US2951171A - High-pressure electric discharge tube - Google Patents
High-pressure electric discharge tube Download PDFInfo
- Publication number
- US2951171A US2951171A US749993A US74999358A US2951171A US 2951171 A US2951171 A US 2951171A US 749993 A US749993 A US 749993A US 74999358 A US74999358 A US 74999358A US 2951171 A US2951171 A US 2951171A
- Authority
- US
- United States
- Prior art keywords
- electrode
- discharge tube
- electric discharge
- pressure electric
- emissive material
- 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
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
- C11D3/43—Solvents
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/04—Electrodes; Screens; Shields
- H01J61/06—Main electrodes
- H01J61/073—Main electrodes for high-pressure discharge lamps
- H01J61/0732—Main electrodes for high-pressure discharge lamps characterised by the construction of the electrode
Definitions
- the cylindrical bore of the electrode opens into a space the sectional area of which exceeds that of the bore, provision being made in this space of a material having a higher electron emision than the material of the hollow electrode body, it has been found that the emissivity of this electrode may cease or at least fall off materially before the supply of emissive material is spent.
- This member may be a helically coiled metal wire. If desired, it may be a double helix comprising two layers.
- reference numeral 1 denotes a substantially spherical quartz discharge tube having an inside diameter of about 20 mms; it is iilled with xenon at a pressure of about atms. at room temperature.
- Tungsten electrodes 20 and 30 are provided in line with each other in the vertical axis of the discharge tube with a relative spacing of about 2 mms.
- the electrode ends facing each other are provided with conical cavities 21 and 31 which at their apices merge into cylindrical bores 22 and 32.
- Tungsten current supply leads 23 and 33 are connected to the electrodes by sleeves 24 and 34 respectively each comprising two layers of helically coiled tungsten wire with engaging turns.
- each electrode In the spaces bounded by each electrode, a current supply lead and a sleeve, provision is made of an emissive material. A member which is in contact with the cylindrical bore is in contact with the emissive material also.
- the said member consists of a helically coiled tungsten wire 37 having a diameter of about microns one end of which is immersed in the supply of emissive material 38 while the other end engages the wall of the cylindrical bore 32.
- the upper turns of the helical wire may have a larger pitch than the lower turns.
- This member promotes the migration of the emissive material to the cylindrical bore so that the emissivity of the electrode is less likely to cease prematurely than without the provision of such a member.
- the helix 37 is provided -by winding back the wire with a second layer 39 which extends to the lower end -face of the electrode body 30.
- This double helix has the advantage of holding more emissive material than a single helix.
- This emissive material may be a mixture of barium oxide and thorium oxide.
- the tubev was operated with alternating current of about 9' amps. with a tube voltage of about 18 volts. The discharge was quiet. At a current strength exceeding about 2 amps. there were no focal spots. The life was about 500 operating hours, the decrease of the luminous flux being about 25%.
- the diameters of the electrode 20 and the current supply lead 23 were about 2 mms., the diameters of the electrode 30 and the current supply lead 33 about 1.4 mms., the diameter of the bore 22 about 0.8 mm. and that of the bore 32 about 0.5 mm.
- the conical cavities 21 and 31 had apical angles of about 120.
- the axial spacing between each electrode 'and its associated current supply lead was about 2 mms.
- a high-pressure electric discharge tube adapted to operate without a focal spot comprising a light-transmissible envelope, an inert gas filling said envelope at a pressure of several atmospheres, a pair of axially aligned spaced conductive electrodes within said envelope, the
- the electrodes being small compared with the ldiameter of the envelope, at least one of said electrodes having a conical depression the base of which faces the other electrode and the apex of which lies within and on the axis of said electrode, said electrode also having, an axial cylindrical recess extending from the apex of said conical depression into a chamber in the electrode having la sectional area exceeding that of the recess and which is at least partially lled with a material having a higher electron emission than the material of said electrode, and a helically coiled metal wire in contact with the wall of said recess and the emissive material to facilitate constant migration of emissive material into said recess.
- a lamp as claimed in claim 1 in which the wire is wound in a double helix having two layers.
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Wood Science & Technology (AREA)
- Organic Chemistry (AREA)
- Discharge Lamp (AREA)
Description
Aug. 30, 1960 T. HOLMES HIGH-PRESSURE ELECTRIC DISCHARGE TUBE Filed July 21, 1958 INVENTOR. 7'. HOLMES wgu;
`MET
United States Patent O HIGH-PRESSURE ELECTRIC DISCHARGE TUBE Thomas Holmes, Eindhoven, Netherlands, assignor to North American Philips Company, Inc., New York, N.Y., a corporation of Delaware;
Filed July 21, 1958, Ser. No. 749,993 Claims priority, application Netherlands Aug. 10, 1957 3 Claims. (Cl. 313-209) In U.S. Patent application Serial No. 640,940, filed February 18, 1957, now U.S. Patent 2,887,603, a highpressure electric discharge tube is described comprising electrodes the relative spacing of which is small as compared with the tube diameter, one of the electrodes, in a vertical arrangement preferably the lower electrode, being provided with a conical cavity, the apex of which merges into a cylindrical bore, while the discharge current is set at a value exceeding that at which the discharge involving a focal spot passes into a discharge without `focal spot.
