US3151265A

US3151265A - Anode electrode for electron discharge devices and method of making the same

Info

Publication number: US3151265A
Application number: US170969A
Authority: US
Inventors: Joe F Stephens
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1962-02-05
Filing date: 1962-02-05
Publication date: 1964-09-29
Anticipated expiration: 1981-09-29

Description

Sept. 29, 1964 J. F. STEPHENS 3,151,265

mom: ELECTRODE FOR ELECTRON DISCHARGE DEVICES AND METHOD OF MAKING THE SAME Filed Feb. 5, 1962 FIG.I.

FIG.4.

FIG.8.

Ec I O VO E6 IO VOLTS INVENTORZ JOE F. STEPHENS,

5;, VUL rs United States Patent 3,151,265 ANUDE ELE CTRGDE FGR ELEQTRON DHSCHARGE DEVECES AND METHQD 9F MAKING THE SAME .loe F. Stephens, (iwenshoro, Kym, assignor to General Electric Company, a corporation ot New York Filed Feb. 5, 1962, Ser. No. 170,9e9 6 Claims. (U. 313-356) This invention relates to power tubes and in particular to the structure of an anode for a beam power tube or the like to minimize various oscillations within the tube and to a method of forming such an anode.

Beam power tubes are electron discharge devices, which usually include a cathode, an anode, a control grid, a screen grid and shaped electrodes for the purpose of concentrating and confining the electrons in the shape of beams. In addition, the grids of said tubes may have parallel spacings to further concentrate the electrons in beams. The electron density affects the space charge region existing between the screen grid and the anode to produce a negative voltage gradient near the anode which acts as a virtual cathode and eliminates the necessity of a supressor grid in reducing secondary emission effects. Beam power tubes have the advantages of high power output, high power sensitivity, high emciency and are consequently extensively used. This type of tube like any other tube has a family of plate voltage versus plate current curves, with different control grid voltages, characterlzed by a sharp rise in plate current with initial increase in plate voltage and a subsequently fairly flat portion with increasing plate voltages. At the juncture of the two portions of the curve, a sharp bend or knee occurs. When this knee is at a high plate potential level the tube may give rise to RF. radiations. This is particularly of concern when the tube is driven to values orplate potential that are less than that at which the knee appears. When using beam power tubes in the horizontal deflection circuitry of television receivers, such RF. radiations may be picked up by the antenna or parts adjacent the tube, and transmitted through the set giving rise to jagged vertical lines at the right hand side of the picture tube, these lines being known in the art as snivets. At lower plate potential levels of the knee, such conditions do not arise. These spurious oscillations or snivets emanating from the beam power tubes may appear as cyclic interference on one side of the picture tube raster as a vertical band or hands, either curved or straight, continuous or broken, depending upon the strength of the spurious oscillations.

in the prior art the removal of the spurious oscillations or snivets has been accomplished by lovering of the knee voltage by bringing portions of the tube anode closer to the grids, but with portions of the anode sufficiently spaced from the beam confining plates so as to prevent flash-over. Protuberances have been extruded from the anode toward the grids to extend the anode electrostatically closer to the grids as shown in Patent 2,857,544. Other prior art devices have utilized internal fins made of strip material jig-held to one half of the anode and welded while so held or by the use of additional material in the form of a fin insert assembly to fit between complementary anode halves of the anode structure of a beam power tube such as shown in Patent 2,843,787. It is to an improvement on the latter type of construction that this invention is directed.

Accordingly, it is a principal object of this invention to provide an improved method for forming an anode of a beam power tube with an internal fin assembly.

A further object is to provide a method of forming an anode with an integral internal fin assembly with greater ease of fabrication and reduced cost.

cs ea Yet another object is toprovide an improved anode structure with an integral internal final fin assembly for use in a beam power tube or the like.

