Oct. 29, 1946. E. LABIN - 2,410,349 VACUUM TUBE 'Filed DeC._ 15, 1942 äww«A_äm1ä,A QN. `/ .\\ \` «Mw ë,www, .. wbÑ wwwH , .È, .ww._ _ I, f/ , __ ww.QN», _ . ___ ._.,_ _ _ _ _ _ Qww. n QN.. mu. mEVLmamw B Patented Oct. 29, i946 2,41' . ,349 UNITED. sfrA'rlëzsk - PATENT orificeg 2,410,349 _ VACUUM TUBE ' Emile Labin, New York, N. Y., assignor` to Fed eral Telephone and Radio Corporation, New ark, N. J., a corporation of Delaware` Application December 15, 1942, Serial No. 469,0_55' 16 Claims. (Cl. Z50-27.5) , 2y . _ This invention relates to improvements in vacuumv tubes, and more particularly to vacuum tubes of the cavity type, adapted for use at high Two equally dimensioned circular metal plates An object of this invention is to provide a novelv improved design for a cavity tube. Another object of this invention is to provide a the necessary strength to withstand atmospheric pressurewhen the resonator is evacuated. The high frequency cavity tube, capable >of handling locus of voltage minimum points,- which can` be I0 and I2 are spaced apart parallel to one an other- by suitable means` such as quartz spacing frequencies. insulators I4, which also provide the cavity with insulators I4‘are- preferably. located along the high power thermionic emission currents. Still another object of this invention is 'to pro Vide a high frequency cavity tube, having large previously determined. Inthe form of invention illustrated, the upperplate I0 is .providedlwith a thin ring-shaped metall member I6, , attached heatndissipating surfaces integral'with the elec trode elements. A further object of this invention is to provide a Vacuum tube in which the electrodes are formed as integral extensions about the periph y to the ‘plate and having its outer periphery ex tending ysubstantially labout ¿ the *outerA periphery of the plate. The lovverplatevIZl is provided with an upstan'ding ringk I8, rigidlyattached thereto with'its outer periphery at about the periphery ery of a resonant cavity, and cooperate with of theV lower- plate; A suitable annular grid other walls of the cavity in constituting the structure 2B Vis attached to the upper edge of the perimeter. ring, I8, so that it is radially spaced from theI pe» In general, the invention relates to a cavity 20 ripheryfof the ring I6,y by a‘desired amount. The tube in which the tube electrodes are built about plates lil and- I2 andtheinner surfacev of the the cavity resonator, in contrast'to usual types ringsrlß and I8 form the resonant cavity for the of cavity tubes in which the resonator is built vacuum'tube. About the A.grid 20 is Apositioneda about the tube electrodes. ringeshaped cathode 22, which may be indirectly Other objects and advantages of the present. heated as by heater coils~24.- The cathode 22 is invention will appear from the following descrip provided with a radial extension 26 whichY maybe tion of a preferred embodiment and a modifica tion of my novel tube, illustrated in the accom- ` panying drawing, in which: ’ supportedby' the spacers I4 for positioning'the cathoderelatively'to.the grid.A A-thin disk 28, open at Vits'- center is also positioned about the Fig. 1 is a vertical cross-sectional View of a 30 'grid 20. and is spaced a short distance from the preferred form of tube construction; and r'adialiextension 26 on the cathode, the extension Fig. 2 is a partial cross-sectional View illus 26‘and the disk 28' forming between thema ca. Atrating a modified structural detail. pacitative'coupling. The electrodes `and theV res While various'forms of cavity tubes have been onant vcavity may bev enclosed by a- suitable glass heretofore proposed, all of such known tubes are 35 'seal 3l),` connected at one end to theangular knife so designed that the resonator structure is built -edge 32, attached'to‘the top'of the plate I0, and about the tube elements; in other Words, the idea on the other hand to the annular knife edge. 34 has been t0 start with a vacuum tube and add the attached to the'bottomÍ of the plate I2. The disk necessary resonator structure to it. This con ception of building a cavity tube has resulted in 40 28 'is >preferably of ‘such diameter that it exteëi‘lds e 'through the seal 30, outside of the tube. structural limitations, both with respect to the heating coil supporting leads 35 will also extend tube elements and with respect to the resonator through seal 30 at 3l. On- the bottom of-the structure, which seriously interferes with the ap plate I2"is provided an annular 'rim> 36, while plication of such types of tubes to ultra~high fre quency work. The present invention is a radical 45 the under side of the disk 28 outside of the tube periphery is also provided wítha depending an departure from previously proposed construc nular rim 38. An open toroid ¿wis setto slidably tions in that I have made the resonant cavity the engage the depending portions of the rims 36 and central part of the tube and have built the tube elements about the cavity. This arrangement 38. The toroid tilithus _forms aivsecond external provides greater freedom and choice in design 50 cavity coupling` ythe grid 2U, through"A the lower and permits the use of the optimum thermionic and electronic relationships~ In Fig. 1 of the attached drawing, there is il plate I2, _to the cathode 24 through the disk 28 capacitatively coupled with the radial extension 26. By slidingthe toroid 43 on the depending lustrated an example of a type of cavity tube rims, the size of the .external resonant cavity can formed in accordance with the present invention, 55 be Varied as desired- YCoupling to the second res 2,410,349 3 ample and not as a limitation on the scope of my invention as set forth in the objects and the ac.d companying claims. What I claim is: 1. A cavity resonator electron tube including a‘ diaphragm __42. A cover 44 over the diaphragm will support a threaded rod 46 connected to the center of the ilexible diaphragm, thus varying the size of the internal resonant cavity. pair of spaced-apart metal plates, each point on'. one plate being at substantially the same distance: from the corresponding point on the other plate,l _ “as measured along a line normal to the surfacet An adjustable coupling to the internal resonan at; these points, an anode electrode electrically' connected to and positioned about the periphery' cavity may be provided by the rod 48, extending into the same through a suitable opening in the` , ' of one of said plates, a second electrode connected upper plate IIl. For this purpose, the. upper sur-> face of the plate I Il may> be provided with a .to and positioned about the periphery of the other plate and spaced from the anode, said electrodes threaded bushing 50, positioned about the open- ' and said plates forming the perimeter of a cavity resonator, and sealing means enclosing said elec trodes, closing the space between the two plates. 2. The combination according to claim l, in ing, the bushing supporting in 'turn a" threaded L collar 52. The collar 52 slides in an annular groove formed in the extension 53 of a ilexible bellows 56, positioned about the opening. A glass which said second electrode is a grid, in combina- e seal 54 is connected about a knife edge on the extension 5,3 and supports the rod 48. It will be obvious that rotation of the collar 52 of the bush ing 50 moves the rod 48 in and out of the cavity, to a limited extent, while the flexible bellows 56 maintains an air-tight fit. The upper surface of the plate III may also be provided with an up standing ring 578 supporting a metal cylinder 60, which may serve as a plate line. ’ A second arrangementwhich is in most respects similar to that illustrated Ain Fig.'l is ‘shown'in 30 Fig. .2. In this‘case, however, the electrode sur trode electrically connected to and positioned grid electrode connected to and positioned about the peripheral edge of the other plate and spaced from the anode, said plates and said electrodes of at right angles thereto.l The ring IIB depend ing from within the plate III isv provided with a radialjrim, serving as the active anode surface, forming the perimeter of a cavity resonator,- a cathode electrode positioned on that side of the grid opposite the anode, and sealing means whileja grid I20~is supported at the upper end of the ring I I 8, so that it is parallel to the radial rim of the; anode. The cathode 122 maybe con structed similarly as in Fig. l, but in this -case it ' 40 may be supplied with the usual heating coil |24 and also has a radialextension I'26 spaced from and’ parallel to the radial disk I 28. The heater coils I24_ may be Supported from the spacers I4 bysuitableheater leads I35. tion with a cathode electrode positioned exteriorly of and on that side of the grid opposite the anode. 3. The combination'according to claim 1, in which said plates are ñat parallel plates and said electrodes are formed as oppositely inwardly di rected rings extended about the peripheral edges of said plates. 4. A cavity resonator electron tube including, a pair of spaced-apart ñat parallel plates forming part of the perimeter of the tube, an anode elec about the peripheral edge of one of said plates, a facesîare mounted parallel to the plates instead . will be positioned below the grid I2Il.- The cathode 4 paratus, is therefore, made only by way of ex onant cavity can be effected in any well-known manner, if desired. In order that the main resonant cavity may be tuned, the lower plate I2 may be provided with a centrally disposed opening covered by a flexible . While Iv have illustrated by way of example, only one modification of the cavity tube structure illustrated in Fig. 1, it is contemplated that in the broad‘aspects of the present invention many modifications will occur to those skilled in this art.` For example, while the plates I0 and I2 have been illustrated as Vsubstantially circular, and enclosing said electrodes between the plates. 5. The combination according to claim 4, in which said plates are circular and said anode and grid electrodes are formed as rings inwardly directed toward one another. 6. A cavity resonator electron tube comprising, ‘a pair of ñat circular metal plates, insulating Aspacing means between said plates positioning them parallel with one another, a thin metal ring connected to the periphery of one of said plates forming .anode electrode, a second thin metal ring connected to the periphery of the other plate, an annular grid supported by the second ring in spaced relationship with the ñrst ring, said plates and said rings deiining the perimeter while `such a coniiguration, having no sharp cor of a cavity resonator, an annular cathode mount ners is generally to be preferred, the invention is ed at the side of the grid opposite the anode, and 55 applicable for use in connection with plates of sealing means enclosing said electrodes and con any desired shape. While the plates have been nected to the two plates. shown as ilat, they also could be curved, provided 7. The combination according to claim 6, in that in any event each point on one plate is at which said cathode has an outwardly directed the same distance from the corresponding point radial extension, in combination with a thin on the other plate as measured along a line nor 60 vmetal ring having a lateral face parallel to and mal to the surface vat these points. While the tube has been illustrated as of the triode type, it is also spaced from said extension, said ring extending through and supported by said sealing means, and forming a »terminal capacitatively coupled contemplated that one 'of the depending rims forming the