US1695746A - Electron-discharge device - Google Patents

Description

Dec. 18, 1928.

K. H. STARK ELECTRON DI SCHARGE DEVICE Filed May 1:5. 1919v 5 Sheets-Sheet 2 /Nl/'ENTR Kj/MEIHLL H. TANK.

Patented Dec. 18, 1928.

UNITED STATES PATENT OFFICE.`

KIMBALL H. STARK, OF NEW YORK, Y., ASSIGNOR TO THE SPEBRY GYROSCOPE COM- PANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

ELECTRON-DISGHARGE DEVICE.

Application led May 13,

This invention relates to electron' discharge devices. More specifically the invention relates to such devices as may he employed to rectify, amplify, or generate oscillations for various uses. For example the invention may be employed in connection With radio or land line, telephony or telegraphy.

Various electron tubes have been proposed and are in use in the arts above mentioned for the purposes stated. These devices, such as the Fleming valve, the audion, the oscillion. the' dynatron, the kenatron, the pliatron. all utilize a thermionio effect to cause the electron emission.

One of the objects of the present invention is to provide a practical electron discharge device in which` a photo-electric effect is utilized to cause the electron emission.

Another object is to provide a vdevice of the class specified in which source of photoelectric energy and the cathode, anode and grid, if one be employed, are all mounted in a single container. Other obj ects and advan- 'tages will be apparent as the invention 1s hereinafter disclosed.

Referring to the drawings which illustrate what I now consider preferred forms of my invention:

Fig. 1 is a sectional elevation of a preferred form of unit.

Fig. 2 is a sectional detail of one formof anode or plate.

Fig. 3 is a section on the line 3 3 of Fig. 1.

Fig. 4 is a view similar to Fig. 1 but illustrating a modified form of device.

l Fig. 5 is an elevation of a further modification.

Fig. 6 is a section on the line 6-6 of Fig. 4.

Fig. 7 is a sectional detail illustrating a form of spark gap which may be employed in connection with the forms of invention shown in Figs. 4 and 5.

Figs. 8 and 9 are sections on the lines 8-8 and 9-9, respectively of Fig. 7.

Fig. 10 is an inverted plan View of the device shown in Fig. 5.

Fig. 11 is a fragmentary sectional detail illustrating a modification of the form of invention illustrated in Fig. 1.

Fig. 12 is a view similar to Fig. 1 but 'illustrating a further modification.

1919. serial No. 296,846.

Fig. -13 is a detail end elevation of the anode or plate shown in Fig. 12.

Fig. '14 is a detail elevation of ring 126 of Fig. 12 and certain parts connected therewith.

While my electron discharge device may be employed as a two-element device by omitting use of a grid or discharge control element, I have illustrated in the present disclosure a three element device, i. e. one containing a cathode, or electron emitting element; an anode, commonly referred to as the plate; and a discharge controlling element,

commonly called a grid. Instead of employing a heated filament as the electron-emitting element I prefer to employ a suitable element which is caused to emit electrons due to photo-electric excitation. Ultra-violet light has been found to be the most satisfactory form of photo-electric energy for the purpose and the spark, or oscillatory discharge between spaced conductors, one of the most efficient sources of ultra-violet light.

Referring to Fig. 1, it will be seen that the spark gap comprises spaced metallic electrodes 1 and 2 mounted in a tube 3 of quartz, fluorite, or other material pervious to ultraviolet light rays. The leads 4 and 5 of the ` electrodes 1 and 2 are carried through a gastight seal at each end of said tube 3 so that the latter may either be evacuated or filled with a suitable gas such as hydrogen, helium, or a mixture thereof. These' seals may assume the form of the lead seal now known in the art. The electron-emitting element in the present illustration the cathode, may be in the form of a coating of zinc, platinum, potassium, or sodium hydride, or other photo-electric metal, or metallic compound 6, extending completely around the tube 3 so as to surround the spark gap. It should be noted that the photo-electric cathode 6 or electron emitting element operates in all instances atan equi-potential, since no current or voltage is developed on the cathode to create a potential gradient. In other words the cathode, according to my invention, need not be connected to the source of energy producing the photo-electric emission. The tube 3 is shown as supporting two annular members 7, 8 of lava or other insulating man terial between which the discharge-controlling element or grid 9 is mounted. The latter, as illustrated, consists of a helix of wire which surrounds the cathode 6 and is supported by a plurality of wires 10 welded or otherwise secured thereto. These Wires 10 are secured at op osite ends to the members 7, 8 in an suitab e manner as being embedded therein. The anode 11 is preferably in the form of a metallic cylinder secured to the members 7, 8 as shown and provided with a reduced spider portion 12 adapted to be gripped around the tube 3 by means of a clamp 12'; somewhat similar to a hose clamp.

