US1501240A

US1501240A - Manufacture and operation of vacuum tubes

Info

Publication number: US1501240A
Application number: US495601A
Authority: US
Inventors: Rottgardt Karl
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-08-26
Filing date: 1921-08-26
Publication date: 1924-07-15
Anticipated expiration: 1941-07-15

Description

Patented July 15, 1924.

KARL ROTTGARDT, OF DAHLEM, NEAR BERLIN, GERMANY.

MANUFACTURE AND OPERATION OF VACUUM TUBES.

No Drawing.

Application filed August 26, 1921.

Serial No. 495,601..

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT, L, 1313.)

To all whom it may concern.

Be it lmown that I, Dr. KARL ROTTGARDT, residing at Dahlem, near Berlin, Germany, Fontanestr. 14, have invented certain new and useful Improvements in and Relating to the Manufacture and Operation of Vacuum Tubes, for which application has been filed in the following countries: Germany, March 30, 1918; Denmark, June 15, 1920; England, July 9, 1920; France, July 2, 1920; Poland, July 2, 1920; Japan, Oct. 19, 1920; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others 1 skilled in the art to which it appertains to make and use the same.

It is well known in the process of manufacturing vacuum tubes having a plurality of metal electrodes, to bring the metal parts in the interior of the tubes, and in particular the anodes, to incandescence by the application of high voltages. This is termed bombardment by electrons. In this way the last remnants of gas are removed from 25 the metal and the highest vacuum considered necessary is produced.

This invention relates to a new improve ment in the manufacture and working of such vacuum tubes. This improvement makes it possible to effect the incandescence of the metal parts with considerably smaller voltages. At the same time the tubes treated in accordance with the invention possesses the property, when in operation, of being able to receive andrectify considerably greater anode charges with much smaller voltages. The new improvement consists in the feature that certain gases or vapours, in particular ether vapour and also other easily volatile hydrocarbons are admitted into the tubes for pumping purposes.

It appears that, at the same temperature of incandescence of the filament, quite a considerable increase in the thermionic current results when these vapours are admitted. This produces a greater receptive capacity of the tubes and thus a stronger heating of the electrons results. The differences are of such a large order that, for example, after admission of the gas a light red glow of the anodes occurs at 300 volts, while before, no visible heating up occurred at 1300 volts with the same incandescing current.

This great increase in the thermionic current is still maintained when the admitted gases or vapours have been again exhausted by the pump, so that in operation also a considerable increase in efiiciency occurs.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed I declare that what I claim is 1. The process of manufacturing vacuum tubes having a plurality of metallic electrodes, which consists in introducing a hydrocarbon vapor into the vacuum tube, applying across two of the elements thereof a voltage sufficient to raise at least one of the elements to 'incandescence, and evacuating the vacuum tube.

2. The process of manufacturing vacuum tubes having a plurality of electrodes, which consists in introducing ether vapor into the vacuum tube, applying a voltage across two of the elements thereof suflicient to raise at least one of the elements to inoandescence, and evacuating the vacuum tube. V

In testimony whereof I aflix my signature.

DR. KARL ROTTGrAQRD'l.v