US3868159A - Method of manufacturing an electric incandescent lamp having a longer lifetime and/or a higher light output - Google Patents

Method of manufacturing an electric incandescent lamp having a longer lifetime and/or a higher light output Download PDF

Info

Publication number
US3868159A
US3868159A US369552A US36955273A US3868159A US 3868159 A US3868159 A US 3868159A US 369552 A US369552 A US 369552A US 36955273 A US36955273 A US 36955273A US 3868159 A US3868159 A US 3868159A
Authority
US
United States
Prior art keywords
temperature
filament
turns
fluorine
atmosphere
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
US369552A
Other languages
English (en)
Inventor
Erhard Kauer
Johann Schroder
Horst Horster
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
Original Assignee
US Philips Corp
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 US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3868159A publication Critical patent/US3868159A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K3/00—Apparatus or processes adapted to the manufacture, installing, removal, or maintenance of incandescent lamps or parts thereof
    • H01K3/02—Manufacture of incandescent bodies

Definitions

  • ABSTRACT ⁇ 301' Foreign Application Priorit D t The invention relates to a method of manufacturing a June 28, 1972 Germany 2231520 gas'fined eleftric lamp, palticulifly a low-voltage mcandescent lamp 1n which the w1re di- [52] us CL 316/1 29/25 17 I ameter of the incandescent civil varies in different [51] Im h M axial sections.
  • Low-voltage lamps are in this connection to be understood especially heavy-loaded electric incandescent lamps whose operating voltage is generally below 42 V. Examples of such lamps are many types of projection lamps, motorcar lamps, etc. in which a high luminance is important.
  • the lamps may comprise a reactive transport gas such as iodine and bromine and bromine compounds such as hydrocarbonbromides, hydrobromic acid, boronbromide, etc. These lamps generally have a coiled filament which consists of a comparatively low number of turns.
  • the temperature of the end turns may be several hundred C lower than the temperature of the turns in the middle of the coiled filament. Consequently the luminance along the coiled filament is not It hasbeen found that in case ofa reduction of the"? 'takes place during operation in addition to the already constant for which reason in projection lamps sometimes only the light emitted by the central turns is used in order to obtain an optimum uniform light intensity on the image surface. It has already been attempted to equalize the luminance distribution along the coiled filament by pre-operation in a halogen-containing gas at- 'mosphere. It was always the aim in such methods of pretreatment to reach a full temperature homogeneization along the filament.
  • An object of the invention is to provide a method of manufacturing an electric incandescent lamp, particularly a low-voltage incandescent lamp having a longer lifetime and/or a higher luminance which is as uniform as possible. According to the invention this goal is achieved by a method in which the filament is preoperated until the temperature T of the end turns of 40 the filament is 20 to l20K lower than the temperature T of the central turn in an atmosphere which comprises a gas which is reactive relative to tun gsten.
  • the invention is based on the following recognitions obtained during experiments which led to the present invention.
  • the temperature of the end turns is often 200 to 400K lower than the temperature in the middle of th e fil ament.
  • Such a coiled filament will burn through in the central hotter part of the filament.
  • the temperature along the filament body is completely equalized; the filament burns through at one of the ends.
  • An extension of the lifetime does not occur, on the contrary the lifetime is generally drastically shortened. Hitherto it has not been taken into account that at equal temper- 60 mentioned radial tungsten transport.
  • the radial tungsten losses of the end turns correspond to the total loss of the turn in the middle of the filament body, which loss is composed of radial and axial transport, so that in addition to a more uniform luminance at a constant temperature T of the middle of the filament an increase in the light output and an extension of the lifetime r are obtained.
  • exa-1+xa 1/3, elal+la ' has a value of between 38 and 29 and in the temperature range about 3,300K which is conventional for
  • a corresponds to the radius of the quasi-stationary layer of gas (Langmuir-layer) surrounding the filament.
  • this radius may assame a value of between 1 and 4 mm.
  • the radius is approximately 2 mm.
  • the incandescent lamp according to the invention may be manufactured by pre-operating the lamp with th mealtime"; lzerlxeakxee:aesr tinsfie ile ment body prior to mounting, the filament body being in an atmosphere comprising fluorine or chlorine.
  • Fluorine is preferred. Only when using fluorine is it possible to preoperate the filament body at a tempera ture which can also be achieved later during operation at the operating voltage which has been found to be favourable in the experiments for adjusting a given temperature profile and hence a long lifetime. With fluorine at temperatures of the filament body of about 3,300K which are conventionally usedin the present-' day high-loaded low-voltage incandescent lamps tungsten is transported from comparatively cold spots to hotter spots of the filament body. With chlorine this is only the case at temperatures of less than approximately 2,700l(. In addition the pretreatment with fluorine has technological advantages relative to a pretreatment with chlorine.
