US2604604A

US2604604A - Mount for electron discharge devices

Info

Publication number: US2604604A
Application number: US105786A
Authority: US
Inventors: George F Elston
Original assignee: Bendix Aviation Corp
Current assignee: Bendix Aviation Corp
Priority date: 1949-07-20
Filing date: 1949-07-20
Publication date: 1952-07-22
Anticipated expiration: 1969-07-22

Description

July 22, 19 G. F. ELSTON MOUNT F OR ELECTRON DISCHARGE DEVICES 4 Filed July 20, 1949 GEORGE F. ELSTGN yond the outer surfaces of the spacers.

Patented July 22, 1952 MOUNT FOR ELECTRON DISCHARGE DEVICES George F. Elston, Bloomfield, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application July 20, 1949, Serial No. 105,786

Claims. (01. 313%261) The present invention relates to. mounts for I electron discharge devices and more particularly to a beam forming electrode for such devices.

Some electron discharge devices employ a cathode, "an anode, a control grid adjacent the cathode and a screen grid between the control grid and the anode. To suppress secondaries from the anode to the screen grid a slotted sheet metal electrode is sometimes used between the anode and the screen grid. This sheet metal electrode is sometimes referred to as a beam plate and is connected to a suitable voltage negative with respect to the anode, or it may be connected to the cathode inside or outside the tube envelope. The beam plate is customarily disposed between two insulating spacers or plates defining the active portion of the device.

Portions of the electrodes referred to extend through apertures in the spacers and project be- These extensions of the electrodes give rise to a problem of shielding, particularly between the projecting portions of the anode and the projecting portions of the control grid side rods. To accomplish a desired shielding between these projecting portions, it has been the custom in certain designs to provide dish-shaped metallic members seated on the outer faces of the spacers with their side walls disposed between the projecting portions of the anode and the other electrodes of the device, and extending from the insulating spacers an appreciably greater distance than the projecting portions referred to, to thereby serve as effective shields.

According to prior practices, the beam plates and each of the dish-shaped shielding members have comprised separate structures. This has required a mounting procedure involving positioning the beam plates between the spacers at the time the other electrodes are mounted between the spacers, with tabs provided on the beam plates extending through the spacers. After the electrodes, including the beam plates are positioned between the spacers the two dishshaped shielding members are welded to the tabs on the beam plate in a plurality of separate welds. Usually the beam plate is provided with four tabs at each end so that eight separate welds have heretofore been required for fixing the beam plate and the shields referred to in a mount. 7 Q

,.It is the object of the invention to provide an improved electron discharge device utilizing a beam plate and having shields at the opposite ends of a mount.

A further object is to provide an electron discharge device having a beam plate and shields wherein the cost of manufacture is reduced.

Another object is to provide a novel beam mounted in the device and which includes as an integral part thereof a shielding member for one end of the mount. y,

A further object is to provide an integral beam plate and shield assembly that is fixed in a mount by a relatively few number of welds applied at one end of the mount only. v j 1 According to one. feature of the invention, 1a combined beam plate and shield comprises a sheet metal structure including legs joinedflat one endby a transverse portion or portions. The

combined beam plate and shield is positioned in the, mount after the other electrodes of .the mount have been fixed therein by threading: the

legs of the beam plate and shield through registering apertures in two spaced insulatingspacers from one end of the mount, the transverse 'portion referred' to. being adjacent the' 'out'er face of one of thespacers where it forms. a partial enclosure for shielding the anode tab from the control grid {side rods projecting through the spacer. According to'one aspect of theinvention the transverse portion includes a flat plate having an aperture for accommodating the projecting portions of some of the electrodes'and which is seated on the outer face of theupper spacerinthemount Ears integral with the flat plate extend upwardlyfrom the mount between the anode tabs and the projectingportions of the other electrodes of the mount for shielding the anode tabs from such electrodes. According to another aspect of the invention the transthe top of the mount.

Other objects and features will become evident as the present description continues. l I

Referring to the drawing: 1 Figure 1 shows an elevation partly in section of an electron discharge device employing the integral beam plate and shield of the invention; Figure 2 is a cross-section along the line 2=- -2 of Figure 1;

