US3134691A - Heating filament assembly and a method of preparing same - Google Patents
Heating filament assembly and a method of preparing same Download PDFInfo
- Publication number
- US3134691A US3134691A US142508A US14250861A US3134691A US 3134691 A US3134691 A US 3134691A US 142508 A US142508 A US 142508A US 14250861 A US14250861 A US 14250861A US 3134691 A US3134691 A US 3134691A
- Authority
- US
- United States
- Prior art keywords
- oxide
- component
- heating filament
- coating
- filament
- 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
Links
- 238000010438 heat treatment Methods 0.000 title claims description 23
- 238000000034 method Methods 0.000 title claims description 8
- 239000000203 mixture Substances 0.000 claims description 26
- 238000000576 coating method Methods 0.000 claims description 24
- 239000011248 coating agent Substances 0.000 claims description 21
- FRWYFWZENXDZMU-UHFFFAOYSA-N 2-iodoquinoline Chemical compound C1=CC=CC2=NC(I)=CC=C21 FRWYFWZENXDZMU-UHFFFAOYSA-N 0.000 claims description 13
- LTPBRCUWZOMYOC-UHFFFAOYSA-N beryllium oxide Inorganic materials O=[Be] LTPBRCUWZOMYOC-UHFFFAOYSA-N 0.000 claims description 13
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 11
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 10
- 230000005855 radiation Effects 0.000 claims description 10
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims description 6
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 6
- ZCUFMDLYAMJYST-UHFFFAOYSA-N thorium dioxide Chemical compound O=[Th]=O ZCUFMDLYAMJYST-UHFFFAOYSA-N 0.000 claims description 5
- 229910001930 tungsten oxide Inorganic materials 0.000 claims description 5
- 229910001928 zirconium oxide Inorganic materials 0.000 claims description 5
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 4
- WZECUPJJEIXUKY-UHFFFAOYSA-N [O-2].[O-2].[O-2].[U+6] Chemical compound [O-2].[O-2].[O-2].[U+6] WZECUPJJEIXUKY-UHFFFAOYSA-N 0.000 claims description 4
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 4
- 229910000449 hafnium oxide Inorganic materials 0.000 claims description 4
- WIHZLLGSGQNAGK-UHFFFAOYSA-N hafnium(4+);oxygen(2-) Chemical compound [O-2].[O-2].[Hf+4] WIHZLLGSGQNAGK-UHFFFAOYSA-N 0.000 claims description 4
- 229910000476 molybdenum oxide Inorganic materials 0.000 claims description 4
- QGLKJKCYBOYXKC-UHFFFAOYSA-N nonaoxidotritungsten Chemical compound O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 QGLKJKCYBOYXKC-UHFFFAOYSA-N 0.000 claims description 4
- PQQKPALAQIIWST-UHFFFAOYSA-N oxomolybdenum Chemical compound [Mo]=O PQQKPALAQIIWST-UHFFFAOYSA-N 0.000 claims description 4
- 229910003452 thorium oxide Inorganic materials 0.000 claims description 4
- 229910000439 uranium oxide Inorganic materials 0.000 claims description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 40
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 7
- 239000010937 tungsten Substances 0.000 description 7
- 229910052721 tungsten Inorganic materials 0.000 description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 239000004411 aluminium Substances 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000004408 titanium dioxide Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000001962 electrophoresis Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 2
- ZSLUVFAKFWKJRC-IGMARMGPSA-N 232Th Chemical compound [232Th] ZSLUVFAKFWKJRC-IGMARMGPSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052776 Thorium Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000011928 denatured alcohol Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000005923 long-lasting effect Effects 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- GQUJEMVIKWQAEH-UHFFFAOYSA-N titanium(III) oxide Chemical compound O=[Ti]O[Ti]=O GQUJEMVIKWQAEH-UHFFFAOYSA-N 0.000 description 1
- DNYWZCXLKNTFFI-UHFFFAOYSA-N uranium Chemical compound [U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U][U] DNYWZCXLKNTFFI-UHFFFAOYSA-N 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/13—Solid thermionic cathodes
- H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
- H01J1/22—Heaters
-
- 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
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/08—Manufacture of heaters for indirectly-heated cathodes
-
- Y—GENERAL 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
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2913—Rod, strand, filament or fiber
- Y10T428/2933—Coated or with bond, impregnation or core
- Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
- Y10T428/2942—Plural coatings
- Y10T428/2949—Glass, ceramic or metal oxide in coating
Definitions
- the new types of cathodes are, for example, boride cathodes and especially impregnated cathodes. However, they require for their operation much higher temperatures. With impregnated cathodes, this temperature is about 1,150 C., While the activation temperature is 100 C. to 200 C. higher. Also, the holders of the cathodes, due to the required high vibration resistivity, are to be produced of rigid materials, due to which the temperature conduction of the cathode is increased, so that the temperature difference between the cathode and the filament is increased to a value of 500- 600 C. The temperature of the heating filament thus increases to a value of 1,700 to 1,850 C.
