US2135706A - Gaseous electric discharge device - Google Patents

Description

Nov. 8, 1938. o. FRITZE 2,135,706

GASEOUS ELECTRIC DISCHARGE DEVICE Filed June 2, 1957 9 Fig. I.

INVENTOR Otiro Fritze A TORNEY conductofl whenthe switch'is'iii its closed circuit position, connectsthe heater eleme'nts of the '-electrodes'inwseries across the terminals of the current source for said .deviceand. short-circuits 20' thermostatic; switch ismounted external to container otthe; device andin-heat receiving relation tosomepart thereof, suchas the container trodes which Patented Nov. 8, 1938 unit es ,0 gaseous elecaa m r P late' tofgas'ecus elecco prisin therlieatedf to a high discharge supporting temthe initiation of the gaseous therebetween. l V 1; abalic' twnai Number 642,8;32, iiled' November fl'6,l932, inventor Andrew H. "Young," a es-ems electricdischarge device of the above "type i disclose hi'ch comprises elecv nitially heated"to"an elevated temperatur'ebythe passage of current and a conductor' "comprising a thermostatic Switch which the discharge'pathbetween the electrodes. The the wall adjacentone ofthe electrodes, so that when the electrode temperature risestO a value at which v the electrode is capable of supporting an arc discharge without appreciable disintegration the thermostatic switch moves to its open circuit position and the discharge starts between the electrodes.

The object of the present invention is to provide a longlived gaseous electric discharge device of the above type comprising a. thermostat protected from the ambient without the need of protecting means external to the lamp container and which thermostat is positive in operation. 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.

The invention attains its objects by enclosing the thermostatic switch in an hermetically sealed vessel and by mounting said vessel closely adjacent one of the electrodes in the container of the gaseous electric discharge device. The sealed vessel is either highly evacuated or is filled with a gas, such as hydrogen, under substantial pressure to suppress any arc between the contacts of the switch.

The thermostatic switch is intensely heated by the heat emanating from the electrode and is, therefore, positive in operation. When desired, a heat retaining element, such as a hollow metal cylinder open in the direction of the discharge path, surrounds the electrode and the thermoan auxiliary starting circuit.

2,135,706 I GASiious ntactrmc mscmmca DEVICE Otto =Fritie, Berlin, Germany, assignor to Gen- 'erai-Electriocompany, a corporation of New Heats; June 2, 1937, swarm). 146,047 Germany June 9, 1936 2'1Claims; (Cl. 176-124) static switch is mounted in the space between said electrode and said heat retaining element.

The thermostatic switch is provided with two current leads one of which is connected to the heater element of the electrode adjacent the switch and the other of which is connected into The external part of the current lead which is connected to the auxiliary circuit is coiled helically and engages with a similarly coiled lead of the auxiliaryg cim cult. The mounting of the thermostatic switch in the container of the device is simplified by this structure since welding operations in close proximity to vitreous parts of the lamp container or of the switch vessel are avoided.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown, in which Fig. 1 is a side elevational, partly sectional view of one embodiment of the invention, and

Fig. 2 is a similar view showing in detail an end assembly of the device illustrated in Fig. 1.

Like numbers denote like parts in both the figures.

Referring to the drawing the gaseous electric discharge lamp device comprises an elongated, tubular container l having a gaseous atmosphere therein, such as rare gas at a pressure of about 1 to 10 mm., metal vapor, or a mixture of starting gas and metal vapor, which is luminosity producing during the operation of the device. Thermionic activated electrodes 2 and 2' are mounted in the ends of said container I. Each of said electrodes 2 and 2 consists of a rod of electron emitting material, such as barium oxide, and a heater filament, such as a tungsten filament wrapped around said rod. Said electrodes 2 and 2 are surrounded by heat conserving shields 3 and 3', respectively, and said shields 3 and 3' having openings 4 and 4', respectively, therein in the direction of the discharge path between electrodes 2 and 2'. The gaseous electric discharge device is connected across the terminals 5 of a 220 v. alternating current source. A choke coil 6 is connected in series with said gaseous electric discharge device and a switch 1 is provided for connecting and disconnecting said device across the terminals 5. Said electrode! is supported by a current lead 8 and the support 8" fused into the press ll of the stem of said container I and the electrode 2 is similarly supported at the opposite end of the said container l. The shields 3 and 3' are supported by a support wire attached thereto, as by welding, which wire is fused into the press of said stems. The stem at one end of the container l is provided with the exhaust tube It.

The bimetallic switch it (shown in detail in Fig. 2) consists of an hermetically sealed vitreous container ll having a contact i2 and a bimetallic strip I mounted therein. when said strip ll is suiflciently heated it moves from its contact making position to its contact breaking position (indicated at I! in Fig. 2). The contact l2 of the switch is connected by lead I! to the support wire 8" of the electrode 2 and the bimetallic strip ll of the switch is connected by lead I! to the current lead 9. The external end of the current lead attached to the bimetallic strip is is coiled helically (as shown at and is (as-- tened to the end of the current lead l5, which is similarly coiled, by screwing these elements together during theassembly of the device. As shown in Fig. 1 the current lead 9 is connected to the electrode 2' at the opposite end of the container I. When potential is first applied to the lamp device by closing switch I the bimetallic switch i0 is in a contact making position and current flows through the heater coils of the electrodes 2 and 2', the bimetallic switch l0 and the conductor 9, short-circuiting the discharge path between said electrodes 2 and 2. The how of current therethrough heats the electrodes 2 and 2' to an electron emitting, arc discharge supporting temperature and the heat emitted bythe electrode 2 heats the bimetallic switch II. In response to this heating the strip l4 bends and moves to a contact breaking position. When contact is broken in the switch It potential is impressed across the terminals of the discharge device and a discharge starts between the electrodes 2 and 2. During the operation of the device the electrodes 2 and 2 are maintained at an electron emitting discharge supporting temperature by the arc discharge incident thereat and the bimetallic strip i4 is maintained in its contact breaking position by the heat emitted by said electrode 2.

While I 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 irom the broad spirit and scope oi the invention, for example, when high frequency starting is desired the bimetallic switch II is used to control the operation of the high frequency apparatus, when desired. or the bimetallic switch I. is used to control the operation of an auxiliary starting discharge in the device when that method of starting is used, and, when desired, the current lead 2 is covered with an insulating material, such as glass, and is mounted inside of the container I.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1 A gaseous electric discharge lamp device comprising a sealed container, a gaseous atmosphere therein, electrodes sealed therein which are.electron emitting when heated, a thermostatic switch mounted in said container and in heat receiving relation to one of said electrodes, a heat retaining means surrounding one of said electrodes and said switch, said switch consisting of a sealed vessel having a bimetallic strip and a contact therein, and an auxiliary starting means for said device, said starting means being controlled by said switch.

2. A gaseous electric discharge lamp device comprising a sealed container, a gaseous atmosphere therein, electrodes sealed therein which are electron emitting when heated, a thermostatic switch mounted in said container and in heat receiving relation to one of said electrodes, said switch consisting of a sealed vessel having a bimetallic strip and a contact therein, and an auxiliary starting means for said device, said starting means being controlled by said switch,

said switch having a helically coiled current lead engaging with a similarly coiled lead of said starting means.

OTTO FRI'I'LE.

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