US2304768A - Electric lamp - Google Patents

Description

A. LEDERER ELECTRIC LAMP Filed June 19, I930 Patented Dec. 8, 1942 ELECTRIC LAMP Austria; Catherine Dan- Anton Lederer, Vienna,

zer and General Conra said Anton d Randa, executors of Lederer, deceased, assignors, by

mesne assignments, of three-fourths to General Electric Company,

and one-fourth to W Manufacturing Company,

Pennsylvania Application 14 Claims. In ordinary gas-filled electricincandescent lamps a spiral shaped tungsten wire is brought far from each other that undesirable discharges through the gas atmosphere are prevented.

In electric lamps according to the present invention such a discharge through the gas atmosphere is not only not prevented but, on the contrary, definite arrangements are adopted to obtain a lighting efiect' consisting of two components, namely, of the lighting effect of the incandescent wire and of the lighting effect caused in the gas by the discharge between the electrodes.

This is obtained by proper selection of the electric quantities concerned, the nature and mutual distance of the electrodes and the nature and pressure of the gas-filling, that is a selection in such a way that the desired effects appear in a. high degree. The lamp may be built for operation on direct current as well as for operation on alternate current. v

The following is an explanation of the invention with reference to the methods of carrying it out as shown in the attached drawing. In the drawing, Fig. 1 is an elevation of a lamp comprising my invention and designed for direct current operation; elevation of a similar lamp. modified for alternating current operation; Fig. 3 is an elevation of another modification for alternating current operation with an elongated discharge path; Fig. 4 is an elevation of another modified lamp of elongated form; Fig. 5 is an elevation of another lamp for alternating current operation having a modified electrode structure; Fig. 6 is an elevation, partly in section and on electrodes of the lamp shown in Fig. 5; and Fig.

, 'Z is a plan view of the electrodes of the lamp shown in Fig. 5.

One end of the incandescent wire b is con; nected to the leading-in wire a; the other Gnu of the incandescent wire is connected to a kind of supporting wire which in turn is connected with the second leading-in wire 'd. If a current of proper voltage is applied to the leading-in wires d and a, the wire b is caused to glow.

It, for instance, the glass bulb of the lamp is filled with a rare gas at a pressure of about to 50 mm. with a proper distance between the incandescent wire b and the carrier 0 acting as electrode, a discharge will take place through the gas atmosphere between thesetwo parts a corporation of New York, estinghouse Electric &

a corporation of June 19, 1930, Serial No. 462,167 In Austria June 1929 incandescent, and in this way the construction an enlarged scale, of one oi the l age a sufiiciently strong lighting favourably influenced by the of the incandescent wire, so that it can take place at a comparatively low voltage. This discharge forms a kind of shunt circuit with respect to the circuit dcba of the incandescent wire b.

It is advisable to adopt the measures and materials generally used in connection with glowing cathodes. ,Thus for instance, part of the incandescent wire may be provided with a coating of substances, such as for instance an earth alkali oxide, which emit electrons at comparatively low temperatures. The discharge will then mainly come from that part, and it is advisable therefore to locate this highly emitting part as close as possible to the joint with the leading-in wire. It is further advisable to give this part of the wire a larger cross section in order to avoid which discharge is thermionic action excessive heating, the emission of such an oxide cathode beginning as low as 700 C. The rest of the incandescent wire should have such a cross section that at the given volteffect is obtained.

As shown in Fig. 1 a small tube e of nickel or the like may be disposed over the incandescent wire b leaving the larger part of the incandescent wire free, which tube is provided on its outer surface with a .thermionically active layer, the heating of which is efiected by the incandescent wire. This small tube e is in electric connection with the leading-in Wire a and the discharge takes place between the electrodes, starting from the tube e. If the tube e is connected withthe leading-in wire a the.discharge voltage is about equal to the voltage which makes the filament b of the lamp is exceedingly simple.

The incandescent 'wire and the carrier 0 which acts as the anode are arranged in series. This, as is evident, also simplifies the construction or the lamp.

In the lamp ternating current, two incandescent wires :i and g are mounted between the leadingf-in wires 71. and i and a carrier it. Each of these wires f and g is at one place surrounded by a short tube 1 and m. These two leading-in wires andprovided with a thermionically active surface layer. By the carrier is the two incandescent filaments and g are connected in series; they are brought to glowing by applying an alternate current to theleadingin wires h and i. By their glowing they heat the thermionic layers of the tubes 1 and m so that shown in Fig. 2 which is for altubes are connected with the preferably of nickel thin coating a discharge takes through the gas atmosphere contained in the glass bulb, while those parts of the incandescent wires fand g which are not covered by the tubes can emit their light freely.

In both cases other bodies than tubes to be heated by the incandescent wire may be used, such as plates or the li e having thermionically active layers.

With-proper gases and proper pressure, the

distance between the two electrodes between which the discharge is to take place may be come paratively great and it may be achieved that the lighting power of the incandescent bodies and that of the gas atmosphere are in good harmony.

When alternating current is used it is advisable to provide the electrodes with projections the mean mutual distance of which is preferably less than that of the electrodes so that the electron currents are taken up by these projections and are diverted from the hot electrodes.

