US2095337A

US2095337A - Vacuum tube electrode

Info

Publication number: US2095337A
Application number: US752929A
Authority: US
Inventors: Everett P Loppacker
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-11-14
Filing date: 1934-11-14
Publication date: 1937-10-12
Anticipated expiration: 1954-10-12

Description

Oct. 12, 1937. E. P. LOPPACKER VA CUUM TUBE ELECTRODE Filed Nov. 14, 1934 INVENTOR Patented Oct. 12, 1937 E i-Si PATENT oFFieE VACUUM TUBE ELECTRODE Everett PsLoppacker, Bloomfield, N. J. Application November 14, 1934, Serial No. 752,929

2 Claims.

first stamped into cup shape from a flat sheet .and theparts of the cup are then appropriately formedto yield the structure desired for the particular tube. is v Another object is to reinforce the open end of the electrode by strengthening means, such as a flange or bead, to increase its resistance to distortion.

Among other objects of the invention are the production of an electrode having increased wall area, and having great strength and rigidity, and also being relatively free from microphonic noises. While preferred forms of the invention are disclosed herein for purposes of illustration, various changes may be made in the structure without departing from the spirit of the invention as hereinafter set forth and claimed.

In the drawing: Fig. 1 is a side elevation of a plate element embodying the invention. V

Fig. 2 is a section on line 2-2 of Fig. 1. Fig. 3'is a fragmentary vertical section. Fig. 4 is a fragmentary horizontal section.

Fig. 5 is a fragmentary plan. view showing in 7 detail the perforations. V

Fig. 6 is a perspective view of a modified shape of electrode. Fig. '7 is afr'agmentary side elevation showing a modified top construction. V i

Fig. 8 is a fragmentary section showing a furthermodification.

Referring to the drawing more particularly,

the electrode element illustrated in Fig. 1 is a 3 and '4. Parts of the side wall are leftimperforate, shown at l3, and are indented so that support'wires may be conveniently, attached to these parts, as by spot welding. 55 A one-piece homogeneous element formed in the manner described avoids the necessity for a joint connecting the top to the side wall, as well as the necessity for a vertical joint in the side wall, and has the following advantages:

1.-Accuracy of manufacture V V By stamping the cup from a single sheet of metal the exact dimensions and alinement of the parts can be controlled within more narrow limits than where the electrode is assembled from sev- 1Q eral separate pieces.

' 2.- -Strength I Theone-piece electrode has greater strength and rigidity than an assembled electrode. 15

3.-No Zooscness possible An electrode assembled from separate pieces of tin has slight looseness between parts that is present from the beginning due to defective as- 20 sernbly, or which develops in use due to the expansion and contraction under repeated heatings and coolings, especially where the tube is subjected to continual vibration as in an automobile radio.

No such looseness can be present in the one-piece 5 electrode of this invention.

Where a rolled tinners seam is used to "join separate parts, the rolling causes local stresses in 30 the metal, and these stresses cause distortion of the electrode when it is heated in the bombardment process and in use. 7

5.Aooids microphonic noises For the reasons pointed out above the onepiece electrode is free from many of the causes of microphonic noises in tubes, these noises causing.

the rejection of a high percentage of tubes during manufacture as well as frequent cases of dissatis- 40 faction in use. i 1 7 In order to further stiffen the open end of the electrode it may be formed with a fiangeilii, and if 7 still greater rigidity is desired a bead iilmay also be used, oreitherfbead or flange may berused alone. This reinforcing of the open end of the electrode cooperates with the'one-piece construction to form a strong electrode that will hold its true cylindrical form under repeated heatings.

Where the protrusions i2 are'used the inclosed surface area is greater than where wire gauze or flat perforated metal is used.

Another way of increasing the surface area is shownin Fig. 8 where the perforated side wall isformed with corrugations I6, the ridges of '55 which run horizontally along the side walls of the electrode.

The advantages of increased wall area are that the tube runs cooler, gives less back emission and gives a greater area for the electronic movement.

The present invention may be applied to electrodes of various shapes, one of rectangular form being illustrated in Fig. 6, and the top may be formed to suit the requirements of the tube, a partly conical top being shown at I! in Fig. '7

The electrode of this invention may be used either as a plate or as a grid, and due to its rigid one-piece construction, it will maintain the characteristics for which it is designed under all temperatures and conditions of use.

I claim:

1. An electrode for a vacuum tube comprising,

a top, a side wall connected with the top, most of the area of the side wall being formed with perforations, the continuity of perforations in said wall being interrupted to provide vertically extending imperforate parts of the side wall for the attachment of support wires.

2. An electrode for a vacuum tube comprising a top formed with an aperture, and a, cylindrical wall having an open end and formed homogeneoils with the top, the top and side wall forming a single piece free from joints, most of the area of the side wallbeing formed with perforations, vertically extending parts of the side wall being bent inwardly and left imperforate for the attachment of support wires, the side wall being bent into a reinforcing part extending circumferentially around the side wall adjacent the open end.

E. P. LOPPACKER.