US2398593A - Support - Google Patents

Description

April 16 1946 l. 4E. MoURoM'rsEhFF r-:rAL

SUPPORT Filed May 9, 1942 INVENTORS 6. M .D//V/V/C/C BY W um WML ATTORNEY EEN .1 Q l n Patented Apr. 16, 1946 .t

SUPPORT Ilia E. Mouromtseif, Montclair, and George M.

Dinnick, Bloomield, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 9, 1942, Serial No. 442,360

7 Claims.

This invention relates to supports and more particularly to electrode supports in electron discharge devices.

Certain electron discharge devices, particularly of the ultra high frequency type, develop high temperatures in normal operation, and the heat conducted along the leadin supports has placed undue strain on the seal between the support and glass envelope. Cracks and defective tubes have resulted, making it necessary r`to devise means for reducing the temperature gradient Without impairing the electrical conductivity. 'I'he present invention is directed to this problem and offers a solution thereof.

The objects of the invention accordingly are to overcome the effects of high temperature gradient between electrode and envelope upon the region where the lead-in for the electrode is sealed with respect to the envelope.

Another object of the invention is to effect a temperature protection without adversely affecting the electrical efficiency.

A further object of the invention is to maintain rigidity of the support while performing the desired obstruction to heat conduction.

Yet another object of the invention is to obtain a simple construction, one readily and economically fabricated, and one which lends itself to effective outgassing or evacuation.

Still further objects will appear to those skilled in the art as the description progresses both by direct recitation thereof and by implication from the context.

Referring to the accompanying drawing in which like numerals of reference indicate similar parts throughout the several views;

Figure 1 is an elevation of an electron discharge device embodying the present invention;

Figure 2 is a sectional view on line II-II of Figure 1; and

Figure 3 is a cross section considerably enlarged on line III-III of Figure 2.

In the specific embodiment of the invention illustrated in said drawing, the reference numeral I indicates an evacuated envelope, here indicated as of glass. At the top of this envelope two protruding stems II are provided which constitute sealing and supporting means for lead-in posts or supports I2, description whereof will follow presently, as the essential feature of the y present invention. These posts or supports have been here illustrated as means for suspending an anode I3 at approximately the middle part ot the envelope. Details of construction of the anode are fully described in a concurrent application herewith, Ser. No. 442,361,11ed in the names of G. M. Dinnick and J. P. Quitter. Sufi'lce it to say' that said anode, as shown, is of an elongated configuration with a metal lining I4 for carbon block body members l5 each of which is suitably recessed for receiving grid I6 and cathodes I1 together constituting the triode of the electron discharge device. The anode includes lateral extensions I8 of looped construction by which a self contained oscillatory circuit is provided in the device.

The device, as shown, is accordingly one generating ultra high frequency oscillations, vis capable of producing high power and unavoidably develops high temperature in the anode. Al-l though this temperature is undesired, neverthe# less it is present as a necessary evil and must be coped with-to overcome detrimental effects. A most serious and ruinous eiect is conduction of the heat up the anode posts or supports to the glass seal, and due to the intensity of the heat, in conjunction with different coeicients of expansion of metal and glass, cracks and crevices appear, air leaks in, and the device becomes useless".

According to the present invention, the posts or supportsV I2 here shown as employed for suspending the `anode I3 are constructed of several parts, namely a stud or electrode attaching portion I9 constituting one end section, a glass adherent outer section 20 and an intermediate heat deterring section'2l all in axial alinement and rigidly secured together. By preference, the electrode attaching section is of electrically conductive metal, preferably molybdenum, and comprises a threaded shank portion 22 passing vertically through the anode and held thereon by a bottom nut 23 acting in opposition to a shoulder on said section immediately above the electrode and formed in consequence of the protruding body of the said section having greater diameter than said shank portion. At the top of the body portion of said section I9 is a reduced neck 24.