- the melting point of aluminium oxide is at 2,050 C. It has been found that on contact of aluminium oxide with metallic tungsten, during a long lasting heating process in vacuum at a temperature of approx. 1,700" C., aluminium oxide is slowly reduced to metallic aluminium, while tungsten changes to tungsten trioxide which reacts together with aluminium oxide to form other compounds, hesion of the aluminium oxide layer sintered on the tungsten filament decreases, and the melting point of aluminium oxide is at the same time successively lowered so that the insulating layer will melt and evaporate at the above indicated temperature within 12 to 400 hours.
- the aforesaid difiiculties are eliminated by the present invention according to which the heating filament is covered with two layers or coatings.
- the first coating is on the filament and consists essentially of aluminium oxide, beryllium oxide, or mixtures thereof.
- the second coating is on the first coating and consists essentially of a major amount, but less than 96% by volume, of a first component and a minor amount of a second component.
- the first component is aluminum oxide, beryllium oxide, or mixtures thereof, While the second component is titanium oxide, zirconium oxide, hafnium oxide, thorium oxide, chromium oxide, molybdenum oxide, tungsten oxide, uranium oxide, or mixtures thereof.
- Insulating material W Mo Ta Aluminium oxide. 1, 700-1,750 1, 700-1, 750 18, 000-1, 850 Beryllium 0xide 1, 750-1, 800 1, 700 1, 600 Magnesium oxide 1 1,750 1, 550-1, 600 1, 700-1,800 Zirconium dioxide... 1, 4001, 500 2 1, 700-1, 750 1, 000 Thorium dioxide. i 2, 000 1, 700 1, 8504, 900
- the temperature difference between the cathode and the filament is decreased by 200 to 250 C., due to which the temperature of the filament is lowered to 1,5001,650 C., i.e., below the limit where there arises the danger of reaction between tungsten and aluminium or beryllium oxide.
- the increased radiation coefiicients of some substances is utilized to essentially increase the volume of radiated heat and to considerably cool down the heating filament.
- the heating filament is covered with a sintered insulating substance of aluminium or beryllium oxide or their mixture.
- This insulating substance is covered by spraying, immersion, coating or by electrophoresis with a layer consisting of a mixture of two components. The latter layer is then sintered at a temperature which is lower than 1,650 C. either in vacuum or in an electric furnace in a stream of dry hydrogen or carbon monoxide.
- One of the referred to two components is aluminium oxide or beryllium oxide or their mixture, whereby the volume of this component is less than 96% of the mixture.
- the other of the two components of the mixture is either a single oxide or a mixture of two or several oxides of the following metals: titanium, zirconium, hafnium, thorium, chromium, molybdenum, tungsten, and uranium.
- the second layer or coating is applied as follows. For example a suspension of aluminium oxide and titanium oxides in methylated spirit, capable of being coated by electrophoresis, is first prepared. Heating filaments covered with a first coating of sintered aluminum oxide are now covered with a second coating of aluminum oxide and titanium oxide to a thickness of approximately 30 The thus coated filaments are sintered in an electric furnace at a temperature of 1,350 C. in a stream of dry hydrogen through 5 minutes. During this sintering, reduction of titanium dioxide to titanum sesquioxide which is black-blue in color occurs. The thermal radiation coefificient is approximately 0.80 as compared with 0.30 with the formerly used aluminium oxide. In order to attain a higher efficiency, the interior wall of the cathode holder may also be coated and sintered in the same way. The temperature difference between the cathode and the heating filament is thus decreased to 350 C.
