US2010824A - Vacuum tube - Google Patents

Description

' Aug. 1935- F. OPPENHEIMER I 2,010,824

VACUUM TUBE Filed June 23, 1932 2 Sheets-Sheet l MW f Aug. 13, 1935. F. QPPENHEIMER VACUUM TUBE fined June 2:5, 1952 2 Sheets-Sheet 2 Fara flppejzlwwzer;

Patented Aug. 13, 1935 UNITED STATES PATENT OFFICE 12 Claims.

The present invention relates to electrical discharge devices, and more particularly to luminous vacuum tubes.

Among the objects of the present invention is to provide a novel luminous electrical discharge device which includes a vacuum tube having a circulating or traveling gas or vapor therein.

Another object within the purview of the present invention is to so influence an electrical discharge within the electrode zone as to produce any desired color efiect within the tube of the device.

At the present time, the lighting effects in the tubes of the type herein disclosed are limited primarily to the natural color cliects produced by the neon, argon or helium gases, which are used as conducting gases within the tube of the discharge device, these inert gases being the preferred gases used in commercial signs and the like. Other lighting effects are obtained only by applying color to the glass of the tubes, which weakens the power and luminosity of the light emanating therefrom. Metal vapors, principally mercury, have been used for producing various color effects, but metal vapors have a tendency to attack the tubes, thereby injuring the same and necessitating their constant replacement. Furthermore, a considerable amount of heat is required for vaporizing the mercury, and the vapors thereof enter the tube with the electrical discharges, thereby weakening the brilliancy of the light and sometimes giving the same a muddy appearance.

The present invention is therefore concerned with the idea of providing a novel luminous electrical discharge device in which a large variety of colors may be elfected by the use of metal vapors corresponding to the colors, at the same time obtaining a moving light display, but results being obtained without decreasing the strength and intensity thereof and without substantially impairing or injuring the tubes of these devices.

The present invention also includes the idea of providing means for effecting a circulation or movement of the conducting gas within the passage of a vacuum tube, as well as means for bringing a metal vapor in sufiicient quantity only in contact with the electrode emission or discharge to give the desired color to the discharge and without introducing these metal vapors into the circulating gas in sufficient quantitles to injure or damage the tube,

Still another object of the present invention is to provide a novel method for producing the lighting effects within the vacuum 'tube of a luminous electrical discharge device which in cludes the steps of creating movement or cir culation of a fluid body within the passage oi the vacuum tube whereby the conducting gaseou body within this vacuum tube is impelled thereby and caused to circulate within the passage of the tube. More particularly, the present invention contemplates the idea of providing novel injector means including a condensable vapor, which i.- caused to move or circulate for impelling the conducting gaseous body within the vacuum tube when the same is brought into association therewith to cause a circulation of this gaseous body. this vapor being condensed outside the luminated zone of this conducting gaseous body.

The present invention also includes the idea of providing a novel method for producing any desired lighting effects within a luminous electrical discharge device which includes the step of introducing limited quantities of metal vapors into the electrode zone thereof to impart their color phase to the discharge, at the same time preventing all but limited quantities of such vapors entering the tube circulation and thereby preventing substantial injury or damage to the tube.

A still further object of the present invention is to provide a novel method of producing varied light effects which includes the step of introducing limited quantities of metal vapors into a circulating body of conducting inert gas, whereby these lighting effects may be obtained and without causing substantial injury or damage to the tube.

Other objects, features, capabilities, advantages and method steps are comprehended by the invention, as will later appear and as are inherently possessed thereby.

Referring to the drawings:

Figure 1 is a view in elevation of a device made in accordance with the present invention;

Figure 2 is a view in elevation of another de vice made in accordance with the present invention; and

Figure 3 is a broken view in elevation of still another device made in accordance with the present invention.

