US2402319A - Electronic tube - Google Patents

Description

June 18, 1946. w. w. EITEL ETAL 2,402,319

- ELECTRONIC TUBE v Filed June 5', 1942 2 Sheets-Sheet 1 INVENTORS WILL/AM W E/TEL BY dAc/r A. MfCL/LLOUGH THEIR ATTORNEY June 18, 1946. w EI L ET-AL 2,402,319

ELECTRONIC TUBE Filed Juhe 5, 1942 2 Sheets-Sheet 2 INVENTORS WILLIAM 14/. EITEL BY (JACK A. M5 CULLOUGH THEIR ATTORNEY Patented June 18, 1946 2,402,319 ELECTRONIC TUBE William W. Eitel, San Bruno, and Jack A. McCullough, Millbrae, Calif., assignors to Eitel- McCullough, Inc., San Bruno, Califi, a corporation of California Application June 5, 1942, Serial No. 445,954

Our invention relates to a thermionic tube, and more particularly to a rectifier.

It is among the objects of our invention to provide a rectifier tube of small physical size, having an improved structure of, arrangement for, and mounting of the electrodes and leads in the en velope.

Another object is to provide a rectifier tube structure adapted for facile assembly.

The invention possesses other objects and fea tures of advantage, some of which, with the foregoing, will be set forth in the following description of our invention. It is to be understood that we do not limit ourselves to this disclosure of species of our invention, as we may adopt variant embodiments thereof within the scope of the claims.

Referring to the drawings:

Figure 1 is a side elevational view of a tube on approximately double scale, embodying the improvements of our invention.

Figure 2 is a plan view of the same.

Figure 3 is a vertical sectional view on still larger scale, taken in a plane indicated by line 3-3 of Figure 2.

In terms of broad inclusion, our tube comprises an envelope enclosing a cathode and plate. A lead coaxial with the plate is sealed to an end of the envelope; and means secured to an end cap on the plate is provided for supporting the plate on the coaxial lead. In our preferred tube the envelope comprises a plurality of cup-shaped sections sealed together along abutting edges. Leads for the cathode are preferably sealed to the base section, and the plate lead is preferably sealed to the body section.

In greater detail, and referring to the drawings, our rectifier tube comprises a cylindrical envelope of glass or the like having a body section 2 and a base section 3, both cup-shaped and sealed together along abutting edges at the bead 4 in a plane lying transversely of the envelope. The base section is shorter than the body; more like a shallow dish compared to the deeper cupped body 2. Base section 3 also preferably has thicker walls than the body to give added strength at the base of the tube. A tubulation for evacuating the envelope is connected to the body section and, after exhaust, is sealed off the pump at point 5. The envelope is of small physical size, say about 1% inches in diameter by about 1 /2 inches in length.

The plate or anode 6 comprises a pair of drumshaped sections, preferably of tantalum, disposed end-to-end. Flanges 1 are integrally formed at Claims. Cl. 25027.5)

the abutting ends of the sections, and the sections are secured together by spot welding the flanges. These flanges thus form an annular heat radiating fin disposed about the mid-portion of the tubular plate. A hemispherical tantalum cap 8 is secured over the upper end of the plate by depending tabs 9 welded to the plate rim. Arched recesses II in the cap between the tabs provide .vent openings.

A plate lead I2, preferably of tungsten, is disposed coaxially of the plate and projects thru the top of envelope section 2 at seal l3. The plate supporting means preferably comprises a yokeshaped bracket M of tantalum having arms spot welded to cap 8. Both parts being of tantalum they weld readily. It is more difiicult to weld to the tungsten however, and we preferably first spot weld a piece of nickel Hi to the bracket and then weld this to the end of lead l2. The body of nickel interposed between the parts alloys or fiuxes readily with both the tantalum and tungsten, providing a strong joint.

Cathode leads I! and I8 are also preferably of tungsten. They project through the base section of the envelope at seals l9. Lead I1 is provided with a reduced extension 20 of tungsten bent to project upwardly thru the center of the plate. The other lead [8 may either be a solid rod as shown in Figure 1 or have a reduced extension 22 as illustrated in Figure 3. The lead extensions are butt welded to the enlarged portions, preferably using nickel 23 as a flux at the welds.

Cathode 24 is preferably of the filamentary type comprising a coil of thoriated tungsten welded at the upper end to lead extension 20 and at the lower end to a tantalum strap 26 which in turn is welded to the other lead.

The tube is fabricated by forming the envelope in two separate sections which, prior to sealing together, are open at one end. The plate assembly is welded together apart from the tube, and, after lead I2 has been sealed in place, plate bracket I4 is welded to the lead. An alternate procedure is to weld the plate assembly to the lead apart from the envelope, and then seal the lead to the glass.

The cathode leads are sealed to the separate base section, and filament 24 is thereafter welded in place. Since the cathode leads project out thru the open mouth of the shallow base section, the filament may be readily positioned and welded. After mounting the electrodes, the filament is centered within the plate and the two envelope sections are fused together along abutting edges at seal 4.

We claim:

1. A rectifier tube comprising an envelope, a tubular plate and a cathode in the envelope, an end cap on the plate, a lead sealed to the envelope, a bracket on the cap for supporting the plate on the inner end of said lead, and leads for the cathode sealed to the envelope.

2. A rectifier tube comprising an envelope, a tubular plate and a cathode in the envelope, an end cap on the plate, a lead coaxial with the plate and sealed to the envelope, a bracket on the cap for supporting the plate on the inner end of said lead, and leads for the cathode sealed to the envelope.

3. A rectifier tube comprising an envelope, a tubular plate and a cathode in the envelope, an annular fin disposed about the plate, an end cap on the plate, a lead sealed to the envelope, a bracket on the cap for supporting the plate on the lead, and leads for the cathode sealed to the g0 envelope.

4. A rectifier tube comprising an envelope embodying a pair of cup-shaped sections sealed together along abutting edges, a tubular plate and a cathode in the envelope, an end cap on the plate, a lead sealed to one of the envelope sections, a bracket on the cap for supporting the plate on the inner end of said lead, and lead for the oathode sealed to the other section of the envelope.

5. A rectifier tube comprising an envelope embodying body and base sections, said sections being cup-shaped and sealed together along abutting edges, a tubular plate and a cathode in the envelope, an end cap on the plate, a lead coaxial with the plate and sealed to the body section, a bracket on the cap for supporting the plate on said lead, and leads for the cathode sealed to the base section.

WILLIAM W. EITEL.

JACK A. MOCULLOUGH.

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