US1878502A - Gas or vapor discharge device - Google Patents

Description

p 1932- R. D. MAILEY GAS 0R VAPOR DISCHARGE DEVICE Filed Oct. 25. 1928 INVENTOR HIS ATTORNEY V Patented Sept. 20, 1932 UNITED' STATES PATENT OFFICE no'z n. EAI EY, or EAST ORANGE, NEW JERSEY, ASSIGNOR 'ro GENERAL ELECTRIC vnron LAMP comrnnr, or HOBOKEN, NEW JERSEY, A conronnrron on NEW JERSEY- GAS OR VAPOR DISCHARGE DEVICE Application filed October 25, 1928. Serial No. 314,929.

The present invention relates to gas or vapor electric dlscharge devicesand methods of operating the same. The lnvention relates more particularly to gas or vapor electrio discharge lamps having a gas or vapor filling of component parts which cooperate to give the lamp uniformity durlng the life of the lamp bothin operating characteristics and in the color lamp.

The main object of the'present invention is the production of an electric gaseous discharge lamp operable on the usual commercial circuits of 110 or 220 volts. For use on direct current a lamp embodying my 1nvention is provided with an anode and a hot cathode such as a filament of pure tungsten or thoriated tungsten, or of the type wherein an oxide coated nickel electrode body s heated by such afilament. In an embodiment of my invention for use on alternating current I use two anodes and a similar hot cathode, connected across an alternating current source in a similar manner tothe well known Cooper Hewitt alternating current rectifying lamp. In both said embodiments, the gas filling comprises a mixture of gases having low average atomic weight, for example, helium 85-95% and neon -570 substantially, wherein one of said-gases, the

of the light emitted from the major component, supports electric conduction, and the other emits its characteristic radiation by excitation by collision, whereby the lamp has the desired radiation characteristic, in this case that of neon. Because of the low average atomic weight of the gas filling deleterious disintegration of the elcctrodes and other partsofsuch lamps which are bombarded by positive carriers is reduced and maintained at a minimum.

Various other objects and advantages of the invention will be obvious from the fol lowing particular description of forms of discharge devices embodying the invention or from an inspection of the accompanying drawing, and the invention also consists in certain new and novel features of construction and combinations of parts hereinafter set forth and claimed.

device envelope,

In the accompanying drawing Figs. 1 too somewhat diagrammaticallyshow for purposes of illustration in vertical elevation electric resistor heater is used in'association' with a body of m'aterial such as an oxide, hydroxide or carbonate of metal'such as calcium, magnesium, barium, strontium, lithium, thorium, or the like, which material is coated over the resistor or is otherwise mounted in operative relation thereto. The gases or vapors used for sustaining a discharge are the rear gases such as neon, helium, argon, etc., mercury', the vapors of sodium, lithium, potassium, calcium and the like or mixtures thereof. In a gaseous discharge device for example, when current is passing therethrough, movement of electrons and atoms and molecules therein results in bombardment of the several parts of the device by the ions and electrons which are in the gas or vapor space. The ions of certain gases are of such mass that-the bombard ment of solid parts of the device thereby results in the breaking down of those parts and in deleterious effects on the device.'- Such blackening of the transparent walls iof the caused by sputteringof the electrodes through positive carrier bombardment and the depositing of the sputtered. off parts onto the envelope wall. The envelope walls themselves are also bombarded and particles thereof. sputtered and in such cases decomposition of the material of'the wall takes place with the resultant freeing of deleterious gases into the envelope space.

The results of such effects are reduction of the efficiency of the operation of the device or the complete 'incapacitating thereof through change of operating characteristics, or through the prevention of passage of de sirable radiations through the device envelope by sucha blackening or darkening by sputtered material.

