US1935702A - Gaseous electric discharge lamp device - Google Patents

Description

Nov. 21, 1.933.

H1. EWE$T ET AL GASEOUS ELECTRIC DISCHARGE LAMP DEVIG'E Filed June 6, 1955 2 Shams-Sheet l 12my111121 912mmwm/imww INVENTORS BY g ATTORN EY Nov. 21, 1933. H, EWEST Er AL WBW GASEOUS ELECTRIC DISCHARGE LAMP DEVICE Filed. June 6, 1955 2 smats shem r2 INVENTORS 25m 69M M 9/" BY WM ATTORN EY Patented Nov. 21, 1933 GASEOUS ELECTRIC DEVI JSCHARGE LAMP Hans Ewost, Berlin-Lichterfelde, and Kurt Wiegand, Berlin-Tempelhof, and Martin Reger, Berlin, Germany, assignors to General Electric Company, a corporation of New York Application June 6, 1933, Serial No. 674,519 and in Germany June 18, 1932 5 Claims.

The present invention relates to gaseous electric discharge lamp devices generally and more particularly the invention relates to improvements in methods and means for starting such devices into operation.

The starting of gaseous electric discharge devices is facilitated by mounting an electrically conducting, straight wire along the gaseouselectrio discharge path in the container of the device. The wire is usually electrically connected to one of the electrodes of the device and when the starting voltage is applied across the electrodes of the device a glow discharge takes place between said wire and the electrode opposite that to which said wire is connected. The glow discharge extends along the length of the wire so that a heavy ionization of the discharge path takes place which facilitates the starting of the main discharge in the device. While this method of and means for starting is successful and effective the wire is frequently subjected to a heavy electronic and ionic bombardment and a spot thereon is raised to its melting temperature by the main discharge during the operation of the device. Under these conditions the wire is apt to break at the heated part to reduce the efiectiveness thereof for starting purposes. The particles knocked off the wire by the electronic and ionic bombardment form deposits of light opaque material on the walls of the container of the device which reduce the efliciency and the useful operating life of the device.

The object of the present invention is to provide a gaseous electric discharge device of the above type in which the above difficulties are avoided. Another object of the invention is to provide a gaseous electric discharge device in which starting is quicker and more positive than those of the same type now known in the art. A further object of the invention is to provide a gaseous electric discharge device adapted to start and operate on 110 or 220 volt current sources of commerce and which has a long useful operating life. 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 and from the appended claims.

.The invention attains its objects by providing an electrically conducting coiled wire along the discharge path between the main discharge supporting electrodes, out of contact with said electrodes, terminating adjacent said electrodes and covered with an insulating material between the exposed end parts thereof. The insulating material protects all parts of the wire except the end parts thereof from an electronic and ionic bombardment during the operation of the device. When the starting voltage is applied to the electrodes of the device an auxiliary discharge develops between each of the main electrodes and the end part of the wire adjacent thereto. The intensity of the auxiliary discharges and the temperature of the end parts of said wire are controlled, among other factors, by the resistance of said wire. As these end parts of the wire are located adjacent the main discharge supporting electrodes any sputtered material therefrom deposits on those parts of the container wall adjacent the electrodes and as these parts are not used for light transmission the light opaque deposits of sputtered material thereon do not reduce the efliciency of the device. The resistance of the coiled wire is suflicient to prevent the development of an arc discharge between the exposed wire ends and the main electrodes and to prevent said end parts from reaching the melting temperature during the starting and operation of the device. We have discovered that a condenser discharge takes place between the wire and the main discharge supporting electrodes and that the intensity of said condenser discharge increases directly as the length of the wire. In the preferred embodiments of our invention the wire is a convolutejand a helical shaped wire is preferred. The condenser discharge and the auxiliary discharges which take place along the discharge path during the starting period cause a heavy ionization of the gas in said path to facilitate the starting of the main discharge in the device.

