US1731282A - Mount for electron devices - Google Patents

Description

' Oct. 15, 1929. P. 1''. WEEKS 1,731,282

MOUNT FOR ELECTRON DEVICES Fil ed Nov. 29. 1922 9 v INVENTC)R' 6 PAUL 7: war/(s- 27 ATTORNEY Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE PAUL THORNE HEIRS, OF CALDWELL, NEW JERSEY, ASSIGNOR TO WESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA MOUNT FOR ELECTRON DEVICES Application filed November 29, 1922. Serial No. 603,891.

This invention relates to the manufacture of electron devices and more particularly to radio tubes and the like.

, An object of the invention is to provide an electron device having the elements so supported and disposed with relation to each other that better electrical characteristics are attained with a reduction in the microphonic effect.

Another object is to provide a mount for an electron-emission device which will be compact and facilitate the assembly and mounting of the component parts thereof.

A further object is to provide a tube in which an effective relation between a grid, a plate and a filament is obtained.

Other objects -and advantages will be apparent from the following description.

The invention may advantageously be embodied in electron-emission devices of the type employed with radio equipment. Devices of the above character usually comprise a bulb having a mount sealed therein, the bulb being evacuated by any suitable means. Such devices are known in the art as radio tubes or radiotrons. The mount, which constitutes the internal construction of a radio tube, may comprise a cathode or filament positioned within a grid, the grid being surrounded by an anode or plate. These three ele ments are usually held in given relative positions by support members and byrelatively rigid leading-in wires embedded in a press; namely the compressed portion of one of the component parts of the mount termed the flare tube.

It is of considerable importance, when manufacturing radiotrons., to have a struc ture which will facilitate the proper positiona relation.

ing of the elements in a desired relation and for efiicent service of the device under practical working conditions, it is desirable to position the elements in a symmetric spaced Various types of radiotrons or radio tubes have been used. For instance, that in which the plate and grid are rectangular in cross section in the three planes.

With this type, the filament has usually been in the form of a V or a W and is supported at three or more points.- The plate and grid actually or in effect, operate" as plain rectangular surfaces parallel to the plane of the filament. Another type of a radio tube is that in. which the grid and plate are concentric cylinders, the filament being disposed along their common axis and supported at the ends only.

It is known that, with a given filament and a given spacin between the filament and grid and the gri and plate, better electrical characteristics are given by the cylindrical construction than by the parallel plane construction. It is also known that in order to secure good characteristics with the parallel plane construction, the clearance between the elements must be much less than with the cylindrical construction. From this it will be understood that a cylindrical or concentric arrangement of the elements is desirable.

It has been found, however, that when a long filament is mounted in the cylindrical construction, it is essential to employ resilient members to support and maintain the filament taut in order to prevent breaking and sagging. A filament so supported is apt to or. rectangular construction involves the ar-- *rangement of the elements with such small clearance spaces between them that the as-' sembly of the elements is extremely diflicult.

In the present invention the above disadvantages are avoided and a relatively long filament may be employed. Good results have been obtained by arranging a filament in angular or inverted V-shape supported at the ends and at the middle point or vertex of the angle. The plate and grid may be formed in the shape of flattened truncated cones. The plate may be provided with suitable lugs or projections for attachment to support members and the filament and grid may also be of the tube, they may be rounded out or separated somewhat at the middle to give greater clearance for the supporting wires. By reason of th1s bulge or increase of the cones, 1t

. will be evident that more room may be had for the disposition of the grid over the filament and of the plate over the grid. The operation of mounting the elements is thus greatly facilitated.

The invention will be more fully understood by reference to the accompanying drawing in which,

Fig. 1 is a side view in elevation of a radio tube'having a mount therein embodying my invention;

Fig. 2 is an end elevational view of the mount shown in Fig. 1;

Fig. 3 is a plan view of the angular filament;

Fig. 4 is a view in elevation of the filament shown in Fig. 3; v

Fig. 5 is a plan view of the grid;

Fig. 6 is a view in elevation of the grid shown in Fig. 5; I Fig. 7 is a plan view of the plate;

Fig. 8 is a view in elevation of the plate shown in Fig. 7; and,

Fig. 9 represents, diagrammatically, the

relative positions of the grid and plate at.

their circular portions and the position ofthe filament with respect thereto.

As illustrated, the invention may comprise a mount 1 including a flare tube 2 provided with the usual flare press 3 in which are embodied support wires 4 and 5, to which a plate 6 may be welded or otherwise secured. Ears 7 and 8, to which the support wires 4 and 5 may respectively be fastened, are provided on the plate." The support wire 5 may have a lead-in wire or conductor 9 connected thereto.

Disposed within the plate, is a grid 11 welded or otherwise secured to a relatively rigid support wire 12, which is also embedded in the press 3 and may have connected thereto a leading-in wire or-conductor 13. A looped filament 14:, which preferably consists of an angular or inverted V-shape wire, may be disposed within the grid and with the legs or straight portions 15 and '16 thereof, disposed in a given symmetric relation tothe sides of the grid. The filament may be supported at its lower ends by welding or otherwise securing to support wires 17 and 18,

which may also be connected with leading-in conductors 19 and 21 respectively.

