US2395043A

US2395043A - Electron discharge device

Info

Publication number: US2395043A
Application number: US463698A
Authority: US
Inventors: Goodchild Frank Douglas
Original assignee: Standard Telephone and Cables PLC
Current assignee: STC PLC
Priority date: 1941-12-02
Filing date: 1942-10-28
Publication date: 1946-02-19
Anticipated expiration: 1963-02-19

Description

` Feb. `19, 1946.

F. `D. GooDcHlLD `ELECTRON DISCHARGE DEVICE Filed Oct. 28,l 1942 2 lSheets-Sheet 1 Inventor Bwy u 60mm/d, 37

L Attorneyl Feb. 19,'1946. 'F. D. GooDcHlLD 2,395,043

ELECTRON DISCHARGE DEVICE Filed oct. 28,'1942 2 sheets-sheet 2 Patented Feb. 19, 1946 y y UNITED STATES ELnc'rRoNpIscHAnGE pE'vloE Frank Douglas Gooacnila, London, England; as# f' f signor to Standard .Telephones and Cables' Limited,` London; England, a. British company u .Application October 28, 1942,v Serial No..46 3,-`698 i f Y In Great Britain December-.2, 17941V Y. t

This invention relates to electron discharge tubes and has for its `main object to provide an .improved construction of ,tube for 'high-fre. quencies which can vbe connected directly into a transmission line and be utilised as a line Voscillator. Triode tubes are known yhaving two f pairs of leads for the plate and grid emerging from opposite ksides of thebulb so that the tube can beconnected directly into a transmissionline; .but this type l'of construction isvvery diicult from the manufacturing standpoint,` as considerable shrinkage is. encountered diie to cracked glass.

A Tungsten is the metal usually employed, sealed whereby'they maybe connected directly to-an externalcircuit such as a transmission line, and

'l assist in the dissipation of kheat.

It i's desirable to support the anode, may

be of molybdenum, so that its working part may attain, a .temperature .considerably in ,excess 'of 1000VC. while still utilising the heatconducting properties of the copper supporting disc` to wget as much heat away as possible. ,-Ifythe copper disc is in immediate contact with the working part of the anode then the anode may not be allowed Y to exceed` 1084 C. which is the melting point of copper: in fact it must not even approach the figure otherwise the copper will volatilise on to the bulb and form a poor insulation'path between grid and anode.

According to a feature of the present invention the anode is attached to its suporting dise via a plurality of iins which are yadapted to provide a Atemperature gradient between the working part of the anode and its supporting disc. With this varrangement; it has been found to be possible to dissipate considerably more heat than was possible with the direct connection between anode and vdisc and at the same time removes any danger of copper depositing on the bulb.

VAccording to another feature of the invention the connection between the grid and grid disc comprises a spider like member mounted on the grid leads and having a plurality of spring ngers adapted to make a wiping contact withy the grid disc. K

Features of the invention will be hereinafter described with reference to the accompanying drawings andV pointedout the appended K:laiins.`

In the drawings Fig.` 1 is a sectionalvelevation;,of a complete 5 Fig.2is an explo'ded'viewthereof. f Y Fig. 3 isfa sectional elevation 'of a'modiiied constructionof tube andf A` c, v

Fig. 4 is an `exploded view thereof..

Sealedy into the venvelope I. ofthe tube are two metallic discs 2and.3 Inthe construction shown i in Figs.l ,1 and V2 the .disc 221s in thel form' .of-a' funnelshapedspinning,v of `which thefunnel por' tion 4 supports the anode 5, which as shown,is of cylindrical form but obviously, 'for the, purposes ofthis'inventiomit may have various fornisoi .f an elongated hollow body, together withainolybdenum-annular disc 6 which is secured at its inner' edge to the anodernear the'mid'dle poi'ntwh'ere the anode is hottest "and, atV its outerledgein the ba'seof the'iunnel bythe ypunched-out lugsffl. Rodslr are welded to the sides of the anodeand to the molybdenum disc Gier additional support. The'gridY 9 Vand cathode. I0, together L'with the heater -leads,'are mounted on the press, Il of the tube, and attached to the grid supportingrods are two contact springs lf2; whichgwhen ,the press is assembled-andsealed into'tlie tube, make 'con-1 tact withthe lower side of the metal disc.v 3 and form theelectrical cl'mnectionY to thegrid.-

i' inthe' constructionshown rigspsxand 'fi fthe tube comprises a glass env'eiope'l having sealed into it the copper anode disc 2 and grid disc 3. The disc 2 has a central .boss portion 41 to support the cylindrical anode 5 through the medium of the radial fins 61 and collar 11. As shown the anode structure is built up of a plurality of molybdenum pressings each shaped to form an integral part of the cylindrical working part of the anode with its associated ns and collar portion,

40 the pressings bein-g suitably secured together as by the slots and lugs 81 and 91 on the ns. The anode assembly is secured in the boss portion 41 of the disc 2 by bent over lugs |01 of the disc engaging the collar 11 the lower edge of the boss 45 portion being provided with an inwardly directedV retaining lip ll1 to engage the collar. It will thus be seen that the working portion of the anode is separated from the disc 2 by the ns 61.

