US2212144A

US2212144A - Anode for electron guns

Info

Publication number: US2212144A
Application number: US218710A
Authority: US
Inventors: John R Beers
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-07-11
Filing date: 1938-07-11
Publication date: 1940-08-20
Anticipated expiration: 1957-08-20

Description

1940- J. R. BEERS 2,212,144

ANODE FOR ELECTRON GUNS Filed July 11, 1958 Patented Aug. 20, 1940 1. 1;" NiTED ST E John RrBeers, Bloomfield, Nt Application July '11, msa Q s ris sm z ar o I g y 3 Claims.

This invention relates to an anode for electron guns. The anode comprises two sheet metal lens electrode elements arranged in a metal tube and spaced apart from one another, as shown on a 5 greatly enlarged scale in the accompanying drawing. Each element comprises a disk having a peripheral flange fitting closely within the tube and by which it is frictionally held' in a desired position within the tube, and the disks have small alined perforations at their centers.

these perforations, which are about the size of a pin hole, are made by a punch which may leave sharp edges or projections at the margins of the perforations, which are objectionable from the electrical standpoint, and sometimes in forcing the elements into their desired positions in the tube the perforations are thrown out of exact alinement by warping of the disks.

The object of the present invention is to so form the elements that the foregoing objections will be overcome. In the preferred way of carrying out the invention the punched perforation in the disk is made slightly larger than the required opening and a small eyelet is inserted. in

the perforation in the disk, and by upsetting the in the tube. Similar results may be accomplished by drawing the metal of the disk in theprocess of making the central perforation, producing a circular flange which is then upset and flattened against one side of the disk by a suitable upsetting mechanism having a mandrel of the exact diameter of the hole which it is desired to produce in the disk, so that when the mandrel is withdrawn the hole in the disk will be a true circular opening of the size desired, free from sharp edges or projections, and the disk will be reinforced at its central portion adjacent. the opening, which will aid in preventing distortion of the disc when it is being pressed to its position in the tube.

In the accompanying drawing in which the anode and its lens element are shown on a greatly enlarged scale,

55 Figure 1 is a central longitudinal section Usually of the element when it is pushed into its place through the anode; showing the lens elements with eyelets in the perforations,

FigureZ is a central section through one of the discs with an eyelet fitting into the perforation in the disc, 5

Figure 3 is a similar view showing the eyelet ends flattened against the faces of the disk around a mandrel of an upsetting tool,

Figure 4 is a central section through one of the discs with the perforation in the disk made 10 by drawing the metal, leaving a circular flange, and

Figure 5 shows the flange flattened against the disk around a mandrel, which, when removed leaves a true circular opening of the exact diam- 15 eter desired and with a smooth edge.

Referring to the drawing, Figure 1, A indicates the anode comprising the metal tube a and the spaced lens electrode elements b. Each lens electrode element comprises a disk I having a 2 peripheral flange 2 which fits closely within the tube and holds the disk frictionally in place. Small central perforations 3, slightly larger than the openings desired are made in the disks by a punch, and eyelets 4, inserted in the perfora- 25 tions, are shown with their ends pressed against the opposite sides of the disks. Figure 3 shows an eyelet fitted into the perforation-in one of the disks, and Figure 4 shows the ends of the eyelet flattened around the margin of the opening in 30 the disk, which is accomplished by applying pressure with a suitable upsetting tool having a mandrel 5, the diameter of which is the same as that of the desired opening to be produced in the lens element, so that when the mandrel is withdrawn 35 the opening through the eyelet will be of the exact diameter required and only smooth and rounded surfaces will be exposed to the electron stream passing through the opening. The lens 1 element will also be strengthened in its central 40 portion, by the eyelet, so that liability to distortion of the lens element will be lessened when force is applied to it in the subsequent handling of the lens element.

In Figures 4 and 5 are illustrated the method 5 of accomplishing the desired result without the use of the eyelets. In this case, in forming the central perforation in' the disk In. of the lens element b, the metal is drawn, forming a circular flange 6 which is cut off to make it of suitable length. Then, as shown in Figure 5, a mandrel l, of the exact diameter of the hole desired in the disc, is inserted in the opening 3a and the flange 6 is compressed against the face of the disk, as shown at 6a, leaving an opening of the exact diameter of the mandrel, with smooth and rounded edges, when the mandrel is withdrawn. The lens element is also strengthened at its central portion by the overturned metal 6a which helps to prevent warping of the element in subsequent manipulation of the same.

What I claim is:

1. An anode for electron guns comprising a metal tube having spaced lens electrode elements therein, each element comprising athin metal disk fitting closely within the tube and having a central perforation, and an eyelet aifixed to the disk fitting within said perforation and covering the edges thereof, the end portions of the eyelet being upset against'the opposite sides of the disc;

2. An anode for electron guns comprising a metal tube having spaced lens electrode elements therein, each element comprising a thin metal disk fitting closely within the tube and having a central perforation with the metal of the disk drawn in making the perforation into the form of a circular flange, said flange being upset against the face of the disk, forming an opening through the disk of definite diameter and with smooth surfaces.

3. An anode for electron guns comprising a metal tube having spaced lens electrode elements therein, each element comprising a thin metal disk fitting closely Within the tube, said disk having a small central perforation therethrough, and metal reinforcing means surrounding said perforation, said reinforcing metal being compressed against one face of the disk, whereby an opening of definite size and with smooth surfaces is produced.

JOHN R. BEERS.