Fig. 3 shows a method of carrying out a lamp for operation on-alternating current which consists so to speak, of two incandescent lamps n and o as in Fig. 1 and of a lighting tube p connecting them. Each of the incandescent lamps may of course also be used with lamps according to Fig. 2.

Fig. 4 shows a method of constructing a lamp according to the present invention which lamp is made similar to the well known Soflit lamps.

In this case the incandescent wire is arranged as in Sofi'it lamps and the ends of the incandescent wire' are surrounded by glowing-tubes u between which the discharge takes place through the gas filling of the tube.

The colour of the discharge light depends upon the nature of the gas so that thereby also, in combination with the incandescent light, various efiects may be obtained. Also the arrangement of the electrodes in the lamp may be varied. Fig. 5 shows a lamp for use on alternating current. Here the heating wire" is absolutely not visible andthe stem is sealed in a globe shaped or lamp like glass vessel. The stem has two leading-in wires, and as appears from the drawing carries the heating filament f. This heating filament or wire consists or tungsten or similar material and is introduced into'a tube t consisting are'closed by stoppers s of insulating material allowing, however, oi passing .the filament ,f at both ends through a small hole of this insulating material. The'tube t has on its surface a of electron emitting substances 0. When the filament or heating wire I is conplace between these two tubes and the two ends or which heating wire and by passing through an electric current a desired temperature of about 1000? C. may easily be obtained. At this temperature the electrons are emitted the tubes 15 glowing,-

also be an elastic spring.

I claim: I 1. A discharge device comprising a sealed envelope having a gaseous filling and comprising a plurality of electrodes, one of said electrodes consisting of a heater element functioning at all times during operation of the device to supply heat to the electrode," and a thermionically active material so disposed as to be heated to electron emission temperature by said heater element and means for connecting another of said electrodes and said heater element in series with a light-giving filament for the passage of electrical energy therethrough to produce a glow discharge between said electrodes and supplement the energy radiated therefrom filament.

2. An electric illuminating device comprising a sealed envelope having an ionizable medium therein and a plurality of'electrodes, one of said electrodes being of the indirectly heated type'and including a heater element functioning at all times during operation of the device to supply I heat thereto and a thermionically active matei at least one of said electrodes being of the inditype and including a thermionically nected through the leading-in wires to a source of electric current, the current passes from the filament end to the next filament, the two being arranged in series for alternating current. This other filament similarly passes through anothertube t carrying the stoppers s and the surface of which .is equally coated with electron emitting substance.

Thus the twoterminals are connected by the rectly heated rial so disposed as to be heated to electron emission temperature by said heater element, in combination with a light giving filament, and means for connecting another of said electrodes and said heater element in series with said light-giving filament for the passage of electrical energy therethrough to produce a glow dicharge between said electrodes and supplement the energy radiated therefrom .by the light from said filament.

3. An electric illuminating lamp comprising a sealed envelope containing an ionizable medium therein, 'a plurality of electrodes in said envelope,

active material, a heater element for continuously rendering said material electron emissive during the operation of the lamp to ionize said medium, an electrical connection between said heater element and said material, and means, including a light-giving filament heated to incandescence during the operation of the lamp, for connecting said heater element and at least another of said electrodes in series.

4. An electric illuminating lamp in which, in addition to the illumination given out by a filament, a luminous gaseous arc discharge having a negative characteristic is caused to arise in shunt with the. filament heating circuit, comprising an I enclosing envelope having an ionizable medium therein, a plurality of spaced apart electron emitting electrodes of the indirectly heated type within said envelope including means withinsaid envelope for continuously supplying heat to the electrodes during the operation of the device, and 'a light giving filament, said means and said filament being connected in series and connected to an arc is formed causing a'lighting of the by the light from said r ment, a luminous gaseous arc the electrodes so as to provide a potential differ" ence therebetween.

5. An electric illuminating lamp comprising an enclosing envelope having an ionizable medium therein, at least one filament capable of being heated to bright incandescence by the passage of electric current through it, at least one metal cathode electrode which is capable of emitting electrons freely when heated, and a-resistance heater adapted to heat said cathode during the operation of said lamp, and means for connecting said filament and said electrode in series to a filament heating circuit whereby in addition to the illuminationgiven out by the filament a luminous gaseous arc discharge having a negative characteristic is caused to arise in shunt with the filament heating circuit.

6. An electric illuminating lamp for alternating current comprising an envelope having an ionizable medium therein, at least one filament capable of being heated .to bright incandescence by passage of electric current through it, two metal cathode electrodes each capable of emitting electrons freely when heated, and a resistance heater means adapted to heat each electrode during the operation of the lamp, said filament and said resistance heater means being connected in series to said electrodes whereby in addition to the illumination given out by the filament a luminous gaseous arc discharge having a negative characteristic is caused to arise in shunt with the filament circuit.

