US1595768A - Arc-suppressing device - Google Patents

Description

Aug. 10 1926.

O. H. ESCHHOLZ ARC SUPPRESSING DEVICE Filed Nov. 29, 1920 INVENTOR 0lt0 11 Exbbolz ATTORNEY WITNESSES:

Patented Aug. 10, 1926.

UNITED STATES PATENT OFFICE.

OTTO H. ESCHHOLZ, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ARC-SUPPRESSING DEVICE.

Application filed November 29, 1920. Serial No. 427,061.

My invention relates to circuit-interrupting, systems and it has for one of its objects to reduce the arcinginormally-attending the opening of a circuit interrupter.

Another object of my invention is to pro"-' vide a circuit-interrupting s stem that shall comprise an electric valve 0 such characteristics and so related to the interrupter as to shunt the circuit current around the interrupter when the latter is opened and to automatically build up resistance to the current until the flow of the latter is stopped.

In practicing my invention, ,1 provide an electric valve, preferably of the so-called hot-cathode type, of which the cathode circuit is connected in shunt to the circuit and in which the anode circuit, taken in conjunction with the cathode circuit, forms a local series-parallel system connected in shunt to an interrupter. When the interrupter is opened, in response to short-circuit or predetermined overload conditions, the main circuit current is shunted through the anode circuit and there will be substantially no arcing at the interrupter contact members. The arrangement is such that, after the opening of the interrupter and when the main-circuit current is passing through the valve, a rapid diminution of the excitation of the cathode will cool the latter to a temperature below that necessary forelectron emission. The valve will, thus, function to rapidly, and by graduated amounts, insert resistance from a valve substantially equal to the resistance of the circuit to be interrupted to infinite resistance preventing the passage of current.

Figure '1 of the accompanying drawings is a diagrammatic view of a circuit-interrupting system embodying my invention and Figs. 2, 3 and 4' are similar views of moditied t'orms thereof.

In all of the figures, a main circuit interrupter 1, connected to a suitable supply gndga. resetting spring ll for the core mem- As shown in Fig. 1, an electric valve 12 comprises a cathode 13 that is connected, at one side through an adjustable resistor 14 and a reactor 15, to the main circuit 2 and,

at the other side, through a'conductor 16,

also to the main circuit 2 but with a device 17, that may be a resistor or a reactor, in the circuit 2 between the cathode terminals. The anode 18 of the valve 12 is connected, by a conductor 19, to the main circuit 2 at a side of the interrupter 1 opposite to that to which the conductor 16 is connected to the circuit 2.

The cathode circuit is adapted to receive local current from the main circuit by reason of the drop of potential across the device 17. This local current may be so chosen, or adjusted by the resistor 14,as to render the cathode 13 normally relatively cold or to malntain it at a predetermined relatively high temperature. Whether the cathode shall be maintained at one temperature or another depends upon the characteristics of the circuit 2, and while it is desirable to normally maintain the cathode relatively cool to conserve the life thereof, certain advantages will obtain by normally maintaining it relatively hot. One of these advantages is that it is easier to raise the oathode temperature from a relatively high value that may be, at the same time, just below that required to give the required electron emission, to that at which the main circuit current will freely traverse the valve,

the anode 18, the electron-filled space be-' tween the anode l8 and the cathode 13, and the conductor 16. The sudden rise of the main circuit current, just previous to the opening ofthe interrupter 2, will so heat the cathode 13 as to cause the emission of a sufficient quantity of electrons to convey the shunted current through the valve with substantially no opposition.

\Vhen the interrupter 2 opens, the cathode 13, being deprived of its source of energy, will quickly, but by graduated amounts, be so cooled as to gradually diminish its electron emission. This action will, thus, automatically buildup resistance to the main circuit current until the latter ceases to flow. The reactor 15 is adapted to cause the local cathode current, and therefore the cathode temperature, to lag sufiiciently to assure the complete transfer of the line current from the breaker to the valve circuit.

