US2054846A - Modulating lamp assembly and circuit therefor - Google Patents

Description

sept. 22, 19361 A. LGE 2,054,846

MODULATING LAMP ASSEMBLv AND CIRCUIT THEREFOR Filed sept. 13, 1935 5 Sheets-sheet 1 ATTORNEY Sept. 22, 1936. A Z|LLGER 2,054,846

MODULATING LAMP ASSEMBLY AND CIRCUIT THEREFOR 6M um .D ATTORNEY Sept. 22,1936. A. ZILLGER 2,054,846

MODULATING LAMP ASSEMBLY AND CIRCUIT THEREFOR Filed Sept. l5, 1935 Sheets-Sheet 3 Patented Sept. 22, 1936 lUNITED STATES PATENT OFFICE MODULATING LAMP ASSEMBLY AND CIRCUIT THEREFOR Application September 13, 1933, Serial No. 689,255 s claim. (ci. 17e-.122)

This invention relates to gaseous discharge lamps particularly adaptable to high frequency modulation such as might be'used for television or sound-on-fllm recording, and includes an operating circuit for such lamps as well as a mounting bracket therefor.

One of the objects of the invention is to provide a gaseous discharge lamp which is easy to start and which may not be readily extinguished while in operation.

Another object of the invention is to provide a means for starting a gaseous discharge lamp without raising the voltage substantially beyond the operating voltage.

Still another object of the invention is to provide a means for mounting a gaseous discharge lamp.

A still further object of the invention is to provide a means for increasing the light of a gaseous discharge lamp in a given direction.

Other objects of the invention and objects relating particularly to the method of constructing and assembling the various parts will be evident as the description of the invention proceeds.

Several forms of the invention have been illustrated in the accompanying drawings in which:

Fig. 1 is a. front elevational View partly in section of a tubular discharge lamp mounted in a supporting standard;

Fig. 2 is a. plan view of the lamp and standard -shown in Fig. 1;

Fig. 3 is a sectional plan view taken on the line 3-3 of Fig. l;

Fig. 4 is a side elevational view of a modified form of the lamp and standard;

Fig. 5 is a sectional plan view of the lamp and standard shown in Fig. 4, taken on the line 5--5 of that gure;

Fig. 6 is a sectional plan view of the lower con nector taken on the line 6 6 of Fig. 4;

Fig. '7 is a side elevational view of a modified form of lamp mounted in its supporting standard;

Fig. 8 is a sectional plan view of the tubular portion of the lamp taken on the line 8- -8 of Fig. 7:

Fig. 9 is a sectional elevational view ci the lower base of the lamp shown in Fig. '7 showing the means for making some of the connections;

Fig. 10 is a plan view partly in section of the socket for supporting the lamp of Fig. '1;

Fig. 11 is a front elevational view of a modified form of lamp showing its supporting sockets;

Fig. 12 is a bottom view 0I the construction shown in Fig. 11; and

Fig. 13 is a circuit diagram showing one manner of connecting the lamp in a circuit.

Referring now more specifically to the drawings the lamp of Fig. 1 comprises a bulb I of glass or other transparent material at the upper 5 end of which is formed an inwardly extending press 2 similar to that used on a radio tube or electric light bulb which has a single supporting wire 3 upon which is mounted a cathode 4. The cathode 4 in the present instance is formed of 10 a strip of wire mesh rolled upon itself and attached to the support wire 3. The mesh may be made of nickel. tungsten, molybdenum, tantalum, iron, or the like. Between the cathode 4 and the press 2 is positioned a disc 5 of mica or other suit- 15 able insulating material. The upper end of the bulb I may be provided with a metallic cap 6 to which the lead-in wire 1 from the cathode may be attached as by soldering. The cap 6 may be heid in position by any suitable plastic cement.

A second bulb 9 shown at the lower end also has an inwardly extending press I0 upon which is mounted a single support rod I i terminating at its upper end at a point adjacent the wall of the bulb in a cup-shaped anode I2.

The bulb 9 is provided with a metallic base I3 similar to the upper base 6 and to which the lead-in wire i4 connected to the support rod l I may be attached as by soldering. A disc I2'l of mica may be positioned between the anode and 30 the press to protect the latter against the discharge.