Referring now more in detail to the drawings, an embodiment selected to illustrate the present invention is disclosed. in Figure 1 as comprising a vacuum tube, generally referred to as 2, within which is disposed electrodes 4 and B suitably connected, as by means of leads 8 and In, to a suitable source of electrical energy. The vacuum tube 2 is provided with a passage l2 adapted to contain a conducting gas, as for example neon, helium, argon, krypton or xenon, which may be referred to as conducting gases of the noble gas group, and which may be commercially used in a luminous electrical discharge device of the type herein referred to. This vacuum tube may be circular, square, or rectangular in cross section, as desired, and the same includes a portion I4 which, although disclosed as substantially oval in shape in Figure l of the drawings, could be made in any desired configuration to provide ornamental shapes, letters, numerals or other descriptive or artistic decorations.

The passage of the portion I4 communicates, as by means of an outlet passage I6, with a tube portion I8 connected to a condensing bulb 20, which in turn communicates as by means of a passage 22 with the passage of the portion I4, this condensing bulb having a return 24 leading into the lower portion of a receptacle 26 of an injector device or means 28. This injector means 28 further includes an ejector tube 30 leading from the top of the receptacle 26 which is formed with a Venturi-like end portion 32 projecting into the end of the tubular portion I8 adjacent the passage I6.

Within the receptacle 26 is provided a suitable fluid body 34 adapted to be vaporized as by means of heating coils 36, this medium 34, upon vaporization, passing upwardly through the tube 30 and Venturi-like end portion 32 and being discharged into the tube I8. The vaporized medium 34 is caused to circulate through the tubular portion I8, thereby impelling the conducting gas within the passage I2 of the tubular portion I4 in the direction as indicated by the arrow in this figure, the impelling of this conducting gas downwardly through the passage i6 causing a circulation and movement of the same within the passage I2 of the tube portion I4. Adjacent the end of the Venturi-like portion 32, the conducting gas is caused to be associated with the vaporized medium 34, and is carried therefrom toward the condensing bulb 20. At that point, the vaporized medium 34 is condensed and is returned as by means of the return 24 to the receptacle 26 to be vaporized again, and for providing a continuous circulation of the same through the tube I8. As the vaporizing medium 34 is condensed in the bulb 20, the conducting gas from the passage I2 is impelled or forced through the inlet passage 22 back into the passage I2 of the tube portion I4, suitable means 38, in the form of coils or the like surrounding the passage 22, being provided to effect a complete condensation of the vaporized medium 34 and to eliminate the same from the conducting gas being introduced into the passage I2. Although I have herein disclosed a pump of the vapor injector type for creating circulation of the conducting gas within the vacuum tube of the present device, it is of course understood that other suitable means may likewise be used within the scope of the present invention.

In the present embodiment, the medium 34 used in the injector means 28 is disclosed as Butylpthalate oil. which has the advantage in a device of this kind in that the vapor thereof is inert and does not interfere in any way with the conducting gas being impelled thereby. This Butylpthalate oil is also to be preferred in a device of this kind because the same can be vaporized by the employment of very little heat, so that water cooling for condensing is not required, which would not only be extremely objectionable in a device of this kind, but likewise would add to the expense and inconvenience of installation.

In the present embodiment, the apparatus disclosed herein is preferably made of glass, quartz or other suitable transparent material, and after the electrodes 4 and 6 have been installed in place and sealed, the air may be pumped out of the tube so as to create as complete a vacuum as possible preferably a vacuum of III millimeters Hg, which may be obtained by employing a molecular pump and which is measured with a Faraday cage. The electrodes may be prepared and installed as usual in commercial lamps, or preferably they should be of the type described in my co-pending application Serial No. 618,863, filed June 23, 1932. The Butylpthalate oil may then be placed in the vaporizer or condenser 26 by any of the well-known methods of feeding liquids into vacuum tubes. After the oil has reached the desired level, the conducting gas which is to be used is fed into the tube portion I4 under just enough pressure to create the least resistance to the current used. After the tube is filled with the gas, the current is applied to the heating coils 36, which heat the oil and cause the same to vaporize, thereby creating a circulation of this vaporized oil within the tube l8.

