US2460398A - Mount for electron tubes - Google Patents

Description

Feb. 1, 1949. o. H. SCHADE MOUNT FOR ELEGTRON TUBES Filed Jan. 11, 1947 IENTOR wf@ @heide Patented Feb. 1, 1949 Otto H. Schade, West Caldwell, N. J., assigner to Radio vCorporation of America, a corporation Voi? Delaware Application January ll, 1947, Serial No. 721,503

(Cl. Z50-27.5)

Claims.

electron tubes and more specifically to heat radiating means incorporated in the structurel of such'mounts. Y

It is recognized that excessive heat developed within an electron tube can cause erratic operation of the device, resulting in loss of eiciency. For example, primary electron emission from the control grid may be'V onev result of high thermal conditions within a tube causing unpredictable changes in the operating characteristics of the tube. Y

In some types of tubes, such asfhigh perveance power tubes, such excessive heat may be a normal condition of operation. In recognition of this, some attempts have heretofore been made to dissipate the heat from the control grid. One way of accomplishing this has been to mount a heat radiator on the grid side rods. Such radiators have usually been mounted on the lends of the grid side rods extending through insulating spacers employed in the mount. While this is a satisfactory expedient in tubes where the elements do not require relatively close spacings and where the electrode assembly comprises a single unit structure, a serious problem is presented where the electrode spacings are relatively close and multiple electrode assembly units are involved. Y l

Accordingly an object of my vinvention is to provide improved means fordissipating the heat generated in electron discharge devices during operation of such devices.

It is an additional object of myinvention to provide a heat radiating structure for grids in multiple' unit electron tubes. y

It is a further object to provide heat radiators for grids in tubes wherein the electrodes are relatively closely spaced.

In certain types of tubes heat radiators employed to dissipate heat from the control' grid are required to be of substantial surface areas in order to contribute tor good operation of the device. In multiple unit tubes, where more than one grid is used, space accommodation for a plurality of such radiators presents serious diiiculty. Moreover the relatively larger area of such radiators required/in sometubes necessitates substantial extensions of the radiators laterally and axially oflthe mount.y Suchextensions present an additional problem of. support. Usually tube mounts are supportedat one end on the tube stem andat the other endby engagement withA the side walls ofthe envelope of the tube. yThe pro- The present invention relates to mounts for *"1 vision of relatively large ,surfaced radiators on the end of the mount remote from the stem re.- sults in a mount structure extendingl above the support at said end yand may contribute to vibration and distortion of the mount.

It is, therefore, a further object of the invention to provide a mount structure for an electron tube which includes a plurality of heat radiators constituting axial extensions of the mount and which is supportedat the end remote from the stem against ylateral forces.

An additional object is to provide a mountV structure vwhich includes a plurality of heat radiators of relatively large surface area at the end thereof remote from the stem which are free from interference with each other and which provide a support for said end of the mount.

A still further object is to incorporate heat radiators of good heat radiating properties in a multiple unit mount at one or both endsthereof without impairing the support function performed by the end of the mount remote from the stem. j V- Another object is to provide a plurality of heat radiators in a vtube mount at least at one. end thereof, having such shape that a relatively large radiating surface is provided on each radiator without physical orelectrical interference occurring between the' several. radiators.

Further objects of my invention will become evident as ythe present description proceeds.

In the drawing to which reference is now made for a better 'understanding of the invention.

Figure 1 shows an elevation of a multi-unit type of electron tube using the novel mount of the invention; f

Figure 2 shows an elevation of the same tube rotated axially through Figure 3 is a section taken along the line 3;-3 of Figure 1 and shows the shape and relationship to the mount of the upper heat radiators of the invention; l

Figure 4 shows a section along the line 4--4 of Figure 1 and illustrates the shape and relation to the mount of the lower heat radiators ofthe invention;

Figure 5' is a transverse sectional view through 5--5 of Figure 1 and shows the electrode arrangement of the tube selected for illustrating the invention; Y

Figure 6 is a top view of the tube'of Figure 1 `with the envelope broken away and shows the rods employed for stiffening the mount and for supporting the getter; Y

Figure 7 is a perspective view of onefof the heat radiators employed in the upper part of the mount.