- a conductor 1 of a filament 4 is covered with a layer 2 consisting essentially of electrically insulating aluminum oxide.
- This layer is coated with a layer 3 of a mixture of beryllium oxide and zirconium oxide, which mixture constitutes a high efliciency thermal radiation material.
- the beryllium oxide is present in an amount of less than 96% by volume of the mixture.
- the method of my invention can be applied to cathodes with a high working temperature as well as to oxide cathodes. In both cases, there is a decrease of the temperature difference between cathode and filament and of the temperature of the heating element proper.
- the invention makes it possible to preserve the structure and composition of the filament, to maintain the filament voltage, and to save tungsten. Another advantage is that due to the increase of the radiation capability of my filament even temperature differences among cathodes of individual electron tubes, which normally occur due to nonuniform coiling of the filaments of the cathodes, are eliminated to a minimum.
- a heating filament assembly for electron tubes comprising a conductive means; an electrically insulating first coating on said conductive means, said first coating es sentially consisting of a material selected from the group consisting of aluminum oxide, beryllium oxide, and mixtures thereof; and a second coating on said first coating, said second coating essentially consisting of a mixture of a major amount, but less than 96% by volume, of a first component and of a minor amount of a second component, said first component being selected from the group consisting of aluminum oxide, beryllium oxide, and mixtures thereof, said second component being selected from the group consisting of titanium oxide, zirconium oxide, hafnium oxide, thorium oxide, chromium oxide, molybdenum oxide, tungsten oxide, uranium oxide, and mixtures thereof.
- said second component being a mixture of at least two of said second component oxides.
- a method of preparing a heating filament assembly for electron tubes which comprises applying a high efficiency thermal radiation coating to a conductive means provided with an electrically insulating coating, said thermal radiation coating being a mixture of a major amount, but less than 96% by volume, of a first component and of a minor amount of a second component, said first component being selected from the group consisting of aluminum oxide, beryllium oxide, and mixtures thereof, said second component being selected from the group consisting of titanium oxide, zirconium oxide, hafnium oxide, thorium oxide, chromium oxide, molybdenum oxide, tungsten oxide, uranium oxide, and mixtures thereof, said application being carried out in vacuum.
- a method of preparing a heating filament assembly for electron tubes which comprises applying a high efficiency thermal radiation coating to a conductive means provided with an electrically insulating coating, said thermal radiation coating being a mixture of a major amount, but less than 96% by volume, of particles of a first component selected from the group consisting of aluminum oxide, beryllium oxide, and mixtures thereof, and of particles of titanium dioxide, and sintering said particles in a stream of dry hydrogen until a portion of said titanium dioxide is reduced to titanium sesquioxide.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Solid Thermionic Cathode (AREA)
- Cold Cathode And The Manufacture (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CS622560 | 1960-10-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3134691A true US3134691A (en) | 1964-05-26 |
Family
ID=5408774
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US142508A Expired - Lifetime US3134691A (en) | 1960-10-18 | 1961-10-03 | Heating filament assembly and a method of preparing same |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US3134691A (enrdf_load_html_response) |
| DE (1) | DE1240998B (enrdf_load_html_response) |
| FR (1) | FR1303897A (enrdf_load_html_response) |
| GB (1) | GB966377A (enrdf_load_html_response) |
| NL (1) | NL269971A (enrdf_load_html_response) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3370978A (en) * | 1964-02-26 | 1968-02-27 | Sperry Rand Corp | Method of stabilizing tunneling insulator films |
