US2087759A - Gaseous electric discharge device - Google Patents

Description

Patented July 20, 1937 PATENT" OFFICE 2,087,759 GASEgUS ELECTRIC DISCHARGE DEVICE Georg Gaidies, Berlin-Pankow, Germany, as-- signor to General Electric Company, a corporation of New York ApplicatiorfMay 28,

1935, Serial No. 23,909

In Germany June 7, 1934 3 Claims.

' The present invention relates to gaseous electric discharge devices .generally and more particularly the invention relates to such devices lamp of simple structure. Another object of the invention is to provide a self-contained gaseous electric discharge lamp requiring no external auxiliary apparatus for starting and operating. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

In accordance with this object the new and novel lamp comprises a sealed, tubular container having Solid, activated electrodes mounted near the ends thereof and current leads for said electrodes sealed into one end of said container. A screw base is fastened to the end of the container wherein the electrode leads are sealed. The ballast resistance for said lamp is a helically coiled wire surrounded by a tube of insulating material and extends along the discharge path between said electrodes in said container. The electrode mounted in the end of the container opposite the endin which the current leads are sealed is supported by a wire anchored in the dome of the container and said electrode is con- 30 nected to said resistance which thus serves as a current lead for said electrode. An auxiliary electrode in the form of a wire extending along the discharge path between said electrodes, electrically connected to one of said electrodes and terminating adjacent the other of said electrodes is mounted in said container to facilitate the starting of the main discharge in the device.

The new and novel lamp is a self-contained unit requiring no external auxiliary apparatus for starting or operation and can be screwed into the sockets customarily used for incandescent lamps. The ballast resistance mounted inside the lamp container gives off heat when the lamp is operating which is of particular advantage when a vaporizable material, the vapor of which is a light emitting element during the operation of the device, is present in said lamp as the heat emitted thereby is useful in maintaining an effective vapor pressure. Thus all the energy consumed by the lamp is utilized therein for a useful purpose whereas in prior lamps with the resistance ,mounted outside the lamp the heat emitted by the resistance was wasted.

In the drawing accompanying and forming part of this specification two embodiments of the invention are shown, in which Fig. 1 is a front elevational, partly sectional View of one embodiment of the invention and Fig. 2 is a similar view of another embodiment of the invention.

Like numbers denote like parts in both th figures.

Referring to- Fig. 1 the new and novel gaseous electric discharge lamp comprises an elongated, tubular container I having a gaseous atmosphere therein consisting of a gas, a mixture of gases, a vapor, a mixture of vapors, or a gas-vapor mixture and preferably of a mixture of a rare, starting gas and a metal vapor, such as a mixture of argon and mercury vapor, or neon, argon and sodium vapor. Said container I terminates in a cone 2 at one end thereof and has a stem 4 fused into the other end thereof. A two-contact base 3 is cemented to the stem end of said container I. Said stem 4 is provided with an exhaust tube 5 opening into the interior of said container I and through which the container I is'exhausted during the manufacture of the device. Current leads I, 8, and 9 are fused into the press 6 of said stem 4 and said current leads I and 9 are attached to the contacts on said base 3. Two cylindrical electrodes I0 and II are axially mounted in said container I and at opposite ends thereof. Said electrodes are hollow, open-ended cylinders of wire mesh, such as nickel, tungsten, or molybdenum gauze cylinders, and are preferably coated or impregnated with electron emitting material, such as alkali earth metals, or the oxides thereof, particularly barium oxide or strontium oxide, or a mixture of these. When desired, said electrodes I0 and II consist of sheet metal, such as nickel, coated with elec-- tron emitting material.

