GB468449A - Improvements in or relating to the manufacture of double or multiple helical tungsten incandescent bodies - Google Patents
Improvements in or relating to the manufacture of double or multiple helical tungsten incandescent bodiesInfo
- Publication number
- GB468449A GB468449A GB451/36A GB45136A GB468449A GB 468449 A GB468449 A GB 468449A GB 451/36 A GB451/36 A GB 451/36A GB 45136 A GB45136 A GB 45136A GB 468449 A GB468449 A GB 468449A
- Authority
- GB
- United Kingdom
- Prior art keywords
- per cent
- tungsten
- cores
- core
- hydrogen
- 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
Links
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
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Resistance Heating (AREA)
Abstract
In a process for manufacturing double or multiple helical tungsten incandescent bodies for use in gas-filled vessels containing nitrogen, particularly gas-filled electric incandescent lamps, by subjecting to at least one heating a tungsten wire wound on at least two cores made of metal of high wetting point, and subsequently removing the cores, the incandescent body, before being mounted in the vessel which receives the gas filling, is heated to such a temperature between 1450 DEG C. and the re-crystallization temperature of tungsten, and for such a time that, not only are the internal stresses eliminated but, under continued heating or re-heating, the content in the incandescent body of material taken up from the core, is less than 0,4 per cent, and preferably less than 0,2 per cent, of the weight of the incandescent body. The heat treatment to which the incandescent body, with the core, is subjected may be such that it takes up less than 0,4 per cent of core material, or it may take up material in excess of 0,4 per cent of its weight, whereupon, after the removal of the core, the body is heated to a white heat in a space free from nitrogen, for instance in a vacuum or in a hydrogen atmosphere to reduce its content of core material to less than 0,4 per cent. In an example, a tungsten wire which assumes a macro-crystalline structure during heat treatment is wound upon primary and secondary cores of molybdenum and drawn for a few seconds through a hydrogen atmosphere in a furnace at a temperature of 1500 DEG C. The secondary helix is then cut into pieces of the required length which are incandesced for one minute at a temperature of 1600 DEG C. in a tungsten tube furnace through which a mixture of 25 per cent hydrogen and 75 per cent nitrogen is passed. The cores are then dissolved out. In another example using a heavier wire which is wound upon primary and secondary cores of molybdenum, the coiled coil is passed for a few seconds through hydrogen in a furnace at 1500 DEG C., cut into lengths, and then incandesced for three minutes at 1700 DEG C. in a tungsten tube furnace through which hydrogen is passed.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
HU468449X | 1935-01-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB468449A true GB468449A (en) | 1937-07-06 |
Family
ID=10979270
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB451/36A Expired GB468449A (en) | 1935-01-07 | 1936-01-06 | Improvements in or relating to the manufacture of double or multiple helical tungsten incandescent bodies |
Country Status (2)
Country | Link |
---|---|
BE (1) | BE413156A (en) |
GB (1) | GB468449A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2439913A (en) * | 1941-10-28 | 1948-04-20 | Gen Electric | Method of treating coiled tungsten filaments |
EP0849770A2 (en) * | 1996-12-20 | 1998-06-24 | Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH | Manufacturing procedure of helicoidally wound coiled filaments and coiled filaments manufactured using said procedure |
CN105047523A (en) * | 2015-06-15 | 2015-11-11 | 成都凯赛尔电子有限公司 | Method for fixing shape of filament |
-
0
- BE BE413156D patent/BE413156A/xx unknown
-
1936
- 1936-01-06 GB GB451/36A patent/GB468449A/en not_active Expired
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2439913A (en) * | 1941-10-28 | 1948-04-20 | Gen Electric | Method of treating coiled tungsten filaments |
EP0849770A2 (en) * | 1996-12-20 | 1998-06-24 | Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH | Manufacturing procedure of helicoidally wound coiled filaments and coiled filaments manufactured using said procedure |
EP0849770A3 (en) * | 1996-12-20 | 1999-06-09 | Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH | Manufacturing procedure of helicoidally wound coiled filaments and coiled filaments manufactured using said procedure |
CN105047523A (en) * | 2015-06-15 | 2015-11-11 | 成都凯赛尔电子有限公司 | Method for fixing shape of filament |
Also Published As
Publication number | Publication date |
---|---|
BE413156A (en) |
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