outer peripheryof the resonant cav 65 with said cathode. ity could be used as a cathode electrode, in which Vcase 'the tube could-be a diode. The principles ‘of the invention are, therefore, equally applicable ‘ to_- diodes as well as triodes. Other modifications, particularly rin details of construction, _will be fairlyobvious to those skilled in the art and it is contemplated that such modifications form part , of the present invention provided that in all cases, the.principle of constructing the vacuum'tube elementsv about the periphery of'a cavity'resonaf tor is retained. The description ci speciñc ap - ` 8;'The combination according to claim 6, in >which said cathode has an outwardly directed radial extension, in combination with a thin metal ring having a lateral face parallel to and spaced from said extension, said ring extending through and supported by said sealing means, and forming a terminal capacitatively coupled , with said cathode, and means outside of said cav » ity resonator and outside of said sealing means, forming a second cavity resonator between the 2,410,849 5 grid-supporting plate and said parallel metal ring. 9. The combination according to claim 6, in which said cathode has an outwardly directed radial extension, in combination with a thin metal ring having a lateral face parallel to and diate and substantially parallel to the two plates, in whîchsaid second metal ring is inwardly di rected toward the other plate, and in which said grid is connected to the outer end of said sec ond ring and extends radially parallel to the ra dial extension on the ñrst ring. spaced from said extension, Said ring extending 14. A cavity resonator tube comprising in com through and supported by said sealing means, and bination, a pair of ñat circular metal plates, in forming a terminal capacitatively coupled with sulating spacing means between said plates po said cathode, a rim depending from said parallel 10 sitioning them parallel with one another, a thin ring outside of said sealing means, a second rim metal ring connected about the periphery of one depending from the outer surface of the grid of said plates, inwardly directed toward the other supporting plate in the same direction as the iirst plate and provided at its outer end with an out rim, and a toroid having an open lateral face ward radial extension intermediate and substan engaging the two dependent rims, and forming 15 tially parallel to the two plates to form an anode with them a second and external cavity reso electrode, a second thin metal ring connected nator coupling the grid to the cathode through about the periphery of the other plate, inwardly said capacitating coupling. directed toward the iirst plate, said plates 10. The combination according to claim 6, in and said rings deñning the perimeters of a cavity which the grid-supporting plate has a substan 20 resonator, a grid connecting to the other end of tially central hollow opening, in combination with a flexible diaphragm covering this opening and sealed at its edges to the plate, means op eratively connected with said diaphragm for moving it to tune the resonator, and resonator coupling means supported by and extending through the other plate. ' 11. The combination according to claim 6, in said second ring and extending radially, parallel to the radial extension on the first ring, an an nular cathode mounted about the side of the ring opposite the anode, said cathode being 25 formed with an outwardly directed radial exten sion, sealing means enclosing said electrodes and connected between the two plates, a thin metal ring having a lateral face parallel to and spaced from said extension, said last ring extending which said cathode has an outwardly directed radial extension, in combination with a thin met 30 through and supported by said sealing means to al ring having a lateral face parallel to and form a terminal capacitatively coupled with said spaced from said extension, said ring extending cathode, and means outside of said cavity reso through and supported by said sealing means nator and outside of said sealing means forming forming terminal capacitatively coupled with said a second cavity resonator between the grid-sup cathode, a rim depending from said parallel ring 35 porting plate and said parallel metal ring. outside of said sealing means, a second rim de 15. The combination according to claim 14, in pending from the outer surface of the grid-sup which said second cavity resonator forming porting plate in the same direction as the ñrst means comprising a rim depending from said rim, and a toroid having an open lateral face ad parallel rim outside of said sealing means, a sec justably, slidably, engaging the two depending 40 ond rim depending from the outer surface of the rims, and forming with them a second and eX grid supporting plate in the same direction as ternal cavity resonator coupling the grid to the the firstK rim, and a toroid having an open lateral cathode through said capacitative coupling. face engaging the two depending rims. 12. The combination according to claim 6, in 16. A cavity resonator electron tube including, which said rings are both mounted at right an a pair of spaced-apart metal plates, a pair of gles, to and between the metal plates, in which spaced electrodes respectively mounted on and said grid surrounds the ñrst metal ring, and in about the outer periphery of said plates to form which said cathode surrounds the grid. with said plates the perimeter of a cavity reso 13. The combination according to claim 6, in nator, and sealing means connected between said which the ñrst metal ring is inwardly directed t0 ward the other plate and is provided at its outer end with an outward radial extension interme ‘ plates and enclosing said electrodes. EMILE LABIN.