Figure 8 is a front view of one of the rods employed in my novel mount; and

Figure 9 is a side View partly in section of the rod shown in Figure 8 along the line 9--9 and illustrates an additional structural characteristioY of the rod.

Referring new in more detail to the drawing there is shown in the gures thereof, various as pects of a double triode which includes my in'- venton. It is not intended that the invention be limited to this type of tube, nor to the exact form shown since it will be apparent to persons skilled in the pertinent art that the invention may be embodied in many different types of tubes and may assume forms differing from the specic forms shown without departing from the scope thereof as pointed out in the appended claims.

Figures 1 and 2 show side views of an electron tube having an envelope i@ enclosing an electrede mount. The mount includes a stern i i and an electrodeV assembly comprising two triode units, 'each unit including anode l2, grid i3 and cathode lli. The arrangement of these electrodes is best shown in Figure 5. Insulating spacers i and i6 'engage end poij'tioris of Ythe electrode assembly between opposite inner faces thereof.

It will be noted from Figures 3, e ando that the Y electrodes in the several units are relatively closely spaced. Furthermore the electrodes are relatively small in cross section, resulting in a relatively close spacing of the side rods i3d of the grids i3. In a tube of the type illustrated relatively high temperatures are produced dur ing operation thereof. Grids i3 as a result may be subjected to temperatures at which. they will emit primary electrons and thus disturb the eiiiV ciency 'of the tube. Primary electron emission from the grid caused by temperature conditions within a tube has long been the source of considerable dilculty in designing a tube for use under relatively high temperatures. In tubes where only 'one electrode assembly unit is utilized, this difficulty is to some extent overcome by providingcylindrical and other laterally closed metallic elements in heat. transfer relation to the upper ends of the grid side rods. Such elements then dissipate heat b`y radiation. However, such radiation is limitedto an appreciable degree to the outer surfaces of the closed elements. When such radiators are made small enough in cross section for use inV heat transfer` relation to the relatively closely spaced endsy i3d of grids i3 of a double triode, their heat dissipating efficiency Y v is below that required for good operation 'of the tube. Y

While the foregoingdifi'culties are associated with laterally closed heat radiators vand suggest that such radiators are unsuited to the cramped space conditions ina multi-'unit tube, a recourse to open sided or flat heat radiators contributes to even greater difculty in solving the problem of adequate Vheat dissipation from grids in multi-unit tubes. Obviously flat radiators would require apreciably greater space accommodations than cy-V According to my invention heat radiators are provided which possess a novel cross sectional configuration rendering them suitable for side-- oy-side mounted relationship in an electron tube, and while physical interference between the radiators themselves and between radiators and other electrodes is eliminated, the heat radiating surfaces of the radiators are sufficiently large to contribute to good operation of the tube.

In Figure '7 one of the radiators il of my invention is shown. This radiator comprises a sheel metal body having a substantially planar portion I and an arcuate portion I9. The arcuate portion iilpreferably subtends an angle of substantially 90. This radiator may be provided with a groove cr a depression 2S on its planar portion to avoid Contact with cathode lil as shown in Figures 3 and 4. Surfaces adjacent the depression ll are adapted to be Welded to adjacent ends of grid side rods 13a.

ln the illustrated embodiment of theV invention two heat radiators of the type provided bymy invention arevmounted at each end of the electrode assembly of a double triodeielectrode tube and are disposed adjacent the exposed faces of insulating spacers Iii- 56. The radiators l'l-lil of my invention, which are of like construction and dimensions, are mounted'in the upper portion of the tube between insulating spacers l5-2 i.

