US2030715A - Gaseous electric discharge lamp device - Google Patents

Description

Feb. 11, 1936.

M. PIRAN! ET AL 2,030,715

GASEOUS ELECTRIC DISCHARGE LAMP DEVICE Filed May 3, 1933 d a 4 H 1 I 2 l 1 I l INVENTORS i M ATTORNEY Patented Feb. 11, 1936- UNITED STATES GASEOUS ELECTRIC DISCHARGE LAMP DEVICE Marcello Pirani, Berlin-Wilmersdorf, and Martin Reger, Berlin, Germany, assignors to General Electric Company, a corporation of New York Application May 3, 1933, Serial No. 669,238 In Germany May 23, 1932 3 Claims.

The present invention relates to gaseous electric discharge lamp devices generally and more particularly the invention relates to improvements in such devices in which baflles interposed between the electrodes causes the gaseous electric discharge to follow a tortuous path.

Bafiles fused'to the walls of a glass, or quartz container are impractical due to the stresses at the fused joints caused by the uneven heating of the baiiles and the container walls by the gaseous electric discharge. The object of the present invention is to provide a practical gaseous electric discharge device wherein the discharge between the electrodes follows a tortuous path.

Another object of theinvention is to simplify the manufacture of such devices. A further object of the invention is to provide a gaseous electric discharge lamp device which is a concentrated Said element is sealed into the container of the gaseous electric discharge lamp device, is separate from the container walls and encloses the electrodes as well as the discharge path between said electrodes. The baflles and walls of the element which do not transmit light are made of metal and the other walls of said element are made of light pervious material such as glass, 5 quartz or wire netting. The element is enclosed in a gas tight container and since the element itself need not be gas tight the glass and metal walls thereof need'not be fused to each other, as in prior devices of this type, mechanical joints 40 therebetween are sufficient. This simplifies the manufacture of such devices and makes available for use in the arts generally a strong practical lamp device of the above type having a long usefuloperating life. When a metal having a high 45 melting point, such as tungsten, is used in the walls of said container which do not transmit light higher current densities can be used in such devices than were practical heretofore and the device is a high intensity, concentrated light 50 source.

metal walls of the element surrounding the discharge. The accomplishing of this same result can be aided or attained by covering the surfaces of said metal walls facing the discharge path with an electrical insulating material, as by oxidizing said surfaces, the insulating material preventing the starting of the discharge between the electrodes and the metal walls of the element.

When desired the metal walls of the element adjacent the electrodes can be used as auxiliary 10 electrodes to facilitate the starting of the gaseous electric discharge between the electrodes of the device. Part of the walls of the element are polished, when desired, to reflect and directjhe light from the luminous positive column dls- 15 charge in a desired direction.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown in which Fig. 1 is a front elevational view of the lamp device, and

Fig. 2 is a top sectional view along the line 2-2 of Fig. 1.

Referring to the drawing the new and novel lamp device comprises a container I having a stem 2 fused therein. An exhaust tube 3 is fused into said stem 2 and current leads 5 and 6 for electrodes I8 and I9 are sealed into the pinchpart 4 of said stem 2. A metal support rod 1 is fused into said pinch-part 4 and the bottom metal wall 20 of the element surrounding the electrodes I8 and I9 and the discharge path between said electrodes I8 and I9 is fastened to said rod 1.

The side and top walls 8, 9 and Ill of the enclosing element as well as the baffles I I, I2 and I3 are made of metal, such as tungsten, and the front and back walls I4 and I5 thereof are light pervious and are made of a material such as glass, quartz or wire net. The bottom edges of the front and back.walls l4 and. I5 rest on the bottom wall 20 and are held in position by flanges on said bottom wall 20. The walls 8, 9, I0, II and I5 are held in position with respect to each other by the flanges on said walls 8, 9, I0 and 20 clamping said walls I4 and I5 and forcingsaid walls I4 and I5 against the baffles I I, I2 and I3.

