US1931630A

US1931630A - Four-electrode tube

Info

Publication number: US1931630A
Application number: US199170A
Authority: US
Inventors: Round Henry Joseph
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1926-07-22
Filing date: 1927-06-16
Publication date: 1933-10-24
Anticipated expiration: 1950-10-24

Description

OC. 24, H' J, ROUND FOUR-ELECTRODE TUBE Filed June 16, 1927 INVENTOR HENRY JOSEPH ROUND AT ORNEY Patented Oct. 24, 1933 Miren STATES PATENT OFFICE FOUR-ELECTRODE TUBE Application June 16, 1927, Serial No. 199,170, and in Great Britain July 22, 1926 3 Claims.

This invention relates to four-electrode tubes, and more particularly to four-electrode tubes of the lrind in which there is provided an outer grid acting as an electrostatic shield between an inner and a plate.

The present invention has for its object the provision of a tube of the kind referred to, which shall be simple to construct and which shall be constructionally similar to as great a degree as possible, to the well known three-electrode 'tubes of the type in which there is provided a filament, a grid substantially surrounding the lament, and a plate substantially surrounding the grid.

Briefly and broadly the object of this invention is to provide a four-electrode tube comprising a filament, an inner grid substantially surrounding the filament, an outer grid electrode substantially surrounding the inner grid, and one or more plate electrodes, said outer grid electrode being formed of a plate-like electrode having one or more Windows filled with grid mesh parallel wires or the like therein, and plate electrode or electrodes being located substantially opposite the said window or windows. n

Preferably the plate electrode or electrodes is or are each slightly smaller than its appropriate window in the outer grid electrode, and is or are supportedirom the support rods for the outer grid electrode, being, or" course, insulated therefrom.

The lead from the plate electrode or electrodes is passed through the bulb oi the tube, the usual four-pin base and connection and supporting arrangements being employed for the remaining electrodes. This arrangement of leads has the considerable advantage that the lead from the plate or plates is comparatively far removed from the other leads, so that the electrostatic coupling between the input and output circuits of the valve is reduced to a very small value.

These and other advantages and objects of the invention will become more apparent, from the specification when read in connection with the herewith appended drawing on which:

Fig. 1 is an elevation of a tube constructed in accordance with my invention, and

Fig. 2 is a plan view of the tube shown in Fig. 1.

Referring to this drawing, 1 is a hair-pin lilament supported upon leads 2 and a filament support 3. 4l is an inner grid carried upon supports 5. 6 is an outer grid electrode formed of a platelike electrode, having a pair of oppositely disposed windows 7, cut in its at sides, the said windows being lled with grid mesh parallel Wires, cross Wires or the like. The electrode 6 is (Cl. Z-27.5)

carried by support rods 8. 9, are plates smaller in area than the Windows 'l and carried by means of yokes 10, supported on and insulated from the support rods 8 by means or" glass beads 11. The lead 12 from the plates 9 is passed through the 60 side of the bulb 13 of the tube, the connections for the other electrodes being passed through the stem 14 to a four-pin base (not shown) in the usual way.

Having now particularly described and illustrated the nature of my said invention and in What-manner the same is to be performed, what claim is:

1. A thermionic valve comprising a lament, an inner grid surrounding the filament, an outer grid electrode surrounding the inner grid, and plate electrodes, said outer grid electrode being formed of a plate-like electrode having windows iilled with grid mesh parallel wires, and said plate electrodes being located opposite to the said windovvs.

2. A thermionic valve comprising a filament, an inner grid surrounding the iilament, an outer grid electrode surrounding the inner grid, and a plate electrode, said outer grid electrode being formed or" a plate-like electrode having a Window filled with grid mesh, and said plate electrode being smaller than the window and located opposite thereto.

3. An electron discharge device comprising a cathode, an inner attened cylindrical grid electrode surrounding the cathode, an outer attened cylindrical grid electrode surrounding the inner grid electrode, the attened portions of the outer grid electrode being provided With openings covered with grid mesh material, and a pair of plate electrodes external to and parallelly-arranged with respect to said grid meshed openings.

`HENRY JOSEPH ROUND.