  • the partial pressure of the inert gas is preferably between approximately- 0.1 and 10 atmospheres.
  • the pre operating temperature must be approximately between 2,800 and 3,600K. Under these circumstances the pre-operation time is approximately 1 minute to 20 minutes.
  • the partial pressure at room temperature of chlorine would be between 10 and 100 Torr.
  • the partial pressure is likewise chosen to be between these limits.
  • the partial pressure of theinert gas is preferably be-.
  • the pre operation temperature must be approximately between 1,700 and 2,7OQK. Under these circumstances the.
  • pre-operation period is approximately to 100 minutes.
  • the lamps with a filament treated according to the invention may be filled with the conventional rare gases such as argon or krypton or may also comprise a chemical transport gas such as iodine or bromine or bromine
  • FIG. 1 diagrammatically shows in a cross-section a pre-operation device 7
  • FIG. 2 shows a complete lamp having a preoperated filament and choosing the partial pressures of fluorine and inert gas r of which are more easy to handle than fluorine, are, for
  • WF tungsten oxyfluoride WF nitrogen fluorides
  • NF N F fluorides of phosphorus and arsenic, sulphur hexafluoride WF tungsten oxyfluoride
  • WF nitrogen fluorides NF N F fluorides of phosphorus and arsenic, sulphur hexafluoride.
  • SP oxygen fluoride (0P selenium hexafluoride (SeF tellerium hexafluoride (TeF ),haIogen fluorides, fluorides of rare gases such as, for example, xenon fluorides.
  • the partial pressure of these compounds is prefera bly chosen to be such that in case ofa complete decomposition of the compound the partial pressure of fluorine at room temperature should be between approximately 0.] and Torr. Also when using fluorine the partial pressure is preferably chosen to be within these limits. In case of partial pressures of less than (H Torr thc required pro-operation time considerably increases and in case of partial pressures of more than 20 Torr the reactions proceed too vigorously and the process becomes uncontrollable.
  • EXAMPLE Tungsten filaments 1 were pre-operated in a preoperation device diagrammatically shown in a crosssection in FIG. 1.
  • the device contained two nickel electrodes 3 provided with nickel tubes 2 which were secured toa base plate 4 of electrically non-conducting material, in which electrodes the filament ends 6were inserted.
  • the gasspace was enclosed within an envelope 5 of nickel.
  • the filaments 1 had 18 turns.
  • the wire thickness was 0.17 mm and the filament length was 5 mm.'The straight wire ends 6 were protected from quick attack by fluorine over a length of approximately 5 mmby the nickel tubes 2 (inner diameter 2 mm).
  • the envelope 5 comprised a gas mixture of argon (partiallpressure 200 I Torr) and nitrogen fluoride (NF (partialpressure3 shown in FIG. 2, provided in a quartz envelope.
  • the curves A and B in FIG. 3 show temperature profiles (pertaining to one half of a filament each) of nontreated filaments.
  • the curves C and D show temperature profiles of filaments treated in accordance with the invention (also pertaining to one half of a filament).
  • the temperature profiles C and D satisfy the temperature requirements very good while the non pre-treated temperature profiles show a temperature profile deviating therefrom.
  • Nr W shows the number of the relevant turn
  • a T(K) shows the temperature difference in K and M shows the middle of the filament.
  • the resultant lighttechnical advantages of the lamps A C and D having pre-treated filaments with respect to those having non pre-treated filaments A and B are apparent from the Table below in which the measured light values and the lifetimes of the four experimental lamps are stated. All lamps were examined at the same operating temperature T,,, (temperature of the middle of the filament). The electrical power N, the luminous flux I, the light output l/N, the temperature difference A T between the middle and the ends of the filament and the lifetime 7 until the wire burnt through were measured. The measuring results are representative of The advantages obtained by the invention thus especially consist in that with the aid of comparatively simple steps an extension of the lifetime and a higher and more uniform luminance of gas-filled incandescent lamps can be obtained.
  • the end turns of the filament is 30 to K lower than the temperature T of the central turns.
  • a method as claimed in claim l wherein said preoperating step takes approximately 1 to 20 minutes in an atmosphere comprising fluorine having a partial i pressure of between 0.1 and 20 Torr and an inert gas having a partial pressure of between 10 and 10 Torr at a temperature T of the central turns of between 2,800 and 3,600K.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Discharge Lamp (AREA)
US369552A 1972-06-28 1973-06-13 Method of manufacturing an electric incandescent lamp having a longer lifetime and/or a higher light output Expired - Lifetime US3868159A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2231520A DE2231520A1 (de) 1972-06-28 1972-06-28 Verfahren zur herstellung einer elektrischen gluehlampe mit verlaengerter lebensdauer und/oder erhoehter lichtausbeute