7. An electric illuminating lamp in which, in addition to the illumination given out by a fila discharge having a negative characteristic is caused to arise in shunt with the filament heating circuit, comprising an enclosing envelope having an ionizable medium therein, a plur lity of spaced apart tubular electrodes of the indirectly heated .type and including filamentary means a portion of which is axially disposed within said electrodes for continuously supplying heat to the electrodes during the operation of the device and the other portion of which is adapted to be heated to incandescence during the operation of the device, said filamentary means being. connected in series and connected to the electrodes so as to provide a potential difference therebetween.

8. An electric illuminating lamp comprising a sealed envelope containing an ionizable medium therein, a plurality of pairs of electrodes in said envelope, one of each pair of said electrodes being or the indirectly heated type and including a thermionically active material, a heater element to render said material electron emissive to ionize said medium, an electrical connection between said heater element and said material, and means including an incandescent filament for connecting said heater element and the other electrode of each pair in series, one electrode of each pair and at least one of the electrodes of another pair being adapted to have a discharge voltage applied therebetween, whereby the potential drop across the filament is used to cause an electrical discharge to take place between each pair of electrodes and the voltage applied between said one electrode of each pair and said one of the electrodes of another pair is used to cause an electrical discharge to take placetherebetween, and the incandescent filament gives off its illumination.

9. An'electric sealed envelope illuminating lamp comprising a containing an ionizable medium therein; a plurality of pairs of electrodes in said envelope; one of each pair of said electrodes being of the indirectly heated type and including a thermionically active material, a shield connected with the indirectly heated electrode, and a heater element to render'said material electron emissive to ionize said medium; an electrical connection between said heater said material; and means for connecting said heater element and the other electrode of each pair in series one electrode of each pair and at least one of the electrodes of another pair being adapted to have a discharge voltage applied therebetween, whereby the potential drop across said heater element is used to cause an electrical discharge to take place the voltage applied between each pair of electrodes and between said one electrode of each pair and said one of the electrodes of another pair is used to cause an electrical discharge to take place therebetween.

10. An electric illuminating lamp comprising a sealed envelope containing an ionizable medium therein; a plurality of pairs of electrodes in said envelope; one of each pair of said electrodes being .of the indirectly heated type and including a thermionically active material, a shield connected with the indirectly heated electrode, and a heater element to emissive to ionize said medium; an electrical connection between said heater element and said material; and means including an incandescentfilament for connecting said heater element and the other electrode of each pair in series one electrode of each pair and at least one of the electrodes of another pair being adapted to have a discharge voltage applied therebetween, whereby the potential drop across the filament is used to cause an electrical discharge to take place between each pair of electrodes and the-voltage applied between said one electrode of each pair and said one of the electrodes of another pair is used to cause an electrical discharge to take place therebetween, and the incandescent filament' gives off its illumination.

11. An electric illuminating lamp comprising a sealed envelope containing an ionizable medium therein including a pair of spaced electrode chambers and a tube connecting the same; a pair of electrodes in each electrode chamber, one of each pair of said electrodes being of the indirectly heated type and including a thermionically active material, a shield connected with the indirectly. heated electrode, and a heater element for rendering said material electron emissive to ionize said medium; an electrical connection between said heater element and said material; and means including an incandescent the potential drop across the filament is used to cause an electrical discharge to take place,

the voltage applied between each pair of electrodes and between said one electrode of each pair and at least one of the electrodes of another pair is used to cause an electrical discharge to take place therebetween, and the incandescent filament gives off its illumination.

12. A discharge device comprising a sealed envelope having therein an ionizable medium, a plurality of heaterelements disposed in spaced parallel relation, means connecting said heater elements in series, a thermionically active electrode body adjacent to each, of said heater eleelement and render said material electron ments to be heated thereby to an electron-emissive temperature, means electrically connecting each of said electrode bodies with its adjacent heater element, and a conductive member electrically connected to each electrode body so as to be at substantially the same potential as the body, said conductive members each having at least a portion thereof so located that the distance between said portion of the member and the opposite electrode body is shorter than the distance between said electrode bodies.

13. A discharge device comprising an envelope having a gaseous filling, current supply lead-in conductors extending into said envelope, heater.

elements disposed in spaced relation and each having an end secured to a lead-in conductor.

and having their other ends connected together, thermionically active electrodes disposed adjacent said heater elements and connected to the adjacent lead-in wires whereby to form a discharge gap between said electrodes in circuit throughsaid heaters, and a conductive member connected to each electrode so as to be at substantially the same potential as the elecmultiple with the trade and so disposed as to receive the discharge current from the opposite electrode. j J 14. An electric illuminating lamp comprising a sealed envelope containing an ionizable medium therein, a plurality of pairs of electrodes in said envelope, one of each pair of said electrodes being of the indirectly heated type and including a thermionically active material, a heater element to render said material electron emissive to ionize said medium, an electrical connection between said heater element and means for connecting said heater element and the other electrode of each pair inseries one electrode of each pair and at least one of the elec trodes of another pair being adapted to havea discharge voltage applied therebetween whereby the potential drop across said heater element is used to cause an electrical discharge to take place I between each pair of electrodes and the voltage applied between said one electrode of each pair and said one of the is used to cause an electrical discharge to take place therebetween.

' A NTQN LEDERER.

said material, and

electrodes of another pair

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