US1901679A

US1901679A - Gas blast circuit breaker

Info

Publication number: US1901679A
Application number: US597585A
Authority: US
Inventors: Uebermuth Werner
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1931-03-10
Filing date: 1932-03-08
Publication date: 1933-03-14
Anticipated expiration: 1950-03-14
Also published as: GB379996A

Description

March 14., 1933. w. UEBERMUTH 1,901,679

GAS BLAST CIRCUIT BREAKER Filed March 8, 1952 Inventor Werner- Uebermuth,

His Attorneg.

Patented Mar. 14,1933

UNITED STATES PATENT OFFICE WERNER 'UEBERMUTH, OF OBERSCHONEWEIDE, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK GAS BLAST CIRCUIT BREAKER Application filed March 8, 1932, Serial No.

' My invention relates to gas blast circuit brea ers, more particularly to means for operating a gas blast circuit breaker with a minimum expenditure of gas energy.

In the operation of gas blast, circuit breakers wherein a common source of gas pressure is utilized to effect the gas blast and interruption of arcing and also mechanical separation of the switch contacts, it has been proposed to use a common valve serving both purposes. Since the arc extinguishing blast is generally effective to interrupt the circuit within a very short time, as of the order of a cycle or so of alternating current, and since the mechanical separation of the contacts to the fully open circuit position involves a much longer time, it will be apparent that the arc extinguishing blast is continued for a much longer time than necessary resulting in appreciable loss of gas energy. The problem may be concisely stated as follows: The are extinguishing blast requires a large volume of gas at high pressure for a short period of time, whereas the circuit opening operation requires but a comparatively small volume of gas at a lower pressure for a considerably longer period of t me. Due to the high pressure required for the arc extinguishing blast, a large amount of gas energy is dis- 3 sipated by the blast after actual interruption of arcing and prior to completion of the switch opening movement.

A principal object of my invention is the provision-of an improved gas blast circuit breaker having means arranged to shut oil or discontinue the gas blast after a brief time and for continuing application of gas pressure to the switch opening mechanism to complete the switch opening operation.

My invention will be more fully set forth in the following description referring to the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the 597,585, and in Germany March 10, 1931.

claims annexed to and forming a part of this specification.

The single figure of the drawing is a partly diagrammatic View, partly in section, of a gas blast circuit breaker embodying the present invention.

The gas blast circuit breaker illustrated by way of example comprises a stationary nozzle-like contact 1 and a movable rod contact 2 mounted for longitudinal, reciprocal movement within an insulating sleeve-like casing 3 at the upper end of which the contact 1 is mounted. As is well known, the operation of this type of switch involves a source of gas pressure, as a reservoir or pressure tank 4, and a main controlling valve 5 arranged to admit gas under pressure to the casing 3 so that a strong blast is directed across the are and through the nozzle-like contact 1 when the rod contact 2 is drawn toward open circuit position.

Referring more particularly to the structure disclosed, there is provided a hollow metallic section 6 supporting the lower end of the insulator 3 guiding and in electrical contact with the rod contact 2. Circuit lead conductors 7 and 8 are suitably connected to the contact 1 and the metallic section 6, respectively. The reservoir 4 communicates with the interior of the switch casing by means of a suitable conduit section 9 and a. hollow insulator 10 interposed between said section and the metallic section 6.

The conduit section 9 is provided with a valve seat 11 for the valve 5 which is illustrated as operated by a. solenoid 12 for the purpose of simplicity. A valve particularly adapted for this purpose is disclosed and claimed in my. copending application Serial No. 451,388, filed May 10, 1930, for a valve system. It is therefore believed unnecessary to describe further the valve system other 1 than to mention that opening of the valve may be effected in any suitable manner as by manual control of a tripping circuit by the operator, or by an overload impulse produced by the usual current transformer.

The operating mechanism for the circuit breaker comprises in the present instance a piston 13 operating within a cylinder 14 and connected, as by pm and slot connection 15, to one arm of a bellcrank 16. The bellcrank is provided with a fixed pivot 17 and is connected at its other end to an insulating connecting rod 18 in turn connected as at 19 to the rod contact 2. Reciprocal movement of the actuating piston 13 is therefore effective to cause engagement and disengagement of the contacts 1 and 2.

