US1791275A - Method of supporting electrodes in electron-discharge devices - Google Patents

Description

H. JONES Feb. 3,1931.

METHOD OF SUPPORTING ELECTRODES IN ELECTRON DISCHARGE DEVICES Filed June 10. 1929" INVENTOR HWdoNEs v ATTORNEY Patented Feb. 3, 1931 i PATENT OFFICE i v Hfieo QJoN ES, or nasal: ORANGE, NEW JERSEY, As'sIGNoB. T wns'rmenonsn LAM? COMPANY, A conroRArIoN on rn NsYLvA iA METHOD or surron'rme jntnornonns In 'nnncrnon-mscnnnqn nnvrons Application filed J'une IQ, 1929. 1 Serial No. 369,758.

This inventionrelates to electron discharge devices and more particularly relates to electron discharge devices employing dummy electrode support members and has for its 5' object the provision of a dummy electrode support member which is substantially free from deleterious effects due to stray oscillating high frequency electrical eddy currents.

, Another object'of thisinvention is to'pro- 1c vide' a method of supporting electrodes in electron discharge devices whichis substantially free from oscillating high frequency electrical eddy currents. e

Another object of th's invention 1s to prow vide a means'of supporting the electrodesin a substantial strain' free position.

Another object of this invention is to facilitate the manufacture and assembly of elece tron discharge devices and to increase the life and efficiency of the same. i c

Other objects and advantages will become apparent as the invention is morefully disclosed. 1

In accordance with the objectsof my invention I have found that dummy sup.-

port members for electrodes in electron dis-' charge devices must be substantially free from what may be termed closed electrical circuits'in which oscillating high frequency electric eddy currentsmay be generated while the device is in operation. I have also determined that the electrodesmust be substantially supported in what might .be termed a strain free position, that is substantially restrained as tomovement in a vertical or lateral direction but free to move during expanding or contracting as a result of the thermal effects experienced and applied to the electrode during operation of the device. Before further disclosing my invention reference should be had to the accompanying drawing wherein V l Fig. 1 shows a fragmentary perspective view of an electron discharge device, partly in cross section, illustrating the method of.

mounting a plateor anode electrode in accordance with the present invention.

Fig. 2 shows a plan view of the edge of one of the. projecting fins 'on the supported electrode; and r c I 3 .is a perspective view of the slotted end of the dummy support member illustrated in Fig. 1, and which comprises one of the features of my invention.

- IniFigyl, the plate/or anode '1, is mounted upon the twin refractorymetal support memameter as: to frictionally engage-the support members 3 and 4. The refractory metal support members: 3*a'nd 4 are usually comprised of tungsten and are sealed into the-glass reentrant stem member 5 1n the usual manner of making straight through tungsten seals and areelectrically connectedon the opposite end-with flexible copper conductors 6, which are electrically connected to anexterior source of electrical energy. r I y Heretofore-in order to rigidly retain the plate member in position it has been cus tomary to support the plate by means of-an oppositely disposedlreentrant stem member sealed into the'enclosing glass envelope having twin supportwires arranged to engage tubulations or slots in a'projecting fin member of the plate or anode'in a manneranalogous to that shown and indicated with reentrant stem member 5.

It is found, however, that when this" method of supporting the electrodes is employed that frequently the tube is destroyed and lost through fracture or puncturing of the glass of the reentrant stem member carrying the twin supportmembers.

I believe that'this fracture or puncture of the glass of the reentrant stem member to be due to one or two effects or to a combination of the two eiiects. The first effect is electrical and may be best described as being due L by the plate electrode 1 and the twin support wires 3 and 4, and the glass of the press into the heating effects caused by oscillating.

termediate the twin support wires 3 and l.

The heat generated by the oscillating currents in this closed circuit is suificient to cause fracture of the glass of the seal, especially following prolonged operation of the device.

The second effect that I have noted that causes fracture of the glass of the seal and which it is one of the objects of this invention to eliminate may be best described as being due to the lack of providing in the prior methods of mounting means for permitting relatively free movement of the electrode upon expanding and contracting whensubjected to heating effects during operation of the device. In electron. discharge devices of the power tube type, the plate or anode electrode is incandesced to a relatively high temperature during operation. As a result it is apparent that a cylindrical electrode of the type indicated would expand materially. This expansion with a rigidly mounted electrode would result in considerable strain upon the metal to glass seal of the press containing the supporting wires 3 and 4.

