US2019331A - Electric incandescent lamp - Google Patents

Electric incandescent lamp Download PDF

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Publication number
US2019331A
US2019331A US572113A US57211331A US2019331A US 2019331 A US2019331 A US 2019331A US 572113 A US572113 A US 572113A US 57211331 A US57211331 A US 57211331A US 2019331 A US2019331 A US 2019331A
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US
United States
Prior art keywords
carbide
filament
carbon
lamp
tantalum
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
US572113A
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English (en)
Inventor
Mary R Andrews
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.)
General Electric Co
Original Assignee
General Electric Co
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
Priority to FR743386D priority Critical patent/FR743386A/fr
Application filed by General Electric Co filed Critical General Electric Co
Priority to US572113A priority patent/US2019331A/en
Priority to GB30556/32A priority patent/GB394557A/en
Application granted granted Critical
Publication of US2019331A publication Critical patent/US2019331A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/52—Means for obtaining or maintaining the desired pressure within the vessel
    • H01K1/54—Means for absorbing or absorbing gas, or for preventing or removing efflorescence, e.g. by gettering

Definitions

  • the present invention relates to electric incandescent lamps and in particular to lamps containing as a light source a body of a carbide of a refractory metal, such as tantalum, hafnium, zirconium, niobium, and the like, or mixtures of such carbides. While such carbides can be operated at exceedingly high temperatures because of their highly refractory nature, it has been found that a slow dissociation occurs which eventually leads to their destruction.
  • a refractory metal such as tantalum, hafnium, zirconium, niobium, and the like
  • dissociation of carbide incandescent bodies is retarded, or prevented, by bringing carbon vapor from a source of uncombined carbon into contact with them while they are at an operating temperature.
  • Carbon vapor may be supplied by a carbonaceous body maintained at incandescence and located at some distance from the carbide body, preferably below it.
  • carbon may be supplied by a carbonaceous member located in the immediate vicinity of the carbide body.
  • the carbon may constitute a core located in a shell of carbide.
  • FIG. 1 a lamp having a carbide lighting body and also a second body 01 carbon from which carbon can be evaporated or sputtered
  • Fig. 2 shows a modification in which the carbonaceous material is contained as a core within a carbide filament
  • Fig. 3 shows an en-' larged cross-section of a filament such as shown in Fig. 2
  • Fig. 4 shows a second modification in which the carbonaceous vapor is obtained from carbonaceous electrodes between which an arc-like discharge is operated
  • Figs. 5 and 6 respectively are vertical and horizontal sectional views of a press suitable for extruding composite filaments such as are employed in the lamp of Fig. 2.
  • the elongated bulb 5 of suitable transparent material such as glass having a stem 6 is provided with a filament 1, consisting of tantalum carbide, hafnium carbide, niobium carbide, zirconium carbide, or other suitable refractory carbide, or their mix-
  • a filament 1 consisting of tantalum carbide, hafnium carbide, niobium carbide, zirconium carbide, or other suitable refractory carbide, or their mix-
  • mixtures suitable for the purposes of my invention (1) a mixture of four parts tantalum carbide and one part hafnium carbide; (2) a mixture of four parts tantalum carbide and one part zirconium carbide.
  • Fig.1 although shown in Fig.1 as of a. simple hairpin shape, may have various configurations well.
  • the carbide filament may be made by the well.
  • tantalum oxide may bevconverted with a suitable paste, 5
  • Fig. 1 there is shown, as a source of carbon vapor a small rod'or filament III of graphite, or other suitable carbonaceous material, attached to leading-in conductors H and l2.
  • the container in either modification is baked, exhausted and filled with a suitable inert gas, such for example as argon or neon, at a pressure sufiiciently high to retard thermal volatilization of the carbide filament during operation.
  • a suitable inert gas such for example as argon or neon
  • I may employ gas pressures within the range or about one-half to two atmospheres.
  • the carbide filament 1 during operation or the lamp may be heated by suitable passage of current to a temperature of about 3400 to 3500 K.
  • the carbon rod is maintained at about 2400 K. or higher.
  • the tem- 3 perature may be controlled by proper coordina-- tion of the voltage, the diameter and length of the carbon rod. Its temperature also depends to some extent on the temperature of the carbide filament.