The grid 9 and cathode I0 are mounted on the press l'l to lie within the anode 5 and in order to provide a low impedance connection between the grid disc 3 andthe grid 9 a spring spider member |21 is mounted on the grid support rods I3 and the spring arms of the spider make a wip-y ing contact with the under surface of the grid disc 3. As shown the grid support rods I3 are provided with glass arbors I4 which help to reduce losses between the grid and cathode supports by increasing the glass path between them. Alternatively a cross shaped press may be provided for this purpose. y

It will 'be seen that with the construction of tube according to this invention transmission lines can .be attached direct to the copper discs 2 and 3 giving connection to the anode vand. grid .re-1 spectively. In addition, it has been .found that the intimate connection of the Acopper with the glass greatly assists the dissipation of heat.

What is claimed is:

1. An electron discharge tube comprising an envelope, a metallic disc sealed through vthewall of said envelope and supporting an elongated hollow anode with its length direction at right yangles to the plane `of the disc, a cathode and grid mounted on supports carried by one end vportion 'of the tube and positioned within said anode, 'a second metallic disc sealed through the wall of the Ienvelope and having a hole through which the grid and cathode supports extend, and means lcomprising spring contacts for making electrical connection betweenl the grid and second disc.

2. An electron .discharge tube comprising an envelope, an anode supported by a metallic disc 2,395,043 f f `f comprises a funnel-shaped port-ion yintegral with said disc and embracing theyanode andan annular disc surrounding and attached to the anode and secured in the base of said funnel portion whereby the anode is supported at two points along its length.

An electron discharge tube according to claim 1, wherein the anode comprises a plurality of sheet metal parts secured together and forming anelongated hollow body having a plurality 'of outwardly fextending hns, and a surrounding collar, each of said metal parts comprising a portionforrning a working part of the anode, a nn forming part, and a circumferential collar lfom1- ing part; Y Y j 7. kelectron discharge tube according to claim 1 wherein the disc vsupporting'the 'anode comprises a funnel' 'shaped' portion integral with said V'disc and embracing the anode and an annular disc 'surrounding said anode and attached at itsA inner edge to said 'anode near the longitudinal center-'of thisA latter whereby theymaximumrcool- I ingfrom contact with the disc is obtained, the

sealedthrough said envelope 4and extending out- 'f' side it providing a direct vconnection to the anode for assisting Vin the dissipation of heat, said anode 'being attached 'to the disc` by a plurality of ns which are adapted to provide a temperature and said disc.

3. An electron discharge tube comprising an envelope, an anode and a grid mounted on sup'- said aniulard-isc being Vsecured atv its outer edge in the base of said" funnel.

8. An electron discharge tube according to claim 2 wherein 'the anodev comprisesy a working part having a plurality of outward'lyjextending gradient between the working part lof the anode ports within the envelope `and a pair of metallic discs sealed through 'said' envelope yand connected within the envelope vrespectively one tothe anode and one to the grid said discs extending outside the envelopev providing direct connections to the anode and grid for assisting inthe dissipa# tionof heat" said grid being connected to its respective disc'by means of a spring spider member mounted' on thev grid' supports with its spring arms making wiping contact with 'the disc.

4. An electron discharge tube according to claim 1" wherein the. anode comprises a working ns anda surrounding collarportion secured in a central vboss in the anode disc.

9'. electron discharge tube 'according to claim 2i wherein the vano-de `comprises 'a Aplurality of sheet metal parts secured togetherv and .forming an lelongated hollow body having a. plurality of outwardly extending hns, and a lsurrounding collar, each ofl said metalA parts comprising a por'- tion forming a vworkinggpart of the anode, a fin forming part and a circumferential 'collar' 'forming part.

- 10. An electron discharge tube according to claim 1 in whichthe contact springs `are carried by the grid supports and make springcontact with the second disc. y

' FRANK. DOUGLAS GOGDCHEID;