The two bulbs I and 9 are connected together by means o1' a glass tube I5, the tube being fused to both of the bulbs so that there is a gas-tight 35 communication between them. 'I'he diameter of the tube i5 may be determined by the diameter of the light source desired and the intensity of the light desired, as the smaller the tube is in diameter the more intense will be the illumina- 40 tion. For the purpose of a television light, a. tube about 1A inch in diameter has been found to give excellent results. While the length of the tube may be left to the discretion of the designer, one nine inches long was used successfully. 'I'he 45 lamp may be filled with an inert gas such as neon, argon, helium, krypton, or xenon or mixtures of such gases may be used, or mixtures of any or all of such gases with a metallic vapor such as mercury vapor or sodium vapor may be used, 50

depending on the color of the light desired and the particular use to which it is put. The pressure of the gas may be in the neighborhood of 10 mm. of mercury.

With a lamp constructed in this manner it has been found that the voltage necessary to start the discharge is somewhat higher than the operating voltage of the lamp and it has been found necessary heretofore to provide some means to give an impulse of a. higher voltage in order to get the lamp started. 'I'his has been done by an induction coil with the secondary connected through a spark gap across the terminals/of the lamp, and also by a high resistance choke which may be shorted across the lamp and then suddenly released. It has also been found that a particularly heavy surge in the current operating the lamp may cause the lamp to go out with the result that the before mentioned operation must be again resorted to in order to continue its operation. I have found that I can lower the necessary starting voltage of the lamp to a considerable extent and also prevent the lamp from going out upon its receiving heavy surges, or at least to cause it to immediately light again without any additional external inuence, by providing a conductor in close contact with one side of the tube throughout its length and connecting that conductor to ground or to some point on the operating circuit.

In order to provide the grounded conductor as explained above and also to make a suitable bracket or support' for the lamp I provide a. rec.- tangular support it of wood, a phenolic condensation product, hard rubber, or other insulating material, preferably somewhat heat resisting, upon which I fasten at the upper end a spring clamp il to receive and support the cap E at the top of the tube and a second spring clamp i8 at the lower end to receive and support the cap i3. The spring supports il and i@ are similar in construction and may comprise a substantially U- shaped fiat strip of spring metal the legs of which have curved portions i@ to t around the cap at the end or the tube, there being outwardly bent ends 2li to facilitate the insertion of the cap in a manner clearly understandable from an inspection of Figs. 2 and 3. The base 2| of the clamp may be attached to the support by means of the bolts 22 as indicated in Fig. 2. Each y clamp may also be provided with a lug 23 for making the electrical connection to the lamp by means of a wire soldered thereto. Thus the wire 2 may be attached to the upper clamp and a wire 25 may be attached to the lower one so that when the lamp is inserted in the clamp the electrical connections will be made to the anode and cathode.

I also provide on the support it a semi-cylindrical metallic member 26 which hasl a sufiicient diameter so that it will just t around half of the tube. This element 26 is preferably highly polished on its interior face so as to redirect any light directed against it back again through the tube and out the other side. The element is supported upon a plurality of spring supports 21 which may be bent to form a sinuous curve as indicated in Fig. 3, and which may be attached to the support by means of the bolt 2li. One of these supports may be connected to ground as by means of the wire 29 shown in Figs. 1 and 3. By means of the resiliency of the supports 2l it is possible to withdraw the reflecting element 26 slightly to the left while the tube is being inserted and thereupon permit it to move to the right where it falls in place, held firmly against the wall of the tube.

It will be seen that this construction permits easy insertion and withdrawal of the tube at the same time insuring the snug attachment of the grounded element.

In Fig. 4 a modiiled construction is shown wherein lthe entire lamp is mounted by means of the-tubular element. To this end a lamp 30 is shown having a bulb 3l at the top and a second bulb 32 at the bottom connected by means of the tube 33. A semi-cylindrical metallic member 34 is supported in `spaced relation upon the base 35 by means of support members 36 which may be held in place by suitable bolts 31. The semi-cylindrical conductor 3e may be provided at its ends with extended clips 38 adapted to spring over the tube 33 to hold it securely in the member Sii. The member Sli may also be polished on its interior surface so as to form a reector for the lamp in addition to the grounded conductor. One of the supports 36 may, of course, bel grounded as by the Wire 39 shown at the lowermost support.

With this type of lamp I may provide insulating caps it on the upper and lower end of the lamp with metallic pins 4i extending outwardly therefrom. The electrical connections may be made by spring terminals i2 which may clip over the ends of the pins 4l as is clearly indicated in Fig. 6. Any suitable connectors may of course be used for this purpose.