The tube 3, together with the mechanism it supports, is adapted to be mounted in a gas-tight glass or other container 13 preferably .opaque to ultra-violet rays. Thus said tube may be provided with annular frames 14, 15 provided with peripheral resilient portions 16 adapted yieldingly to engage the inner wall of the tube 13. These frames may be securely gripped to the tube 3 by means of clamps 17, 18 each secured to a corresponding frame. For holding the tube 3 in position with respect to the tube 13 a spider 19 secured to the frame 15 may be clamped to the stem 20 through which certain of the lead-in wires are carried. The elements 6, 9, and 11 are each provided with a lead designated 21, 22, and 23, respectively. The leads 4, 5, 21, 22, and 23 should preferably be insulated with some material from which gas may be completely withdrawn, for example spun glass. It will be noted that the end 21 of the cathode lead 21 is embedded in the wall of tube 3 and said lead has an exposed portion on the exterior of tube 3 between the members 7 and 8. The function of this feature will appear hereinafter. i

The device thus far described may be assembled as follows: The gap leads 4, 5 are slipped through openings in the end portion 24 from the inside, then sealed in, and the tube 3 together with the structure carried thereby is slipped into the tube 13. The end 25 may then be sealed onto the tube 13, and the tube evacuated through an openin at 26 which is subsequently sealed. It is toe understood, of course, that any of the Well known processes for ridding the elements within the tube of gas maybe employed.

Preferably the cathode 6 should be formed on the tube 3 after the tube 13 has been evacuated and sealed. This may be accomplished by connecting the leads 22 and 21 to a suitable source of E. M. F., preferably high tension, high frequency A. C., after the said tube 13 has been evacuated and sealed so as to sputter a deposit of metal from the grid 9 onto the tube 3. The grid may be made of platinum or other metal or compound so that a clear untarnished coating of this metal or compound, never exposed to the atmosphere, is formed by the above mentioned process. If desirable the lead 23 may be substituted for, or connected to, the lead 22 in the sputtering process.

By 'connecting the leads 4 `and 5 to a Suitable source ofA. C. a spark discharge may be set up in the gap 12 which will emit ultraviolet rays. Thesel rays cause the cathode 6 to emit negative electrons so that the cathode acts similar to, but more effectively than, the filament in a thermionic tube such as the audion, etc. The cathode 6, discharge controlling element 9, and anode'11 may be connect-l ed in a. number of Well known Ways for the purpose of rectification, generation, regeneration, or amplification.

Fig. 4 illustrates a modified form of electron discharge device. In this form of the in- .vention the elements 1, 2', 3', 4', 5 6', 9 10', 113.13', 19', 2o', 21', 22', 23', 24', 25', and 26', correspond to the elements in Fig. 1 designated by the same reference characters without the primes. In this form of the invention the cathode assumes the form of a cone of'zinc or other suitable metal directly supported on the stem 20. The id or discharge controlling element 9' is preferably in the form of a conical spiral supported by wires 10 secured to the insulating ring 30. The latter may be made of lava or other suitable insulating material'and is connected to the spider 19', by means of bolts 31 which bolts serve also to support the anode 11 and the lava ring 32. The anode 11 may be secured to the rods 31 by means of struck up ears 33 so perforated as to lit snugly said rods. A third ring 34 may be supported from the ring 32 yby means of rods 35 in all respects similar to the rods 31 except that the two sets of rods are staggered with relation to each other. In this form of the invention the ultra-violet ray generator is shown in the form (see Figs. 4, 6, 7, 8, and 9) of a comparatively large tube provided with tubular extensions 36 of much smaller diameter than the body portion.