Publications (1)

Publication Number Publication Date
US3868159A true US3868159A (en) 1975-02-25

Family

ID=5848989

Family Applications (1)

Application Number Title Priority Date Filing Date
US369552A Expired - Lifetime US3868159A (en) 1972-06-28 1973-06-13 Method of manufacturing an electric incandescent lamp having a longer lifetime and/or a higher light output

Country Status (11)

Country Link
US (1) US3868159A (enrdf_load_stackoverflow)
JP (1) JPS4957683A (enrdf_load_stackoverflow)
AU (1) AU5723573A (enrdf_load_stackoverflow)
BE (1) BE801466A (enrdf_load_stackoverflow)
CA (1) CA975420A (enrdf_load_stackoverflow)
DE (1) DE2231520A1 (enrdf_load_stackoverflow)
FR (1) FR2191265B1 (enrdf_load_stackoverflow)
GB (1) GB1431575A (enrdf_load_stackoverflow)
IT (1) IT989449B (enrdf_load_stackoverflow)
NL (1) NL7308786A (enrdf_load_stackoverflow)
SE (1) SE381953B (enrdf_load_stackoverflow)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4535269A (en) * 1983-08-01 1985-08-13 General Electric Company Incandescent lamp
DE4343989C2 (de) * 1993-12-22 2002-12-19 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Halogenglühlampe

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3619701A (en) * 1968-12-27 1971-11-09 Tokyo Shibaura Electric Co Halogen cycle incandescent lamps
US3759602A (en) * 1971-08-30 1973-09-18 Gen Electric Inhibiting d-c notching effect in incandescent lamp filaments

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3619701A (en) * 1968-12-27 1971-11-09 Tokyo Shibaura Electric Co Halogen cycle incandescent lamps
US3759602A (en) * 1971-08-30 1973-09-18 Gen Electric Inhibiting d-c notching effect in incandescent lamp filaments

Also Published As

Publication number Publication date
CA975420A (en) 1975-09-30
SE381953B (sv) 1975-12-22
IT989449B (it) 1975-05-20
JPS4957683A (enrdf_load_stackoverflow) 1974-06-04
FR2191265B1 (enrdf_load_stackoverflow) 1977-12-23
DE2231520A1 (de) 1974-01-17
FR2191265A1 (enrdf_load_stackoverflow) 1974-02-01
AU5723573A (en) 1975-01-09
NL7308786A (enrdf_load_stackoverflow) 1974-01-02
GB1431575A (en) 1976-04-07
BE801466A (fr) 1973-12-26

Similar Documents

Publication Publication Date Title
US2883571A (en) Electric incandescent lamp
EP0204061B1 (en) A compact low-pressure mercury vapour discharge lamp and a method for its manufacture
US4319162A (en) Fluorescent lamp having a convoluted tubular envelope of compact tridimensional configuration
KR960016763B1 (ko) 몰리브덴 기본합금 및 그로부터 제조된 인입선
US3868159A (en) Method of manufacturing an electric incandescent lamp having a longer lifetime and/or a higher light output
US2820920A (en) Manufacture of coated electrodes
US4288239A (en) Method of making a convoluted tubular envelope for a compact electric discharge lamp
JPH0760672B2 (ja) タングステン―ハロゲン・ランプ
US3719853A (en) Halogen lamps containing methyl bromide or methylene chloride
US3585435A (en) Electric incandescent lamp
US3619701A (en) Halogen cycle incandescent lamps
US2441863A (en) Electrode for discharge devices
EP0153776B1 (en) Mains voltage incandescent lamp
US3294125A (en) Electrode coil and method
US9252007B2 (en) Light source device, method for manufacturing the same and filament
US3382396A (en) Superhigh-pressure mercury vapor discharge lamps
US2714685A (en) Low pressure fluorescent and discharge lamps
US3831053A (en) Differential output lamp containing chlorine and hydrogen
US3148267A (en) Tungsten filament fabrication
US1644712A (en) Electric lamp
US274295A (en) Incandescent electric lamp
US3189396A (en) Method for processing discharge devices
US1647591A (en) Gaseous-discharge lamp
US1240700A (en) Incandescent tungsten lamp.
US395962A (en) Thomas a