In the foregoing figures I have shown the grounded conductor element to be a separate part of the lamp. It can, howeverr be integrally formed as a part oi the lamp if desired. Where such a construction is desired the most convenient way may perhaps be to silver one side of the tubular portion of the lamp as is indicated in Figs. '7 and 8, where the lamp d3 comprises an upper bulb it and a lower bulb i5 connected by the tubular member 35. This tubular member has half of its outer surface coated with the silver surface il which may be applied in the same manner as the surface is applied to an ordinary mirror, or may be painted upon the surface of the glass, or sprayed on, or put on in any desired manner, as cementing a piece of foil thereon.

For this type of lamp I have shown a metallic cap d@ on the upper bulb which may be sprung into spring clips Eid, similar to those already described, acting not only to support the upper end of the lamp but to maire the electrical connection thereto by means of the wire te. L have shown an ordinary vacuum tube base di on the lower end of the lamp provided with two pins 52 and 53, The first pin 52 may be connected by means of the wire 5d to the cathode 55, (shown in Fig. 9) while the pin 53 may be made smaller in diameter andmay be connected outside of the lamp to the silvered surface lll by the expedient of extending this surface downwardly in a strip 55 around the surface of the lower bulb.

pushed down upon a socket 56 provided with a pair of spring receptacles 57 and 5t, one for the large pin 52 and the other for the smaller pin 53. A lug 59 attached to the clip 5l? may be used for making the electrical connection of the lamp while a lug 6B attached to the spring 58 may be grounded by means of the wire 6i for grounding the conducting surface il on the tube of the lamp.

The upper clip 49 may be attached to the top of an insulating support 62 while a ange 63 integral with the lower end of the support 52 may receive the socket 66 and hold it in place by means of a suitable bolt 64. Thus both the cathode and grounded shield are connected by merely inserting the lower lamp base into the socket provided for it. In Fig. 10 the plan view of the socket shown in Figs. '1 and 9 indicates the use of a standard four point socket for this purpose, two only of the terminals being used.

While the foregoing figures show a lamp in which the axes of the end bulbs are in a line with the tube of the lamp it may be desirable to use the construction of Fig. 11 wherein the bulbs have their axes at right angles to the tubular portion of the lamp. In this construction the lamp 65 has its upper bulb 66 and lower bulb 61 lying with their axes parallel to each other while the straight or tubular portion 68 has its upper and lower ends bent at right angles at 69 and 10 to enter the bulbs 65 and 61. The bulb 66 is provided with a metallic cap 1| which fits into a spring clip 12 secured to the base 13 while the bulb 61 is provided with a metallic cap 14 which iits into a spring clip 15.

The reflecting conductor member 16 is supported in spaced relation v.to the upright 13 by means of a spring 11 attached to the upright 13 by the screw 18 to which may be secured the wire 1S leading to ground. Thespring 11 gently urges the conducting reflector 16 outwardly against the tube 68 of the lamp so that good contact is insured at all times.

In Fig. 13 a circuit diagram of one way of connecting the lamp is shown. Here three output power tubes connected in parallel are shown mounted in one envelope as described and claimed in my application Serial No. 689,256, filed September 13, 1933. The tube 80 has the three plates 8l connected together and to the cathode terminal 82 of the lamp 83 by means of the Wire 84, while the anode terminal 85 may be connected to a positive potential as for instance to the B battery 85a the negative side of which is of course grounded. The laments 86 of the tube are connected in parallel and to a suitable source of filament current, there being a resistor 81 across the filament circuit with its midpoint connected to ground through a resistance 88 and a by-pass condenser 89. The grids 9U are also connected together and by means of a wire 9i to one side of the secondary 92 of a transformer 93, the other side of the secondary being connected to ground by means of a wire 94. The primary of the transformer 93 may have its ends connected to the plates of a pair of amplifying tubes arranged for push-pull amplification in a manner well known in the art and as also described in the application last above referred to. The conductive shield 96 is grounded as at 91 and when thus connected produces the beneficial results described above.

With this invention I have provided an improvement over the type of lamp heretofore used for modulating purposes in that the starting voltage of the lamp is greatly reduced. It is only necessary to turn on the amplier filament and plate supply to have the lamp light up, even before the tubes come up to their proper temperature, and all necessity of any additional operation upon the lamp to start it is eliminated. Also it is again pointed out that the operation of the lamp is greatly improved because it will seldom go out due to a sudden surge of current and if such occasion should arise it will immediately light itself again so that no attention need be paid to it nor is it necessary to provide any auxiliary starting apparatus.