Figure 3 is a perspective view of one form'iof Referring in more detail to Figure l, thereis shown an electron discharge device havingan envelope I closed at one end by a stem and enclosing a mount. The mount includes an anode I2 comprising two partsconnected by con- 'tshown-in Figure 3,- -the legs I1, I13, I 9,: 2B oft he beamplateareintegral with the transverse por- "tion 25,"having upstandingears26, 2I- and' an aperture 28 for accommodating the portions of the cathode, the control grid and-screen grid that extend through the upper spacer" 23 and project from the outer faceofsa-id spacer. The

ears

25, 21 are positioned between anode tabs-29,60 and grid side rods 3|, extending through the spacer 23 for shielding the anode tabs 'from-the'projectlng grid side rods, particularly the control grid side rods. The legs I], I8, I9, '20 of the beam plate terminate in tabs-'32,:which when'the beam plate is positioned in amount, extendbelowthe outer face of the "lower spacer and. are'iixed to .a lower dish-shaped shield '33-as by welding. .If each of the four le s referred toare welded to thelower shield 33,, atotal'number of. four welds are required. Under .prior. practice where i h uppershield was separate from the beam plate and four tabs are provided .in the beam plate for mount, the'noyel .coImb-inedbeam plate and. shield of the jinventionis superior -to-prior. separate beam plates andshields ingthatitpermits mounting the beam-plate after the other electrodes have been mounted and fixed-to the-spacers 23, .24.

: Under the previous practice Where the beam plate was provided with-tabsfor extending through each of the spacers,-it -Was necessary that ..the spacers 23,124 be-separated'for a mounting of'the "beam plate therebetween: This practice therefore made it impossible to fire-the other-electrodes to the spacers pr-iortothe mounting of the beam plate. 1

-:In mounting electrodes-between twos-pacers of the type "described, theoperation becomes more difiicult'with an increase-in the number of-electrodes to be mounted at one time. by eliminating the beam plate from theelectrodes requiring,mounting-priontofixing of the spacers to some of the,.e1ectr0des,..the manufacture of a device in which the integral beam plate .and

shield of theinvention'is' .usdis facilitated.

Moreover, the integral beam plate. and shield of the invention may be formed from one sheet metal blank "in a relatively simple stamping and forming operation,"thusfi'further contributing to facilityan'd economy inmanufacture. An addi- 'tional advantage is that the integral beam plate and shield of the-inventionreduces the number of separate 'elemen tsrequiring individual handling during manufacture of an electron dis- ;charge device.

Therefore, -3

'legs.

31, while connector 39 lies in the plane of legs A modified form of integral beam plate and shield .is .shown in Figure 4. According to this modified form the legs'34; 35, 36, 31 are joined by

connectors

38, 39, 40, which are integral with the Connector 38 lies in the plane of legs 36,

.34, 35. Connector 4E3 lies in a plane normal to the plane of

connectors

38, 39. Thus, when the beam plate shown in Figure 4 is used in a mount of the type illustrated in Figure 1, the lower edges of

connectors

33, 39, 40 abut against the outer face of-the upper spacer 23, with the

connectors

38, 39 disposed between the anode tabs extending above the spacer 23 and the grid side rods extending also above this spacer, to eifectively shield the anode tabs from the grid side rods. To shield the end'of. the mount a cover :or flap AI ='integral with-connectorlfi :may be provided, which "is foldable to engage the upper-edges of

connectors

38, 39 to form therewith a box closed'at three sides. The free ends of the-

legs

34, 35, 36,31 project below the lowerspacer' 24 for welding to the dish-shaped shield'33. I

It, will be appreciated from the foregoing tha the invention provides for an advantageous integral structure that combines a beam plate and a shield in one unit. Thestructure can be made readily from a single sheet metal blank'and contributes to economy in the manufacture of an electron discharge device in a number of ways including reducing the'num'ber of parts requiring handling, facilitating the .mounting operation, and reducing the number of welds requiredfor fixing the beam plate and one shield in a. mount.

Departures from the described embodiments of the invention are possible Within the spirit of the invention and it is desired to include such departures within the scope of the appended claims.

I claim:

'1..A mount for an electrondischarge device including two fiat spaced insulating-spacer plates disposed in parallel-relation and electrodes supported betweensaid {plates and having portions projecting beyond. the outer faces-of said plates, said electrodes including a beam forming sheet metal electrode comprising two spaced portions, means, for shielding said projecting portions, said means comprising shields extending normal to said outer faces of said spacer plates 'and disposed between certa-inof said electrodes, oneof said shields being vintegral-Withand joining said spaced portions of said beam forming sheet metal electrode for reducing the number of parts in said mount and for permitting said mount to be assembled in an advantageous manner- 2. A mount for an electron discharge device including two spaced co-extensive insulating spacers and electrodes supported between said spacers including an anode, a control grid and a beam forming electrode between the anodeand control grid, a portion of said anode and control grid extending beyond the outer faces of said spacers, and shields engaging said outer faces of said spacers and disposed between said extending portions of said anode and control grid,

' one of said shields being integral with said beam forming electrode, and including a portion in edge engagement with a face of one of said spacers.

3. A mount for an electron discharge device including two spaced parallel insulating spacers, a plurality of electrodes supported between said spacers and extending through said spacers beyond the outer faces thereof, and shields adjacent said outer faces for shielding the portions of said electrodes extending through said spacers, one of said electrodes comprising a sheet metal beam forming electrode, one of said shields being integral with said beam forming electrode and engaging the outer face of one of said spacers, said beam forming electrode having legs extending through the other of said spacers, the other of said shields being fixed to adjacent ends of said legs.