When the cylindrical bore of the electrode opens into a space the sectional area of which exceeds that of the bore, provision being made in this space of a material having a higher electron emision than the material of the hollow electrode body, it has been found that the emissivity of this electrode may cease or at least fall off materially before the supply of emissive material is spent.
It is an object of the present invention to obviate this disadvantage.
According to the present invention, provision is made in the said space of a member which is in contact with the wall of the cylindrical bore and with the emissive material. This member ensures a constant migration of the emissive material to the cylindrical bore.
This member may be a helically coiled metal wire. If desired, it may be a double helix comprising two layers.
In order that the invention may readily be carried into eiect, two examples thereof will now be described in detail with reference to the accompanying drawings.
In the gures, reference numeral 1 denotes a substantially spherical quartz discharge tube having an inside diameter of about 20 mms; it is iilled with xenon at a pressure of about atms. at room temperature.
The electrode ends facing each other are provided with conical cavities 21 and 31 which at their apices merge into cylindrical bores 22 and 32.
Tungsten current supply leads 23 and 33 are connected to the electrodes by sleeves 24 and 34 respectively each comprising two layers of helically coiled tungsten wire with engaging turns.
In the spaces bounded by each electrode, a current supply lead and a sleeve, provision is made of an emissive material. A member which is in contact with the cylindrical bore is in contact with the emissive material also.
This member and the emissive material are not shown in Fig. 1.
In Figures 2 and 3 the lower electrode is drawn to an enlarged scale for the sake of clarity.
In the embodiment shown in Fig. 2 the said member consists of a helically coiled tungsten wire 37 having a diameter of about microns one end of which is immersed in the supply of emissive material 38 while the other end engages the wall of the cylindrical bore 32. The upper turns of the helical wire may have a larger pitch than the lower turns.
This member promotes the migration of the emissive material to the cylindrical bore so that the emissivity of the electrode is less likely to cease prematurely than without the provision of such a member.
In the embodiment shown in Fig. 3, the helix 37 is provided -by winding back the wire with a second layer 39 which extends to the lower end -face of the electrode body 30. This double helix has the advantage of holding more emissive material than a single helix.
This emissive material may be a mixture of barium oxide and thorium oxide.
Through an impedance (not shown) the tubev was operated with alternating current of about 9' amps. with a tube voltage of about 18 volts. The discharge was quiet. At a current strength exceeding about 2 amps. there were no focal spots. The life was about 500 operating hours, the decrease of the luminous flux being about 25%.
The diameters of the electrode 20 and the current supply lead 23 were about 2 mms., the diameters of the electrode 30 and the current supply lead 33 about 1.4 mms., the diameter of the bore 22 about 0.8 mm. and that of the bore 32 about 0.5 mm. The conical cavities 21 and 31 had apical angles of about 120. The axial spacing between each electrode 'and its associated current supply lead was about 2 mms. 'Ihe length of the sleeve 24, which consisted of a wire having a diameter of about 0.7 mm., was about 6 mms. and that of the sleeve 34, which consisted of a wire having a diameter of about 0.5 mm., was about 5.1 mms.
What is claimed is:
1. A high-pressure electric discharge tube adapted to operate without a focal spot comprising a light-transmissible envelope, an inert gas filling said envelope at a pressure of several atmospheres, a pair of axially aligned spaced conductive electrodes within said envelope, the
spacing of the electrodes being small compared with the ldiameter of the envelope, at least one of said electrodes having a conical depression the base of which faces the other electrode and the apex of which lies within and on the axis of said electrode, said electrode also having, an axial cylindrical recess extending from the apex of said conical depression into a chamber in the electrode having la sectional area exceeding that of the recess and which is at least partially lled with a material having a higher electron emission than the material of said electrode, and a helically coiled metal wire in contact with the wall of said recess and the emissive material to facilitate constant migration of emissive material into said recess.