Simultaneously with the application of current to the heating coils 36, a circuit may be completed through the leads 8 and It! for the electrodes 4 and Ii, whereby the electrodes will cause the emission of electrons through the tube to start the electron discharge through the conducting gas. The device will then operate to cause a continuous movement of the conducting gas within the tube portion I4. It is of course to be understood that any suitable means may be provided for causing intermittent flow of electrical energy to the electrodes 4 and 6, whereby the laminating effects are intermittent, and if desired, the present embodiment may be provided with suitable means whercby reversal of flow of the conducting gas within the passage I2 may be effected.

As previously indicated, the present invention is also concerned with the idea of providing a luminous electrical discharge device of brilliant colors in which various luminating effects may be provided by means of metal vapors without substantial injury or damage to the tube of the same. In Figures 2 and 3 is disclosed an embodiment made in accordance with the present invention, wherein suitable metal vapors may be introduced into the conducting gas to color the same as desired, this embodiment comprising a vacuum tube, generally designated as 40, which comprises a tube portion 42 corresponding to the tube portion I4 of the hereinbefore described embodiment, and although disclosed as being elongated and substantially straight, it is of course understood that the same may be formed to provide various ornamental shapes, letters, numerals or othere descriptive or artistic decorations. Adjacent one end of the tube portion 42 is a tube portion 44 within which is disposed an electrode 46 having a lead passing outwardly through the tube portion 44 which may be connected to a source of power 48. The vacuum tube 40 is also provided with a portion 50 which extends downwardly, as shown, from the tube portion 42, and communicates with a tube portion 52, which in turn communicates with the condensing bulb 54. The present embodiment likewise includes the idea of incorporating an ejector means 56 corresponding to the ejector means 28, which comprises a vaporizer or receptacle 58 provided with OLHI'iUH nuum a tube 60 formed with a Venturi-like end portion 62 inserted within the end of the tube 52 adjacent the tubular portion 56. This receptacle 58 has a return 64 leading into the same adjacent the bottom thereof from the lower part of the condenser bulb 5d, all of this structure being in accordance with the corresponding structure shown in Figure l of the drawings.

Extending upwardly from the condensing bulb 5 3 is a tube portion 66 which leads into a bulb or receptacle 68, this tube portion 66 having a tube portion Ill concentrically arranged therein,

which communicates with the tube portion t2, the

tube portion 1!] leading into the receptacle 68 and forming an annular passageway at the end of the tube portion 66 adjacent the receptacle or bulb 68. This bulb or receptacle 68 has a supply of metal l2 disposed in the lower portion thereof and encloses an electrode 14 which has a lead 16 extending therefrom to the source of power 18.

Disposed within the vacuum tube 4!] is con ducting gas which is preferably of neon, helium,

argon, krypton or xenon, and this conducting gas is caused to circulate by the vaporization and condensation of thevaporizing material within the vaporizer 53,'this material, as in the hereinbefore referred to embodiment, being preferably Butylpthalate oil, which is vaporized by means of heating coils l8 and caused to condense in the condenser 54 and be returned through the return 64 to the condenser 58, suitable cooling coils being provided around the tube portion- 66 adjacent the condenser 54 to provide for the con densation of any traces of this oil as the conducting gas passes upwardly through the tube portion 65.

Any desired metal 12 may be provided in the receptacle 68 for producing any desired color to the conducting gas. As for example, by using the metal strontium, brilliant red lighting efiects may be produced in the tube portion d2, while if barium metal is used, a vivid green light may be effected, or if sodium is used, a brilliant yellow light may likewise be obtained. Many other colors'may be secured by using the proper metals within the receptacle 68 corresponding to those colors which are desired, and it is of course understood that the present invention includes the use of any metal to obtain the desired effects. It is also understood that metals of varying vapor pressure will require higher or lower vacua and/ or more or less heat, which latter, if desired, may be obtained from an external source.