In case the gas supply is applied directly;

by means of the valve 5, to both the switch chamber and the piston 13 it will be apparent that the time required for piston 13 to complete its stroke and move the contact 2 to its final open position is much longer than the time required for interruption of arcing by the high pressure blast exhausting through the nozzle contact 1. For the purpose of eliminating the waste of gas energy at the nozzle contact I have provided means for shutting off the main blast within a short time and for utilizing stored gas energy for completing the switch opening operation. More specifically, a quantity of gas under pressure is temporarily stored or entrapped upon opening of the main valve sothat notwithstanding closure of said valve after ad mitting a brief high pressure blast to the switch contacts, the stored gas energy is effective to complete the opening movement of the contact actuating piston.

To this end the cylinder 14 is connected to the conduit section 9 at a point beyond the main valve 5, as by a pipe 20, including a storage space or gas accumulator 21. For the purpose of preventing reverse flow of gas through the accumulator 21, the same is provided with a suitable one-way valve as a flap valve 22. It will be understood, of course, that the accumulator 21 may comprise a portion of the cylinder 14 on the working side of the piston 13.

The operation is as follows: When the main valve 5 is opened, as at the will of the operator or in response to an abnormal circuit condition, a supply of gas at high pressure is directed from the reservoir 4 through the conduit section, 9 so that pressure is applied practically simultaneously to the switch contacts and to the actuating piston 13. The valve 22 within the accumulator 21, it will be noted, does not prevent full application of the gas pressure to the piston 13. As the contacts 1 and 2 separate the resulting high pressure blast through the nozzle contact 1 quickly extinguishes arcing so that the main valve 5 may beclosed, in so far as the interrupting blast is concerned, during the remainder of the circuitopening movement. Immediately upon closure of the valve 5 gas under high pressure is entrapped within the accumulator 21 by reason of the valve 22, so that the stored energy of this gas continues to move the piston 13 to its limiting open circuit position. Accordingly, the gas energy is applied in the most effective manner wit out unnecessary waste. The circuit breaker may be closed in any suitable manner as by mechanical means or by a pressure connection (not shown) to the opposite side of the cylinder 14. t

It should be understood that my invention is not limited to specific details of construction and arrangement thereof herein illus-. trated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A gas blast circuit breaker comprising relatively movable contacts, a source of gas pressure, a valve controlling flow of gas from said source for extinguishing arcing between said contacts and for causing separation thereof, and means for completing separation of said contacts after closure of said valve.

2. A gas blast circuit breaker comprising a source of gas pressure, relatively movable contacts, a valve controlling flow of gas from said source, means directing said gas flow simultaneously to operating means for separating said contacts and to said contacts for extinguishing arcing, and means utilizing .stored gas energy for completing separation of said contacts after closureof said valve.

3. A gas blast circuit breaker comprising relatively movable contacts, a source of gas pressure, a main valve controlling flow of gas from said source, a piston for causing relative movement of said contacts, opening of said valve causing application of gas pressure simultaneously to said piston and to said contacts so that arcing between said'contacts is extinguished upon separation thereof, and a gas accumulator disposed between said source and said piston arranged so that said piston is moved to its limiting position by gas pressure subsequent to closure of said valve.

4.v A gas blast circuit breaker comprising relatively movable contacts, a source of gas pressure, a piston for effecting relative movement of said contacts, a main valve controlling flow of gas from said source, means directing said gas upon opening of said valve simultaneously to said piston and to said contacts, a gas storage spaceinterposed between said piston and said main valve, and a oneway valve preventing reverse flow of gas from said storage space, said storage space being proportioned so that gas entrapped therein after closing, of said main .valve is efiective to cause continued movement of said piston to its limiting open circuit position.

5. A gas blast circuit breaker comprising relatively movable contacts operating means including a piston for eifecting relative movement of said contacts, a source of gas ressure, a main valve for controlling flow gas 5 from said source for a limited time corresponding to the blast required at said contacts for extinguishing of arcing, and an accumulator provided with a valve preventing reverse flow interposed between said piston and said source for continuing application of gas pressure to said piston after closure of said main valve.

In1 witness whereof I have hereunto set my han WERNER UEBERMUTH.