It is believed that these two efiects acting independently or together have been the .ause heretofore for loss of the electron discharge devices by fracture or puncture of the glass of the seal of the electrode support member of the device.

I have found that by eliminating this type of twin support member and utilizing one in which no oscillating eddy currents may develop, that the life and maintenance of the device is materially lengthened and loss thereof due to puncture of the glass of the stem of the support member is substantially eliminated.

l have also found that by providing means in said support 1 ember for permitting rela tive free movement of the said electrode during expanding and contracting while being heated and cooled during operation of the device, that the deleterious fracture and puncture of the glass of the reentrant stem members of the supporting member is also substantially eliminated.

One method I have devised for accomplishing this is shown in Fig. 1 wherein a single refractory metal (tungsten) support memher 9 disclosed which may be sealed in any convenient well known manner into a reentrant stem 13 of the enclosing glass envelope 8. The end of the tungsten rod opposite the seal is cut away to form a grooved portion 10-, arranged to receive the fin member 2 of the plate electrode. Any means of restraining the movement of the electrode vertically within the groove may be utilized ,such as indicated by projections 1% on either side of the electrode support member 9, on the face of the fin 2, which projections may be comprised of rivets, pins, or raised portions of the fin formed there during manufacture or s iaping of the same.

In this method of mounting, the plate or anode electrode has great freedom of move ment upon expanding and contracting as a result of the heating efiects developed during operation of the device. The electrode, however, is restrained with respect to lateral displacement as a result of shock, twist or strains incident to handling, shipment, operation during use and the like.

I have found that the use of such a single dummy support member rather thanthe twin or dummy support member heretofore employed has substantially eliminated the deleterious effects heretofore experienced and the life and efiiciency of the device utilizing the same materially benefitech'andthe loss of the device due to puncturing of the dummy support member seal substantially eliminated. I i

In addition the manufacture and assembly of the device has been greatly facilitated due to the fact that it is a'relatively simple procedure to seal in the plate or anode mount by first positioning the dummy support member in the enclosing glass envelope, thereafter inserting the anode mount within the envelope with the electrode fin 2 engaging the grooved portion of the support wire 9, and sealing the electrode mount in such position. ,Subsequently'the stem mounts carrying the cathode and two control grids may be inserted from opposite sides of the enclosing glass envelope in theusual manner. The position o-fthese cooperating electrodes is indicated but not shown in Fig. 1 by numerals 11 and 12;

Having broadly and specifically disclosed the nature of my invention it is apparent that there may be many variations ofthe specific embodin'ient disclosed herein without departing necessarily from the nature of my invention and such departures and variations are anticipated which fall within the scope of the following claims.

Whatis claimed is: 4

1. An electron discharge device comprising a glass envelope, a refractory member, means for rigidly securing one side of said member to a wall at one end of said envelope, a support member rigidly secured to and extending from the opposite end of saidenvelope, a fin on said member, said support member having a slot to receive said fin to loosely retain said member for free move.- ment due to expansion and contraction.

'2. An electron dischar e device comprising a glass envelope, a plate electrode, fins extending from said electrode, means for rigidly connecting one of said line to one end of said envelope, and means for loosely connecting another of said fins with the opposite end of said envelope to retain said electrode for free movement under contraction and expansion'.

3. An electron discharge device comprising a glass envelope, a reentrant stem at one end of said envelope, a plate electrode, a

pair of support members extending from said stem, means for rigidly connectingsaid support members to said electrode, a .reentrant I stem at the other end of said envelope, a

single support member extending from said last vmentioned stem, and means forloosely connecting said single support member with said electrode. Y I I 4. An electron discharge device comprising a glass envelope, a tubular electrode having radially projecting fins, a reentrantstem at one end of said envelope, a pair of support members extending fromsaid stem and mgidly secured to one of the'fins'of said electrode, a reentrant stem at the opposite end of said envelope and means for loosely connecting an oppositely disposed fin with saidv last mentioned stem.

5. An electron discharge device comprising a glass envelope, an electrode having op-v positely disposed fins within said envelope, means for rigidly connecting one of said fins with one end of said envelope and means for loosely connecting anvoppositely disposed fin with the other end of saidenvelope for the free expansion and contractionof said elec- I stem, a reentrant stem at the opposite end of i said envelope and means for loosely connecting an oppositely disposed fin with said stem. 7

In testimony whereof, I have hereunto subscribed my namethis 29th day of May, a 1929.

HUGO w. JONES.

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