Each of the gap electrodes 1, 2 is provided with a substantially cylindrical portion 37 which seats in a corresponding one of the tubes 36. In order to prevent rotational or other displacement of these gap electrodes, they are each constructed with a portion having a sector-shaped cross section 38 and a strap 39 of quartz or other suitable material is secured to the quartz wall of the member 3 in such a. manner as to hold the electrodes firmly in position. The ultra-violet generator 3 may be supported on the rings 32 and 34 as shown in Fig. 4. In order to prevent longitudinal displacement of the generator Wires 40 may be passed around the tubular extensions 36, as indicated in Fig. 6, and se`- cured to the ring 34.-

`This form of the invention, While different from that previously described, may be assembled in substantially the same Way and in general its operational characteristics are the same as those of the form previouslyldescribed. It will be noted that in this form instead of the cathode surrounding the ultraviolet ray generator said cathode 6 is located below thegenerator in a position to receive the rays of ultra-violet light upon the exterior thereof.

Fig. 5 illustrates another modification somewhat similar to the device shown in Fig. 4 andthe elements 6", 9, 10, 13, 19, and 36 will at once be recognized. In this form of the invention the cylindrical anode 11a is directly secured to the spider 19 and a cylinder 50 which supports the ultra-Violet ray generator is in turn supported by the said anode by means of brackets 51. The cathode 6 may be supported in the same manner as the cathollt` 6. The dlscharge controlling element 'r grid 9 is shown in the form ot a helix and is sup rted by, but insulated from, the anode or p ate 11".

Fi s. 5 and 10 -illustrate also a feature whic 1 may be employed in connection with the other` forms of the invention. Each end of the tube 13a is provided with a ferrule 52 cemented or otherwise secured to said tube and provided with an end plate 53 of insulating material. Blades 62, 63 are supported from the bottom plate 53 and blades 64, 65 from the upper plate 53. The leads from the cathode, grid, plate, and the two gap electrodes are electrically connected to the flexible lead 61 and blades 62, 63, 64, and 65 respectively. The device may be mounted in suitable clips (not shown) similar to the blade-receiving clips of the ordinary knife switch and the electrical connections made to these clips.

The rings 7 and 8 shown in Fig. 1 may be dispensed with by mounting the gridV as shown in Fig. 11. The elements 3b, 9b, 10b, 11b, 21h, 22", and 23b will at once be recognized and need no further description. The grid supporting Wires 10b are shown secured at their upper ends to a ring 80 mounted on the tube 3". The portions of the said Wires 10b between the ring 80 and the grid 9b are provided with a coating of spun glass or other suitable insulating material to prevent short circuiting of the grid and cathode by the sputtering operation.

A further modiication, in which the ultraviolet ray generator assumes the form of a mercury Vapor arc lamp, is shown in Figs. 12 to 14. This lamp per se forms no part of my invention and comprises a quartz tube or envelope 103, a metallic mercury cathode 101 and an anode 102. Direct current may be supplied to the lamp through leads 104, 105 suitably insulated. It will be noted that the elements 101, 102, 103, 104, 105, 106, 109, 110, 111, 113, 119, 120, 121, 122, and 123 correspond to the elements 1, 2, 3, 4, 5, 6, 9, 10, 11, 13, 19, 20, 21, 22, and 23 respectively disclosed in Fig. 1 and consequently need no detailed description. The elements contained infthe tube 113 may be supported by the structure illustrated and constructed sub# stantially as follows.

A disc 124, of suitable insulating material, is secured to the spider 119 by means of a plurality of bolts or rods 127. The stem 120 may be provided with a teat 128 adapted to register with an opening in' the hub of the spider 119 to hold the'latter securely in position. The rods 127 have also secured thereto a ring'125 spaced from the disc 124 as shown. A second ring 126 is supported from the ring 125 by means of rods 129 similar to rods 127 but staggered with respect thereto. Calling attention to Fig. 14 it will be seen that the ring 126 is slit, or formed of two parts 126 and 126, adapted to grip the tube 103 and held in position by a continuous ring 130. The spider 119 and ring 130 may each be provided with resilient ears 116 in order to splice the structure from the walls of the tu e.