A third filament support member 22 secured'in the press 3 may extend directly to the vertex of the filament or may be, offset from the press and extend upwardly above the plate andbe connected by a flexible support 31 to the vertex of the filament to aid in maintaining it in a given position on the mount.

The wires of the conical helix comprising thegrid, are preferably held together by a stiffening bar 29 which may be welded to the sup port member 12 for securing the grid in place.

The filamentmay be so proportioned as to be symmetrically spaced from the grid when the elements are intheir operative positions.

The effective portions of the grid and plate being the circular ones, it is desirable to properly dispose these surfaces with respect to each other and by the use of a V-shaped filament together with the peculiarly shaped grid and plate, a construction is provided whereby the filament may be supported in a practical and efficient manner and, at the same time, the greater portion of the filament will be disosed in effective relation, that is, substantialy at the centers of the circular portions of grid and plate as shown in Fig. 9 in which the filament 14' is shown centrally disposed with respect to the circularly curved portions 27 of the grid and 24 of the plate.

Where desirable, the circular portions 23 and 24 of the plate and the circular portions 26 and 27 of the grid may be connected by arcuate portions which bulge outwardly from their axial line to a greater or less degree, as desired. This allowance provides for the more convenient positioning of the elements during the mounting operation.

When a radiotron mount is to be manufactured, the filament 14 is properly positioned and secured to the support members 17 and 18. The grid 11 may then be placed over the filament in the proper plane and adjusted by moving the grid axially until the filament legs 15 and 16 are substantially at the centers of the circular portions 26 and 27 of the grid which may then be secured to the support member 12. Finally the plate is symmetrical- 1y disposed about the grid and secured to the supportwires 4 and 5.

When the several elements have been thus ositioned, the upper end or vertex of the amentmay be secured or hooked upon a.

proportions of the elements. Also, it will bev seen that the filament may be so disposed that practically its entire length is made effective, since its position approaches the ideal with respect to the grid and plate, the'axial line of the legs of the filament being so disposed as to coincide with the axis of the semi-circular portions of the grid and plate.

The peculiar tapering shape of the elements as employed in my invention makes it possible to more readily adjust them to obtain a symmetric spaced relation. Where a filamentisin place, it will be seen that the grid may be placed thereover and, by an axial adjustment of the grid, a greater or lesser space may be provided. The same is'true with respect to the plate when disposed over the grid.

It will therefore be evident that not only may the desired spaced relation be conveniently lad but the distances between the elements may be adjusted without altering the symmetrical relation of the elements.

With the above construction, a mount is provided in which the most effective portions of the elements are utilized and in which the tendency toward microphonic efiects isgreatly reduced.

Although I have shown and described the preferred embodiment of my invention, it is to be understood that modifications may be made therein without departing from the spirit and scope of the appended claims.

What is claimed is:

1. A mount for: an electric device comprising an angular filament, a gridof flattened truncated cone shape disposed about said filament, a plateof truncated cone shape disposed about said grid, the legs of said filament being disposed in uniform spaced relation to the inner surface of said grid.

2. A mount for an electron device comprising a filament of inverted V-shape, a grid of flattened truncated cone-shape disposed about said filament and a plate of flattened truncated cone-shape disposed in nested spaced relation to said grid.

3. A mount for an electron device comprising a filament of invertedV-shape, a grid having sections in the form of partial cylinders connected by substantially flat portions and so disposed about said filament as to position said filament substantially concentric to said partial cylindrical portions and a plate similarly shaped but proportionately larger than said d to permit its being positioned about saif g rid and in a symmetric spaced relation thereto.

4. A mount for an electron device comprising a filament of inverted V-shape, a grid having portions in the form of partial cylinders connected by substantially flat portions and so disposed about said filament as to position the filament in symmetrically spaced relation to said partial cylindrical portions, and a plate having partial cylindrical portions connected b straight portions and so disposed about said grid that the partial cy- ,lindrical portions of said plate are concentrically disposed with respect to the partial cylindrical portions of said grid.

5. A mount for an electron device comprising a grid consisting of a coil which uniform- .ly increases in size from ehd to end and is of elongated curved transverse cross section, a plate comprisin a hollow body of similar shape but of su ciently greater dimensions than the grid, so that said plate may be dis-- posed about said grid and symmetrically spaced therefrom and a filament so disposed as to pass substantially through the centers of the curved end portionsof said grid and plate. Y

6. A mount for an electron device comprising a filament of inverted V-shape, a .grid having sections of relatively small radii connected by substantially straight portions and so disposed about the filament as to position the legs of said filament upon the axial line of said sections and a plate having substantially partial cylindrical portions connected by substantially straight portions disposed about said grid with the axial lines of said partial cylindrical portions coincident ,with the axial lines of the legs of said filament.

7. A mount for an electron device comprising a filament of inverted V-shape, a tapering I grid having sections of relatively small radii connected by relativel flat portions and so disposed about said ament as to position said filament substantially concentric to said sections and a plate similarly shaped, but proportionately larger than said grid, to permit its being positioned. about said grid and in a desired spaced relation thereto.

In testimony whereof, I have hereunto subscribed my name this 28th day of November 1922.

PAUL THORNE

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