As previously indicated, coloring effects in a luminous electrical discharge tube of the kind herein disclosed have been obtained only by a coloring of the tube itself, or otherwise applying color on the outside of it. This has been necessary because of the fact that metal vapors in troduced into the tubes have a great affinity for the same and attack and injure t-hese tubes, thereby necessitating constant replacement. In the present embodiment, however, the metal vapors within the bulb or receptacle 68 and surrounding the electrode M are substantially all retained within this receptacle, inasmuch as the upward flow or circulation of conducting gas through the tube portion 66 tends to push or crowd these metal vapors away from the end of the entrance to the tube portion '10, whereby a very small amount of metal vapor is introduced into the inner tube portion Ill for passage through the vacuum tube 40. The amount passing through the vacuum tube 40, however, is suificient to give the desired lighting efiects, yet not surfiof the tube portion 8 5.

shown in Figure 2 of the drawings, each of the cient to cause substantial damage or injury to this vacuum tube.

It is of course understood that the bulbs may be so designed, and the rate of vaporizing of the metal and the oil so controlled that the circulation of the conducting gas in the tube 30 is controlled, and the amount of vaporized metal entering this vacuum tube suitably controlled to produce the desired efifect. The embodiment disclosed in Figure 2 of the drawings is particularly adapted for use in connection with low voltage sources of electrical energy, as likewise for use in direct current circuits. If desired, a suitable absorbing agent may be placed within the tube Ill or a retainer.interposed between the receptacle 68 and tube portionAZ to absorb excess metal vapors. This absorbing agent may be activated'carbon or any other desired substance.

In Figure 3 of the drawings is disclosed another embodiment made in accordance with the present invention, particularly adapted for use with sources of electrical energy having high voltage and in devices of the kind in which a substantially long display tube is desired. This embodiment corresponds in all essentials to the embodiment shown in Figure 2 of the drawings, and includes a vacuum tube 82 which includes a tube portion 84 corresponding to the tube portion 1-2 of Figure 2 of the drawings. Associated with this vacuum tube is an ejector means 86 which corresponds with either of the ejector means heretofore disclosed, and cooperates with the vacuum tube in the same manner to cause a circulation of conducting gas within the vacuum tube 82. In the present embodiment, however, the electrodes 88 and 90 are each disposed within a receptacle 92 and 94, respectively, adjacent the ends of the vacuum tube 82, and are suitably connected as by means of leads 96 and 98 with a source of electrical energy. In this embodiment, the circulation of the conducting gas through the vacuum tube 82 is in a counter-clockwise direction, and passes from the tube portion 84 into the tube portion MW at the end thereof, which is adapted to discharge into the receptacle 92 and which is concentrically arranged within an outer tube portion N12 which communicates with the receptacle 92, as likewise the tube lad connected to the condenser bulb Hit of the ejector means 86. a

The conducting gas within the vacuum tube 82 is caused to circulate by means of the ejector means 86 and passes from the condenser Hi5 through the tube portion I08 merging with an enlarged tube portion H0 entering the receptacle 94 and concentrically arranged with an inner tube portion l l2 likewise communicating with the receptacle 9d and formed integral with the end As in the embodiment receptacles or reservoirs 92 and 9-1 has a source of metal H4 disposed therein, which is suitably vaporized as by means of the electrodes 83 and 90, and in accordance with the above disclosure, limited quantities only of these metal vapors gain entrance to the vacuum tube 82, these limited quantities, however, being sufiicient to produce the lighting efiects desired without substantially injuring or damaging the vacuum tube 82. An absorbing agent, such as activated carbon or the like, may be used for absorbing excess metal vapors and to prevent passage thereof into the vacuum tube 82.

While I have herein described and upon the drawings shown an illustrative embodiment of the invention, it is to be understood that the invention is not limited thereto but may comprehend other constructions, arrangements of parts, details, features and method steps without de-- parting from the spirit of the invention.

I claim:

1. An electrical discharge device comprising a vacuum tube having a portion adapted to conform to any desired configuration and a portion communicating therewith to provide a continuous passage, a conducting gas in said tube, electrodes disposed in said tube and connected to a source of electrical energy, injector means for introducing a fluid body into said second-named portion, and means for condensing said fluid body to effect a continuous circulation of said gas and to remove the same before entrance thereof into said first-named portion of said tube.