As stated above the ring 126 grips the tube 103 adjacent one end thereof. The opposite end of the latter seats in a suitable depression formed in the disc 124 so that the ultraviolet generator is securely supported. A clamp 131 secured to the disc 124 and extending partially around ythe tube 103V may be provided to insure that the latter will be held in the proper position. The discharge controlling element or grid 109 may be supported by securing opposite ends of the Wires 110 to the rings 125 and 126. The electron emitting element 106 may be sputtered upon the exterior of the tube 103, as previously described in connection with the element 6, or formed in any other suitable manner.

The anode, or plate, 111 is preferably cylindrical in form and may be provided with flanges 140 in turn provided with openings 141 to receive the rods 129. These flanges may be drilled out, as indicated at 142 in Fig. 13, to lighten the structure without reducing materially its mechanical strength. B providing spacing sleeves 143 on the rods 129 between each of the flanges and the corresponding one of the rings 125, 126 the anode or plate 111 may be securely held in the proper position. The manner of assembling this form of the invention and the operation thereof will be clear from the foregoing dcscription.

The anode or plate ot each of the forms of the invention may be constructed of any suitable metal such, for example, as nickel, steel, tungsten, molybdenum, etc.

Among other advantages it will be noted that my invention does not depend for its operation on a heated or incandescent filament which is subject to disintegration due to bombardment when a gas is employed in the tube, main tube, or envelope. In my device the tube 13, 13 13a or 113 may be filled INI with any desirable gas, preferably potassium vapor which is easily ionized at a suitable pressure and the plate or anode vcurrentvxnna be greatly increased due to ionization by co` lision in the enclosed gas.

In accordance with the provisions of` the patent statutes, I have herein described the principle of operation of my invention, together with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the an anode element, a cathode element comprising a glass member having al photo-electric metallic coating sputtered thereon, a discharge-controlling element, and means comprising a spark gap for causing said cathode to emlt electrons. I

2. An electron discharge device comprising a gas-tight container, a generator of ultra-violet light, an anode within said container and acathodesputtered on the exterior of said genera-tor.

3. -In combination, agas tight tube, a spark gap Withinh Said tube, an electron emitting element wrapped around said tube adjacent saidgap, a discharge controlling element surroundingA said first named element, and an anode surrounding said controlling element.

4. In combination, a gas tight tube, a spark glap `within said tube, an electron emitting e ementwrapped around'said tube adjacent said ap, a discharge controlling element surroun ing said first named element, an anode element surrounding said controlling element and a gas tight tube enclosing said first named tube and said elements.

5.,An electron discharge'device comprising a gas tight tube, a source of light therein, a p ate, and a metallic photo-electric electron emitting coating formed by sputtering same on glass and located between said light source and plate.

6. In combination, a gas-tight container, an anode element, a photo-electric cathode element, a discharge-controlling element, and means comprising a spark -ga for vcausing said cathode toemit electrons Ey photo-electric emission, said elements and spark gap bein enclosed in Said container.

g. An electron-discharge device ,comprising a cathode, a discharge-controlling element surrounding said cathode, an anode surrounding said element, ,and-means comprising a mercury vapor are .for causin said cathode to emit electronsby'photo-e ectric action. ff f 8. An electron dischar e device comprising a source of ultra-vio et light, .a' -photo.- electric, equi-potential cathode surrounding said source,l a vdischarge-controlling device surrounding' said cathode, and 'an anode surrounding said device.

9. An electron discharge device comprising a cathode, an anode surrounding said cathode, a source of ultra-violet light for,

causing said cathode to emit electrons by photo-electric action, said device operating in an atmosphere of easily'ionized gas.

In testimony whereof 'I have affixed my signature.l

KIMBALL H. "STARK,

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