| US3418164A (en) * | 1963-02-06 | 1968-12-24 | Philips Corp | Filament wire for use in the cathode of a thermionic valve |
| US4176293A (en) * | 1978-02-17 | 1979-11-27 | Varian Associates, Inc. | Thermionic cathode heater having reduced magnetic field |
| US5811934A (en) * | 1994-06-13 | 1998-09-22 | Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen Mbh | Electric incandescent halogen lamp with barrel-shaped bulb |
| US20090085456A1 (en) * | 2007-09-29 | 2009-04-02 | Osram Sylvania Inc | Automotive lamp coil |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1281039B (de) * | 1963-09-25 | 1968-10-24 | Telefunken Patent | Verfahren zur Herstellung einer indirekt geheizten Kathode fuer Elektronenroehren |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US212860A (en) * | 1879-03-04 | Improvement in electric lights | ||
| US1821359A (en) * | 1928-04-13 | 1931-09-01 | Rca Corp | Wehnelt-cathode |
| US2128270A (en) * | 1928-04-30 | 1938-08-30 | Hans J Spanner | Lighting device |
| GB684141A (en) * | 1950-03-29 | 1952-12-10 | Loewe Opta Ag | Method for applying insulating coatings to metallic conductive wires employed for heating |
| US2734857A (en) * | 1951-10-11 | 1956-02-14 | snyder | |
| US2985548A (en) * | 1957-12-26 | 1961-05-23 | Sylvania Electric Prod | Method of making a low density coating for an electron discharge device |
| US3029360A (en) * | 1958-04-29 | 1962-04-10 | Rca Corp | Heater wire coating process |
| US3041210A (en) * | 1959-12-02 | 1962-06-26 | Tung Sol Electric Inc | Method of making cold cathodes for vacuum tubes and article |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2043720A (en) * | 1933-11-25 | 1936-06-09 | Rca Corp | Thermionic cathode heater and method of making it |
| DE1090774B (de) | 1959-03-20 | 1960-10-13 | Siemens Ag | Heizelement fuer mittelbar geheizte Kathoden und Verfahren zur Herstellung eines Isolierueberzuges |
| NL268393A (enrdf_load_html_response) | 1960-08-19 |
-
0
- NL NL269971D patent/NL269971A/xx unknown
-
1961
- 1961-10-03 US US142508A patent/US3134691A/en not_active Expired - Lifetime
- 1961-10-04 DE DET20889A patent/DE1240998B/de active Pending
- 1961-10-09 GB GB36179/61A patent/GB966377A/en not_active Expired
- 1961-10-17 FR FR876207A patent/FR1303897A/fr not_active Expired
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US212860A (en) * | 1879-03-04 | Improvement in electric lights | ||
| US1821359A (en) * | 1928-04-13 | 1931-09-01 | Rca Corp | Wehnelt-cathode |
| US2128270A (en) * | 1928-04-30 | 1938-08-30 | Hans J Spanner | Lighting device |
| GB684141A (en) * | 1950-03-29 | 1952-12-10 | Loewe Opta Ag | Method for applying insulating coatings to metallic conductive wires employed for heating |
| US2734857A (en) * | 1951-10-11 | 1956-02-14 | snyder | |
| US2985548A (en) * | 1957-12-26 | 1961-05-23 | Sylvania Electric Prod | Method of making a low density coating for an electron discharge device |
| US3029360A (en) * | 1958-04-29 | 1962-04-10 | Rca Corp | Heater wire coating process |
| US3041210A (en) * | 1959-12-02 | 1962-06-26 | Tung Sol Electric Inc | Method of making cold cathodes for vacuum tubes and article |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3418164A (en) * | 1963-02-06 | 1968-12-24 | Philips Corp | Filament wire for use in the cathode of a thermionic valve |
| US3370978A (en) * | 1964-02-26 | 1968-02-27 | Sperry Rand Corp | Method of stabilizing tunneling insulator films |
| US4176293A (en) * | 1978-02-17 | 1979-11-27 | Varian Associates, Inc. | Thermionic cathode heater having reduced magnetic field |
| US5811934A (en) * | 1994-06-13 | 1998-09-22 | Patent-Treuhand-Gesellschaft Fur Elektrische Gluhlampen Mbh | Electric incandescent halogen lamp with barrel-shaped bulb |
| US20090085456A1 (en) * | 2007-09-29 | 2009-04-02 | Osram Sylvania Inc | Automotive lamp coil |
| US8215002B2 (en) | 2007-09-29 | 2012-07-10 | Osram Sylvania Inc. | Method of making a lamp coil |
Also Published As
| Publication number | Publication date |
|---|---|
| FR1303897A (fr) | 1962-09-14 |
| NL269971A (enrdf_load_html_response) | |
| DE1240998B (de) | 1967-05-24 |
| GB966377A (en) | 1964-08-12 |
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