US2439641A - Arrangement for conducting heat and high-frequency currents - Google Patents

Description

A ril 13, 1948,

H. A. WHEELER ARRANGEMENT FOR CONDUCTING HEAT AND HIGH-FREQUENCY CURREN'IS Filed Feb. 21, 1946 FIG! I M Pulse (-)Mod. Pulse -INVENTOR.

HA OLD A.WHEELERV BY Xg? Heater Supply fi Patented 'Apr. 13, 1948 R CONDUCTING HEAT AND HIGH-FREQUENCY CURRENTS ARRANGEMENT F0 Harold A. Wheeler, Great Neck, N. Y.,

by memo assignments, to Hazeltlne IlL, a corporation of Inc., Chicago,

osclgnoc, Research, Illlnolc Application February 21, 1946, Serial liloc 64%,3463 6 Claims. (filo 178-44) This invention relates to improved conductive arrsuceuts cclapeecl to be employed in the genemizlom oml ereusmlssion cl high frequency cur rents cool, more pertlculssly, to on arrangement for eillcleutly dissipating heat from conductor wlllle all the some time crowding s low lmocclccce path for high frequency col-recto. As used throughout the specification eml in the eccenclecl claims, lice term lilgh frequency" refers to smile l'reoueuclec so high llzci; the current path ill for ls lcieclomluemtly determined lay the well= elem efleci'. While the iuveucicu may "so high frequency cum-em: dis-'- "lrlbullcu swsiem, ls escecielly sultcol fol use Wllls eleclromdischccce devices and will Toe coc liculczrly clescflbec in thee connection.

e we of laeciz=concluci7ive em; WL, previously econ used :loc cool the goose of o vecuum tube cscillelcc consists of u plurality reellclor elements, ll'ccsvelscly mccullecl on exsensiou of the ccocle lead and ccolecl og; ureter o1" cc sir lo such cose ls accesses to ccc'cecl; izhe ccccle to around in such as molecules" as to complete cl le high frequency cleculc Wl'llscul: lice {oeceece of current through the molester assembly. Acoisher lrype of heatcomluc'blve mrcueement which lace been usecl cocof 'clucclll of cooling eleluectc mounted in loucuucliml :relctloc to on cuode concise-col". fluclc c, cooling arrangement is lcefilcles'll when ueecl willie e crecsvei'sely clireclecl all lolest cud it can lie usecl in on oceu scoce where Elli may directed along the cooling e cu object of this invention, therefore, to prcvlde arrangement fill conveying heel and 17125211 leecuency currents which avoids one or more of ihe ulseclvcntcces of prior arrangements.

Eli: is e fucllser object of the invention coercvicle an improved arrangement for conveying heel; end high fleoueucy currents including one set of elements for efilclenl; heel, dissipation and mother sell of. elements for eficlent current ixui'lsmlsslou.

flu ecccz'dence will: the invention, an arrangemeci; cclcctecl to convey heel; and high frequency cumeuts from a source comprises c conductor oi heel; cool high frequency currents and a thermal rcelleicr which incluces c plurality oi l1eei=conoluciive elements of relatively large areas secured in transverse seletiocto, and spaced along, the longitudinal cells of ihe conductor to provide a large heal-dissipating area but presenting a high impedance to the flow of high frequency currents clone the radiator. The arrangement also includes a plurality of longitudinally extending current conductive elements spaced from each other about the periphery of the radiator and connected to provide around at least a portion of the radiator, a shunt, path having an impedance to high frequency currents which is much less than that of the radiator.

Ill?

, to engage anode ring M.

luleiicc'seel between the cethocle 'curlecl co the cathode.

