US2040883A

US2040883A - Electronic tube

Info

Publication number: US2040883A
Application number: US24148A
Authority: US
Inventors: Solomon Guillermo
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-05-29
Filing date: 1935-05-29
Publication date: 1936-05-19
Anticipated expiration: 1953-05-19

Description

May 19, 1936. G. SOLOMON ELECTRONIC TUBE Filed May 29, 1935 INVENTOR 5mllermaflozomolz BY WMou/ ATTORNEY WITNESSES Patented May 19, 1936 EJITED STATES PATENT OFFICE ELECTRONIC TUBE Application May 29,

2 Claims.

This invention relates to electronic tubes, and more specifically to electronic tubes of the type that are used in radio detectors and amplifiers.

It is an object of this invention to provide an improved electronic tube which may be used in radio detection and amplification and which will be substantially free from the troublesome outside interference caused by static or the discharge from high frequency machines and spark gaps.

A further object is the provision of an improved type of shielding for radio tubes which will be economical to manufacture, which will occupy a minimum of space, and which will not interfere with the proper operation of the tube.

With these and other objects in mind, reference should be had to the accompanying drawing, in which:

Fig. 1 is an elevation of an electronic tube embodying the present invention; and

Fig. 2 is a sectional view in the direction of the arrows on the line 22 of Fig. 1.

In the accompanying drawing my invention is illustrated as applied to a vacuum electronic tube of a conventional type which is quite frequently used in radio receivers and comprises a suitable glass casing or envelope l enclosing the op erative elements of the tube and secured at its lower end to a base portion ll made of dielectric material.

Supported in a glass stud l2 projected upwardly inside the tube are a series of posts [3 to which are secured the plate [4, the two portions l5 and I6 of a screen grid, and a control grid I1. Also supported in the glass stud I 2 are the cathode I8 and the heating filament I9. Extending through the base of the tube are a plurality of prongs 20 adapted to be fitted into a suitable socket. Two of the prongs are connected to the two ends of the filament l9, another prong is connected to one portion of the screen grid I6, another to the plate l4, while the fifth prong is connected to the control grid 11. The two portions of the screen grid 15 and iii are secured together in conventional manner as by a metal disk or plate attached over the upper end of the elements. A wire 2| extending through the top of the tube and connecting with a contact member 22 is connected to the cathode l8.

While the tube herein shown and described is one type of electronic tube to which my invention may be applied, it is to be understood that it may be used in association with any desired type of electronic tube.

To protect the operative elements of the tube from outside interference due to static or to the operation of high frequency machines or spark gaps, I encase the operative elements of the tube 1935, Serial No. 24,148

in an improved type of shield disposed inside of the glass casing or envelope It. My improved shield is composed of an outer layer of metal foil 24 made of a good conducting material, and an inner layer of insulating material such as the sheet of dielectric paper 25, which are wrapped around the plate, grid, cathode and filament of the tube so that they overlap as at 26 and are suitably secured together at the upper end as by the twisted wire 21. The lower end is tightly tied around the upper end of the glass stud I2 as by another strip of wire 28, which is preferably provided with a lead 29 extending through the glass stud l2 and connecting with a prong 30 which projects through the base of the tube.

The prong 30, when the tube is in use, is con nected to a suitable ground 3| so as to cause all interference entering the tube to be grounded. To insure a good electrical contact between the lead wire 29 and the foil 24 a solder connection may be employed. The wire 2! passes through the upper end of the wrapping or shield in such a manner as not to contact the layer of foil 24 but to be insulated therefrom by the paper 25.

An electronic tube embodying a shield of the type illustrated and described herein will be substantially free from outside interference in that all static and stray electrons will be grounded. The provision of the shield, however, will not materially increase the cost of producing the tube nor will it cause the tube to occupy any additional space in a radio set.

Of course, it is to be understood thatmy improved type of shielding may be applied to electronic tubes of other types than the one herein illustrated and described.

I claim:

1. In an electronic tube, a shield comprising an outer layer of metal foil and an inner layer of dielectric material disposed inside the tube and encasing the operative elements thereof, said layer of metal foil being connected to a conductor projecting through said tube for connecting it to a ground.

2. An electronic tube comprising a glass envelope, a base portion secured to the envelope, electron emitting means, electron receiving means, and control means disposed inside of said envelope and having connection with a plurality of conductors projecting through the base portion, and a shield comprising an outer layer of metal foil and an inner layer of dielectric material disposed inside said envelope and encasing said electron emitting, electron receiving and control means, said metal foil having connection with a conductor projecting through the base of the tube.

GUILLERMO SOLOMON.