therein, said metal foil having secured to it the end of a current supply wire projecting outside the lamp, as well as the end of a pole wire projecting inside the lamp, with the special feature that said gas-tight seal is formed by a single end piece connected to the outer bulb in a gas-tight manner, wherein said single end piece is also made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass.

Description

An electric lamp
The present invention relates to an electric lamp comprising an outer bulb at least substantially made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass, wherein said outer bulb is provided at least at one end thereof with a gas-tight seal having at least one metal foil sealed therein, said metal foil having secured to it the end of a current supply wire projecting outside the lamp, as well as the end of a pole wire projecting inside the lamp. The invention also refers to a process for manufacturing said electric lamp.
Such an electric lamp and such a manufacturing process are generally known. It is common practice to lead the current supply wires projecting outside the lamp to the exterior through the narrow limits of the seal formed by a flat pinch remote from the lamp space. Use is made of an elongated metal foil in the form of a strip embedded in the flat pinch, wherein the current supply wires and the pole wires are connected to the strip on opposing ends thereof. As a result, the flat pinch has a relatively large size and therefore a comparatively large space must be available for such a lamp to be mounted in a car headlight, for example, viewed in the longitudinal direction of the lamp. Further, as said seal is made by a pinching operation, the shape of the flat pinch cannot be accurately controlled. As a result, the position of the pole wires inside the lamp cannot be accurately controlled either.
It is an object of the invention to obviate this drawback and in order to accomplish that objective an electric lamp of the type mentioned in the introduction to the description is characterized in accordance with the invention in that said gas-tight seal is formed by a single end piece connected to the outer bulb in a gas-tight manner, wherein said single end piece is also made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass. Preferably, said single end piece is adhered to said outer bulb using an adhesive. In an alternative, said single end piece is welded to said outer bulb. Alternatively, said single end piece is soldered to said outer bulb using a soldering material. It is the merit of the present invention that it has been made possible to seal said metal foil in a single end piece and to subsequently fix said single end piece to the outer bulb, wherein both the outer bulb and the single end piece are made of hard glass, a ceramic material or quartz glass, that is a material having a very high melting temperature compared to soft glass, i.e. particularly with a melting temperature above 12000C. Said single end piece acts as a glass base for lamp elements inside the outer bulb. The invention ensures that (i) the position of the pole wires inside the lamp can be accurately controlled, (ii) said single end piece can have a very compact form, (iii) said outer bulb may have any suitable form, (iv) multiple spaced-apart metal foils can be accurately positioned in said single end piece, and (v) an exhaust tube may not be necessary. In the latter case, said single end piece with the metal foil sealed therein is connected to said outer bulb in an suitable gas environment, that is the electric lamp is filled with a suitable gas during or before attachment of said single end piece to said outer bulb.
Hard glass and quartz glass have a melting temperature of approximately 14000C and 22000C, respectively, while soft glass usually has a melting temperature below 10000C. In particular, said outer bulb and said single end piece are made of the same material having such a high melting temperature.
In a preferred embodiment of an electric lamp according to the invention, the electric lamp is provided at one end with a single end piece acting as a gas-tight seal having two spaced-apart metal foils sealed therein. In an alternative, the electric lamp is provided at two opposing ends with a single end piece acting as a gas-tight seal having one metal foil sealed therein.
In another preferred embodiment of an electric lamp in accordance with the invention, the electric lamp comprises a filament, wherein the ends of the filament bridge the remote ends of the pole wires. In another preferred embodiment the pole wires support electrodes or the pole wires serve as electrodes themselves in order to generate a discharge arc between them. In an alternative, the present electric lamp comprises a discharge vessel surrounded by an envelope (e.g. said outer bulb) with clearance, wherein (outer ends of) said discharge vessel bridge the remote ends of the pole wires.