Some vapors and gases however, have ions whose mass orweight is considerably less than that'of others and these are most desirable for carrying current through the de-' vice. It is not always the case, however, that gaseswhich have comparatively low weight or 'mass have desirable radiation characteristics. I have found that certain gasesor vapors of comparatively high weight or mass have desirable characteristics of radiation and further that the radiations from such gases or vapors will predominate over those of certam other gases or vapors even when they are present w1th other gases or vapors 1n only very small amounts. I have further'discovered'that there are certain combinations of gases such, for example, as a combination or m1xture of two gases in which one having ions of comparatively large mass or weight 'can be used in very small proportions with the other having ions of comparatively low mass or weight in correspondingly great proportions. I have further discovered that gases or vapors can be chosen in the above said relationwith the further relation that the gas having the greater mass or weight and the number of its ions over those of the heavier weight gas contributes to the efli-:

ciency in the transmission of radiation producing energy to said heavier gas. A particular example of a combination 0 gases according to the above statement of he invention is a mixture comprising about 95% helium and about 5% neon. The weight of the helium ion is so low that a discharge device having electron emissive material of the substances above noted will have a com-' paratively long and useful life. On the other hand the neon, whose ions have comparatively large mass or weight, is present in sucha comparatively small amount and thepercentage of neon ions present is so small that bombardment of the electron emissive material by ions thereof is so comparatively infrequent that the operative life oat the device is not materially afiected. Further, when helium and neon are used in .a discharge device in the amounts above stated visible light and other radiations from the neon greatly predominate over any radiations which may be produced from the helium. A specific example embodying the purposes and advantages of the invention above noted or otherwise apparent comprises a sealed envelope of glass or quartz having the multiplication of current carriers.

a solid anode therein, a. filling comprising on the order, of to helium and 10% to 5% neon and a cathode which consists of an electric resistance heater having posit1oned in operative relation thereto or more particularly, formed as a coating thereover, alayer or layers of barium oxide. connected to a suitable source of current,

-- alternating or direct,'of a voltage suflicient to produce a discharge therethrough, radiations characteristic of the neon will be pro duced, the helium will operate as the main current carrying medium and the neon will serve as the main light producing medium. The barium oxide under the influence of the electric heater cathode will serve as a prolific source of electrons which will be accelerated through the potential gradients in the discharge space and willbombard particularly the helium atoms and 'ionize them and cause In a device of this kind having a discharge distance of about 18 inches in a tubular envelope of about 1 mch in diameter and with 300 'volts alternating current supply and with vapor ressure of about 3 to 10 mm. of mercury, he device will operate for more than 6000 hours. V

In Fi 1 is illustrated a direct current lamp em odying the invention in which the longitudinal envelope 1 has sealed thereinto at one end the anode 3 which is conne'cted to the lead 5 for connection to thepositivej side of a source of direct current. At the'o posite end of said envelope is mounted t e cathode, shown more in detail in Fig- 6, comrising the resistor v6, connection to which is made through the leads 8 and 10 sealed through said envelope .1, and the cylindrical shield 12 of a metal such' as nickel, iron, tungsten or other suitable material, mounted about said resistor 6 and having upon its outer surface a coating 13 of an oxide, a hydroxide or a carbonate of a metal such as barium, or other electron-emissive material. Connection is made from said electrode 12through thelead 14 to said resistor 6 by way "of said lead 10 at a point outside said envelope 1. Said lead 10 is also connected through the resistance 16 and the in ductance 18 to the negative supply main-20. Connection is made from the other side'of said resistor 6 through said lead 8, switch 22 and adjustable resistance 24 to said main 5.