Encircling said neck 24with its outer surface forming a continuation of the body portion surface of the electrode attaching surface, is a metallic tube constituting the said intermediate heat deterring section 2l. This section, by virtue of being tubular, has a minimum mass but adequate rigidity which introduces desired heat deterring effect without weakening the structure of the complete post. Furthermore, the metal employed is preferably one which is adequately conductive of electrical current or energy. but which is highly resistive to conduction of heat. The preferred www material used is an alloy of nickel, cobalt and iron sold under the trade name of Kovar and more fully described in patent to Scott, No. 2,062,335. Suitable rigid attachment of the two sections may be obtained, and as one means a rivet 25 is employed which extends diametrcally through juxtaposed parts of the' neck and tube.

.At the upper end ofY tubular or intermediate section 2| another neck 26 is mounted therein,

this said neck depending from the glass adherent outer section 20. The contiguous outside surfaces of the intermediate tubular section and glass adherent outer section are preferably flush, Uni-i' cation of these two sections. may be obtained 1n` suitable manner such as by use of hard solder, by welding or otherwise. Preferably the said outer section is composed of tungsten for its desirable characteristics of electrical conductivity and ability to form adhesive union with glass applied thereto in molten or highlyA plastic state, and because of the nearness of coefficients of expansion of glass and tungsten.

The glass stem I I forming part of the envelope I is of elongated character for applying the contacting or pinch region 2l of glass to the post at a considerable distance from the anode and on the far end portion of the outerpost section. The seal is accordingly protected by distance and by intervening heat resisting or deterring'.r material in the post from heat from the anode. The intermediate section 2|, whilereceiving the attaching necks of the adjacent sections, is, for the greater part of its length-entirely hollow, the

structure lending itself to effectively cleterring transition of heat and obtaining thereby and by virtue of the heat-resistance characteristic ofthe Kovar of which it is composed, a desirably high heat gradient between end portions ofr said section. Electrical conductivity of thefKoVar is adequate to avoid undesirable opposition to the transition of electrical energy, Holes 28 may be provided through the side wall ofthe said section for assisting in fully evacuating gas within said section when evacuating the device envelope.

Various modifications and-changes as to precise structure `vand materia-1s aref contemplated means to one end section; successive sections` having their entireA support from saldi-means through successive-attachment to eachother.Y

2. An electrode support-comprising an elongated composite rigid member of sections successively juxtaposed endwise to each other and of which one section is of material and crosssection more resistive to heat conduction than a next adjacent section, said sections having substantially equal diameters and continuity of exterior surfaces from one section to the next, and means rigidly mounting said support by attachment of said means to one end section, successive sections having their entire support from said means through successive attachment to each other,

3. An electrode support comprising a rigid member of successive sections juxtaposed each at the end of another of which one section is interposed as an intermediate section between two other sections adjacent thereto, said intermediate section being less heat conductive than the other sections adjacent thereto, said sections having substantially equal diameters and continuity of exterior surfaces from one section to the next, and means rigidly mounting said support by attachment of said means to one end section, successivev sections having their entire support from saidmeans through successive attachment to each other.

4. An electrode support comprising a plurality of elongated sections juxtaposed endwise successively -to each other whereby one section is intermediate of two other sections, said intermediate section being hollow for the entire length thereof between the two other sections and less conductive of heat than said other sections.

5. An electrode support comprising a plurality of sections of which one section is tubular from end to end and another section solid, the solid section having an end portion inserted for a short part of the length of the tubular section and secured thereto and leaving the major part of said tubular member hollow for maintaining low heat conductivity of said tubular section,

6. An electrode support comprising a plurality of sections of which one section is tubular and another section solid, all ci the plurality of sections being physically alined and electrically conductive and electrically in series, said sections having substantially equal diameters and continuity of exterior surfaces throughout the length of each and fromone section to the next, and said hollow section presenting obstruction to heat conduction more effectively than said solid section.

7..An electrode support comprising a plurality of sections of .which one section is tubular for its entire length and of high resistance to heat conduction, and of which two other sections of less resistance to heat conduction are juxtaposed to the tubular section at the ends thereof with the tubular section intermediate thereof, and all of said sections being in electrical series and having good electrical conductivity characteristics.

GEORGE M. DINNICK.

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