US1267858A - Inclosed-arc device. - Google Patents

Description

C. V. FERGUSON.

INCLOSED'ARC DEVICE APPLICATION FILED JULY 3|19l6- Inventor: Charles V. Ferguson,

i MHIES V. FERGUSON, OF SCHENECTADY, NEW YORK, ASSIGINOR 'JlO GENERAL ELEC- A eoaaroe TION 01F Y0 a environ.

application tiled July 3, 1916. Serial No. 107,276.

To all whom it may concern:

Be it known that T, Crmmens V. Fnneoson, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements .in Inclosed- Arc Devices, of which the following is a specification.

The present invention relates to devices in which an arc is operated between an in-. candescent cathode and an anode operating below 'thetemperature of appreciable electron emission, ina' sealed envelop, such, for example, as the incandescent cathode rectifier describedin Meikle Patent No. 1,182,290. In the rectifier described in this patent an arc is operated between a heated tungsten cathode and an anode of tungsten, or other suitable conductive material, in-an atmosphere of inert gas, such, for example, as nitrogen, argon, or mercury vapor. ][t is stated in the patent that electronegative gases such aswater vapor, oxygen and chlorin must be carefully excluded to avoid deleterious disintegration of the cathode.

I have discovered that iodin vapor constitutes a striking exception among electroaid negative gases in an incandescent cathode device. Not only is the electrical disintegration of the cathode in an arc device containing iodin negligible, but iodin on the other hand possesses distinctive properties advantageous to the operation of an arc particularly in a rectifier. One of the main advantages of iodin vapor in a rectifier is the substantial inhibition of arcing from an electrode not intended to act as cathode,

for example, from anode to cathode, or between two anodes. The voltage drop of an arc in iodin vapor is relatively low and substantially invariable. The accompanying drawing shows one specific form of hot cathode device embodying my invention. T wish it to be understood that this is shown for illustrative purposes only as my invention is of general application. The particular cathode structure shown is described and claimed in another copending application.

Referring to the drawing, the device shown comprises a cathode 1, consisting of tungsten, or other suitable refractory material, and an anode 2, which also consists of tungsten, molybdenum, copper or other suitable conductive material. An anode conductor 3, and cathode conductors 4, 5, are sealed into the envelop 6 in the usual manner. The structural features of the electrodes are not part of thepresent invention.

When the envelop has been evacuated in the usual manner, water vapor being carefully removed, some ure iodin is introduced, for example, t rough a side tube afterward sealed ofl' and not shown in the drawing. The quantity of iodin should be suflicient and the operating temperature of the bulb high enough to create a pressure of iodin vapor equal to at least about one-half millimeter of mercury. The best rectification appears to be obtained at pressures up to about millimeters.

The drop of voltage in an arc of about five amperes in iodin vapor is about 23 volts. The tendency for arcing to occur from anode to cathode upon the reversal of polarity is so low that alternating currents of high voltage, for example, 700 to 800 volts, may be readily rectified in iodin vapor..

What T'claim as new and desire to secure by Letters Patent of the United States, is

ate at incandescence, a cooperating anode and a quantity of iodin, an inclosing container, said container operating at a temperature at which the iodin has a vapor pressure exceeding about one-half millimeter of mercury.

3. The method of suppressing deleterious arcing from anode to cathode in an are de-.

vice provided with a cathode operating at incandescence and an anode operating below the temperature at which electronem ss on is, appreciable, which consists in providing an environment of iodin vaporfor the arc during the operation of. the device.

In witness whereof, T have hereunto set my hand this 30th day of June, 1916.

, cLEs v. rnnensou.

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