The method of obtaining the foregoing objects of forming an anode of a beam power tube with an integral internal fin assembly includes, in one embodiment, the steps of first, forming a first channel-shaped member having a pair of side walls and an end wall with the respective flange member extending outwardly from one end of each side wall. Each flange member forms an essentially right angle with the ends of each side wall. The second step includes bending each flange member to form respective first and second sections with the second sections overlying the first sections and extending inwardly past respective side walls to form internal fin members for the anode when finally assembled. It is these fin members which operate to lower the knee voltage of the beam power tube, thereby removing the spurious oscillations by bringing portions of the tube anode closer to the grids. The third step includes forming a second sheet of material into a second channel-shaped member having a pair of side walls and an end wall with a respective flange member extending outwardly from one end of each side wall. Each of the flange members of the second channel-shaped members forms an essentially right angle with the ends of each side wall and is adapted to overlie respective flange members of the first channel-shaped member, when the two channel-shaped members are joined. The fourth step in the forming of the anode with integral internal fin assembly includes securing said first and second channel-shaped members together by any known means which may include welding of the respective flange members together.

Other objects, features and many of the attendant advantages of the invention will be appreciated more readily as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. i is a side elevation view of a first piece of blank stock from which the anode is to be formed;

FIG. 2 is a side elevation view of the first piece of lank stock following a first forming step;

FIG. 3 is a side elevation view of the first piece of blank stock following a second forming step in which the integral fin assembly is produced;

FIG. 4 is a side elevation view of a second piece of blank stock;

FIG. 5 is a side elevation view of the second piece of blank stock following a first forming step;

FIG. 6 is a side or end View of the tubular anode assembly after manufacture but prior to final assembly within the discharge device;

FIG. 7 is a sectional view of a beam power tube comprising the anode structure of the invention; and

FIG. 8 is a graph of plate current versus plate voltage characteristic curves showing the comparison between beam power tubes incorporating an internal fin assembly and those without such an assembly.

Referring to the drawings and particularly FIG. 1, there is shown an elevational view of a piece of blank stock prior to being worked to form one half of the anode assembly of a discharge device such as a beam power pentode. FIG. 2 shows the first piece of blank stock 1 after it has been formed through some suitable process such as punching die forming, or extruding into a substantially channel-shaped member 1 having a pair of side walls 3 and 4 and an end wall 5 with respective flange members 6 and 7 extending outwardly from one end of each side wall. Each flange member forms an essentially right angle at the ends of each side wall.

In FIG. 3 the flange members 6 and 7 have been bent in a second forming step to form first sections 8 and 8a and second sections 9 and 9a with the second sections '3 cl? overlying respective first sections and extending inwardly past respective side walls 3 and 4 to form

fin members

10 and 11.

FIG. 4 is an elevational view of a second piece of blank stock prior to forming steps to produce second half of the anode assembly. The blank piece of stock as shown in FIG. 4 has previously been subjected to an embossing

operation forming corrugations

13 and 14, which extend longitudinally the length of the piece of stock. It should be obvious to one skilled in the art that the embossing to form

corrugations

13 and 14 can be done prior to the forming steps in manufacturing the anode and fin assembly or it can be done after the piece of blank has been formed into the desired shape for the anode structure. FIG. is an elevational view of the second piece of blank stock after the first forming operation, which again may be a punching operation die forming, or extruding process to form a second channelshaped member 15 having a pair of side walls 17 and and an end wall 19 with respect to

flange members

21 and 22 extending outwardly from each end of the

side walls

17 and 18 and adapted to overlie respective flange members of the first channel-shaped member 1.

At this juncture in the operation, the two channel shaped members shown at FIG. 2 and at 15 (FIG. 5) may be secured together by any known securing means such as welding or staking or by striking tongues in one set of flange members e.g. 6. 7 on channel-shaped member 21 and openings in the flange members 21, of the second channel-shaped member 15 through which the tongues on the first flange members will pass as shown in Patent 2,843,787. However, an additional operation which will provide an improved anode structure is produced by bending the ends of

flange members

21 and 22 of the second channel-shaped member 15 to form

portions

23 and 24 at essentially 90 angles with respective flange members. When the two channel-shaped members are joined together, these

bent portions

23 and 24 may, if desired, be formed to overlap the flange members 5 and 6 of the first channel-shaped member 1, as shown in FIG. 6, to more firmly secure the two channel-shaped members together, or, the

portions

23 and 24, as shown in the top View of the completed anode assembly in FIG. 7 may extend beyond the flange members 5 and 6.

