US2447719A

US2447719A - Electron tube

Info

Publication number: US2447719A
Application number: US573875A
Authority: US
Inventors: Harold E Sorg
Original assignee: Eitel Mccullough Inc
Current assignee: Varian Medical Systems Inc
Priority date: 1945-01-22
Filing date: 1945-01-22
Publication date: 1948-08-24
Anticipated expiration: 1965-08-24

Description

H. E. SORG ELECTRON TUBE Aug. 24, 1948.

2 Sheets-Sheet 1 Filed Jan. 22, 1945 INVENTOR Harold E. Sory BY M m,

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ATTO R N EY 1948. H. E. SORG ELECTRON TUBE Filed'Jan. 22, 1945 Patented Aug. 24, 1948 UNITED STATES PATENT OFFICE ELECTRON TUBE Harold E. Sor'g', Redwood City, i'falif "a'ssiignorto 'Ei'tel-M'cCull'ough, 1110., San Bruno, Calif 2, 'eorporation of California Application Januar 22, I945, 'Serial No. 73;875

8 Cla'ims. (Cl. EEO- 2755) My invention relates to an electron tube having a cup-shaped cylindrical body 2 and an upturned an external anode. end flange 3 terminating in a downturned sealing It 'is-among the objects of my invention to 'prorim 4. This folded type of anode structure posi- Vide improved means for cooling the external tions the lower end of the anode-down within the anode of a tube. 5 envelope "for compactness of the electrode assem- Another object is to provide an improved tube "bay. The tube illustrated is a triode including a structure adaptin'git'for operation 'at'higher Iregrid 6 and cathode 7, these electrodes being sup- 'quencies. ported from the lower portions of the envelope The invention possesses other objects and feaand projecting upwardly into anode body 2. times di'advantageysome of which, with the fore- To Grid Ti is connected with and support y a going, will be set forth in the following descripmetallic terminal ring 8 sealed to the lower end tion of my "invention. It is to be understood that 'of "an "annular vitreous envel pe section 9, the 'I do not limit myself to this disclosure of species il 'p e'II'db'fW h is sealed'to r m l of the anode. of my invention as I may adopt variant embodi- The 'l'nfold'ed anode structure provides sufiicient ments thereof within the scope of the claims. spacing between -rim 4 and terminal rin 3 for Referring to the drawings: insulation Tpu'rposes, yet keeps the electrical path Figure 1 is "a. vertical sectional view of 'a tube ffiom ring '8 to gr d 6 "re tively short. This is embodying the improvements of 'myinventio-n. imp t ntff r 'hi h frequency op r i Th re- Figure 2 is a, sectional view showin the anode 'maih r of th ri s pp rt p y comprises portions of the tube and illustrating a modified a transverse 'ap rt r d disk H ca ying a conical cooling arrangement; and -br'a'cl r'et l2 tow'hich the grid is'secu'red.

Figure 3 is a similar View showing another "Cathode '1 is connected'with and supported by a modification. stem structure preferably comprising a tubular t rms of ad in lus on, my electron tube metallic stem member l3 and an inner concentric comprises a metallic external anode forming 'porm m m er 4 hel by a spacin rin or head 'tions of the tube envelope. In my preferred t b l6 of vitreous material sealed between the memthe anode of reentrant construction to provide l'lfier's'te'm member 13 has a metallic flan e a compact electrode assembly. The grid of the I sealed to an annular vitreous envelope sectube is mounted on a terminal ring below the ren '8 h r being s d at s upp r en entrant anode, and the cathode is preferably sup- 0 te'miindl Cathode T s preferably of ported on a concentric stem structure. In one 5118 filamentary typ prising a thoria'ted type of anode cooling arrangement embodyin tungsten filament secured at its lower end to stem myinven'tion a finned metal cooler is mounted on member 13 and at s upp end to a Center rod the anode with a heat conducting core extending v 4 l9 Projecting from m member It is undert t t 't portions of th anode T "st'o'o'd of course that an oxide coated cathode may cooler is inserted in a conduit through which a l nstead ofth'e thoriated typ cooling fluid such as air is forced, this conduit Inner m' I418 preferably hollow and preferably being electrically connected to the Ported into the Env pe through Opening 2! anode and forming .part of the anode circuit. Ina D F bf evacuating the tube- A ass modified tube structure adapted for increased 40 fi n 0n t low r e d o me ber H is anode di si ation a .jacket is arranged on the sealed on at tip 22 after the exhaust. The coaxial anode into which a cooling fluid or refrigerant l lf'p of "Stem tr above described s p under pressure is expanded to lower th te fer'red because it further improves the tube for ture. The jacketed cooler construction may be high eq en y work.