In the drawings accompanying and forming part of this specification several embodiments of the invention are shown in which:

Fig. 1 is a side elevational view of one type of gaseous discharge lamp device embodying the invention, the circuit therefor being shown schematically,

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

Fig. 3 is a detail view of another form of conductive element useful in the invention,

Fig. 4 is a side elevational perspective view of another type of gaseous electric discharge device 105 embodying the present invention,

Fig. 5 is a detail view of another form of insulated wire useful in the invention, and

Fig. 6 is a similar view of still another form of insulated wire useful in the present invention.

Like numbers denote like parts in all the figures.

Referring to Fig. 1 of the drawings the new and novel gaseous electric discharge lamp device comprises a container 1 having a stem 2 at either end thereof. Inleads 3 and 4 for each of said electrodes 5 are sealed into each of the stems 2. Said container 1 has a gaseous atmosphere therein comprising rare gas, common gas, mixtures of gases, metal vapor, or gas-vapor mixtures and is, for example, neon, or a mixture of argon and mercury vapor. The starting and operating mixtures of gases well known in the art are used in said container 1 where desired. Said electrode 5 comprises a heater filament, such as a tungsten filament, wrapped around a rod made of a sintered mixture of a metal having a high melting point, and electron emitting material, such as a mixture of tungsten, barium oxide and strontium oxide. The tungsten filament is connected across the current inleads 3 and 4. Each pair of said leads 3 and 4 are connected to the secondary of a transformer 12 adapted to supply the heater current for said electrodes 5. Said leads 4 are the main current leads for said electrodes 5 and each of said leads 4 is connected to a terminal 16 of a commercial alternating current source of or 220 volts. A choke coil 13 is connected into one of the leads 4 which regulates the potential across said electrodes 5 after the device has been started into operation. The primary of each of said heater transformers 12 is connected in parallel with said lamp device 1 and between the choke coil 13 and the electrodes 5. The potential on said transformers 12 is thus less during the operation of the lamp device 1 than during the starting period which prevents overloading of the heater filament of said electrode 5 during the operation of the lamp device 1.

An electrically conducting helically wound wire 8, enclosed in a straight glass insulating tube 9, is supported in said container 1 by two pairs of semi-circular spring members 10 attached to said glass tube 9 and pressing against the inher wall of said container 1, as shown in Fig. 2. The straight end parts 14 of said wire 8 are not enclosed in said tube 9 and are located a distance from said electrodes 5 less than the striking distance of the potential applied across said electrodes 5. When a voltage of 110 or 220 volts is applied to the above described device the electrodes 5 are quickly brought to an electron emitting temperature by the heater current supplied by transformers 12. Simultaneously an auxiliary discharge takes place between each of the electrodes 5 and the respective ends 14 of the wire 8 adjacent thereto which assists in quickly heating each of said electrodes 5 to an electron emitting temperature. A condenser discharge takes place between that part of the wire 8 enclosed in said tube 9 and the electrodes 5. The intensity of the condenser discharge depends on the length of said wire 8, and the intensity of the auxiliary discharge depends, among other factors, upon the resistance of said wire 8. The resistance of wire 8 is suflicient to prevent the end parts 14 thereof from reaching a melting temperature during the starting and operating periods of the device. The auxiliary discharges and the condenser discharge speed up the electrons emitted by the heated electrodes 5 which increases the ionization of the gas in the discharge path between said electrodes 5 to facilitate the starting of the gaseous electric discharge between said electrodes 5. As said wire 8 is of helical shape and extends along the full length of the discharge path between said electrodes 5 the condenser discharge is an intense one and speeds up the electrons throughout said discharge path which results in a heavy ionization of the gas in all parts of said path as well as at the ends thereof in the region surrounding the auxiliary discharges between said electrodes 5 and said end parts 14. This, of course, is very advantageous in starting such devices into operation.

The structure of the tube 9 and wire 8 illustrated in Fig. 3 is used in electric discharge lamp devices of equal or greater length than those in which the wire 8 and tube 9 shown in Fig. 1 are used. In this structure the helically wound wire 8 is divided into two parts of equal length and the adjacent straight end parts 15 of said wire 8 project from the wall of the tube 9. Said end parts 15 are separated a slight distance from each other. The element consisting of tube 9 and wire 8 is mounted in the container of a gaseous electric discharge lamp device as shown in Fig. 1. When the starting voltage is applied across the terminals of the device an auxiliary, starting discharge of the same type as that between each of the ends 14 and the electrode 5 adjacent thereto takes place between said end parts 15 in addition to the other discharges discussed in connection with Fig. 1. This of course results in a heavy ironization of the gas throughout the length of the discharge path which facilitates the starting of the main discharge in the lamp device. It will be understood, of course, that the wire 8 is divided in more than two parts of equal length, when desired.

