US2020736A - Gaseous electric discharge device - Google Patents

Description

Nov. 12, 1935. M. PIRANI EIAL GASEOUS ELECTRIC DISCHARGE DEVICE Filed Jan. 20, 1933 INVENTORS Patented 12, 193

"PATENT OFFICE GASEOUS ELECTRIC DISCHARGE DEVICE Marcello Pirani, Berlin-Wilmersdorf, and Martin Reger, Berlin, Germany, assignors to General Electric Company, a corporation of New York Application January 20, 1933, Serial 'No. 652,736

- In Germany February 22, 1932 5 Claims. (01. 17e-i22) The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to improvements in electric discharge lamp devices operating on a 5 110 or, 220 volt current source in which the container of the device is of U shape and is mounted in a gas tight envelope approximately the .size of the well known incandescent lamp bulb.

, The object of the present invention is to improve the luminous efiiciency of such devices without increasing 'the sizethereof.

The invention attains its object by utilizing the ballast resistance of the lamp as a heater element for the container of the gaseous electric discharge lamp device. Where the gaseous filling' of the lamp device comprises a vaporizable material, such as sodium, the heater increases the luminous efficiency of the device by heating the container of the device to a higher temperature which maintains the vapor of the vaporizable material at a correspondingly higher pressure during the operation of the device than would be the case if such heater'element were not provided in said lamp device. v

The invention will be readily understood by an inspection of the accompanying drawing. and a perusal of the following description thereof.

Fig. 1 of the drawing is a front elevational view of a gaseous electric discharge lamp device embodying the present invention, and I v Fig. 2 is a side elevational, partly sectional view of the device shown in Fig. 1 rotated 90.

Like numbers denote like parts in both views of the device. I J

The new and novel electric discharge lamp device comprises an outer envelope I resembling in size and shape an incandescent lampbulb. Said envelope I has a screw base I, 8 cemented thereto. A stem 4 is fusedto said envelope I and elec- 40. trode leads 5 and 6, connected to the contacts I and 8, respectivelyfof the base I, 8, are sealed into said stem 4. Said envelope I is exhausted through tubulation 3 fused to said stem 4 and opening into the interior of said envelope I. The 45 U shaped container II of the gaseous electric discharge lamp device is supported in said envelope I by rod 9 sealed into the stem 4. The

upper part ID of said rod 9 is looped around, the upper part of saidcontainer II on each side 55 sodium vapor. Anelectron emitting electrode I3 is sealed into an electrode chamber I 2 at each. end of said container- I I. Said electrodes I3 are hollow, sheet metal electrodes, such as nickel electrodes, coated with an electron emitting material, such as an alkali earth metal or a com- 5 bination thereof, barium oxide, for example.

An electrically conducting wire I4 extends along the discharge path between said. electrodesl3 and the terminals thereof are, physically connected to, but electrically insulated from said 10 electrodes l3 by glass beads I5. The distance between saidjelectrodes I3 and the terminals of said wire I4 is such that the voltage required for the operation of the lamp is suflicient to start the discharge between said electrodes I3 and the T5 terminals of wir 14., A heater element l6, n is supported in said envelope I by clamps I8 fastened to said rod 9 and said heater element I6, I! is located between the parallel. legs of said container II, as shown in Fig.1. Said heater 20 element I6, I! comprises a body of insulation material, such. as a magnesium plate I6, and a filament l1 embedded therein, as shown in Fig. 2.

The filament I! of said heater element I6, I! is connected in series with the electric discharge 25 I between said electrodes I3 by the leads 5 and t9 and said heater element serves as thecballast resistance for the" electric discharge lamp device during operation-thereof. The other of said electrodes I3 is connected to current inlead 6 by 30' lead 20.

When current is applied to the above described lampdevice av glow discharge takes place along said wire I4 which'ionizs the gaseous electric discharge path between said electrodes i3 to fa- 35 'cilitate the starting of a gaseous electric glow discharge in the neon-helium mixture in said lamp device. The heat from said glow discharge and the heatfrom the heater'element I6, l1 quickly vaporizes the sodium present in' said 40 container II. -The sodium vapor participates in conducting the discharge between said electrodes I3 and the glow discharge then changes to a positive column" discharge. The heat radiated. by said series connected heater I 6, I1 maintains said container II' at a high temperature during the operation of the lamp device. The vapor pressure therein corresponds to the high temperature of said container II so that the electric discharge lamp device has a higher luminous efiiciencythan would be the case if said heater element I6, I! were not used. The sodium spectrum dominates the light emitted by the device during the operation thereon The outer envelope I, when desired, is filled 5.

with a heat absorbing gas, such as carbonic acid gas, at a pressure of approximately 1.0-' mm.

to'reduce the radiation of heat from said, con-' tainer ll to a minimum during the operationof the lamp device.

A lamp device having the above structure- The lampdevice isparticularly useful for con-h tinuous, general illuminating and' advertising" pointed out in the annexed claims certain novel features of the invention, it will be understood 'purposes due to its small wattage consumption l and its 'monochromatic yellow light. I l While we have shown. and described andh'ave' cent to, but spaced apart from said electrodes. an envelope completely enclosing and spaced from said container and a ballast resistance for said that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operationmay be made by 'those skilled in the art without departing from the spirit of the invention, for example, other types of electron' emitting electrodes, such as the sintered, self-heating, mixedfmetal and oxide electrodes known in the art as Pirani eleea trodes, or holl0w,- closed, perforated, metal shells having an electron emitting material in the interior thereof areused' in place of electrodes l3 when desired, and an internal or external electrical conducting body on the walls of said container ii, and extending between said electrodes I3, is ,used in place of said wire ,whe-n desired.

What we claim as new and desire to secure by Letters Patent of the United States is:--.

1. An electric discharge lamp device compris ing a container,- electrodes sealed therein, a gaseous atmosphere therein comprising a vaporizable material, an envelope completely en closing and spaced from said container and a. ballast'resistance for said device 'mounted in said envelope, said ballast resistance being a heater element for said container. 1

-' tainer. r

' 2. An electric discharge lamp .device comprising a container, electrodes sealed therein, a gaseous atmosphere-therein comprising sodium, an envelope completely enclosing and spaced from "said container and a ballast resistance for said device mounted in said envelope, said ballast resistance being a heater, element Ior said con- 3. An electric discharge lamp device comprising a container, electrodes sealedtherein, a

electrode, the terminals of said body being adjamaterial, an envelope completely enclosing and spaced from said container,- said envelope being filled with agas'having poor heat conductivity characteristics and a series connected ballast resistance for said device mounted in said'envclope, said ballast resistance being a heater element for said container.

5. An electric discharge lamp device comprising in combination, a tubulanu shaped coniainer, electrodes sea'ledtherein at the ends thereof, a gaseousatmosphere therein comprising a -vaporizable material an exhausted envelope for said container, and a ballast resistance for said device mounted in said envelope, said ballast gaseous atmosphere therein comprising a va-- porizable material, a'body of electrically con- 1 ducting material extending from electrode to resistance being mounted between the parallel parts lofsaid U-shaped container andbeing a heater element for said'container. a

5 MARCELLO PIRANI.

MARTIN REGER. I

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