As has been previously stated, when a beam power tube of the type described above is used in the horizontal deflection system of a television receiver, the tube may cause transient or spurious oscillations or snivets to be generated which will result in vertical. lines on the picture tube of the television receiver. In a beam power tube using the fin assembly produced by the method of manufacture described above and resulting in internal fins 9 and 1; (FIG. 6), spurious oscillations are eliminated or so greatly reduced that no interfering lines are apparent on a television receiver. It, should be obvious to one skilled in the art that beam power tubes incorporating this feature may 3150 be used toreduce high frequency interference in the outputof radio receivers.

It should be further noted that in the process of manufacture ofthe anode the longitudinaledges of the fins and 11 may be serrated to thereby offer substantially reduced secondary-electron-producing surfaces.

FIG. 7 is a top view of a beam power tube with the tube envelope 30 enclosing the anodestructure of the subject invention comprising the two channel-shaped halves 1 and along with cathode 31, control grid 52, screen grid 33, and beam confining plates 34. disposed so as to confine oppositely directed electron beam 35-35 therebetween.

In FIG. 8 there is showna graph indicating an improvement in the tube characteristicsresulting from utilizationof the internal fin assembly of the inventionwhich removes the sharpness in the knee of the tube characteristics as indicated by the broken lines therein.

An anode structure as shown by FIG. 6 may be pro-.

duced with greater easeof fabrication and reduced cost. The fin assembly is integral with the anode halves, therefore no additional material in the form of fin inserts is required. Further, it should be noted that in lining up the anode halves 1 and 15 prior to joining them, there is no need to line up an additional structure such as a fin insert assembly.

Although a particular embodiment of the subject invention has been described, many modificaitons may be made and it is understood to be the intention of the appended claims to cover all such modifications that fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An anode electrode for a discharge device compris- (a) a first substantially channel-shaped member having a pair of side walls and an end wall with a respective flange member extending outwardly from one end of each side wall and each forming an essentially right angle with each side wall,

(b) each of the flange members having means defining first and second sections having an intermediate bight portion, the second sections integral with and overlying the first sections and extending inwardly past the side walls to form respective fin members,

(0) a second channel-shaped member having a pair of side walls and an end wall, a respective flange member extending outwardly from one end of each side wall and overlying respective flange members of the first channel-shaped member, said flange members of said second channel-shaped member further having portions bent toward and disposed adjacent to the bight portions of the respective flange members of said first channelshaped member, and

((1) means securing said first and second channel members together.

2. An electron discharge. device, comprising an anode electrode, said anode electrode comprising,

(a) a first subtantially channel-shaped member having a pair of side walls and an end wall, a respective flange member extending outwardly from the free end of each side wall,

(b) each of said flange members having respective first and second sections having an intermediate bight portion, said first and second sections being integral with said channel-shaped member and in continuous heat conducting relation therewith, the second sections overlying the first sections and extending inwardly beyondthe side walls to form respective fin members,

(c)- a second channel-shaped member having a pair of side walls and an end wall, said side walls having respective flange members extending outwardly therefrom and overlying respective flange members of the first channel-shaped member,

(0!) the free ends of the flange members of the second channel-shaped member projecting beyond the free ends of andpositioned adjacent to the bight portions of the flange members of the first channel-shaped member, and

(e) means securing said first and second channel-shaped members together.

3. The method for forming an anode electrode for discharge device comprising,

(a) forming a sheet of material into a first substantial channel-shaped member having a pair of side walls and an end wall with a respective flange member extending outwardly from one end of each side Wall and each forming an essentially right angle with the ends of each side wall,

([2) bending each of the flange members to form respective first and second sections having an intermediate bight portion with the second sections overlying the first sections and extending inwardly to pass the side walls to form respective fin members,

(c) forming a second sheet of material into a second channel-shaped member having a pair of side Walls and an end Wall with a respective flange member extending outwardly from one end of each side Wall and overlying respective flange members of the first channel-shaped member, said flange members of said second channel-shaped member further having bent portions,

(d) embossing each flange member of said second channel-shaped member to form corrugations extending longitudinally the length of each flange member,

(e) positioning said second channel-shaped member so that the bent portions of the flange members of said second channel-shaped member are directed toward and disposed adjacent to the bight portions of the respective flange member of said first channel-shaped member, and

(f) securing said first and second channel-shaped members together.