For a, cello? mulecsicndlcc cl lshe present inventlon, iogether with miller and further objects thereof, reierence is lmcl to the following descrlp-= lion leken in connection with the accompanying chewing", end. lizs scope will be penile-cl out in the cgcceuclecl claims.

the c lclcll. leeo ueucy come-actor lhe leccnctoc t me which includes the creseci; wevectiou lo one form; 2 is cecllonel View co cl'bemcze form of one invention; cool 53 a croccmectloccl view eel-sec Blue =3 cl 1 Helereuac to cl in. mine, there ls represented cccse cecticccl i of Duls moelulcsccl cleiucl cecel'esor 6823:3'2712285386 fill. high frequency ultlc-ellcrl wcw ocecetlc ul includial'le llco ceuecci'lcc comcllcee c vlclecl 813i Gl-fifiill'lllllifi lulce ill of 5 sectional view or? c,

1 clevice r vacuum cc lciccie ulip-e cull c oi closeclcleel cec soul; cavities cool v lube ill lacs a luculcc ccll'lozle c clug type anode ac bovine; c cllcc or clziei;

elcclrocle cl" grlcl ill. The {grid is in anode. A one cud of o crlcl supporting conduw tel ii) there is rcclielor ll, constructed la cc ccrcielcce with the invention described a fully lzereluclces. A contact spring 58 connects the c criel conductor which is coupled lo lemuuol W an insulator bushing Glass envelopes E12 cool 23 melee up the remainder cl tulle elemenlc. lice 'w' e also has :2, cell1- c-cle connector eucl heme? which are recelvecl, rcececiaively, icy coring connectors and 2&3 of ac oeecciciecl coehccle lead-4c structure 22 for supplying; excitullou potentials and heating The cathode modulating ooieuilol lo applied irom c terminal ill while the leeclec cux'reul, is supplied through trcnsfozmer The oi reeoncni; ceviisiec l l, l2 associated wllzll the lube i0 complete the oscillatory circuit. The first cavity ll lacs a hollow cyllnclrlcol outer conductor 2c c hollow cylindrical loner c0l1= elucior Nee? the lnslde end of inner concluclor 3Q insulator sleeve 38 is positioned with a conducior co in contact with the inside surface of the sleeve, lhe arrangement forming a blockinc condenser for the grid. The corresponding end of conductor 28 ls closed by a disc 36, contrally apertured to receive cube ll and shaped Disc 36 orients tube W connects its anode structure to and electrically conductor 28.

Thesecond resonant cavity l 2 also has a hol ow cylindrical inner conductor 32 and a hollow cylindrical outer conductor M. The ends of these condoctors which are remote from the triode tube are closed as indicated, and insulating spacers 43 maintain the conductors in coaxial alignment. A resilient contact device 44 for engaging anode ring 24 of the tube is secured to outer conductor 3|. 1

The described resonant cavities ii and ii are separable to permit inserting the tube into operative relation with reference thereto. A mechanical locking arrangement, designated 45, couples the resonant cavities into one assemblage after the tube has been inserted.

The generator of Fig. 1 is similar to the wellknown Colpitts oscillator. It is operated with the anode electrode of the triode vacuum tube maintained at ground potential as indicated by the connection 48. The first resonant cavity ii is coupled between the anode and control electrode of the tube. It is the wave-length determining portion of the oscillator. The second resonant cavity is' conductively coupled to the anode and capacitively coupled to the cathode. It represents a capacitive reactance atthe frequencies generated. The oscillator is normally maintained in a nonoscillatory condition but is excited for pulse modulation by modulating potentials of negative polarity and pulse wave form applied to terminals 30 and M. Each pulse of applied potential initiates oscillations in the generator which rapidly build up to saturation value and endure for the duration of the modulating pulse, thereby to generate one pulse of a pulse-modulated carrier-Wave signal. In this fashion, the oscillator responds to a modulating potential of pulse wave form and produces a modulated carrier-wave signal having an envelope similar to the wave form of the modulating potential. The generated signal may be derived from a pick-up device, projecting into cavity I I through a port 81. I

Referring now more particularly to the grid structure i6-l1, embodying the present invention, it is a conductive arrangement adapted to convey heat and high frequency currents from the control electrode 15 of the electron-discharge device I and comprises the conductor 16 of heat and high frequency currents and the thermal radiator 11 which includes a plurality of heat-conductive elements 34. These elements as shown in Fig. 1 are flat discs, coaxially aligned and secured in transverse relation to conductor i6 by brazing or other fastening means. The elements 34 are spaced along the longitudinal axis of the conductor at equal intervals to provide a large heat-dissipating area which is suit able for cooling purposes by an air blast or convection currents of other cooling gases.