In Fig. 2 is illustrated an alternating current rectifying lamp comprising the sealed envelope 30 having sealed thereinto at one end the spaced apart anodes 32 and 33 which are connected respectively through the resistances 35 and 36 to opposite endsvof the transformer secondary 38 which is in operable relation to the primary 40. At the end of said envelope 30 opposite from said anodes 32 and 33 is mounted a hot cathode'structure the heater 42 of which is connected through When the leads 44. and 45 to spaced apart intermediate points on said secondary 38. Positioned about said cathode-heater 42-is an activated slecveor cathode 46 similar to the corresponding part 12 of Fig. 1. This element 46 is connected through the lead 48 to said conductor 45. at a point outside the envelope. v

In .the embodiment of the invention illustrated in Fig. 3 the closed envelope 130 of glass, quartz or other suitable material has sealed thereinto at one end the spaced apart anodes 132 and 133 which are connected is a through the resistances 54 and 55 respectively to opposite ends of a transformer secondary 56 ,which is inoperable relation to the transformer primary 58. At the end of said en- Telope130 opposite from said electrodes 132 and 133 is mounted the hollow cylindrical cathode 60 which is of, a material such as pl'atinum, nickel, iron, tungsten or other suit- I lead 68 to said conductor 62.

, able material which has over its outer surfaces a coating of an ox1de, hydrox1de, or

carbonate of a metal such as calcium or 62 through'the inductance 64 to a midpoint on said secondary 56. About said electrode 60. is positioned the cylindrical shield 66 which is of iron, nickel, tungsten or other suitable material and is connected through a Positioned within said cylindrical electrcde60 is the resistance heater 82 of tungsten, molybdenum or the like which is connected through the 5 leads 84' and 85 to a coil 86 which is in position to be energized through said primary 58.

In Fig. 4 is shown a sealed envelope 90 having mounted therein, one at each end, the hollowcylinders 92 and 94 ofmetal such as iron, nickel or tungsten each of which has on either-or both of its surfaces'a coating of an oxide, hydroxide or carbonate of a metal such as barium, strontium or, calcium. 5 Within said cylinders 92 and 94 respectively,

are mounted the heatingresistors 96 and 98 respectively, resistor 96 being connected through'the conductors 100 and 102 to the ends of a coil 104 mounted in operative relation to a transformer primary 106. In like manner the resistance 98 is connected through conductors 108 and 110 to the coil 112 which is also in operative relation to said-primary 106. Connection is made from the cathode 5 92through the conductor 114, ballast resistance 116, to one end of a transformer secondary 118 the other end of which secondary is connected through conductor 120 and re sistance 116, to the cathode 94. Connection is also made from cathode 92 to'lead 100 and from cathode 94 to lead'llO, if desired.

- In Fig. 5 illustrated a closed envelope 130 which has mounted at one end thereof the two. anodes 132 and 133 which connect through the resistances 136 and 138 respec-' barium and which is connected by conductor tively to opposite ends of the transformer secondary 140 which is in operative relation to the transformer primary 142. At the end of said enve ope 130 o posite'said anodes is mounted the ollow cylinder 144 which is of metalsfich as iron, nickel or, tungsten and which has over either or both of its surfaces. .a coating of anoxide, hydroxide or carbonate of bariumor calcium or the like.

tiverelation tosaid inductance 148 for the,

inovmg of said switch 154 into the open circuit position by said inductance 148 when the latter is energized! About said electrode 144 is positioned the sleeve 160 of metal such as nickel, iron or tungsten which is connected through the lead 162 to said conductor 146. A heating resistor 164 mounted withinsaid cylinder 144is connected to the transformer secondary 166 through the leads 168 and 170.

In the envelope of the devices'illustrated in- Figs. 1 to 5 there is provided an atmosphere of gas or vapor such as one of the rare gases, mercury, caesium .orother suitable gas or vapor, or a mixture of some'of these. A preferred embodiment of the invention is any one of the discharge devices illustrated in the drawing and herein described with an. atmosphere'comprising about 90% helium and 10% neon.

In the use and operation of, the device and apparatus of Fig. 1 a direct current potential is applied from the leads 5 to 20 across the anode 3 and cathode 12 through the inductance 18 and resistance 16 which serve to stabilize and regulate the current flow. Said cathode 12 is brought to an electron emitting condition by heat supplied from said resistor 6 which is connected on one side to said main 20 at a point between lead 14 and resistance .16 and on the other through the switch 22 and resistance 24 to said main 5.