2. The method of circulating a gaseous body within an electrical discharge tube, comprising the steps of causing movement of a fluid body, directing said gaseous bodyv into the path of movement thereof whereby the same is impelled, effecting a separation of said gaseous and fluid bodies, and directing said gaseous body into said tube beyond in the normal direction of movement thereof.

3. A luminous electrical discharge device, comprising a vacuum tube having a passage containing a conducting gas, electrodes disposed in said tube, a reservoir communicating with said passage and containing a supply of metal, one ofsaid electrodes being adapted to vaporize said metal, means for circulating said gas and vapor through said passage and means for limiting introduction of metal vapors into said passage whereby the desired lighting effects are obtained without substantial injury to said tube.

4. A luminous electrical discharge device, comprising a vacuum tube having a passage containing a conducting gas, electrodes disposed in said tube, a reservoir disposed in an electrode zone and communicating with said passage, said reservoir containing a supply of metal adapted to be vaporized by said electrode, means :[or circulating said gas and vapor through said passage, and means for limiting introduction of said metal vapor into said passage whereby the desired lighting effects are obtained Without substantial injury to said tube.

5. A luminous electrical discharge device, comprising a vacuum tub-e having a passage containing a conducting gas, said tube including a metal reservoir containing a supply of metal and communicating with said passage, electrodes disposed in said tube, one of said electrodes being within said reservoir and being adapted to vaporize said metal, means for circulating said gas and vapor through said passage, and means for limiting introduction of said metal vapor into said passage whereby the desired lighting efiects are obtained Without substantial injury to said tube.

6. A luminous electrical discharge device, comprising a vacuum tube having a passage containing a conducting gas, electrodes disposed in said tube, means for causing circulation of said gas in said passage, said tube including a reservoir communicating with said passage and containing a supply of metal, means for vaporizing said metal, and means for limiting introduction of metal vapor into said passage to color said gas and to give the desired lighting effects without substantial injury to said tube.

7. A luminous electrical discharge device, comprising a vacuum tube having a passage contain ing a conducting gas, electrodes disposed in said tube, means for causing circulation of said gas in said passage. said tube including a reservoir communicating with said passage and containing a supply of metal, one of said electrodes being disposed within said reservoir and being adapted to vaporize said metal, and means for limiting introduction of said metal vapor into said passage whereby the desired lighting effects are obtained without substantial injury to said tube.

8. An electrical discharge device comprising a vacuum tube having a passage, conducting gas in said passage, a reservoir containing a volatile material, said tube having ends in spaced relation in association with said reservoir whereby gas from said passage enters said reservoir, and means for effecting circulation of said gas.

9. An electrical discharge device comprising a vacuum tube having a passage, conducting gas in said passage, a reservoir containing a volatile material, said tube having ends associated with said receptacle and. in radial spaced relation whereby gas from said passage enters said reservoir, and means for effecting circulation of said gas.

10. An electrical discharge device comprising a vacuum tube having a passage, conducting gas in said passage, a reservoir containing a volatile material, said tube having ends associated with. said reservoir and in radial and axial spaced relation whereby gas from said passage enters said reservoir, and means for eiiecting circulation of said gas.

11. A luminous electrical discharge device, comprising a vacuum tube having a passage containing a conducting gas, means for exciting said gas comprising electrodes, means for causing circulation of said gas in said passage, said tube including a reservoir communicating with said passage and containing volatile material, one of said electrodes being disposed within said reservoir, and means for passage of volatile material from said reservoir into the passage of said tube to obtain desired lighting effects.

12. A luminous electrical discharge device, comprising a vacuum tube having a passage containing a conducting gas, means for exciting said gas comprising electrodes, means for causing circulation of said gas in said passage, said tube including a plurality of reservoirs each communicating with said passage and containing volatile material, each of said reservoirs containing an electrade and means for passage of volatile material from said reservoirs into the passage of said tube to obtain desired lighting effects.

FRANZ OPPENHEIMER.

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