US3686454A - Gas-blast circuit interrupter with primary and secondary blast valves - Google Patents

Abstract

A gas-blast type of circuit breaker is provided having separable contacts with a primary blast valve closely adjacent the point of abutment of the separable contacts, and a secondary blast valve controlling the flow of gas through at least one of the separable contacts. In one embodiment of the invention, there is provided a pair of tubular separable contacts, through which the gas exhausts, and the region within both tubular separable contacts is controlled by downstream secondary blast valves mechanically connected together, and operated in response to opening motion of the separable contacts.

Description

United States Patent Berkebile 1451 Aug. 22, 1972 '[22] Filed:

[54] GAS-BLAST CIRCUIT INTERRUPTER WITH PRIMARY AND SECONDARY BLAST VALVES [72] Inventor: Lee E. Berkebile, 11979 Frankstown Rd., Pittsburgh, Pa. 15235 Sept. 16, 1968 21 Appl. No: 759,992

[52] US. Cl ..200/148 R, 200/148 BV [51] Int. Cl. ..H01h 33/82 [58] Field of Search ..200/148 BV, 148 B, 148

[56] References Cited UNITED STATES PATENTS 2,972,666 2/1961 Forwald ..200/148 BV 3,040,149 6/1962 Easley et a1. ..200/148 BV 3,093,717 6/1963 Forwald ..200/148 B 3,185,802 5/1965 Amalric ..200/148 B 3,278,711 10/1966 Thuries et a1. ..200/148 B HIGH PRESSURE SF GAS I IN THIS REGION LOW PRESSURE SF GAS IN THIS REGION 3,286,066 1l/l966 Floessel ..200/14813 Primary Examiner-Robert S. Macon Attorney-A. T. Stratton, C. L. McHale and W. R. Crout ABSTRACT A gas-blast type of circuit breaker is provided having separable contacts with a primary blast valve closely adjacent the point of abutment of the separable contacts, and a secondary blast valve controlling the flow of gas through at least one of the separable contacts.

In one embodiment of the invention, there is provided a pair of tubular separable contacts, through which the gas exhausts, and the region within both tubular separable contacts is controlled by downstream secondary blast valves mechanically connected together, and operated in response to opening motion of the separable contacts.

6 Claims, 5 Drawing Figures (A CLOSED CONTACT POSITION P'ATENTED M1822 m2 SHEET 1 [IF 4 LOW PRESSURE SP GAS PATENTEDmszz m2 SHEEI 2 BF 4 FIG.2

K GAS-BLAST CIRCUIT INTERRUPTER WITH PRIMARY AND SECONDARY BLAST VALVES CROSS-REFERENCES TO RELATED APPLICATIONS The broad concept of a high gas-pressure region surrounding the region of separation and abutment of the separable contacts with the gas blast arranged to flow through the separable contacts and controlled by a lo BACKGROUND OF THE INVENTION Prior-art gas-blast circuit breakers generally involve a pair of seperable contacts with an arrangement for providing a gas blast to effect extinction of the arc drawn thereat. To create this gas blast, previous gasblast types of circuit breakers have employed blast valves that open just prior to contact part. Opening the blast valves creates a pressure differential, and this differential pressure creates the gas blast. A limitation to this method is the time needed for the gas blast to travel from the blast valves to the are at the moving contacts. This time delay requires that the blast valves must be opened before the moving contacts are separated. In such a system, the maximum pressure difierential (and therefore the greatest gas blast) does not occur at the moving contacts at the time of. contact part. This inherent time delay for maximum pressure differential limits the interrupting capability of such prior-art compressed-gas circuit breakers in their operation.

A typical patent illustrating the use of a gas-blast valve disposed remotely from the separable contacts is US. Pat. No. 2,568,008 issued Sept. 18, 1951 to G. E. Janssen.

More recently, there has been proposed the use of separable contacts separating in a high-pressure atmosphere with the gas blast exhausting through at least one of the separable contacts. Such an arrangement is set forth in'U.S. Pat. No. 3,275,778 issued Sept. 27, 1966 to Shoji Morioka.

SUMMARY OF THE INVENTION In accordance with an embodiment of the present invention, there is provided a pair of separable contacts in a high-pressure gaseous atmosphere. A primary blast valve is disposed closely adjacent the point of abutment of the separable contacts, so that upon separation of the contacts there occurs an immediate radial inward flow of high-pressure gas into at least one of the separable contacts. Controlling the flow of exhausting gas through said one contact, or in particular arrangements through both separable contacts, is one or more secondary blast valves disposed downstream of the gas flow.

The mechanical arrangement is such that the downstream secondary blast valves remain open for a predetermined time to insure an interruption of the are established between the separable contacts. At the point in time, where assurance is had that the arc has been extinguished, the mechanical arrangement is such that the secondary blast valves close, thereby halting any further exhausting of the high-pressure gas through the separable contacts.

During a closing operation of the circuit breaker, the

primary blast valve, disposed immediately adjacent the point of abutment of the separable contacts, insures a sealing condition at this point, and the mechanical arrangement during such a closing operation is such as to open the one or more secondary blast valves, to thereby permit a lowering of the pressure communicating with the region interiorly of the separable contacts.

