US3646378A - Low-pressure sodium vapor discharge lamps - Google Patents

Low-pressure sodium vapor discharge lamps Download PDF

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Publication number
US3646378A
US3646378A US48045A US3646378DA US3646378A US 3646378 A US3646378 A US 3646378A US 48045 A US48045 A US 48045A US 3646378D A US3646378D A US 3646378DA US 3646378 A US3646378 A US 3646378A
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US
United States
Prior art keywords
lamp
electrode
discharge tube
low
discharge
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
US48045A
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English (en)
Inventor
Urbaan Paul Marguerit Goossens
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
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 US3646378A publication Critical patent/US3646378A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
    • H01J61/74—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a main light-emitting filling of difficult vaporisable metal vapour, e.g. sodium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H01J61/34—Double-wall vessels or containers

Definitions

  • ABSTRACT A low-pressure sodium vapor discharge lamp having small [30] Fomgn Apphcauon P'mmy Data reservoirs of sodium positioned near the electrodes in :1 Feb. 28, 1970 Netherlands ..7002s94 as Satisfy wherein B represents the overall contents of those reservoirs whose distance up to the nearest electrode is between 10 and 35 per- [52] U.S. Cl ..3l3/27, 313/220, 33113522257, cent of half the length of the discharge path and T represents [51] Int n 61/34 the overall contents of all reservoirs.
  • a heat-reflecting layer is positioned between the outer en- 313/220, 225, 227 velope and the discharge tube and extends over part of the length of the lamp to keep the reservoirs nearest the elec trodes at cooler temperatures.
  • the invention relates to a low-pressure sodium vapor discharge lamp provided with a U-shaped discharge tube including an electrode near both ends, the wall of the discharge tube having at least several humped bulges (small reservoirs of sodium) and the discharge tube being surrounded by an outer envelope.
  • the object of the present invention is to provide a simple solution for a sodium lamp of the kind described in the preamble by which it is avoided or at least the risk is reduced that the sodium near the electrodes disappears completely.
  • a low-pressure sodium vapor discharge lamp according to the invention is provided with a U-shaped discharge tube that includes an electrode at both ends within an outer envelope.
  • the wall of the discharge tube has at least several humped bulges and is characterized in that the condition (B/T) 20.5 is satisfied, wherein B represents the overall contents of all those bulges located at distance from the nearest electrode that lie between percent and 35 percent of half the length of the discharge path, and T represents the overall contents of all bulges on the wall of the discharge tube.
  • the discharge path is to be understood to mean the path from one electrode through the so-called bend of the U- shaped discharge tube to the other electrode.
  • An advantage of this lamp is that much sodium can be stored near the electrodes in the relatively large reservoir of bulges. However, when sodium travels towards the bend of the discharge tube clue to the operation of the lamp, sufficient sodium will remain present for a very long period in the said reservoir of bulges (near the electrodes) so that also sodium vapor remains present near the electrodes which gives rise to the wattage of the lamp varying only to a slight extent.
  • a transparent heat-reflecting layer such as a layer of indium oxide, extends over part of the length of the lamp between the wall of the discharge tube and the inner wall of the outer envelope.
  • This layer is preferably only present on areas whose distance to the nearest electrode of the discharge tube is larger than the distance between said electrode and the bulge located nearest said electrode.
  • An advantage of this preferred embodiment is that at least the first bulge near the electrodes can now be somewhat cooler than when the heat-reflecting layer would extend throughout the total length of the outer envelope. This gives rise to a delay in the movement of the sodium from the reservoir of bulges near the electrodes towards the bend.
  • the lamp shown is a ISO-watt lamp.
  • the reference numeral 1 denotes a U-shaped discharge tube.
  • One of the limbs of the tube 1 is denoted by the reference numeral 2, the other limb is denoted by the reference numeral 3.
  • An electrode 4 is provided at one end of the limb 2
  • anelec' trode 5 is provided at one end of the limb 3 of the tube 1.
  • the tube 1 is surrounded by a glass outer envelope 6.
  • the reference numeral 7 denotes a lamp cap.
  • the reference numerals 8 and 9 denote electric wires which connect the electrodes 4 and 5, respectively, to the lamp cap 7.
  • the limb 2 is provided with seven humped bulges.
  • Half the length of the discharge ath (approximately one limb length) is ap roximately 96 cm. he bu ge a 18 located at a distance of 12. cm. from the electrode 4.
  • These distances for b, c, d, e,fand g are 17.5 cm., 22.5 cm., 27.5 cm., 45 cm., 62.5 cm. and cm., respectively.
  • the reference numeral 10 denotes a heat-reflecting indium oxide layer. This layer is provided on the inner side of the outer envelope 6 and does not extend any farther than approximately 23 cm. from the electrodes 4 and 5. Due to this layer the bulges a and b are somewhat colder than they would have been if this layer would have extended throughout the total length of the outer envelope 6. As a result the transfer of sodiurn from these bulges a and b towards the bend ll of the discharge tube is delayed. In the given case, the Wattage of the lamp had varied only less than 5 percent after 2,500 hours of operation.
  • a low-pressure sodium vapor discharge lamp comprising an outer envelope, a U-shaped discharge tube having an electrode at both ends within said envelope, the wall of the discharge tube having at least several humped bulges for maintaining a uniform distribution of sodium in the discharge space characterized in that the condition (B/T) 0.5 is satisfied, wherein: B represents the overall contents of all those bulges whose distance up to the nearest electrode is between 10 percent and 35 percent of half the length of the discharge path, and wherein Trepresents the overall contents of all bulges on the wall of the discharge tube.