The embodiment of the invention illustrated in Fig. 4 is used in conjunction with the circuit described in connection with Fig. 1 and this embodiment is similar in all respects to that illustrated in Fig. 1 except that in this embodiment the ends of wire 8 are rods 6 made of material similar to the material in the rod of electrodes 5. The rods 6 are supported by metal rods 7 sealed into the stems 2. Said rods 6, as well as the electrodes 5, are heated to an electron emitting temperature by radiation of heat from said electrodes 5 and by the auxiliary discharge which takes place between each of the electrodes 5 and the rod 6 adjacent thereto. The provision of two additional, prolific sources of electrons in the lamp device facilitates further the starting of the main discharge between said electrodes 5. In other respects the starting and operation of the device is the same as that described in connection with Fig. 1. It will beunderstood, of course, that an element similar to that shown in Fig. 3 is used in the above described device, when desired.

A helically wound glass tube 9 having a similarly wound wire 8 enclosed therein is illustrated in Fig. 5. This tube 9 is more flexible than that illustrated in Figs. 1 and 4 and is used in lamp devices similar to those illustrated in Figs. 1 and 4 and in lamps having a curved tubular container. Such a lamp device has, when desired. two parallel tubular legs of equal length, electrodes sealed into one end 01' each of said legs and a curved portion connecting the ends of said legs opposite the electrodes. Such a lamp device is of U-shape, the electrodes thereof are approximately in the same plane and the tube 9 and wire 8 sourrounds the discharge path between the electrodes.

Another flexible, insulating tube for said wire 8 is illustrated in Fig. 6 of the drawings. In this case a number of overlap lns conically shaped 150 beads 11, known in the art as fishspine beads, surround said wire 8. This type of flexible tube is used in curved or straight containers similar to those discussed in connection with Fig. 5.

It will be understood, of course, that the method and means described above is used in electric discharge devices wherein the gaseous electric discharge between'the main discharge supporting electrode is a positive column discharge of either the glow or arc type, when desired.

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, said rods 6 are electrically connected to the electrode 5 adjacent thereto, when desired, and said electrodes 5 are, when desired, of the self-heating, mixed metal and oxide type lrnown in the art as Pirani electrodes.

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

1. An electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, a body of electrically conducting material extending along the discharge path between said electrodes and terminating adjacent said electrodes and a covering of insulating material for the part of said body in-= termediate its ends to protect said part from an electronic and ionic bombardment during the operation of the device.

2. An electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, a convoluted body of electrically conducting material having a high resistance, extending along the discharge path between said electrodes and terminating adjacent said electrodes and a covering of insulating material for the part of said body intermediate its ends to protect said part from an electronic and ionic bombardment during the operation of the device.

3. An electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, two convoluted bodies of electrically conducting material extending along the discharge path between said electrodes, one end of each of said bodies being adjacent one of said electrodes, the other end of each of said bodies being adjacent the end of the other of said bodies, and a covering of insulating material for the part of said bodies intermediate the ends thereof to protect said part from an electronic and ionic bombardment during the operation of the device.

4. An electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, a body of electrically conducting material extending along the discharge path between said electrodes and terminating adjacent said electrodes, the end parts of said body being of a material capable of emitting electrons when heated, and a covering of insu lating material for the part of said body intermediate its ends to protect said part from an electronic and ionic bombardment during the operation of the device.

5. An electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, a convoluted body of electrically conducting material having a high resistance, extending along the discharge path between said electrodes and terminating adjacent said electrodes, the end parts of said body being of a material capable of emitting electrons when heated and a covering of insulating material for the part of said body intermediate its ends to protect said part from an electronic and ionic bombardment during the operation of the device.

HANS EW'EST. KURT WJIEGAND. MARTIN REGER.

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