used. with tubes having various types of anode Heat is removed from the ano e y a 1 design, although I prefer to employ the reentrant having a 0T d t Conducting type of anode with the jacket arranged to extend terial, such s pp encircling anode b y 2 into its reentrant portion. The fluid duct or and extending into the reentrant space between ducts connected with the jacket are preferably the anode body and upturned flange 3. The arranged within the electrical conduit terminateo'ole'r also includes an annular finned section M ing at the anode. 'o'fmetal secured to core 23 and having radial fins In greater detail, and referring to Figure 1 of extending outwardly from the anode body the drawing, my improved electron tube c'omabove flange 3. A curved bottom plate 2'! on see- .pri'ses a metallic reentrant anode forming'the 'up- 'tion 24 serves to direct a cooling fluid outwardly per end ortions ofthe tube envelope and having atthebase of the fins.

One important advantage of the reentrant anode and cooler combination above described is that heat conducting core 23 contacts the full length of the anode body, including that portion projecting into the envelope, and serves to conduct heat uniformly away from the anode. As a result the advantage of an inwardly projecting anode structure for high frequency-work is obtained without decreasing the heat dissipation properties of the tube, it being understood that the power output of a tube is proportional to' its anode dissipation capabilities.

While I have shown anode body 2 and coller core 23 as separate pieces, it is understood that they may be formed integrally. The separately,

formed anode of sheet material is preferred however because the fabrication problem is simplified and it is possible to heat the anode on the pump to a higher temperature for outgassing purposes, it being preferred to apply core 23 to the anode after the tube has been evacuated.

As shown in Figure 1, anode body 2 with its cooler assembly is inserted in the end of a conduit 28 so that fins 2b lie in the space between the anode and conduit. A cooling fiuid such as air is forced down through the conduit 50 that it flows past fins 26 and out through openings 29. Conduit 28 is metallic and makes electrical contact with the anode through the cooler so that the conduit also functions as the anode line or circuit for the tube.

In a modified anode cooler structure shown in Figure 2 a metallic jacket 3! is fitted on anode body 2, with the lower end of the jacket extending into the reentrant portion of the anode. This jacket is preferably inserted into the lower end of anode circuit conduit 28. In this cooling system jacket 3| provides an expansion chamber, a suitable pressure fluid being expanded into the jacket through a small orifice in nozzle 32. A duct 33 in conduit 28 connects nozzle 32 witha suitable source 36 of the pressure fluid. Duct 33 is arranged in conduit 28 so as not to interfere with the electrical properties of the anode circuit.

The expanded fluid is discharged to the atmosphere from jacket 3i through outlets 36.

Another cooler structure is illustrated in Figure 3 which includes a second duct 31 connected with jacket SI for returning the low pressure fluid back to source 3 3. In this case the source 34 preferably includes a compressor for re-compressing the fiuid. The cooling medium or refrigerant may be any suitable fluid such as sulphur dioxide or methal chloride.

It will be seen that the tube structures shown in Figures 2 and 3 both comprise a metallic anode having a heat dissipation portion projecting externally of the envelope; a fluid expansion chamber thermally connected with the projecting portion of the anode; and means for expanding a pressure fluid into the chamber. As previously mentioned, the hollow end of the anode unit preferably extends within the tube envelope. These structures have a decided advantage for high power high frequency tubes because it is possible to achieve large heat dissipations [in tubes of relatively small size.

I claim:

1. An electron tube comprising a sealed-off evacuated envelope, a reentrant metallic external anode forming the upper portion of the tube envelope and having a cylindrical body and an upturned end flange, and a cooler on the anode" having a heat conducting core encircling the body and extending into the space between the ing part of the envelope wall below said sealing rim, a vitreous envelope section sealed between said rim and terminal ring, cathode conductor means at the lower end of the envelope, a vitreous envelope section sealed between the terminal ring and cathode conductor means, a grid in the envelope connected to said terminal ring, and a cathode in the envelope connected to said conductor means.

