US1450413A - Vacuum electric discharge device - Google Patents

Description

Apr. 3, 1923.

H. w. EDMUNDS-ON ET AL. v

VACUUM'ELECTRIC DISCHARGE DEVICE.

FILED MAR. 10, 919-v L MGAB.

Inventors Herbert W. Edrn undson,

\X/i Ham Tmur'xro, by 1 .f' A?! 7 Att orn ey.

Their Patented Apr. 3, 1923.

NHTE sr T E S HERBERT W. EDMUNDSON AND WILLIAM '1. MUNRO, OF RUGBY, ENGLAND, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

VACUUM ELECTRIC DISCHARGE DEVICE.

Application filed March 10, 1919. Serial No. 281,649.

To all whom it may concern:

Be it known that we, HERBERT WATSON EDMUNDSON and WILLIAM TOM MUNRO, subjects of the King of Great Britain, residmg at Rugby, in the county of Warwickshire, England, have invented certain new' and useful Im rovements in Vacuum Electric Discharge .evices, of which the follow- ;in%is a specification.

nated as far as possible.

According to our invention a shield preferably of metal is mounted within the device in such a position as to cut off the heat radiated from the anode durin operation of "the device. This shield may e of difierent shape according to the construction of the discharge device, and is separated from the anode so that the vacuous space between it and the latter serves to prevent it from becoming heated to any considerable extent.

In applying the invention to a form of valve in which the cathode is located within .{a cylindrical anode, the whole being mounted on a glass stem within an evacuated bulb,

the stem carrying the leading-in conductors for the device, the shield may be in the form of a cylinder of thin sheet metal almost completely, or completely, surrounding the anode or interposed between the anode and stem in any convenient way so as to prevent the stem through which the leading-in wires pass from being heated by direct radiation from the surface of the anode. As a result the heat radiated from the anode will be prevented from injuriously affecting the seal.

If allowed to act on the seal the heat radiated from the anode might cause electrol-- ysis with the evolution of gas from the glass itself. This heat might also cause cracks to form along the leading-in conductors thus allowing the surrounding gases to leak into the interior of the device and impair the vacuum. In devices of the general class to which our invention, relates, the allowable voltages which may be applied between the various leading-in conductors depends largely upon the temperature of the glass between the conductors. It is therefore of importance, where high voltages are to be used, thatthe seals should be maintained at as low a tem perature as possible.

The accompanying drawings illustrate one form of our invention, Fig. 1 being an end elevation and Fig. 2 a side elevation partly broken away.

In the drawing, 1 represents an evacuated receptacle provided with the glass stem 2 into which the supporting wires and the conductors through which current is supplied to the various parts are sealed. 3 is a filament adapted to operate as a hot cathode,

and'4 is the anode which receives the bom-v bardment of electrons given off by the cathode. Surrounding this anode we provide a shield 5 which is held in place by a support 6 sealed into the stem 2. In the modification illustrated the shield is formed by doubling a sheet of thin metal and bending it into the form of a cylinder, the two portions of the plate bein spaced apart so that they form substantiafiy two concentric cylinders concentric with the anode 4, which in this case is shown as a cylinder. The shield 5 may be secured to the supporting wire 6 many convenient manner, for example, a tongue 7 may be stamped from the sheet in proximity to the bend and bent upwards. This tongue may be soldered or welded to the end of the supporting wire in any well known suitable manner.

The shield also prevents conductive material due to the disinte ration of the anode or cathode from being leposited on the stem and seals where it is usually largely depositedv and where it may act as a conductive bridge between the leading-in wires and impairs the efliciency of the device.

While we have illustrated and described only one form of our invention, it will be apparent to those skilled in the art that many variations may be made in the form of the shield as well as in the manner in which it is placed and supported in the device with out departing from the scope of our invention as setforth in the appended claims.

What we claim as new and desire tose-.

cure by Letters Patent of the United States, is

1. The combination in an apparatus of the class described of an evacuated receptacle containin a cathode adapted to be heated to incan escence and an anode adapted to receive electrons from said cathode, leadingin conductors sealed into the walls of said.

receptacle for supplying current to said cathode and anode, and ashield interposed between said anode and the region where said leading-in conductors are sealed into the walls of the receptacle for intercepting receptacle.

heat radiated from the anode said shield being out of contact with the walls of the 2. The combination in an apparatus of the class describedof an evacuated recepand anode, and a shield interposed between said cathode and anode and, the region where said leading-in conductors are sealed into tacle.

the walls of the receptacle for preventing the overheating of that region otthe walls which surrounds the leading-in conductors said shield being out of contact with the.

adapted to be bombarded by electrons from said cathode, leading-in conductors for supplying current to said cathode and anode, a stem for said receptacle through which said leading-in conductors are sealed, and a shield interposed between said cathode and anode and said stem for preventing the overheating of the stem said shield being out of contact with the In Witness whereof, we have hereunto respectively set our hands the 12th day of February, 1919, and the 8th day of March,

i H. W. EDMUNDSON.

I WILLIAM T. MUNRO. Witness to the signature of the said Herbert Watson Edmundson:

JOHN HALFORD, DOROTHY WHITE.

walls of the recep-

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