Radiators 22, 22, Ywhich are similar to radiators iiii?! in cross section ybut of shorter lengths,

Y required for accommodation to the crowded conditions in the'lower 'part of the tube, are disposed adjacent th'e'exposed face of the lower insulating spacer i5. The-lower ends of radiators 22, 22 are free.Y Y

. It will be noted from Figures 3 and i that the ends of grid side rods i3d projecting above the upper insulating spacer lo are fixed to the planar surfaces i8, i8 of radiators il', il in good heat transfer relation thereto. The planar surfaces lB-'i of radiators I 'l-l 'l extend towards the inner wall of envelope lil and are bent adjacent the wall to form arcuate portions it? which follov,7 the curvature ofthe envelope it and are in proximity thereto. While the arcuate portion i3 of one of the radiators Vextends in'one direction it willrbeinoted that the arcuate portion of the other radiator extends in an opposite direction The arcuate extensions of the radiators do not, therefore, approach each other nor reduce the space between theV radiators. the radiators that are closest'spaced with respect to each other are the edges 213 thereof. rlCheA portions of the radiators which are farthest spaced from each other are the inner surfaces of the arcuate portions l.V rIhis edgeV and surface relationship between the radiators i`i-il`results in a minimum of interference between lthem in the performance of their heat dissipatingfunctions as well as minimising theirinterelectrode capac-Y itance. A

The absence of physical and functional interference between adjacent radiators of my invention is further contributed to by the unique construction of each of 'the radiators.. To propeily perform its function of, Ydi'ssipating heat from a grid, each of theheat radiators, il, 2,2 should be called upon to perform this function only. The radiator should not, for example, be Ycalled upon to dissipate heat that may be radiated to it by an adjacent radiatorffhe novel construction of my heat radiators effectively prevents any approoi-ableA radiation of heat Vfrom (one adjacent heat radiator 4'to another. Thus the exposed face The portions ofV 5 ofthe'planar portion-'ofeachlof the radiators emits heat waves normal to'its suiflaceK-This results Yin anunobstructed --radiation of heat from this Asurface to the exterior ofthetubefThe outer face of the arcuate -portion is also free -to radiate heat waves to the exterior portionfof Vthe envelope-without striking -any intermediate element within the tube. VThe' innersurfaces".-oftheA heat radiators also direct heat Waves along-a free path to the exterior of. the tube envelope.- Thus the heat rays emanating normally from the inner surface of theV planar portion of each'radiator strike the inner surface of the 'arcuate-portion and are. reected ina direction substantially parallel Vto the .planarsurface The heatv/aves .that emanate from thefinner surfaces of the arcuate portion of each radiator-strike theA inner surfacek of the planar portion and are .reflected ina direction which includes a free path to the exterior of the tube envelope. The novel struc-- ture of my heat radiators, therefore, results in an efficient heat'dissi'pation from. the grids of the tube Without physical `or functional interference between adjacent radiators.`

While the radiators of my invention have been described as including an arcuateportion I9, it is obvious that this portion may be planar and angularly disposed with respect to the. planar portion i8 of the radiator. An arcuate shape is preferable, however, in connection with portion i9 of the radiator since this'shape provides a larger surface area .and greater mechanical strength than a planar portion would provide;

Radiators Il, |l appearing in the upper part of the mount may be provided with any desirable longtitudinal extension required for proper heat dissipation. 1t will be appreciated however', that a substantial longitudinal extension of the radiators I1 Will necessitate a support at their free ends. Normally the electrode mount of the tube in question is supported against lateral forces at the end thereof remote from the stem I| by means of insulating spacer plate I5. However, the mounting of heat radiatorson the upper face of spacer I5 will result in an elongationof the mount beyond the point at which it is supported against lateral forces. If no aditional supportis provided at the upper ends of the radiators, it is possible that harmful vibrations may be set up in the mount, resulting in distortion in tube output. According to my invention,therefore, Irprovide a support at the upper ends .of radiators This support includes insulating spacer disc 2|, which is provided with aperturesthrough which suitable ears 23 of the radiatorsl are adapted to extend. Metallic fingers 21 may be provided along the periphery of the spacer disc 2| to engage interior Wall portions of the envelope l0. Y