  • FIG. 4 there are shown, as a source of carbon vapor, cooperating electrodes I3, I 4 consisting of carbon or graphite and being attached to conductors l5, l6 serving as supports as well as to conduct current.
  • an arc-like discharge is operated between the electrodes l3, I4, the discharge being initiated by high frequency or any other known manner.
  • Lighting the filament I before starting the arc renders starting easier as the gas becomes ionized by contact with the heated filament.
  • the are is operated with a current value sufficiently high to heat the electrodes I3, M to such a temperature that. carbon is evaporated or sputtered in quantities which will maintain thefilament as carbide. The quantity necessary depends upon the construction of the filament and the temperature at which this filament is operated.
  • the carbonaceous material may be employed as a core 20 within a carbide shell 2
  • the composite filament 22 (Fig. 2) is mounted attached to leading-in wires 23, 24 in a bulb 25 which contains an inert gas as above described.
  • Figs. 5 and 6 an extrusion press suitable for this purpose.
  • the press here shown comprises a container having an outer wall 26 and an inner wall 21 connected by the ribs as shown in Fig. 6 and supported by a bed plate 28 ,held on a frame 29.
  • the annular space between the walls 21 and 26 contains a quantity 3B of paste made of carbide (or carbide-yielding) material and a suitable binder, for example, starch paste.
  • the space within the inner enclosure 21 contains 8.
  • a plunger 32 having an annular member 33 and a central member 34 is arranged as shown to exert pressure on these extrudable pastes.
  • a composite 5 filament 36 issues from the orifices at the bottom of the press.
  • This filament has a shell of carbide (or carbide-yielding material) and a core of graphite, or other suitable carbonaceous material, and is after baking ready for mounting in w alamp.
  • a lamp comprising a bulb, a lighting body therein consisting essentially of carbideof the 15 group of metals consisting of tantalum, hafnium, zirconium, and niobium, a separate body of carbon located adjacent to but spaced out of direct contact with said lighting body, and means for heating said carbon body.
  • a lamp comprising a bulb, a filament therein for giving light when at incandescence and consisting essentially of a mixture of carbides of metal including tantalum, hafnium, niobium and zirconium, a second filament of carbon spaced 25 apart from said carbide filament and terminal conductors for said carbon filament.
  • An incandescent lamp containing an incandescible body comprising a member consisting of tantalum carbide, and a source of uncombined 30 carbon for recarbidizing said member during operation of said lamp.
  • An electric lamp comprising a container, a lighting filament therein consisting essentially of tantalum carbide, a carbonaceous body 10- 5 cated adjacent to be out of direct contact with said lighting filament, and separate means for heating said carbonaceous body to supply carbon therefrom to said filament.
  • An electric lamp comprising a container, a 40 lighting body therein consisting essentially of carbide of the group of metals consisting oi. tantalum, hafnium, zirconium, and niobium, and a source of uncombined carbon in said container adapted to be heated during operation of said lamp for supplying suilicient carbon to said carbide to counteract dissociation thereof at a temperature of bright incandescence.

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US572113A 1931-10-30 1931-10-30 Electric incandescent lamp Expired - Lifetime US2019331A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
FR743386D FR743386A (enrdf_load_html_response) 1931-10-30
US572113A US2019331A (en) 1931-10-30 1931-10-30 Electric incandescent lamp
GB30556/32A GB394557A (en) 1931-10-30 1932-10-31 Improvements in and relating to incandescent electric lamps

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US572113A US2019331A (en) 1931-10-30 1931-10-30 Electric incandescent lamp

Publications (1)

Publication Number Publication Date
US2019331A true US2019331A (en) 1935-10-29

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Family Applications (1)

Application Number Title Priority Date Filing Date
US572113A Expired - Lifetime US2019331A (en) 1931-10-30 1931-10-30 Electric incandescent lamp

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US (1) US2019331A (enrdf_load_html_response)
FR (1) FR743386A (enrdf_load_html_response)
GB (1) GB394557A (enrdf_load_html_response)

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Publication number Publication date
GB394557A (en) 1933-06-29
FR743386A (enrdf_load_html_response) 1933-03-29

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