US2355083A

US2355083A - Electrode assembly for discharge tubes

Info

Publication number: US2355083A
Application number: US373006A
Authority: US
Inventors: Norman B Krim
Original assignee: Raytheon Manufacturing Co
Current assignee: Raytheon Co
Priority date: 1941-01-03
Filing date: 1941-01-03
Publication date: 1944-08-08
Anticipated expiration: 1961-08-08

Description

Aug- 8, 1944 N. B. Kmm 2,355,083

ELECTRODE ASSEMBLY FOR DISCHARGE TUBE Filed Jan. 3,. 1941 2 Sheets-Sheet 1 ls- Imi m Iulmm |9 S: I i

Willi/Ilm: vll; l EN 7 u G n V{ 42 lNvENToR,

No RMAN B. KRIM,

ATTY.

Aug. 8, 1944.

vN. B. KRIM ELCTRODE ASSEMBLY FOR DISCHARGE TUBE Filed Jan. 5, 1941 2 Sheets-Sheet 2 Y: m. w m NRWA F, 0K EB AV .WN A M n Y., NB Z. Gt. F

Patented ug. 8, 1944 2,355,083 o Emoment: ASSEMBLYr Foa DISCHARGE 'mass Numan B. Krim, Cambridge, Mass., assis-nor, by

mesne assignments, to Raytheon Manufacturing Company, Newton, Mass., a corporation of Delaware Application January 3, 1941, Serial No. 373,006

f 9 Claims. (Cl. Z50-27.5)

This invention relates to an electrical space discharge tube of the vacuum type in .which the dimensions of the tube are reduced to relatively small value s. Such tubesare particularly useful` in small portable devices, such as hearing aids and pocket radios. Devices of this kind are so small in size that they may be carried by the user concealed in the clothing. Therefore, it is important that the tubes be made extremely small in order that they may be utilized in such 'I'he foregoing and other objects of this inven-V tion will -be best understood from the following description of an exempliiication thereof, reference being had to the accompanying driwings wherein:

Fig. 1 is a cross section of my novel tube taken along line I I of Fig. 2;

Fig. 2 is a cross section taken along line 2 2 of Fig. l;

Fig. 3 is a longitudinal cross section of the tube shown in Fig. 1, taken along line 3 3 of Fig. 2;

Fig. 4 is a cross section of the lower portion of the tube taken along line 4 5 of Fig. 2; and

Fig. 5 is a fragmentary cross section of a. detail of the tube vtaken along line 5 5 of Fig. 2.

The tube assembly illustrated is contained Within a sealed envelope I of some suitable material such as glass. 'llhe electrodes consist of a pair of anode plates 2 2, a iilamentary cathode 3, and a plurality of

grids

5, and 6 interposed between the' cathode and the anode plates. Proper spacing and support of the electrodes is provided by upper and lower insulating spacers 1l and 8, preferably of mica. 'I'he edge of these spacers is provided with a plurality of resilient projections 9 which are adapted to resiliently engage the inner walls of the envelope I.

The anode plates 2 2 are each mounted upon and I2 are inserted 4through holes in the upper spacer 1 and the frame I0 is pushed down until its straight top portion engages the top of said insulating spacer 1. Thereupon the associated anode plate 2 is welded to the side arms II and I2 with the upper edge of said anode plate engaging the lower side of the upper insulating spacer As indicated in Fig. 2, the anode plates 2 may each be formed with grooved side edges to more readily receive the side arms II and I2 to be welded thereto. Thereupon the side arms II and I2 of each of the frames I0 are inserted through openings in the lower insulating spacer 8 which in this way is assembled in place on the anode structure. A double-armed anode bracket I3 is then welded to the lower ends of each of the side arms I2. Each arm of the anode bracket I3 is provided with a pair of ears I4 whichengage the lower side of the insulating spacer 8. In this hway, the anode assembly is completed with the two anode plates 2 electrically connected and securely fastened in place on the insulating spacers i and 8.