Apertures are also provided in spacer 2| for permitting the passage therethrough of U-shaped rods 24. These `U-shaped rods are most clearly shown in Figures 8 and 9. The legs of each ofthe U-shaped rods 24 are fixed togrooves 2,5 of a pair of anode elements l2, forming a part of each of the two triodes of the tube. The U-shaped rods are offset as at 25 to result in a fixed engagement between the U-,shaped rods 2,4 and the spacer disc 2i. This engagement supports the upper portion of the rods 24 against lateral movement and prevents yaxial displacement of the spacer disc 2i resulting in a stiifening of. the

mount. v f

In addition to performing amount stiening adjacent their closed ends, gett'ers 2'8JfThes`up`- 6 port of-thegetters 28 atrthis portion of the mount results vin an eiective'shielding of the electrodes thereof from any evolved getter material, the spacer 2| serving .as an eiective shieldbetween the getter andthe electrode assembly.

In addition to performing support functions inthe mount the rods 24 also serve to connectthe ano'diparts |2|2 of each anodefele'ctrically.

'It is clearly to be understood that the invention is not limited to the specific embodiment illustrated, but that various modifications may be made therein,` as will .be apparent Sto persons skilled. inthe art, without departing from; the scope of my invention as pointed out vin the ap'- pended claims. n u I claimt.

l. Amount for an electron tube of thek multiunit type vincluding independent control grids having side rods lying in a common plane and coextensive with each other', and heat radiators connected to adjacent ends of said rods, said heat radiators comprising sheet metal bodies Lhaving two surface portions, one of said surfaceportions being substantially planar and extending between two of said side rods of one of said grids and the other of, said surface portions being yarcuate and extending from one edge of said planar portion. j` 2. A mount for an electron tube having a plurality of electrode systems including control grids, the elements of'each of said systems being relatively closely spaced and a heat radiator connected to each of said grids-at a predetermined end thereof, said heat radiator having a surface of substantial area, a portion of said surface extending radially of -said mount and an additional Yportion of said surface of arcuate'cross section having a center of curvature concentrically disposed with respect to said mount. '3io 3. An electron tube having an envelopeand a mount Vprovided with a stem, said mount includinga plurality of electrode systems including control grids, two insulating spacers between which said electrode systems are supported, portions of t said control grids extending through said spacers and projecting from the outer surfaces thereof, one of said spacers being more remote iromthe stem of said tube than the other of said spacers, heat radiators mounted on the outer face of the more remote of said spacers, each of said heat radiators being connected to the projecting portion VVof one of said control grids, said radiators having edges disposed adjacent the outer face of said more remote spacer, and additional edges displaced from and parallel to said rst-named edges, an'l insulating rplate engaging and xed'to said additional edges, and means on said insulating plate for engaging a portion of the inner Walls of said envelope whereby said mount is supported at the end thereof remote from the stem against lateral forces.

. 4. A mount for an electron tube comprising a plurality of electrode systems, two insulating spacers engaging opposite ends of said electrode systems and having inner and outer faces with respect to said systems, one of said spacers being more remote than the other from the stem of the mount, heat radiators for said systems supportedV on the outer face of said more remoteof said spacers; each of said radiators being` connected to an electrode of one of said systems, each oflsaidiradiators having a planarsurface portion extending yradially of said mount and an additiener-surface portion extending angularly 'from sai'd'rst-na'med portion, whereby said radiators are provided with relatively Ylarge :surface area-s which are free from physical and electrical nterference with each other, and an -insulatng plate engaging the ends of said vradiators remote from said outer face of said more remote spacer for supporting the mount Vagainst lateral forces.

V5. A mount for an electron tube comprising va plurality of electrode systems, two insulating spacers engaging opposite ends of said systems and having inner and outer faces with respect :to said systems, one of said spacers being more :remote than the other from the stem of said mount, and heat radiators for said systems supported .on the outer face of said spacers, each of said radiators being connected to an electrode of yone of said systems, a third insulating spacer facing said one of said spacers, one edge'of two of said ,radiators engaging saidouter face of said other of said spacers and the inner face of said .third spacer, said radiators having all surfaces lying in planes parallel to the Vlongitudinal axis .of the mount, one portion of each of said radiators being planar and extending radially of the mount and the other portion thereof being angularly disposed with vrespect to said first-named portion.