The thermal radiator H, as so far described, presents a high impedance to high frequency currents because skin effects at the operating frequency of the oscillator cause the current to flow along the outer surface or skin of each element 34 and, hence. produce a long path of high resistance.

A shunt path for the high frequency currents is provided around a major portion of the radiator by current conductive elements 35 which preferably extend in a longitudinal direction parallel to the conductor l8 and are preferably equally spaced from each other about the periphery of the radiator. As shown in Figs. 1 and 2, the outermost radiator elements 34' and 34" may be made larger than the intervening elements 34. Strips or wires 35 of current conducting material are then secured by brazing or soldering to the two outside elements 34' and 34". At least four such. shunt paths are provided, six are preferable, and they are proportioned so that the spacing between adjacent ones of these current conductive elements is appreciably greater than any transverse dimension of such a current conductive element to provide adequate openings through which a cooling gas may flow.

The shunt path for high frequency currentsprovided 'by elements 85 has considerably less impedance than the path through the radiator i'l because the current conductive elements are placed in a path that is direct, short, and on the outside of the heat radiator.

In considering the operation of the conductor shown in Fig. 1, let it be assumed that proper pulse-modulated voltages have been applied to the oscillator system and it is in working order. The major portion of the heat produced in the tube it, as a result of the generated oscillations. is concentrated at the anode electrode. For that reason the heavy metallic disc as is soldered to the anode and is clamped to a heavy conductive supporting member 3%. The anode electrode is grounded through the outer cylinders 2t, 81 of the two resonant cavities ii, is and because of I this direct path, adequate cooling of the anode to cool because connection is is assured.

The control electrode or grid is more dimcult 7 preferably made to it through the center of one of the resonant cavities and because it is at a high negative potential. As a means for providing an emcient heat-dissipating structure, the control electrode is secured to a heavy conductor it by welding or brazing. The heat generated at the grid of the vacuum tube it flows along the conductor i8 to the radiator H for dissipation by way of the heat-conductive elements as. The current conductive elements 35 also help to dissipate heat.

To dissipate heat quickly, an air blast is preferably provided. This may be supplied by a blower (not shown) forcing air through an input port (not shown) to the radiator and out an exit port 31. In accordance with well-known design principles, the heat-conductive elements are thin in comparison to their diameter which, in turn, is large in comparison to the diameter of the heat conductor is on which the elements are mounted.

The path of high frequency current from the control electrode 15 to the cavity resonator ii is along the surface of conductor It until the first or lowest heat-conductive element 34 is reached. Then the current travels along the bottom surface or skin of the lowest element 34' to the peripheral edge thereof. From that point the current is shunted aroundthe four intermediate elements of the radiator by current conductive elements 35 to the topmost element 34 where it is collected by the spring connector l8. From the connector IS the current may flow through the condenser 33 to the resonant cavity wall 30.

If the current conductive elements 35 are not provided to furnish the shunt path as explained above, the high frequency currents flow over the surface of each of the heat conductive elements 84 in a long path of high resistance.

The form of the invention shown in Figs. 2 and 3 is the same as that shown in Fig. 1 except that the conductor IB is continued through the radiator I! to make a structure which is mechanically rigid. Such a form is used where the detachable spring connector i8 is not necessary. In order to facilitate the flow of high frequency currents from conductor I8 to the shunt-conductive elements as.

a cone-shaped conductor I 8 may be employed. It has been found that such a device reduces the impedance of the arrangement. A similar conductor may be used at each end of the radiator.

The operation of the conductor shown in Figs. 2 and 3 is generally the same as that shown in Fig. 1 except that the high frequency currents flow over the upper surface of heat-conductive element 34" to conductor i8 instead of being collected by a spring connector, such as I8.