'Ihe

grids

4, 5 and 6 are wound upon and supported by grid side rods I5 I5, I 6 I6, and Il I'l respectively. These side rods likewise project through openings in the upper and lower insulating spacers l and 8. The assembly of these grids on the insulating spacers may take place at any convenient time during the assembly of the electrode structure. One of the side rods I'I of the grid Ii is adapted to support the lament 3 as will be described below. In' order to prevent motion of the grid E and its associated side rod II relative to the spacers 'l vand S, a pair of tabs I8 and I9 are welded on to one of the side rods Il, engaging the lower side of the insulating spacer d and the upper side oi the insulating spacer Il respectively. A. ring 2U of getter material may be conveniently supported on the electrode assembly by being welded to the upper end of one of the side rods Il.

`The lament 3 is supported between a conducting spring member 2i at its upper end' and a lament clip 22 at its lower end.A The spring member 2i is welded at one end to the upper end of the iilamentary cathode 3 and at its other end to one of the side rods Il. The lower end of the filament ii is Welded to the filament clip 22 by means of a connector tab 25. The lamentary cathode 3 is retained in the apexes of a pair of triangular slots 23 formed in the upper and lower insulating spacers 'I and 8, through the tension exerted on said filament by the spring 2l.

The form of these triangular slots and their relationship to the cathode supporting arrangement is more fully described and claimed in the copending applicatio of Alan C. Rockwood for "Discharge tube s ers, Serial No. 353,108, nled August 1'7, 1940, now Patent No.' 2,266,080, dated December 16, 1941. l'Ihe filament clip 22 is made in a V-shape with two end portions 24-24. These end portions are firmly secured to the insulating spacer 2 by being inserted through holes in said lower insulating spacer and by being bent over so as to engage both the top and the bottom of said insulating spacer 2. In the small space available, the points at which the ends 24 of the filament clip' 22 are'secured to the insulating spacer 8, are substantially in line with the anode plates 2-2. In order to provide space for the ends 2l, and to avoid electrical contact there- `with, the anode plates 2--2 areeach cut away to provide an opening- 26 adjacent the respective ends 2| of the clip'22.

A plurality of lead-in

conductors

21, 22, 28, 20 and 2l, are provided for the

electrodes

2, 5, 2, l,

assaoss and 2 respectively. For this purpose, the lead-in 21 is welded to the anode bracket I2, ltheklead-in 22 is welded to one of the side rods I8 of the grid 5, the lead-in 29 is welded to the iilament clip 22, the lead-in 20 is welded to one oi.' the side rods I5 of the grid l, and the lead-in 2i is welded to one of the side rods I1 of the grid 6. All of the lead-.ins are sealed through la lower press 22 formed externally on the envelope I. In this way the electrode assemblyis retained in place within said envelope and external electrical -connections are provided to the respective electrodes.

One of the main factors determining the maximum width of the electrode assembly is the space necessary for the i'll'ament 2, the side rods II, II and I1, and the associated grid windings. -A certain minimum amount of space is necessary to be left between .these various elements. It will be noted that the filament 2 occupies a minimum amount of space by being made as a straight nlament, the return connection for said lament being made through one of the side rods I1. In

the present structure, I have also decreased the,

overallfdimensions by making the width of each of the plate elements 2 narrower than the maximum width of the'grid 2. This is possible because the electron stream which passes from the lament 2 to the `plates 2 is substantially nonexistent or non-eiective upon the dimensionsv of the plate as described above. By narrowing the plate in this way, the sides of the glass envelope I in the cross section as illustrated in Fig. 2 can be curved inward soonerv'thus decreasing sub'- stantially the minor width of the tube, permitting the use of the comparatively iiat tube cross section illustrated.

. From Figs. 3 and 4 it will be seen that the sides of the anode bracket l2 and the lament clip 22V are tapered toward the bottom portions thereof.

'This is done so that these members do not come lof the lament clip 22, a considerable amount of space is saved and the spondingly reduced.

' By the above arrangement, I have,l been able size of the tube correto produce tubes as illustrated herein of very small size on a mass lproduction basis. For example,

a tube exactly as described above has been constructed withthe outside overall dimensions ol spaced from the tube being .285 man thick. .ses inch wide.- ,and 1 V, inches long.