6. A mount for an electron tube comprising an electrode assembly having a plurality of units, including control grids, said control grids having adjacent end portions, heat radiators yconnected to said end portions, each of said radiators comprising a planar surface portion and lan additional surface portion angularly disposed with respect to said planar surface portion, said additional surface portion in adjacent radiator-s extending in substantially opposite Vdirections whereby a relatively large surface area is provided foreach of said radiators without causing physical interference between adjacent radiators. '7. An electron tube comprising an envelope and .a mount `enclosed thereby, said Vmount including aplurality of electrode systems, each of -said systems vhaving a plurality of electrodes, said sysstems and said electrodes being 'relatively closely spaced, heat radiators for two analogous electrodes in said system made of sheet metalof substantial surfaceV area, said heat radiators being Imounted on end portions of said two analogous electrodes, each of said radiators including a substantially planar portion extending Vtowards --the adjacent wall of said envelope, and an vadditional 1 portion angularly extending from said `iirstnamed portion adjacent said wall transversely of said mount.

8. .An electron tube comprising an envelope and a mount enclosed thereby, said mount including Yapltufality -of electrode systems, each ofsaid systems Yhaving al plurality of electrodes, said systems andsaid electrodes `being-relatively closely spaced, 'heat radiators for said-electrodes made-of sheet metal of substantial surface area, ,said heat radiators being mounted onend'portions of said electrodes and including substantially :planar portions extending towards the adjacent wall of said envelope, and additional portions angularly extending from said rst-named V portions adjacent saidwall transversely of 'saidmount said heat radiators forming an end portion of the mount remotefromthe stem thereof, 4andmeans on the free end of said end portionengaging'the inner wall of said envelope for supporting said mount against lateral forces.

9. A mount for an electron tube ,including 4a heatfradiator comprisinga sheetmetal body having `a substantially Aplanar surface Dortpn `lying in aplane lWhichlincludes lthelongitudi-nalfaxis ,of

the :mountand an additional .surface Partien .extending aneularly :from said mstnamed portieri, an electrode rin .said mount, YSaid heat radiator ibaing ,connectedtoan end portion Aof said electrode, whereby jsaid heat radiator is provided with a relatively large surface-area for efiicient heat dissipation from said electrode, and means Afor supporti-ng said :heat radiator independently lof said electrode.

1 0. An electron tube of the multiple unit type having an envelope, at least two control grids in said-tube, vsaid grids having side rods lying in ,a common planefand coextensive with each other, heatv radiators for said grids, said heat radiators being mounted on end portions of said side rods in Lheat :transfer relation thereto, each of said heat radiators including a planarrsurface .portion, land 1an additional surface portion angularly disposed :with respect to said planar surface por.- tion, said planar portion extending towards a side Walibi-said envelope, sailiadditional surface portion `extending from said planar surface portion adjacent said side wall whereby each .of said radiators has a relatively large surface area and adjacent radiators are free vfrom physical and have small Yelectrical interference with respect to leach vother and with vrespect to the other electrodes of :the tube.

1v1. An electron tube ccmprising an envelope and a mount enclosed thereby, said mount including at least two .electrodes for operation at relatively low temperatures, said electrodes being parallel and in .registering relationship, end `porticins ,of :said electrodes lying in a common planc, `heat radiators having relatively large surface areas fixed to said end portions, said heat ra- ,diators comprising sheet metal bodies and `being vinspacededge relationship at portions thereof in closest proximity/.and in spaced surface relationship Lat portions thereof farther removed from .each other.