As shown in Fig. 2, the arrangement is substantially the same as that shown in Fig. 1, with the exception that the local catho e circuit may be mechanically interrupted, by a switch 20, at the end of a predetermined interval of time after the opening of the interrupter 1. The switch 20 may comprise a stationary contact member 21- and a pivoted switch arm 22 that is biased toward the closed osition, by a spring 23, and is provided with a projection 24 for cooperation with a projection 25 carried by the movable parts of the interrupter 1.

As shown in Fig. 3, a battery 26, that takes the place of the device 17 in the forms shown in Figs. 1 and 2, is provided for enerizing the cathode 18. Also, as shown in ig. 3, the resistor 1 1 is rendered automatically adjustable by the co-operation of terminal taps 27 thereof with a switch arm 28 that is biased toward one position by a spring 29 and actuated toward another position by an electromagnet 30 having a core member 31 and a coil 32 connected to the circuit 2.

Vi hile all of the above shown and described forms of my invention are readily adaptable for either alternating or directcurrent circuits, the form shown in Fig. 4.- is particularly adapted for an alternatingcurrent circuit.

As shown in Fig. 4:, the system is substantially a combination of the systems shown in Figs. 1 and 3, it having two of the valves 12 each similarly connected on opposite sides of the interrupter 2. Since the valves 12 are asymmetric, the arrangement shown in Fig. 4-, will ensure the interruption of the main circuit current in the one or the other of the valves during the first halt cycle of the alternating-current wave.

While 1 have shown and described particular "forms of my invention, changes may be effected therein without departing from the spirit and scope thereof, as set forth in the appended claims.

' claim as my invention A circuitintcrrupting s 'stem compriscircuit, a circuit interrupter, an electron emission valve connected in shunt to the interrupter and means effective only upon an overload in the circuit for energizing the valve.

2. A circuit-interrupting system comprising a circuit, a circuit interrupter, an electron emission valve connected in shunt to the interrupter and means for energizing and for radually changing the amount of energization of the valve.

3. A circuit-interrupting system comprising a circuit, a circuit interrupter, an electron emission valve connected in shunt to the interrupter and automatically actuable means for energizing the valve only upon the occurrence of an abnormal condition in the circuit.

4. A circuit-interrupting system comprising a circuit, a circuit interrupter, an electron emission valve connected in shunt to the interrupter, and automatically actuable means for energizing and for controlling the amount of energization of the valve.

5. A circuit-interrupting system comprising acircuit, and electron-emitting means connected thereto and adapted to interrupt the circuit at the end of a predetermined interval of time after the occurrence of predetermined conditions therein.

6. A circuit-interrupting system comprising a circuit interrupter, and an electron emission valve adapted to conduct the circuit current after the opening of the interrupter and to interrupt the current at the end of a predetermined time interval.

7 A circuit-interrupting system, comprisin na circuit interrupter, and an electric valve connected in shunt to the interrupter and having a cathode circuit connected in parallel wlth a portion of the circuit at one side of the interrupter. 8. A circuit-interrupting system compris- 111 a circuit lDtGII'UDtGI, and an electric valve having a cathode circuit connected in shunt to a portion of the circuit, and an anode circuit that, with the cathode circuit, constitutes a series-parallel shunt circuit, the anode and cathode circuits each being conhected at one end to opposite sides of the interrupter.

9. In an electric circuit, the combination with a circuit interrupter, of a hot-cathode valve connected across the interrupter, and means responsive to the circuit conditions for controlling the cathode of the valve.

10. In an electric circuit, the combination with a circuit interrupter, of a hot-cathode valve connected across the interrupter, and means responsive to the circuit conditions for controlling the heating of the cathode of the valve. 7

11. In an electric circuit, the combination with a circuit interrupter, of a hot-cathode valve connected across the interrupter, and

means responsive to the current traversing the circuit for controlling the heating of the cathode of the valve.

12. A circuit-interrupting system comprising a circuit, an electron-emitting means connected thereto, means governed by predetermined conditions in the circuit for rendering the electron means effective to maintain the circuit, and means for controlling the period of time during which the electron 10 means remains effective.

In testimony whereof, I have hereunto subscribed my name this 17th day of N0- veinher, 1920.

' OTTO H. ESCHHOLZ.

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