Said electrode I0 is electrically connected to said lead 9 by the support wire I2 fastened thereto and fused into the press 6 of said stem 4. Said electrode II is supported in said container I by wire I3 fused into the cone shaped end 2 of said container I. A cone shaped cap I4 of insulating material is fastened to the tip of cone 2 to prevent objects from coming into contact with the end of the support wire 3 projecting from the tip of the cone 2. A helically coiled resistance wire I5 closely surrounded by a thin tube I 6 of insulat ing material, such as glass, is fused to the pinch 6 of the stem 4 and is eccentrically mounted inside said container I. Said resistance I5 extends along the discharge path between said electrodes I0 and II and is connected at one end thereof to 5 the current lead I and at the other end thereof to the electrode ll. One end of an elongated, auxiliary starting electrode I1 is fused into the press 6 of said stem 4 and the other end thereof is adjacent the electrode Ii. Said auxiliary electrode I! is in the longitudinal axis of the container I and the electrode l and is connected to. the cur- I rent lead-9 of said electrode ID by the current lead 8. The end of the auxiliary electrode II adiacent the electrode H is thus at the same potential as the electrode in and facilitates the starting of the main discharge between said elec- The glow discharge thereby to an electron emitting temperature.

When said electrodes Ill and I] have been heated to a temperature at which a proliflc emission'of electrons therefrom takes place the glow discharge changes to anarc discharge. The heat from the discharge, the electrodes l0 and il and the resistance l quickly vaporizes the metal vapor during the starting period and maintains an effective vapor pressure in the lamp duringthe operation thereof. By an effective, vapor pressure is meant a pressure such that the light emitted by the lamp is rich in rays characteristic of the metal vapor.

The gaseous electric discharge device illustrated in Fig. 2 of the drawing is similar to that shown in Fig. 1 except that in this embodiment the re sistance l5 and the insulating tube l6 are mount- The end of the resistance I5 is connected to a ed in .thelongitudinal axis of the container I.

support wire l8 fused into said conical part 2. Electrode II is supported by wire i1 attached thereto, and to the support I8. The auxiliary electrode I1 is mounted eccentricallyin the container -l pin this embodiment, The starting and operating characteristics are the same as those described in connection with Fig: 1. Mounting the resistance I5 axially in the container l isadvantageous in securing an even distribution of the heat emitted thereby over the walls of the con tainer I.

. It will be understood of course that when a chemically active metal vapor, such as sodium vapor, is used in the lamp the container thereof is made of a glass chemically resistant to such vapor, such as the boro-silicate glasses now known in the art. A heat conservatonsuch as a doublewalled jacket in which the lamp is mounted, is

useful in minimizing the heat losses from the} lamp container to improve the efiiciency of the lamp.

While I have shown and described and have pointed out in the annexed claims certain novel j features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the inventiomfor exlast resistance mountedin said container, and a tube of insulating material surrounding said ballast resistance, one of said electrodes being mounted in the end of said container opposite the end thereof in which said current leads are sealed, said resistancenextending along the discharge path between said electrodes and being connected to said last named electrode, another of said electrodes. being an auxiliary electrode extending along the discharge path between said aelectrode's, terminating adjacent one of "said electrodes and bei'ngelectrically connected to the other of said electrodes.

2. A gaseous electric discharge device comprising an elongated, tubular container, thermionic electrodes sealed therein, current leads for said electrodes sealed into one end of said container,

a' raseous atmosphere therein, a ballast resistance mounted in said container, and a tube of insulating material surrounding said ballast resistance, one of said electrodes being mounted in the end of said container opposite the end thereof in which said current leads are sealed, said resistance extending along the discharge path between said electrodes and being connected to said last named electrode, another of said electrodes being an auxiliary electrode extending along the discharge. path between said electrodesjtermina ing adjacent one of said electrodes and beia-gkklectrioally connected to the oth'inof said electrodes, said resistance being eccentri'aily mounted in said container and said auxiliary-, electrode being mounted axially in said containers; "1'

3. A gaseous electric discharge device comprising an elongated, tubular container, thermionic electrodes sealed therein, current leads for said electrodes sealedinto one end of said container, a gaseous atmosphere therein, a ballast resistance mounted in said container, and a tube of insulating material Surrounding said ballast resistance, one of said electrodes being mounted in the end of said container opposite the end thereof in which said current leads are sealed, said resistance extending along the discharge path between said electrodes and being connected to said last named electrode, another of said electrodes being an auxiliary electrode extending along the discharge path between said electrodes, terminating adjacent one of said electrodes and being electrically connected to the other of said electrodes, said resistance being axially mounted in said container and said auxiliary electrode being eccentrically mounted in said container.

GEORG GAIDIES.

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