2. A lamp as claimed in claim 1 in which the wire is wound in a double helix having two layers.
3. A lamp as claimed in claim 1 in which the emissive material is a mixture of barium oxide and thorium oxide.
References Cited in the file of this patent UNITED STATES PATENTS 2,304,412 Kern Dec. 8, 1942 2,821,647 Rigden Ian. 28, 1958 2,887,603 Haidinger May 19, 1959
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL219805A NL99793C (en) | 1957-08-10 | 1957-08-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2951171A true US2951171A (en) | 1960-08-30 |
Family
ID=42270268
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US749993A Expired - Lifetime US2951171A (en) | 1957-08-10 | 1958-07-21 | High-pressure electric discharge tube |
Country Status (5)
Country | Link |
---|---|
US (1) | US2951171A (en) |
DE (1) | DE1084374B (en) |
FR (1) | FR1201219A (en) |
GB (1) | GB854752A (en) |
NL (1) | NL99793C (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3258632A (en) * | 1966-06-28 | Shielded cathode | ||
US3419947A (en) * | 1965-12-10 | 1969-01-07 | Gen Electric | Compact source discharge lamp manufacture |
US3989973A (en) * | 1971-01-02 | 1976-11-02 | Siemens Aktiengesellschaft | Cold-cathode gas-discharge device |
US20060238127A1 (en) * | 2003-08-11 | 2006-10-26 | Koninklijke Philips Electronics N.V. | High-pressure discharge lamp |
US20080315769A1 (en) * | 2007-06-25 | 2008-12-25 | Agoston Boroczki | High intensity discharge lamp with enhanced dimming characteristcs |
JP2011077057A (en) * | 2003-01-16 | 2011-04-14 | Patent Treuhand Ges Elektr Gluehlamp Mbh | Electrode for high-pressure discharge lamp |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL296948A (en) * | 1963-08-21 | |||
NL296949A (en) * | 1963-08-21 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2304412A (en) * | 1939-10-04 | 1942-12-08 | Gen Electric | Electric high pressure discharge lamp |
US2821647A (en) * | 1951-08-09 | 1958-01-28 | Gen Electric | High pressure metal vapor lamp |
US2887603A (en) * | 1956-02-24 | 1959-05-19 | Philips Corp | Compact source lamp |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE880360C (en) * | 1943-07-14 | 1953-06-22 | Patra Patent Treuhand | Electric spherical high pressure discharge lamp |
DE887979C (en) * | 1944-06-25 | 1953-08-27 | Quarzlampen Gmbh | Electrode heated by the discharge for electric discharge lamps, especially high-pressure mercury lamps |
DE1740085U (en) * | 1953-03-06 | 1957-02-21 | Felix Dr Ing Mueller | ELECTRODE FOR DISCHARGE VESSELS. |
-
1957
- 1957-08-10 NL NL219805A patent/NL99793C/xx active
-
1958
- 1958-07-21 US US749993A patent/US2951171A/en not_active Expired - Lifetime
- 1958-08-05 DE DEN15442A patent/DE1084374B/en active Pending
- 1958-08-07 GB GB25356/58A patent/GB854752A/en not_active Expired
- 1958-08-08 FR FR1201219D patent/FR1201219A/en not_active Expired
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2304412A (en) * | 1939-10-04 | 1942-12-08 | Gen Electric | Electric high pressure discharge lamp |
US2821647A (en) * | 1951-08-09 | 1958-01-28 | Gen Electric | High pressure metal vapor lamp |
US2887603A (en) * | 1956-02-24 | 1959-05-19 | Philips Corp | Compact source lamp |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3258632A (en) * | 1966-06-28 | Shielded cathode | ||
US3419947A (en) * | 1965-12-10 | 1969-01-07 | Gen Electric | Compact source discharge lamp manufacture |
US3989973A (en) * | 1971-01-02 | 1976-11-02 | Siemens Aktiengesellschaft | Cold-cathode gas-discharge device |
JP2011077057A (en) * | 2003-01-16 | 2011-04-14 | Patent Treuhand Ges Elektr Gluehlamp Mbh | Electrode for high-pressure discharge lamp |
US20060238127A1 (en) * | 2003-08-11 | 2006-10-26 | Koninklijke Philips Electronics N.V. | High-pressure discharge lamp |
US7423379B2 (en) | 2003-08-11 | 2008-09-09 | Koninklijke Philips Electronics, N.V. | High-pressure gas discharge lamp having tubular electrodes |
US20080315769A1 (en) * | 2007-06-25 | 2008-12-25 | Agoston Boroczki | High intensity discharge lamp with enhanced dimming characteristcs |
DE112008001624T5 (en) | 2007-06-25 | 2010-05-12 | General Electric Co. | High intensity discharge lamp with improved dimming properties |
US8460045B2 (en) | 2007-06-25 | 2013-06-11 | General Electric Company | High intensity discharge lamp with enhanced dimming characteristcs |
Also Published As
Publication number | Publication date |
---|---|
NL99793C (en) | 1961-11-15 |
DE1084374B (en) | 1960-06-30 |
FR1201219A (en) | 1959-12-29 |
GB854752A (en) | 1960-11-23 |
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