Of course it io be understood that this invention is not 'limited to the particular details as described above as many equivalents will suggest themselves to those skilled in the art. For example, the invention can be applied to tubes ofother types in which otherlnumbers oi' grids might be used. Various other changes embodying the teachings of this invention will suggest themselves to those skilled in the art.

What is claimed is:

1. An electrical spacedischarge tube comprising an insulating spacer, a metal frame member having a portion engaging one side of said spacer and a portion projecting through said spacer, an electrode secured to said latter portion and engaging theother side of said spacer 'and at least one additional electrode spaced from said rst named electrode by said spacer. A,

2. An electrical space discharge tube comprising an insulating spacer, a metal frame member having a portion engaging one side of said spacer electrode spaced from said ilrst named electrode by said spacers.

3. An electrical space discharge tube comprls" ing an insulating spacer, a U-shaped metal frame member having its end portion engaging one side of said spacer and its` leg portions projecting through said spacer, an electrode secured to said leg portions and engaging the other side of said spacer and at least one additional electrode said iirst named electrode by' said spacer. f

4. An electrical space' discharge'tube compris- I ing an insulating spacer, a U-shaped metal frame member having its end portion engaging one side of said spacer and its leg portions projecting through said spacer, an electrode secured to said leg portions and engaging the other side of said spacer, a second insulating spacer, said electrode engaging one side of said second spacer, said leg portions of said frame member also projecting through said second insulating spacer, a stop member secured to one of said leg portions and 'rst named electrode by said spacers.

5. An electrical space discharge tube comprising an insulating spacer, a pair of metal frame 60 members eachhaving a portion engaging one side of said spacer and a portion projecting through said spacer, an electrode element secured to said latter. portion and engaging the other side of said spacer, a secondinsulating spacer, said electrode element engaging one side of said second spacer, said latter portion of said framel member also projecting through said second insulating spacer, an electrically conducting yoke member secured to and electrically interconnecting the latter portions of both of said frame members and engaging the other side of said second spacer and at least one additional electrode spaced from said nrst named electrode by said spacers.

' 6. An electrical space discharge tube comprising am insulating spacer, a pair -of U-shaped metal frame members each having its end portion engaging one side of said spacer and its leg portions projecting through said spacer, an electrode element secured to said leg portions and engaging the other side of said spacer, a second `insulating spacer, said electrode element engaging one side of said second spacer, said leg portions of said frame` member also projecting through said second insulating spacer, an electrically conducting yoke member secured to and electrically interconnecting both of said frame members and engaging the other side cf said second spacer and at least one additional electrode spaced from said iirst named electrode by said spacers. Y, l

'7. An electrical space discharge tube comprising an insulating spacer, a relatively extended electrode closely adjacent said spacer, a conducting fastening member secured to said insulating spacer and lying substantially in the plane of said electrode, said electrode being provided with an opening adjacent said fastening member whereby said fastening member projects into said opening and is insulated from said electrode.

8. An electrical space discharge tube comprising an electrode assembly having a planer spacer at one end thereof, an envelope enclosing said electrode assembly and having a non-circular cross-sectional area providing a plurality of cor- 'ner regions of substantially increased curvature, the distances between diagonally opposite corner regions constituting the maximum straight line distances within said cross-sectional area, said spacer likewise having a. plurality of corners prol jecting into and intimately contacting the inner wall of said envelope at said corner regions. whereby said spacer can be inserted into said envelope only in a predetermined orientation.

9. An electrical space discharge tube comprising an electrode assembly having a. planer spacer at one end thereof, an envelope enclosing said electrode assembly and having a cross-sectional area with one cross-sectional dimension substantially shorter than another,v producing four corner regions of substantially increased curvature, the distances between diagonally opposite corner regions constituting the maximum straight line distances within said crossfsectional area, said spacer having likewise four corners projecting into and intimately contacting the inner wall of said envelope at said corner regions, whereby said spacer can be inserted into said envelope only in a predetermined orientation.

NORMAN B. KRIM.