4. The method of forming an anode electrode for a discharge device comprising,

(a) forming a sheet of material into a first substantially channel-shaped member having a pair of side walls and an end wall with a respective flange member extending outwardly from one end of each side wall and each flange member forming an essentially right angle with the ends of each side wall,

(b) bending each of the flange members to form respective first and second sections having an intermediate bight portion with the second sections overlying the first sections and extending inwardly past the side walls to form respective fin members,

(c) forming a second sheet of material into a second channel-shaped member having a pair of side Walls and an end wall with a respective flange member extending outwardly from one end of each side Wall and adapted to overlie respective flange members of the first channel-shaped member,

(d) embossing each flange member of said second channel-shaped member to form a corrugation extending longitudinally the length of each flange member,

(e) bending the ends of the flange members of the second channel-shaped member to overlap the flange members of the first channel-shaped member, and

(f) securing the first and second channel-shaped members together.

5. An anode electrode for a discharge device compris- (a) a first substantially channel-shaped member having a pair of side walls and an end wall with a respective flange member extending outwardly from one end of each side Wall and each forming an essentially right angle with the ends of each side wall,

(b) each of said flange members comprising integral first and second sections having an intermediate bight portion with the second sections overlying the first sections and extending inwardly past the side walls to form respective fin members,

(0) a second substantially channel-shaped member having a pair of side walls and an end wall with a respective flange member extending outwardly from one end of each side wall forming an essentially right angle with the ends of each side wall and overlying respective flange members of the first channel-shaped member, said flange members of said second channelshaped member further having portions 'bent toward and disposed adjacent to the bight portions of the respective flange members of said first channel-shaped member, and

(d) means to secure said first and second channelshaped members together to thereby form the anode assembly.

6. An anode electrode for a discharge device compris- (a) a first substantially channel-shaped member having a pair of side walls and an end wall with a respective flange member extending outwardly from one end of each side wall and each forming an essentially right angle with the ends of each side wall,

(b) each of said flange members comprising integral first and second sections having an intermediate bight portion, with the second sections overlying the first sections and extending inwardly past the side walls to form respective fin members,

(0) a second substantially channel-shaped member having a pair of side walls and an end wall with respec tive flange members of said second channel-shaped member overlying the adjacent second section of the first channel-shaped member,

(d) tab members projecting from the free ends of the respective flange members of the second channelshaped member and overlapping the bight portions of the respective flange members of the first channelshaped member securing said first and said second channel-shaped members together, and

(e) additional means to secure said first and second channel-shaped members together to thereby form the anode assembly.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. AN ANODE ELECTRODE FOR A DISCHARGE DEVICE COMPRISING, (A) A FIRST SUBSTANTIALLY CHANNEL-SHAPED MEMBER HAVING A PAIR OF SIDE WALLS AND AN END WALL WITH A RESPECTIVE FLANGE MEMBER EXTENDING OUTWARDLY FROM ONE END OF EACH SIDE WALL AND EACH FORMING AN ESSENTIALLY RIGHT ANGLE WITH EACH SIDE WALL, (B) EACH OF THE FLANGE MEMBERS HAVING MEANS DEFINING FIRST AND SECOND SECTIONS HAVING AN INTERMEDIATE BIGHT PORTION, THE SECOND SECTIONS INTEGRAL WITH AND OVERLYING THE FIRST SECTIONS AND EXTENDING INWARDLY PAST THE SIDE WALLS TO FORM RESPECTIVE FIN MEMBERS, (C) A SECOND CHANNEL-SHAPED MEMBER HAVING A PAIR OF SIDE WALLS AND AN END WALL, A RESPECTIVE FLANGE MEMBER EXTENDING OUTWARDLY FROM ONE END OF EACH SIDE WALL AND OVERLYING RESPECTIVE FLANGE MEMBERS OF THE FIRST CHANNEL-SHAPED MEMBER, SAID FLANGE MEMBERS OF SAID SECOND CHANNEL-SHAPED MEMBER FURTHER HAVING PORTIONS BENT TOWARD AND DISPOSED ADJACENT TO THE BIGHT PORTIONS OF THE RESPECTIVE FLANGE MEMBERS OF SAID FIRST CHANNEL-SHAPED MEMBER, AND (D) MEANS SECURING SAID FIRST AND SECOND CHANNEL MEMBERS TOGETHER.