In another preferred embodiment of an electric lamp according to the invention said metal foil comprises molybdenum. The invention also refers to a process for manufacturing an electric lamp in accordance with the invention comprising the steps of providing at least one end thereof with a gas-tight seal having at least one metal foil sealed therein; securing said metal foil to the end of a current supply wire projecting outside the lamp, as well as to the end of a pole wire projecting inside the lamp; characterized in that said gas-tight seal is formed by a single end piece that is connected to the outer bulb in a gas-tight manner, said single end piece being made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass.
In a preferred embodiment of a process in accordance with the invention said end piece is made using a slip-casting technique. In particular, such a slip-casting process comprises the steps of providing a mould; positioning said metal foil into said mould; introducing a suspension comprising a material chosen from the group consisting of hard glass, a ceramic material and quartz glass into said mould; - drying the mould and said material provided therein at a drying temperature; removing said dried material from said mould; sintering said dried material at a sintering temperature.
Preferably, a de-binding step is carried out before said sintering step in order to have (organic) solvents released.
In another preferred embodiment of a process according to the invention said end piece is made using a sol-gel technique. More particularly, such a sol-gel process comprises the steps of providing a mould; - positioning said metal foil into said mould; introducing a sol-gel comprising a material chosen from the group consisting of hard glass, a ceramic material and quartz glass into said mould; drying the mould and said material provided therein at a drying temperature; removing said dried material from said mould; - sintering said dried material at a sintering temperature.
In order that the invention may be readily carried into effect, it will now be described in greater detail, by way of example with reference to the accompanying drawings, in which Figure 1 and Figure 2 are a schematic side view of an embodiment of the present lamp according to the prior art (seen on the flat side of the foil) and according to the invention (seen in perspective), respectively.
Figure 1 shows an inner bulb or discharge vessel 1 in the form of a cylinder of quartz glass of a discharge lamp according to the prior art. On each end of the discharge vessel 1 electrodes 2,3 are provided, said electrodes 2,3 being sealed in a vacuum-tight manner through quartz glass pinches 6,7 (acting as seals) of the discharge vessel 1 by means of molybdenum foils 4,5. The inner bulb or discharge vessel 1 is disposed inside a quartz outer bulb or envelope 8, so that an intermediate space 9 is present. The molybdenum foils 4,5 are secured on one end thereof to a current supply wire 10 projecting outside the discharge vessel 1 and on the other end thereof to a pole wire 11 projecting inside the discharge vessel 1.
Figure 2 relates to an electric lamp having pole wires 11 supporting electrodes 12, wherein parts that correspond to those of Figure 1 are designated with the same reference numerals. A quartz end piece 13 is melted onto said quartz outer bulb 8 in a gas-tight manner, using a laser. Said end piece 13 with the molybdenum foils 4,5 sealed therein is made using a slip-casting or sol-gel technique. In particular, a mould is provided for manufacturing said end piece 13, wherein said metal foils 4,5 are positioned into said mould. Subsequently, a suspension (slip-casting) or a sol-gel (sol-gel technique) of quartz (with a melting temperature equal to or less than 22000C) is introduced into said mould. The mould and said quartz present therein are dried for approximately 1 hour at room temperature. Thereafter the mould and said quartz are dried for approximately 1 hour at a drying temperature of approximately 275°C so that solvents and binders may be removed into the ambient air. After the mould has been removed, said quartz is finally sintered for approximately 1 hour at a sintering temperature of approximately 14000C. As a result, said single end piece 13 with the molybdenum foils 4,5 is realized, being ready for use, that is ready to be attached to the outer bulb 8 with the help of a laser.
The composition of the suspension and the sol-gel mentioned above is as follows. Suspension: ceramic pearls 600 gram, butylacetate 21.2 gram, nitrocellulose
(1.3 wt%) 44.4 gram and SiO2 165 gram.
Sol-gel: sol-gel compositions can be found at the website www.solgel.com. It should be noted that the present invention is not restricted to the embodiments shown, but extends also to other variants within the scope of the appended claims.

