US1194140A - Lewis w - Google Patents

Description

VACUUM TYPE CONVERTER.

APPLICATION FILED nor. 1. m5.

CHUBB.

Patented Aug. 8, 1916.

R% W mm m N T 6 Ag LEWIS W. CHUBB, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR To WESTINGHOUSE.

ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

y VACUUM-TYPE CONVERTER.

Specification of Letters Patent. I

Patented Aug. a, rare.

Application file'd October 7, 1915. Serial No. 54,558.

gheny and State of Pennsylvania, have invented a new and useful Improvement in- Vacuum-Type Converters, of ,which the following is a specification.

My invention relates to vacuum-type converters, and it has for its object to provide a device of the character indicated wherein the temperature of the arc space and of the cathode may be maintained at any-desired figure and wherein, at the same time, desirable electrostatic conditiong within the The single figure of the accompanying drawing is a side. view,'partially in elevation and partially in section, of a vacuumtype converterv embodying the preferred type of my invention.

In the manufacture of vacuum-type converters, it is frequently desirable that the containing receptacle be formed of metal in order to have sufficient strength to with stand the conditions of severe service.

\Vhen designing for operation under heavy loads, the material of the cathode should be in intimate contact with said metal wall in order that its heat may be readily dissipated.

. I find that the negative electrostatic charge imparted to the wall of a converter by having the cathode in contact therewith exerts a more or less harmful influence on the operation of the device. The power are frequently transfers itself, wholly or in part, fromthe cathode proper to the metal of or to mercury globules on the inner surface of the walls, resulting in sudden and violent changes in the resistance and length of the arc path and consequent disturbances in the equilibrium of thesystem, itbeing mani-' festly difficult to electrically insulate the cathode from the container wall without interfering with the proper heat dissipation.

I propose to surround the entire arc space,

within the container from a point well above the active portions of the anodes to a point adjacent the surface of the cathode with a shield o'r skirt of conducting inaterial. Said shield is insulated from both the anodes and-the cathode and is maintained at such a high voltage with respect to the cathode that the tendency of the power are to strike thereto is reduced to a minimum.

Referring to the accompanying drawing erably formed of vaporizable reconstructing material, such, for example, as mercury or suitable amalgams. Each of the anodes 2 and 3 may be provided with shielding members 5, if desired. A cylindrical shield or skirt 6 is mounted within the container 1 and shields substantially the entire inner exposed surface of the container. A source of unidirectional'voltage 7 is connected between the shield 6 and the container -1 through a current-limiting device 8 to maintain said shield 6 at substantially the maxi mum positive potential of the anodes 2 and 3, the flow of an arc from the member 6 to the cathode 4 being limited by the device 8.

In the operation of the converter, there is ,no tendency for the main power arc to strike from the anodes 2 and 3 to the member 6 because of the small difference of potential therebetween, and said are is prevented by the shielding action of said member 6 from impinging upon thewall of container 1. The temperature of the cathode 4 is thus rendered subject to control in the ordinary manner, as by a' cooling bath 9, while the electrostatic conditions within the container are as favorable as when employing an insulated cathode.

While I have shown my invention in its preferred form, it will be obvious to those skilled in the art that it is susceptible of various minor changes and modifications without departing from the spirit thereof and I desire, therefore, that only such 11mitations shall be placed thereupon as are im-' posed by the prior art or are specifically set forth in the appended claims.

I claim as my invention: v 1. In a vacuum-type converter, the combination with a casing, of an anode and a cathode therein, a conducting shield surrounding substantially the entire arc'path therebetween,- and means for maintainlng a positive charge on said shield.

2. In a vacuum-type converter, the combination with a casing, of a plurality of anodes and a cathode therein, a conducting shield surrounding substantially the entire arc path therebctween, and means for maintaining a positive charge on said shield.

3. In a vacuum-type converter, the com bination with a conducting casing, of an anode and a cathode therein, said cathode being in intimate contact therewith, a conducting shield surrounding substantially the entire ar'c path, and means for maintaining an electrostatic charge on said shield that is positive with respect to said cathode.

4. In a vacuum-type converter, the combination with a conducting casing, of a plurality of anodes and a cathode therein, said cathode being in intimate contact therewith,

a conducting shield surrounding substantially the entire arc path, and means for maintaining an electrostatic charge on said shield that is positive with respect to said cathode.

5. In a vacuum-type converter, the combiv nation With a conducting casing, of a cathode therein and in intimate contact therewith,'a plurality of anodes therein and insulated therefrom, a shielding member for each anode, a conducting shield surrounding all of said anodes and extending into proximity to said cathode, and means for imparting to said last mentioned shield a charge that is positive with respect to said cathode.

In testimony whereof, I have hereunto subscribed my name this 28th day of Sept, 1915;

LEWIS W. cnnnn.

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