US2084037A - Electric rare gas filled lamp - Google Patents

Description

June 15, 193?. A. YLEDERER 2,084,03?

ELECTRIC RARE GAS FILLED LAMP Filed Dec. 20, 1930 INVENTOR Anton Leder'er,

afia ATTORNEY -cury in the lamp Patented June 15, 1937 UNITED STATES PATENT OFFICE Anton Lederer, Vienna,

zer and General Co said Anton Lederer,

Ernest Anton Lederer,

nrad Randa,

Catherine Daub executors of deceased, more to Glen Ridge, N. J.

Austria;

Application December 20, 1930, Serial No. 503,804 In Austria December 28, 1929 Claims. (Cl. 176-122) This invention relates to electric rare gas filled lamps, and more especially to those of the class disclosed in my prior co-pending applications, Ser. No. 468,884 filed July 18, 1930, and Ser. No. 497,025 filed November 20, 1930, containing electrodes which are so spaced apart in relation to the rare gas pressure that the rare gas is excitable thereby to luminescence as an intense aureole.

In lamps of this kind which have hot electrodes or at least a hot cathode and wherein the rare gas filling sometimes with an admixture of other gases, has an addition of mercury, a rise in temperature in the interior of the lamp, above that which is necessary for its proper operation is often disadvantageous owing to overheating or excessive evaporation of the mercury by which the lighting effect of the lamp is unfavourably infiuenced the lamp giving a bluish light. This phenomenon depends also on the position of the liquid mercury with respect to the gas filling of the discharge space. For instance, in the case of neon and other rare gas filled lamps containing an addition of mercury and oxide electrodes, hot electrodes heated by heating wires of a diameter of about 0.12 to 0.13 mm. for example, more or less evaporation of the mercury will take place, according to the pos'tion of the lighting portion of the lamp. This is because the part containing the liquid mercury may be more or less easily accessible to the heated neon gas; consequently the light which with proper evaporation of the merom is white or nearly white is strengthened at the violet end of the spectrum by the formation of an excess of mercury vapour or by the overheating of the mercury so that the lamp emits a bluish light.

According to the present invention this disadvantage is removed by locating the liquid merin such a manner that it is not exposed directly or in its entirety to the heat of the heated gas filling in the discharge space of the lamp. Excessive heating and evaporation of the mercury and consequently with some lamps a bluish light due to the mercury is thereby avoided.

One method of carrying out the invention is to locate the liquid mercury, and in some cases also the getter which is a material employed for the purpose of freeing the filling gas or gases from the last traces of impurities, in a part of the lamp beneath the discharge space. The liquid mercury is therefore not so directly, or at least not in its entirety, exposed to the action of the heated gases and excessive evaporation is avoided. Also, the quantity of liquid mercury to be introduced need not be measured exactly because the whole of the mercury will not evaporate. When however the liquid mercury is located above the discharge space, the exact and correct quantity of mercury is dimcult to find, for instance, in the case of a lamp taking a current of from 0.4 to 0.5 ampere, because under the intense action of the circulating heated gases a very intense evaporation of the mercury takes place mostly extending to the whole amount of mercury present.

It is advantageous to have the liquid mercury located beneath the discharge space in the neck of the lamp. This neck may be at any desired position in the lighting part of the lamp container, provided it is beneath the discharge space. In the case of an electric gas-filled lamp with a globe shaped glass bulb and a neck, the mercury, and in some cases placed in the neck and vertical or inclined position so that the neck extends downward perpendicularly or at an angle and consequently lies beneath the discharge space.