While in all of the cases I have shown the conductive reflecting member connected to ground it may also be connected either to the anode or tubes have all been shown straight in the various figures but the lamp may be constructed with much longer tubes and with the tubes bent in any desired configuration, as, for instance, to form letters. I, therefore, do not desire to limit myself to any particular type of construction of the lamp but I wish tointerpret the invention broadly limited only by the scope of the appended claims.

What I desire to secure and claim by Letters Patent is:

1. -A- lamp comprising an envelope, an anode within said envelope, a cathode within said envelope andspaced from said anode, a restricted passage'between said anode and cathode, a support, means to secure said envelope to said support, a separate movable, conducting member, and means mounted on said support to hold said conducting member in close proximity to said restricted passage.

2. A lamp comprising a tubular member, a bulb at one endv of said tubular member, an anode within said bulb, a second bulb at the other end of said tubular member, a cathode within said second bulb, an ionizable gas within said tubular member and bulbs and surrounding said anode and cathode, a support, means to releasably attach one of said bulbs to said support, means to releasably attach the other of said bulbs to said support, a separate movable conducting member, and means to hold said conducting member in close proximity to said tubular member.

3. A lamp comprising a tubular member, a bulb at one end of said tubular member, an anode within said bulb, a bulb at the other end of said tubular member, a cathode within said second bulb, a cap on the end of one of said bulbs, means to connect the anode to said cap, a cap at the end of the other of said bulbs, means to connect said cathode to said cap, a support, means to releasably attach one of said caps to said support, means to releasably attach the other of said caps to said support, a separate, movable, semi-cylindrical conductor, and means mounted on said support to resiliently urge said semi-cylindrical conductor against said tubular member.

4. A lamp comprising a tubular member, a bulb at one end of said tubular member, an anode within said bulb, a second bulb at the other end of said tubular member, a cathode within said second bulb, a metal cap on the end of said first bulb and connected to said anode, a second cap on the end of said second bulb and connected to said cathode, a support, a metallic spring clip on one end of said support and adapted to releasably hold said anode cap,` a second metallic spring clip on the other end of said support and adapted to releasably hold said second cathode cap, and a separate, movable, conducting member in contact with the outer surface of said tubular member.

5. A lamp assembly comprising a tubular.

transparent member, a bulb connected on one end of said member, an anode within said bulb, a

second bulb connected on the opposite end ot said member, a cathode within said second bulb. an ionizable gas within said bulbs and tubular member including neon and a small amount of a metal vapor, a conductor extending longitudinally of said tubular member and in close contact with the outer surface thereof, a base attached to one of said bulbs,`a pair of terminals on said base, means to connect one of said terminals to the element within said bulb, means to connect the other of said terminals to said conductor on said tubular member, a support, a socket mounted on said support, and adapted to receive said base, and means to releasably secure the other bulb upon said support;

6. In a lamp assembly a transparent tubular member, a bulb integral with one end of said tubular member, an anode AWithin said bulb, a second bulb integral With the other end of said tubular member, a cathode within said second bulb, a support, a conducting member rigidly secured in spaced relation to said support, and means to releasably secure said tubular member to said conducting member so that it is maintained in close contactftherewith.

7. -A lamp assembly comprising a tubular member, a bulb at one end of said tubular member and extending at right angles thereto, a second bulb at the other end of said tubular member and extending at right angles thereto,` an anode within said iirst bulb, a cathode within said second' bulb, an inert gas and a small amount of a metal vapor within said bulbs and tubular member, a cap on said first bulb and connected to said anode, a cap on said second bulb and connected to said cathode, a support, means to releasably hold said caps upon said support, a conducting member having substantially the same length as said tubular member, and means to mount said conducting member upon said support in such a position that it will lie against said tubular member when the lamp is positioned on said support.

8. A lamp comprising an envelope, an anode within said envelope, a cathode within said envelope but spaced from said anode, an ionizable gas within the envelope, a restricted passage between said anode and cathode, asupport, means for holding said lamp upon said support in operative position with reference to an electric circuit whereby a diii'erence cf potential is applied between the anode and cathode, and additional means attached to said support and effective only when said lamp is in said operative position, for modifying the breakdown potential of the gas of said lamp.

9. A lamp comprising an envelope, an anode within said envelope, a cathode within said envelope but spaced from said anode, an ionizable gas within the envelope, a restricted passage between said anode and cathode, releasable means for holdingsaid lamp in operative position with reference to an electric circuit whereby a diiference of potential is applied between the anode and cathode, and additional separable means including a conductor adapted to contact the exterior surface of the envelope between the anode and cathode and effective only when said lamp is in said operative position for modifying the breakdown potential of the gas of said lamp.

ARNO ZILLGER.

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