Although the above-described embodiments disclose the invention as applied to an electron discharge device, it is to be understood that ap-' plication may also be made to any source of heat and high frequency currents.

While there have been described what are at present considered to be the preferred embodiments of this invention. it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is: 1. An arrangement adapted to convey heat and high frequency currents from a source comprising, a conductor of heat and high frequency currents, a thermal radiator including a plurality of heat-conductive elements of relatively large areas secured in transverse relation to and spaced along the longitudinal axis of said conductor to provide a large heat-dissipating area but presenting a flow of high frequency currents along said radiator. and a plurality of longitudinally extending current conductive elements spaced from each other about the periphery of said radiator and connected to provide around at least a portion of said radiator a shunt path having an impedance to high frequency currents much less than that of said radiator.

2. An arrangement adapted to convey heat and high frequency currents from a source comprising. a conductor of heat and high frequency currents, a thermal radiator including a plurality of heat-conductive elements of relatively large areas secured in transverse relation to and coaxially aligned with but spaced along the longitudinal axis of said conductor to provide a large heat-dissipating area but presenting a high impedance to the flow of high frequency currents along said radiator, and a plurality of longitudinally extending current conductive elements spaced from each other about the periphery of said radiator and connected to provide around at least a portion of said radiator a shunt path having an impedance to high frequency currents much less than that of said radiator.

8. An arrangement adapted to convey heat and high frequency currents from a source comprisa conductor of heat and high frequency currents. a thermal radiator including a plurality of heat-conductive elements of relatively large areas secured in transverse relation to and spaced along the longitudinal axis of said conductor to provide a large heat-dissipating area but presenting a high impedance to. the flow of high frequency currents along said radiator, and a plurality of longitudinally extending current conductive elements spaced from each other about the periphery of said radiator and connected between the two outside heat-conductive elements thereof to provide around a major portion of said radiator a shunt path having an impedance to high frequency currents much less than that of said radiator.

4. An arrangement adapted to convey heat and high frequency currents from a source comprising, a conductor of heat rents, a thermal radiator including a plurality of heat-conductive elements each having an exposed area large in comparison to the cross-sectional area of said conductor, said conductive elements being secured in transverse relation to and spaced along the longitudinal axis of said conductor to provide a large heat-dissipating area but presenting a high impedance to the flow of high frequency currents along said radiator, and a pinrality of longitudinally extending current conductive elements spaced from each other about the periphery of said radiator and connected to provide around at least a portion of said radiator a shunt path having an impedance to high frequency currents much less than that of said radiator.

5. An arrangement adapted to convey heat and high frequency currents from a source comprising, a conductor of heat and high frequency currents, a thermal radiator including a plurality of heat-conductive elements of relatively large areas secured in transverse relation to and spaced along the longitudinal axis of said conductor to provide a large heat-dissipating area but presenting a high impedance to the flow of high frequency currents along said radiator, and a plurality of longitudinally extending current conductive elements so spaced from each other about the periphery of said radiator that the space between adjacent ones of said current conductive elements is greater than any transverse dimension of a current conductive element and connected to provide around at least a portion of said radiator a shunt path having an impedance to high frequency currents much less than that of said radiator.

6. An arrangement adapted to convey heat and high frequency currents from a source comprising, a conductor of heat and high frequency currents, a thermal radiator including a plurality of heat-conductive elements each having a large surface area and a thickness which is small in comparison to the diameter of said conductor. said conductive elements being'secured in transverse relation to and spaced along the longitudinal axis of said conductor to provide a-large heatdissipating area but presenting ahigh impedance to the flow of high frequency currents along said radiator, and a plurality of longitudinally extending current conductive elements spaced from each other about the periphery of said radiator and connected to provide around at least a portion of said radiator a shunt path having an impedance to high frequency currents much less than that of said radiator.

HAROLD A. WHEELER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS and high frequency cur-

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