Preferably said resistance 6 is maintained.

energized during operation of the device to keep said cathode element 12 heated and in an electron emitting condition but switch 22 may be opened after the starting of discharge operation incertain cases where current passage through element 12 keeps that element in a sufiiciently heated condition to maintain electron emission therefrom. It is to be un-' derstood that said resistor 6 can be heated by oxide is applied as such in the form of a paint with water, zapon, cellulose or varnish as the vehicle, or the oxide coating is obtained by applying a coating of the hydroxide or carbonate which-is decomposed by heat to leave the oxide on the electrode.

In the use of the device said resistor 6 is utilized to heat the electrode 12 and the oxide coating 13 on electrode 12'to bring it to an electron emitting state. These electrons will be emitted into the space in the device in which there is a potential gradient and willbe impelled-toward said anode '3 and be discharged thereat, thereby efi'ecting current flow in the device. Further, in their movement across the space the electrons will be accelerated and they will collide with gas or vapor atoms or molecules and thereby transfer to these atoms or molecules energy which The device'of Fig. 4 is for use on menial-- ing current and for conductin the currentm causes them to emit radiations in the visible and in the invisibleranges.

The operation of the device and system of Fig. 2 is similar to that of Fig. 1 as regards the function of the cathode. The device of this figure is for use on alternating current and is adapted for rectifying alternating current according to the functioning and manner of operation of the Cooper Hewitt rectifying lamp well known in the arts. The resistor 42 is energized from an intermediate section of the transformer secondary 38 which is connected thereto by said leads 44 and 45. The electrode 46 is connected to an intermediate point on said secondary 38 through lead 48 and oneof said leads 44 and 45.

. The device of Fig. 3 functions somewhat similarly to that of Fig. 2 except that a separate energizing coil 86 positioned in operafive relation tothe primary 58 is connected across the resistor 82'to supply heating current thereto. Connection is made from an intermediate point on the secondary 56 through.

the ind-uctance64 to said electrode 60 and-to the cylindrical shield 66,, the ends of said secondary 56 being connected through resistances 54 and 55 respectively-to anodes132 and 133.

both directions between sai distant, electrodes 92, 94. During alternate half cycles of current flow resistors 96 and 98 serve to maintain the electrodes 92 and 94 in cathode condition by continuous energization of the oxidecoatings thereon to keep them in the electron emitting state. current will flow alternately from opposite During operation in the case of the device of Fig. 1, in some,

cases discharge producingcurrent flowing through said electrodes 92 and 94 will be suflicient to heat the metal oxide coatings thereon and maintain them in the electron emissive condition through the zero point -of alternations of current flowing therethrough, the heaters then being unnecessary after a discharge has been initiated.

The device of Fig. 5 is similar to that of Fig. 3 but includes means comprising inductance 148 and switch 154 for producing a high voltage surge across the lamp to start it into operation, in cases where desired. In the operation of the starting means, before current commences to flow between the electrodes of'the discharge device and whensaidprimary 142 is properly energized, current will. flow from the midpoint of said secondary 140 through the lead 150, inductance -148, switch 154, resistance 153, lead 152, resist ance 155, which is the heater element ,of thermostat 159, back to the secondary. The current flowing through the circuit just described is insufiicient to open the mercury switch 154'and the heating of the resistance 155 continues for a predetermined time, that is, the time it will take the heater resistance 164 to bring the oxide coated cathode 144 to a temperature at which it will operate efliciently as a cathode. During this interval the bimetallic member 157 of the thermostat 159 is affected by the heat from the resist-ance 155 and in forty-five seconds, say, the bimetallic bar will deform and come into contact with ;ance 155 and thereby increasing the current through the circuit to energize the inductance 148' to a value sufficient to attract the armature 156 on the mercury switch 154, thus pro- ,ducing a sudden break in the current flowing.