Claims

CLAIMS:
1. An electric lamp comprising an outer bulb at least substantially made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass, wherein said outer bulb is provided at least at one end thereof with a gas-tight seal having at least one metal foil sealed therein, said metal foil having secured to it the end of a current supply wire projecting outside the lamp, as well as the end of a pole wire projecting inside the lamp, characterized in that said gas-tight seal is formed by a single end piece connected to the outer bulb in a gas-tight manner, wherein said single end piece is also made of a material chosen from the group consisting of hard glass, a ceramic material and quartz glass.
2 An electric lamp according to claim 1, wherein said single end piece is adhered to said outer bulb using an adhesive.
3. An electric lamp according to claim 1, wherein said single end piece is welded to said outer bulb.
4. An electric lamp according to claim 1, wherein said single end piece is soldered to said outer bulb using a soldering material.
5. An electric discharge lamp according to any of the preceding claims 1 through 4, wherein said end piece has two spaced-apart metal foils sealed therein.
An electric discharge lamp according to any of the preceding claims 1 through 5, wherein the electric lamp is provided at two ends with a single end piece acting as a gas-tight seal, each end piece having a metal foil sealed therein.
6. An electric lamp according to any of the preceding claims 1 through 6, wherein the electric lamp comprises a filament and wherein the ends of the filament bridge the remote ends of the pole wires.
7. An electric lamp according to any of the preceding claims 1 through 7, wherein the pole wires support electrodes or wherein the pole wires serve as electrodes themselves in order to generate a discharge arc between them.
8. An electric lamp according to any of the preceding claims 1 through 8, wherein said metal foil comprises molybdenum.
9. A process for manufacturing an electric lamp according to any of the preceding claims 1 through 9 comprising the steps of providing at least one end thereof with a gas-tight seal having at least one metal foil sealed therein; securing said metal foil to the end of a current supply wire projecting outside the lamp, as well as to the end of a pole wire projecting inside the lamp; characterized in that said gas-tight seal is formed by a single end piece that is connected to the outer bulb in a gas-tight manner, said single end piece being made of a material chosen from the group consisting of a hard glass, a ceramic material and quartz glass.
11. A process according to claim 10, wherein said end piece is made using a slip casting technique.
12. A process according to claim 11, comprising the steps of providing a mould; - positioning said metal foil into said mould; introducing a suspension comprising a material chosen from the group consisting of hard glass, a ceramic material and quartz glass into said mould; drying the mould and said material provided therein at a drying temperature; removing said mould from said dried material; - sintering said dried material at a sintering temperature.
13. A process according to claim 12, wherein said end piece is made using a sol- gel technique.
14. A process according to claim 13, comprising the steps of providing a mould; positioning said metal foil into said mould; introducing a sol-gel comprising a material chosen from the group consisting of hard glass, a ceramic material and quartz glass into said mould; drying the mould and said material provided therein at a drying temperature; removing said mould from said dried material; sintering said dried material at a sintering temperature.
PCT/IB2006/053970 2005-11-03 2006-10-27 An electric lamp WO2007052201A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP05110299.4 2005-11-03
EP05110299 2005-11-03

Publications (2)

Publication Number Publication Date
WO2007052201A2 true WO2007052201A2 (en) 2007-05-10
WO2007052201A3 WO2007052201A3 (en) 2008-02-28

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2006/053970 WO2007052201A2 (en) 2005-11-03 2006-10-27 An electric lamp

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WO (1) WO2007052201A2 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002528880A (en) * 1998-10-22 2002-09-03 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Incandescent lamp
EP1071114A1 (en) * 1999-07-21 2001-01-24 Oshino Lamps Ltd. Lighting device
US6611102B2 (en) * 2000-03-10 2003-08-26 Matsushita Electric Industrial Co., Ltd. Tungsten-halogen light bulb, and reflector lamp using the same
CN1754246A (en) * 2003-02-27 2006-03-29 皇家飞利浦电子股份有限公司 High-pressure discharge lamp

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None

Also Published As

Publication number Publication date
WO2007052201A3 (en) 2008-02-28

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