3. An electron tube comprising a sealed-oil? evacuated envelope, a reentrant metallic external anode forming the upper portion of the tube envelope and having a sealing rim disposed above the lower end of the anode, a grid terminal ring forming part of the envelope wall below said sealing rim, 9, vitreous envelope section sealed between said rim and terminal ring, cathode conductor means at the lower end of the envelope comprising a tubular stem member and an inner stem member concentric with the tubular member, a vitreous envelope section sealed between the terminal ring and cathode conductor means, a grid in the envelope connected to said terminal ring, and a cathode in the envelope connected to said conductor means.

4. An electron tube comprising a sealed-off evacuated envelope, a reentrant metallic external anode forming the upper portion of the tube envelope and having a sealing rim disposed above the lower end. of the anode, a grid terminal ring forming part of the envelope wall below said sealing rim, a vitreous envelope section sealed between said rim and terminal ring, cathode conductor means at the lower end of the envelope, a vitreous envelope section sealed between the terminal ring and cathode conductor means, a grid in the envelope connected to said terminal ring, a cathode in the envelope connected to said conductor means, and a cooler on the anode having a heat conducting core extending into the reentrant portion of said anode.

5. An electron tube comprising a sealed-off evacuated envelope having a tubular anode with a hollow cylindrical body projecting from the envelope at one end and a pair of coaxial stem members at the other end, a cooler surrounding said hollow body of the anode and having a cylindrical terminal portion coaxial with the stem members, a terminal ring interposed in the envelope wall between the outer stem member and the anode, a helical cathode in the envelope connected to the stem members, and a tubular grid in the envelope connected to the terminal ring, said cathode and grid and anode having a common axis and said terminal ring and stem members being concentric with said axis.

6. An electron tube comprising a sealed-off evacuated envelope having a tubular anode with a hollow body projecting from the envelope at one end and having a pair of coaxial stem members at the other end, a terminal ring interposed in the envelope wall between the outer stem member and the anode, a helical cathode in the envelope connected to the stem members, a tubular grid in the envelope connected to the terminal ring, and

a cooler having fins disposed about said hollow body of the anode, said cathode and grid and anode having a common axis and said cooler and terminal ring and stem members being concentric with said axis.

7. An electron tube comprising a sealed-oil? evacuated envelope having a tubular external anode with a hollow cylindrical body projecting from the envelope at one end and a pair of coaxial stem members at the other end, a cooler surrounding said hollow body of the anode and having a cylindrical terminal portion coaxial with the stem members, a terminal ringinterposed in the envelope wall between the outer stem member and the anode, a filamentary cathode connected to and supported wholly by said stem members, and a grid connected to and supported wholly by said terminal ring.

8. An electron tube comprising a sealed-off evacuated envelope having a tubular external anod with a hollow cylindrical body projecting from the envelope at one end and a pair of coaxial stem members at the other end, a cooler surrounding said hollow body of the anode and having a cylindrical terminal portion coaxial with 25 the stem members, a terminal ring interposed in the envelope wall between the outer stem member and the anode, a center rod on the inner stem member projecting upwardly into the anode,

a filamentary cathode supported at the top by the center rod and at the bottom by the outer stem member, and. a grid connected to the terminal ring.

HAROLD E. SORG.

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

UNITED STATES PATENTS Number Name Date 1,555,677 Leblanc Sept. 29, 1925 2,124,428 Nolte July 19, 1938 2,174,382 Elder et al Sept. 26, 1939 2,176,657 Finch Oct. 17, 1939 2,217,421 Scott Oct. 8, 1940 2,267,128 Mouromtseff et al. Dec. 23, 1941 2,289,984 Mouromtsefi et al. July 14, 1942 2,330,032 Dailey Sept. 21, 1943 2,341,752 West Feb, 15, 1944 2,411,522 Chevigny Nov. 26, 1946 2,431,337 Litton Nov. 25, 1947 FOREIGN PATENTS Number Country Date 514,651 Great Britain Nov. 14, 1939 553,805 Great Britain June 7, 1943 852,989 France Nov. 18, 1939