through said part of said secondary 140 whereby there is produced a static discharge from said anode 132 and said cathode including the cylinders 144 and 160. In the meantime said resistor 164 has been energized from said secondary 166 and the oxide coating on .fsaid cylinder 144 brought to the electron emissive state. Such a. high potential discharge between the cathode and the anode will .start current flow from the anode to the cathode because potential difference has been maintained from the beginning between said electrodes. Upon commencement of regular discharge current flow through said cathode said inductance 148 will be maintained in the energized condition and will hold said switch 154 in the open circuit position.

While.I have described the invention in" quantity of a material having a re ucing etfeet on the oxides, such as potassium, magnesium or carbon, whereby there is maintained a continuous supply of electron emitting material on the cathode, as well as the desired purity of the gas when neon alone is used, or of the components of a mixture such as neon and helium when that mixture is used.

It is to be understod that while I have described the invention as applied to a neonhelium lamp the elements in combination are applicable to lamps in which one gas alone is used as the radiation and current carrying material. i

In the claims the term gas has been freely used, and is intended to cover vapor as well as gas.

I claim as my invention 1. A gaseous-discharge device comprising an envelope, electrodes therein, one of which is adapted to emit electrons when heated, means for heating said electrode, and a mixture of helium and neon therein, the helium constituting at least of said mixture.

2. A gaseous discharge devicecomprising an envelope, electrodes therein, one of which is adapted to emit electrons when heated, means for heating said electrode, and a mix-. ture of helium and neon therein, the helium comprising substantially of said mixture.

-3. A gaseous discharge device comprising an envelope, electrodes therein, one of which is adapted to emit electrons when heated, means for heating said electrode, and a mixture of gases within said envelope in combination with means for initiating a discharge through said device and means for delaying the operation of said means for initiating a discharge until said electrode has reached an operating temperature.

trodes.

means for heating said electrode, and a mix ture of gases therein, said mixture having a low average atomic weight, in combination with means for initiating a discharge through said device and means for delaying the operation of said means for initiatinga discharge until said electrode has reached an operating temperature.

6. A gaseous discharge device comprising an envelope, electrodes therein, .one of which emits electrons when heated, means for heating said electrode, means within said envelope reacting with said electron emitter to maintain it in electron emitting condition, and a mixture of gases within said envelope in combination with means for initiating a discharge through said device and means for delaying the operation of said means for initiating a discharge until said electrode has reached an operating temperature.

7. A gaseous discharge device comprising an envelope, electrodes therein, one of which emits electrons when heated, means for heating said electrode, a mixture of gases within said envelope, and means in said envelope for maintaining the purity ofsaid gas mixture in combination with means for initiating a discharge through. said device and means for delaying the operation of said means for initiating a discharge until said electrode has reached an operating temperature.

8. An electric gaseous discharge device comprising an envelope, electrodes within a said envelope, one of said electrodes being capable of emitting electrons when heated, means for heating said electrode, a gas of low atomic weight and given ionizing potential in said envelope, and another gas having a higher atomic weight and a lower ionizing potential than said first mentioned gas inter- .mixed therewith, the proportion of said gas of higher atomic weight being the minimum which will cause the characteristic radiations of said gas to redominate'upon passa e of an electrical g charge between said elec- Signed at Hobok en in the county of 'Hud- October, A. D. 1928.

ROY MAILEY.

son and State of New Jersey this 24th day of 4'. A aseous discharge device comprising an envelope, electrodes therein, one of which is adapted to emit electrons when heated,

means for heating said, electrode, and a mixture of rare gases within said envelope, in

combination with'means for initiating a discharge through said device, and means for delaying the operation of said means for an envelope, electrodes therein, one of whic is adapted to emit electrons when heated,

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