Coaxial power grid tube having improved internal lead structures

Claim 2

In a coaxial power grid tube: cylindrical cathode emitter electrode means for supplying copious thermionic cathode emission; cylindrical anode electrode means disposed coaxially surrounding said emitter means for collecting electron current flowing from said cathode emitter to said anode means; cylindrical control grid means coaxially surrounding said cathode emitter means and being interposed between said cathode emitter means and said anode means for controlling the flow of electron current to said anode means; evacuated envelope means for containing said cathode and control grid; control grid and cathode lead structures passing through said envelope means and having axially coextensive portions; said control grid lead structure having a portion thereof disposed on the axis of revolution of and completely surrounded by said cathode lead structure; and cross-over means within said evacuated envelope for passing said control grid lead structure through said cathode lead structure in electrically insulative relation thereof.

Claim 3

The apparatus of claim 1 wherein said cross-over means includes, generally axially directed spoke portions of said cathode lead structure passing through apertures in outwardly directed portions of said control grid structure.

Claim 4

The apparatus of claim 1 wherein said cathode lead structure includes first and second concentric radially spaced cylindrical wall portions closed together at their inner ends and having hollow axially directed spoke portions projecting from the closed inner ends of said cathode lead structure, said hollow spoke portions communicating with the hollow space between said first and second concentric cylindrical cAthode lead wall portions, a third cathode lead electrode structure portion disposed within the hollow interior defined between said first and second concentric cathode lead wall portions, said third cathode lead portion having rod portions extending through said hollow spoke portions in electrically insulative relation thereto and being electrically connected to a first end of said cathode emitter electrode, and said first and second cylindrical portions of said cathode lead structure being connected to a second end of said cathode emitter means, whereby an operating electrical potential applied between said third cathode lead portion and said first and second cathode lead portions causes electrical current to flow through said cathode emitter for directly heating same to thermionic cathode emmission temperature.

Claim 5

The apparatus of claim 1 including, cylindrical screen grid means disposed coaxially surrounding said cathode emitter means and being disposed intermediate said control grid means and said anode means, screen grid lead structure passing through said envelope means and having axially coextensive portions with said control grid and cathode lead structures, and wherein said screen grid lead structure is disposed surrounding said cathode lead structure.

Claim 6

In a coaxial power grid tube: directly heated cylindrical cathode emitter electrode means for supplying copious thermionic cathode emission; cylindrical anode electrode means disposed coaxially surrounding said emitter means for collecting electron current flowing from said cathode emitter to said anode means; cylindrical control grid means disposed coaxially surrounding said cathode emitter means and interposed between said cathode emitter means and said anode means for controlling the flow of electron current to said anode means; evacuated envelope means for containing said cathode and control grid; control grid and cathode lead structures passing through said envelope means and having axially coextensive portions; said control grid lead structure having a portion thereof disposed within and surrounded by said cathode read structure; and said cathode lead structure including first and second concentric radially spaced cylindrical wall portions closed together at their inner ends and having hollow axially directed spoke portions projecting from the closed inner ends of said cathode lead structure, said hollow spoke portions communicating with the hollow space between said first and second concentric cylindrical cathode lead wall portions, a third cathode lead electrode structure portion disposed within in the hollow space defined between said first and second concentric cathode lead wall portions, said third cathode lead portion having portions extending through said hollow spoke portion in electrically insulative relation thereto and being electrically connected to a first end of said cathode emitter electrode, and said first and second cylindrical wall portions of said cathode lead structure being connected to a second end of said cathode emitter means, whereby an operating electrical potential applied between said third cathode lead portion and said first and second cathode lead wall portions causes electrical current to flow through said cathode emitter means for directly heating same to thermionic cathode emission temperature.

Claim 7

In a coaxial power grid tube: directly heated cylindrical cathode emitter electrode means for supplying copious thermionic cathode emission; cylindrical anode electrode means disposed coaxially surrounding said emitter means for collecting electron current flowing from said cathode emitter to said anode means; cylindrical control grid means disposed coaxially surrounding said cathode emitter means and interposed between said cathode emitter means and said anode means for controlling the flow of electron current to said anode means; evacuated envelope means for containing said cathode and control grid; control grid and cathode lead structures passing through said envelope means and having axially coextensive portions; said control grid lead structure having a portion thereof disposed within and surrounded by said cathode read structure; and said cathode lead structure including first and second concentric radially spaced cylindrical wall portions closed together at their inner ends and having hollow axially directed spoke portions projecting from the closed inner ends of said cathode lead structure, said hollow spoke portions communicating with the hollow space between said first and second concentric cylindrical cathode lead wall portions, a third cathode lead electrode structure portion disposed within in the hollow space defined between said first and second concentric cathode lead wall portions, said third cathode lead portion having portions extending through said hollow spoke portion in electrically insulative relation thereto and being electrically connected to a first end of said cathode emitter electrode, and said first and second cylindrical wall portions of said cathode lead structure being connected to a second end of said cathode emitter means, whereby an operating electrical potential applied between said third cathode lead portion and said first and second cathode lead wall portions causes electrical current to flow through said cathode emitter means for directly heating same to thermionic cathode emission temperature.

Claim 8

The apparatus of claim 5 wherein said control grid structure includes a generally radially directed portion, and wherein said generally axially directed spoke portions of said cathode lead structure pass through said apertures in said control grid structure.

Claim 9

The apparatus of claim 5 including, cylindrical screen grid means disposed coaxially surrounding said cathode emitter means and intermediate said control grid means and said anode means, screen grid lead structure passing through said envelope means and having axially coextensive portions with said control grid and cathode lead structures, and wherein said screen grid lead structUre is disposed surrounding said cathode lead structure.

Claim 10

The apparatus of claim 1, wherein said crossover means connects said control grid lead structure to the adjacent end of said cylindrical control grid means and connects said cathode lead structure to the corresponding adjacent end of said cylindrical cathode emitter electrode means.

Claim 11

The apparatus of claim 1 wherein said crossover means comprises a portion of each of said control grid and cathode lead structures shaped to provide an open space between conductive portions thereof, and each of said control grid and cathode lead structures having a portion thereof passing through the open space in the other.

Claim 12

The apparatus of claim 1 wherein said cathode lead structure comprises a first conductor surrounding said control grid lead structure, a second conductor surrounding said first conductor, a third conductor for connecting heater current to said cylindrical cathode emitter, and said third conductor being positioned between said first conductor and said second conductor.