US1712403A

US1712403A - Means for producing high vacuums

Info

Publication number: US1712403A
Application number: US71542A
Authority: US
Inventors: William A Ruggles
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1925-11-27
Filing date: 1925-11-27
Publication date: 1929-05-07
Anticipated expiration: 1946-05-07

Description

May 1929. w. A. RUGGLES v 03 MEANS FOR PRODUCING HIGH VACUUMS Filed Nov. 2'7, '1925 Inventor VVL LL'Lam A.RuggLes, k3}! His Attorngy.

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l ateuted Ma l-hfid,

wrritr'aia a. success,

sra'rss a 0F SCEIENECTADY, NEW YQBEZ, AEfilliiNOlIt T0 GENERAL ELEC- TRIG COMPANY, A OOHPURATIUIE till NEW" YORK.

MEANS FOR PRODUCING HIGH. 'V'AGUUMS Application filed November My present invention relates to means for producing and "maintaining a vacuum in electric discharge devices,

lln devices of this character, and especially in such devices which employ heavy currents, the life of the discharge device depends on the maintenance of a substantially perfect vacuum dince the forces which produce gasing in a discharge device are roughly proportional to the power involved, any overload or'starting transient is particularly likely to cause the evolution of some gas in the device 'lhe gassing efiect is cumulative, the first gassing probably being small and unimportant. A small amount of gas, however, makes the discharge device even more susceptible to gassing from abnormal conditions so that the discharge device soon evolves gas continuously and vigorously. At such a time the discharge device is unlit f or further use and is usually destroyed,

it is an object of my invention. to pro vide a particular means which may be 'em ployed in connection with electric discharge devices to efficiently and quickly produce a vacuum therein either initially or when the discharge device has begun to emit gas lhe means employed to efiect this result comprises a bulb having acoiled filament wlnch may be heated to incandescence; Within the filament and spaced therefrom is mounted a perforated metal holder containing a magncsiuin covered calcium wire. When the filament is heated the alkaline earth metal is distilled on the surface of the bulb and ab sorbs whatever water vapor or other gases may exist in the bulb or discharge device, If desired, the filament may be operated in 'termittently or constantly in order to maintain the vacuum,

The novel features which if believe to be characteristic of my invention are set forth with particularity in the appended claims. lvly invention itself, however, both as to its organization and method of operation will best be understood by reference to the following specification talren in connection with the accompanyingdrawing in which Fig. 1 shows a tube partly broke. away and which embodies the features of my invention; llig. shows a cross sectional. view of the metal to be distilled and the holder therefor; lFic.

rows in elevation the metal wire to be disand the holder therefor before asseml, I; ll shows my invention as applied 15, such Q7, 1925 Serial No. 'ZLME.

to an electron discharge device of the threeelement type, although obviously tube 1 may be employed with any type of electron discharge device desired. a Referring to the drawing, l have indicated at 1, a glass tube or bulb which is adapted to be connected to an electric discharge device 2 by a glass extensin 3 or by any suitable means desired, The bulb-1 has a reentrant portion dwhich is provided with the usual glass seal or press 5 through which extends Dumet lead-in wires 6. The portions of wire 6 within the tube 1 are made of nickel, and the'ends of the nickel wires are connected to a spiral filamentary conductor 7. of refractory metal, such for example, as tungsten, or any suitable heater wire. lllounted on. the lead-in wires 6- is a'pairof nickel dislrs S which act as shields for the seal 5.

it. third conductor 9 of Duinet and nickel wire is mounted on the seal 5. it hollow nickel cylindrical. member 10 is attached to one endof the conductor 9 by means of a pairs of extensions ll which are permanently connected to the conductor 9 and cylinder 10 in any suitable manner as by welding. 'lhe hollow cylindrical member 10 is provided with

extensions

12 and 13 which are adapted to be bent to a horizontal'position to thereby close the ends of the cylindrical member. A plurality of relatively small. circular openings ll are placed at substantially diametri cally opposite points of the member 10. Within themembcr 10, an alkaline earth metal is placed, which in the present in stance is a magnesium covered calcium wire as disclosed in my copending application Scrial lilo, 80,322, filed January 9, 1926. tlrdinarily, calcium oxidizes and,