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Discharge Lamps And Accessories Thereof (AREA)
US48045A 1970-02-28 1970-06-22 Low-pressure sodium vapor discharge lamps Expired - Lifetime US3646378A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7002894.A NL165885C (nl) 1970-02-28 1970-02-28 Lagedruknatriumdampontladingslamp.

Publications (1)

Publication Number Publication Date
US3646378A true US3646378A (en) 1972-02-29

Family

ID=19809463

Family Applications (1)

Application Number Title Priority Date Filing Date
US48045A Expired - Lifetime US3646378A (en) 1970-02-28 1970-06-22 Low-pressure sodium vapor discharge lamps

Country Status (7)

Country Link
US (1) US3646378A (enExample)
JP (1) JPS4942396B1 (enExample)
BE (1) BE749235A (enExample)
DE (1) DE2027265C3 (enExample)
FR (1) FR2080287A5 (enExample)
GB (1) GB1243000A (enExample)
NL (1) NL165885C (enExample)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4028578A (en) * 1973-02-16 1977-06-07 Owens-Illinois, Inc. Gas discharge dielectric containing a source of boron, gallium, indium, or thallium
US4080545A (en) * 1976-12-27 1978-03-21 Xerox Corporation Sodium vapor lamp with emission aperture
US4731560A (en) * 1970-08-06 1988-03-15 Owens-Illinois Television Products, Inc. Multiple gaseous discharge display/memory panel having improved operating life
US4794308A (en) * 1970-08-06 1988-12-27 Owens-Illinois Television Products Inc. Multiple gaseous discharge display/memory panel having improved operating life

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1158700A (fr) * 1955-10-18 1958-06-18 Philips Nv Tube à décharge, en particulier dans la vapeur de sodium et à remplissage gazeux
GB817100A (en) * 1955-12-22 1959-07-22 Gen Electric Co Ltd Improvements in or relating to electric discharge lamps

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1158700A (fr) * 1955-10-18 1958-06-18 Philips Nv Tube à décharge, en particulier dans la vapeur de sodium et à remplissage gazeux
GB817100A (en) * 1955-12-22 1959-07-22 Gen Electric Co Ltd Improvements in or relating to electric discharge lamps

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4731560A (en) * 1970-08-06 1988-03-15 Owens-Illinois Television Products, Inc. Multiple gaseous discharge display/memory panel having improved operating life
US4794308A (en) * 1970-08-06 1988-12-27 Owens-Illinois Television Products Inc. Multiple gaseous discharge display/memory panel having improved operating life
US4028578A (en) * 1973-02-16 1977-06-07 Owens-Illinois, Inc. Gas discharge dielectric containing a source of boron, gallium, indium, or thallium
US4080545A (en) * 1976-12-27 1978-03-21 Xerox Corporation Sodium vapor lamp with emission aperture

Also Published As

Publication number Publication date
NL165885B (nl) 1980-12-15
DE2027265C3 (de) 1978-12-14
GB1243000A (en) 1971-08-18
FR2080287A5 (enExample) 1971-11-12
BE749235A (fr) 1970-10-20
DE2027265A1 (de) 1971-12-02
JPS4942396B1 (enExample) 1974-11-14
DE2027265B2 (de) 1978-04-20
NL7002894A (enExample) 1971-08-31
NL165885C (nl) 1981-05-15

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