It will be understood, of course, that either of said walls I 4 or .I5 is made of metal where it is desired to send out the light of the luminous positive column discharge in one direction and in this case it is advantageous that the surface of the metal wall I 4 or I5 facing the discharge path have a polished surface to reflect and direct the light of the positive column discharge in a desired direction. The electrodes I8 and I9 are electron emitting when heated and are heated by the gaseous electric discharge therebetween during the operation of the lamp device. Said electrodes I8 and I9 are located in extensions I6 and I1 respectively of the enclosing element and the external ends of said extensions I6 and H are closed by plugs of insulation material such as mica, or lavite. Said extensions I6 and I! are formed by parts of the front and back walls It and I5, the side walls 8 and Ill and the baffles I I and I3 respectively. The bafiles II, I2 and I3 are arranged in parallel planes and overlap for at least part of their length to form a tortuous discharge path between said electrodes I 8 and I9. Said baffles II and I3 are fused to the bottom wall 20 of said enclosing element and the baflle I2 is fused to the top wall of said element. As the joints between the metal walls 8, 9, I0 and 20 and the glass walls I4 and I5 and between the metal bafiles -I I, I2, I3 and the glass walls I 4 and I5 are mechanical joints rather than fused joints strain thereon due to their difierent coeflicients of expansion and the uneven heating of said parts by the gaseous electric discharge between said electrodes I 8 and I 9 is reduced to a minimum to avoid fracturing said joints during the operation of the lamp device. The container I is filled with an electric discharge conducting gaseous atmosphere consisting of a rare gas, such as neon, or a mixture of gases, such as a mixture of argon and mercury vapor. The gaseous atmosphere in said container I flows easily through the mechanical joints of the enclosing element in said container and is present in the discharge path between said electrodes I8 and I9 at all times.

The above described lamp device is a concentrated light source of high intensity useful inthe illuminating arts generally and particularly in beacon or signalling work.

While we have shown and described and have pointed out in the annexed claims certain novel 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 invention, for example, all the walls of the enclosing element are made of metal net, when desired, the metal wall of the enclosing element adjacent one or both of said electrodes I8 and I9 is connected through a resistance to the electrode opposite that to which it is adjacent to act as an. auxiliary electrode during the starting and operating of the lamp device and it will be understood, oi. course, that in such case such wall is insulated fram the other metal walls of said enclosing element, and the metal walls are of nickel, iron, or tungsten as desired.

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

1. An electric discharge device comprising a container, electrodes sealed therein a gaseous atmosphere therein and a gas pervious element therein separate from the walls of said container and surrounding said electrodes and the positive column discharge path between said electrodes and including a plurality of baflles whereby the discharge path is caused to deviate from a straight line between said electrodes in a multiplicity of overlapping parallel paths, said baflles having a different coeificient of expansion than the other parts of said gas pervious element, the joints between said baflles and said other parts being mechanical joints.

. 2. An electric discharge device comprising a container, electrodes sealed therein a gaseous atmosphere therein and a gas pervious element therein separate from the walls of said container and surrounding said electrodes and the positive column discharge path between said electrodes and including a plurality of bafiles in parallel planes whereby the discharge path is caused to deviate from a straight line between said electrodes in a multiplicity of overlapping parallel paths, the voltage drop in the positive column discharge being less than the value of both the anode and cathode voltage drop at said electrodes, said bafiles having a diiferent coefficient of expansion than-the other parts of said gas ervious element, the joints between said baflles and said other parts being mechanical joints.

3. An electric discharge device comprising a container, electrodes sealed therein a gaseous atmosphere therein and an element therein comprising metal walls, metal baffles and glass walls, the joints between said glass and metal walls being mechanical joints, said bames being in parallel planes and overlapping for part of their length, said element being separate from the walls of said container and surrounding said electrodes and the positive column discharge path between said electrodes whereby the dis charge path is caused to deviate from a straight line between said electrodes.

MARCELLO PIRANI. MARTIN REGER.

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