4. A mount for an electron discharge device comprising two spaced parallel co-exten'sive insulating spacers, a plurality of electrodes including a control grid, an anode and a beam plate electrode supported between said spacers, a portion of said electrodes extending through said spacers and projecting from the outer faces thereof, said beam plate including two pairs of legs extending normal to said spacers, the legs of said pairs being joined by portions integral therewith lying in spaced parallel planes, said portions being integrally joined by a further portion lying in a plane normal to said parallel planes and said spacers, said portions being disposed between a portion of said anode and a portion of said control grid for electrostatically shielding the one from the other, said portions and said further portions having edges engaging an outer face of one of said spacers.

5. A mount for an electron discharge device comprising two spaced parallel co-extensive insulating spacer plates, and electrodes supported between said spacer plates including an anode, a control grid and a sheet metal beam forming electrode, said beam forming electrode having legs and a transverse portion integral with said legs joining adjacent ends of said legs, said transverse portion engaging the outer face of one of said spacer plates and including ears extending normal from said face, said anode and control grid extending through said spacer plates and projecting beyond the outer faces thereof, said ears being disposed between the projecting portions of said anode and control grid for shielding the anode projecting portions from the control grid projecting portions, the free ends of said legs extending through the other of said spacer plates, and another shield adjacent the outer face of the other of said spacer plates and connected to the free ends of said legs.

6. A mount for an electron discharge device comprising two spaced parallel insulating spacer plates, electrodes including an anode, a control grid and a beam plate electrode supported between the inner faces of said spacer plates, said anode and control grid having portions extending through and projecting beyond the outer faces of said spacer plates, said beam plate electrode comprising a sheet metal structure having a plurality of parallel legs joined at adjacent ends by a transverseportion integral with said legs, said transverse portion including portions lying in planes parallel to the longitudinal axes of said legs, said last-named portions being adjacent the outer face of one of said spacer plates and disposed between said projecting portions of said anode and control grid for shielding said electrodes from each other, the free ends of said legs extending through and projecting from the outer face of the other of said spacer plates, and a shield adjacent the outer face of the lastnamed spacer plate and fixed to said free ends of said legs for shielding the portions of said anode and control grid projecting from the outer face of said last-named spacer plate and for restraining said beam plate electrode against movement in said mount.

7. A mount for an electron discharge device including a cathode and grid arranged to provide electron paths from two opposite sides of said cathode, an anode in registry with said paths, and a sheet metal electrode having four legs joined by an integral connecting portion at one end of said legs, said legs being disposed parallel to the longitudinal axis of said cathode and positioned to lie on opposite sides of said electron paths between said anode and grid.

8. A mount for an electron discharge device including two spaced insulating spacer plates, a cathode, grid and anode in coaxial relation supported between said spacer plates, and a sheet metal electrode having two pairs of elongated legs and a connecting portion integral with said legs and joining one end of said legs, said spacer plates each having two pairs of registering apertures for receiving said legs, each pair of said legs being disposed with one leg on each side of an electron path from said cathode to said anode.

9. A mount for an electron discharge device including oppositely disposed spaced spacer plates, a coaxial array of electrodes between said plates including a cathode for providing electrons along oppositely disposed electron paths, a grid surrounding said cathode, and an anode farther spaced from said cathode than said grid and having portions disposed on opposite sides of said cathode for receiving electrons from said cathode along said paths, and a sheet metal electrode having two pairs of elongated legs and a connecting portion integral with said legs and joining said legs at one end thereof, said spacer plates each having two pairs of registering aper- A tures for receiving said legs, one pair of legs of said sheet metal electrode being positioned between each side of said cathode and said anode, one leg of each pair being on one side of said electron paths, said connecting portion lying adjacent a face of one of said spacer plates outside the space between said spacer plates.

10. A shielding grid for an electron discharge device comprising two parallel U-shaped structures each having two legs adapted to extend between two spaced parallel spacer plates and including an integral transverse portion engaging a face of one of said plates for electrostatically shielding an electrode of said device, said structures being integrally joined by a portion thereof extending transversely of said structures and engaging said face for further electrostatically shielding elements of said device.

GEORGE F. ELSTON.

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

UNITED STATES PATENTS Number Name Date 2,067,825 Bullimore Jan. 12, 1937 2,107,519 Shoenberg et al Feb. 8, 1938 2,225,465 Scharfnagel Dec. 17, 1940 2,411,184 Beggs Nov. 19, 1946 2,459,072 Haines Jan. 11, 1949 2,476,940 Wood July 19, 1949