In another method tion the part of the the lamp is used in a of carrying out the invenlamp containing the liquid mercury, and in some cases the getter also, is

separated from the discharge space of the lamp by a partition which does not prevent communication between these parts, that is to say the access of gas from one part to the other, but renders it more diflicult. The partition may be, for example, a plate leaving an annular passage free. By the partition an excessive evaporation of the mercury is prevented and the circulation of the gas into the space which contains the liquid mercury is limited. The partition is preferably made of an insulating, heat insulating or electrically insulating material, such for instance as mica, glass, quartz or the like; it is further advisable to use a transparent material for the partition. 4

Both the methods above described may be combined by locating the mercury and the getter in a neck lying beneath the discharge space, the interior of which neck is' almost completely separated from the discharge space by means of a partition so arranged that between the interior of the neck and the discharge space the passage of gas can still take place.

The accompanying drawing is a view, somewhat diagrammatic, illustrating by way of example only an electric lamp constructed in accordance with the invention.

Referring to the drawing, l is a globe or portion the getter also, may be depending carrier of the lamp intended to emit light; 2 are the electrodes provided with leading in wires 3 and supported on supports 4 in an ordinary manner. The

globe I has a downwardly extending neck 5 in and is of such diameter that its edge is spaced apart from the neck as indicated at ii.

In the manufacture of the lamp the getter is located on the ring]; and when vaporized deposits on the neck portion 5 of the-lamp bulb so that it does not interfere with the emission of light through the globe I.

The liquid mercury is contained in the bottom of the neck as shown at H and is screened from the direct heat of the discharge space'in the globe I by the partition 8. Free communication between the. space in the neck and the discharge space is allowed round the edge of the partition.

When a getter is used and vaporized from the ring 6 it will deposit only on the neck portion.

No claim is made in this application for the construction of the light emitting portion of the lamp per se as shown in the upper part of the drawing, such being claimed in my co-pending application hereinbefore referred to.

I claim:

1. An electric illuminating lamp comprising an envelope having a filling consisting of at least one rare gas, cooperating electrodes therein at least one of which is of the indirectly-heated by avoid predominance of mercury light.

2. An electric illuminating lamp comprising an emissive type, means for applying a potential between said electrodes, said electrodes having such a spacing in relation to the rare gas pressure that the rare gas is excitable thereby to luminescence as an intense aureole, and a small quantity of mercury located within a part of said envelope in a position where the mercury will be subject to the heat of the hot rare gas and be vaporized thereby, said mercury containing part of the envelope being removed from the gaseous discharge space and having such restricted comenvelope having a main munication therewith in relation to the heating effect of the hot rare gas on the mercury in said position that the mercury will be vaporized incompletely and to anextent to produce a substantially white light.

3. An electric illuminating lamp comprising an envelope having a filling consisting of at least one rare gas, cooperating electrodes therein at least one of which is of the indirectly-heated electron emissive type, means for applying a potential between said electrodes, said electrodes having such a spacing in relation to the rare gas pressure that the rare gas is excitable thereby to luminescence as an intense aureole, a small quantity of mercury located in a partof said envelope which is out of the gaseous discharge path, the mercury in said art of the envelope being in a position to be heated and thereby vaporized by the hot rare gas, and a partition largely but not completely screening said mercury from the gaseous discharge path and shielding the mercury in said part of the envelope from the heat of the hot rare gas and thereby controlling the vaporization of the mercury so as to avoid predominance of mercury light.

4. An electric illuminating lamp comprising an envelope having a main portion and a neck portion through which electrical leads pass and having a filling consisting of at least one rare gas, cooperating electrodes in the main portion of the envelope at least one of which is of the indirectlyheated electron emissive type, means for applying a potential between said electrodes, said electrodes having such a spacing in relation to the.

sage that the mercury will be vaporized to an ex- 4 tent which will avoid predominance of mercury light.

5. An electric illuminating lamp comprising an portion and a neck portion through which electrical leads enter, a filling of at least one rare gas and mercury vapor, cooperating electrodes in the main portion of the envelope at least one of which is of the indirectlyheated electron emissive type, said cooperating electrodes being capable of exciting both the rare gas and the mercury vapor to luminescence simultaneously, a getter substance deposited on said neck portion of the envelope, and a partition mainly but incompletely separating said neck portion from the main portion of the envelope.

ANTON LEDERER.

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