therefore, deteriorates so rapidly that it can not easily be handled. By providing the calcium with a magnesium coating, however, l have found that the wire thus formed may be exposed to the atmosphere for several hours without producing any harmful effects,

ln operation, whenever the tube Q begins to emit gas, current issupplied to the lilamcnt l he calcium within the nickel cylinder it will then distill through the openings 14: in the side of the tube 10 and through the ends of tube. The area of the receptacle 1 is relatively large, and since the distilled vapor travels in. straight line from the openings in the niclrel container 10 practi ltlli llll cally the entire inner surface of the receptacle 1 is quickly covered with a metallic calcium deposit which immediately absorbs any water vapor or othergases which may exist within the receptacle 1. A large surface on which to deposit the alkaline earth metal is particularly desirable owing to the fact that the ability of the distilled metal to absorb gases depends on the amount of surface which may be covered by the distilled metal. I have found the present arrangement of a relatively large receptacle with a perforated elongated cylindrical holder filled with an alkaline earth metal to be particularly efficient in quickly producing and in maintaining a perfect vacuum; If desired conductor 9 may extend through the glass seal 5 so that a potential may be applied thereto as well as to the filament 7. In this manner tube 1 may act as two-element rectifier having an anode 10 and a filamentary cathode 7.

While I have shown the receptacle 1 in combination with an electron discharge device 2, obviously the invention is not restricted to the combination shown. The device may be employed for maintaining a vacuum in a receptacle such as the tube 1 without reference to any other electric discharge device.

Various modifications of my invention will,

readily suggest themselves to persons skilled in the art without departing from the scope of my invention as set forth in the appended claims.

' \Vhat I claim as new and desire to secure by-Letters Patent of the United States, is:

In combination, a receptacle, an elongated metallic cylinder mounted within said receptacle, an alkaline earth metal mounted in the cylinder, a heater wire surrounding the cylinder and spaced therefrom, means whereby current may be supplied to said heater wire to distil said alkaline earth metal, said cylinder being provided with openings so arranged that the distilled metal will cover the greater portion of the inner surface of said receptacle.

2. In combination, a vacuum device comprising a press, a pair of conductors extending through said press, a coiled heater wire connected. to said conductors, a supporting element mounted on said press, a hollow elongated receptacle having perforated sides mounted on said supporting member and within said coiled heater wire, and an alkaline earth metal mounted within said hollow receptacle.

3. In combination, a receptacle, a coiled heater wire within the receptacle, a tubular metal container mounted within the coiled heater wire and spaced therefrom, said container being provided with a series of openings extending longitlulinally of said container, and an alkaline earth metal mounted within said container, and means wherein; current may be supplied to said heater wire to distil said alkaline earth metal upon the inner surface of said receptacle.

4. In combination, a receptacle, a coiled heaterwire mounted within the receptacle, an elongated integral metal container mounl ed within the receptacle, said container. being provided with openings in the ends and sides thereof, an alkaline earth metal mounted within said container, and means whereby current may be supplied to said heater wire to thereby distilsaid alkaline earth metal upon the inner surface of said receptacle.

5. In combination, a receptacle, means for absorbing gases within said receptacle, said means comprising an integral tubular member provided with a series of openings extending longitudinally of said member, an alkaline earth metal mounted within the member, and means for heating the member to vaporize said alkaline earth metal and thereby absorb gases within said receptacle.

6. In combination, a absorbing gases within said receptacle, said means comprising a container, a metal, adapt ed to be vaporized, mounted in the container, means including a filament spaced from the container and adapted to be heated to incandescence to vaporize the said metal, said c mtainer being provided with a plurality of openings so arranged that the vaporized metal will be deposited upon the inner surface of the receptacle.

7. In combination, an electron device comprising a container, a coiled lilu mentary cathode and an anode mounted in said container, said anode comprising a hol low perforated cylindrical member mounted within the cathode, and an alkaline earth metal mounted in said cylindrical member.

In witness whereof, I have hereunto set my hand this 25th day of November, 1995.

WILLIAM A. RUGGLES.

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