12. An electron tube having an envelope and a mount `'enclosed thereby, means in said mount deiiningatleast dwo cylindrical spaces, an elec- Itrode assembly supported in one of Said spaces,

said means'being located at .oneend of said assembly, electrodes in said assembly requiring lower operating temperatures than the temperatures insaid one of said spaces, Vand heat radiators inthe otherl of said spaces in heat transfer relation with said electrodes, said radiators being made of sheet metal and having portions thereof `partly' defining an enclosure in said other of said spaces, vother portions of said radiators having edges longitudinally of said mount and oppositely disposed.

13. An electron tube having an envelope and a mount enclosed thereby, means in said mount defining at least two Vcylindrical spaces, ran electrode assembly supported in one of said spaces, said means beinglccatedrat one end of said assembly, electrodes in said assembly requiring lower operating temperatures thanthe temperatures in said one of said spaces, heat radiators inthe otherl `ofvsaid spaces in heat transfer relation with said electrodes, said radiators being made of sheet metal and having portionsthereof partly defining an enclosure in said other of said spaces, other portions of said radiators 4having edges in spaced .faced Vrelationship .and extending longitudinally -ofsaid mount, and means extending into one of said spaces and xed to another electrode therein, said,means traversing said other of saidspaces and :extending beyond the same to stiffen .said m0111113 Biginsi lateral OlCeS.

14. A mount for an electron tube including in combination at least two heat radiators of sheet metal body, a portion of each of said radiators forming part of a cylindrical wall concentric with said mount, another portion of each of said radiators extending from said rst-named portion toward the axis of the mount, and electrodes in said mount requiring heat dissipation, eachfof said radiators being connected to an end of one of said electrodes.

1,5. An electron tube having a pair of adjacent sheet metal radiators and including two electrodes having end lportions connected to said radiators, said radiators extending axially of said tube and each including a surface portion extending radially of said tube and connected to one of said electrodes, an additional surface portion of each of said'radiators extending parallel to the side walls of said tube, said additional surface portion of one of said radiators extending in the same rotary direction as said additional surface portion of the other of said radiators.

16. A mount for an electron tube having a pair of adjacent sheet metal heat radiators, portions of said radiators forming parts of a cylindrical wall concentric with said mount, other portions of said radiators extending from said first-named portions thereof toward the longitudinal axis of said mount, said first-named portions being oppositely disposed, said last-named portions lying substantially on a diameter of said mount, and being more closely spaced with respect to each other than said first-named portions, and electrodes in said mount connected to said radiators at said last-named portions thereof, whereby radiators of substantial heat dissipating property are provided in a relatively small space.

17. An electron discharge device having an electrode mount including agrid having a pair of oppositely disposed side rods, a radiator for said grid including a sheet metal element having a substantially planar portion secured to one end of said side rods and extending parallel to said side rods, and an arcuate shaped Iportion extending from one end of said planar` portion transversely of said mount, all flat surfaces of said radiator being parallel to the longitudinal axis of said mount.

18. An electron discharge device having an l0 electrode mount, an electrode assembly in said mount, a pair of insulating spacers defining extremities of said electrode assembly, at least one 'heat radiator supported axially of the mount, and

a pair of insulating spacers for said radiator, one of said insulating spacers being common to said electrode assembly and said radiator.

19. An electron discharge device having an envelope and a mount enclosed thereby, three parallel insulating spacers displaced axially of said mount, said mount including a stem, an electrode assembly, and at least one heat radiator for one of the electrodes in said assembly, said electrode assembly being supported between two of said spacers, said radiator being supported between two of said spacers, said last-named spacers including the spacer most remote from said stem, spring nger spacers on said spacer for engaging inner walls of said envelope whereby said mount is supported against lateral forces at the end thereof remote from said stem.

20. A mount for an electron tube including two oppositely disposed heat radiators of sheet metal, said radiators including substantially planar surface portions extending along a diameter of said mount and separated at the center of said mount, and arcuate surface portions extending from said planar portions at the ends thereof remote from REFERENCES CITED The following references are of record in the le of this patent:

'UNITED STATES PATENTS Number Name Date 2,125,317 Ronci Aug. 2, 1938 2,213,162 Feindel Aug. 27, 1940 2,320,120 Depew et al May 25, 1943

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