Accordingly, a general object of the present invention is to provide an improved high-speed compressedgas circuit interrupter having primary and secondary blast valves, the primary blast valve being disposed closely adjacent the point of separation of the separable contacts, and the one or more secondary blast valves being located downstream of the gas flow.

Another object of the present invention is the provision of an improved compressed-gas circuit interrupter in which the separated open-circuit condition of the contacts occurs in a high-pressure medium, thereby assuring a minimum separation distance because of the high-dielectric strength of the high-pressure gas.

Still a further object of the present invention is the provision of an improved high-speed gas-blast circuit interrupter in which the time occurring between the opening of the blast valve and the separation of the separable contacts is at a minimum.

Another object of the present invention is the provision of an improved compressed-gas circuit interrupter in which the consumption of the gas flow during an opening operation is maintained at a minimum.

Another object of the present invention is the provision of an improved simplified-type of compressed-gas circuit interrupter of low cost and highly efficient in operation.

Still a further object of the present invention is the provision of an improved compressed-gas circuit interrupter in which the arcing time is maintained at a minimum to prevent voltage surges on the line, and a loss of synchronism of equipment connected to the line.

Further objects and advantages will readily become apparent upon reading the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view taken through a circuit interrupter embodying my'invention, the contact structure being illustrated in the closed-circuit position;

FIG. 2 is a sectional view taken substantially along the line 11-11 of FIG. 1;

FIG. 3 is an enlarged view of the separable contact structure showing the primary blast valve closed with the secondary blast valves opened, the contact structure being illustrated in the closed-circuit position;

FIG. 4 is a view similar to FIG. 3, but showing the separable contact structure at an intermediate point during the opening operation, with the primary blast valve opened and the secondary blast valves opened; and,

FIG. 5 illustrates the open-circuit position of the contact structure with the primary blast valve opened and with the secondary blast valves closed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 designates generally a compressed-gas circuit interrupter.

The lower end of the arc-extinguishing assemblage 2 of FIG. 1 is electrically connected by a curved electrical conductor 4 to the other terminal of the interrupter, not shown.

The compressed gas circuit interrupter 1 of the present invention is generally of the dual-pressure type in which high-pressure gas 5 is stored in a tank, not shown, and is disposed within container means 6 immediately adjacent the separable contact structure 7 in the region designated by the reference numeral 8 in FIGS. 1, 3-5. The region 9 (FIG. 3) rearwardly of both contact structures 10, 11 is at relatively low pressure. These regions are designated by the reference numeral 9, and are pneumatically interconnected by at least one interconnecting conduit designated by the reference numeral 12 in FIG. 1 of the drawings.

Generally, the manner of operation of the circuit interrupter l illustrated in FIGS. 1-5 is the actuation of tripping valves. The actuation of such tripping valves through a linkage causes the entrance of high-pressure gas 5 below piston structures not shown.

The upward movement of the piston structure, not shown, causes a corresponding upward opening motion of the mechanical linkage, or reciprocal operating means 19 (FIG. 2) which, in turn, causes upward movement of a generally ladder-type operating rod linkage 21, (FIG. 2) which interconnects the two secondary blast valves 23a, 23b associated with the arc-extin guishing unit 25 of the assemblage 2. In more detail, referring to FIGS. 3-5 of the drawings, it will be noted that there is a pair of separable contacts 10, 11 having a primary blast valve structure 27, and a pair of secondary blast- valve structures 23a, 23b. The secondary blastvalve structures 23a, 23b are mechanically interconnected by the laddershaped operating linkage 21 (FIGS. 1 and 2), and are simultaneously actuated.

Accordingly, to effect the opening operation of the compressed-gas circuit interrupter l of the present invention, the tripping valves is opened to cause the entrance of high-pressure gas 5 upwardly through the conduits and against the lower surfaces of the a piston structure, not shown. This causes upward opening movement of the ladder linkage arrangement 21, and, in addition, causes upward movement of an operating rod 30 mechanically connected to the movable contact structure 10. Reference may be directed to the operating rod 30 of FIG. 3, which is connected mechanically to the same operating rod 19 as shown in FIG. 2 of the drawings.

Upward opening movement of the ladder-shaped linkage 21 causes opening of the movable contact away from the primary blast-valve seat 32 and separation thereof from the stationary contact fingers 34, which make engagement therewith in the closed-circuit position of the device, as illustrated in FIG. 3 of the drawings.

During the initial portion of the opening operation, both blast valves 23a, 23b are opened, and the highpressure gas in the region 8 flows radially inwardly and through both separable tubular contacts 10, 11 exhausting therethrough into the regions 9 downstream of the separable contacts 10, 11. This exhausting flow is controlled by the secondary blast valves, 23a, 23b which are operated in unison.

With reference being particularly directed to FIGS. 3-5 of the drawings, it will be observed that the are 38, which is drawn between the contact fingers 34 and the extremity 10a of the moving tubular contact, is quickly transferred to the inner stationary tubular arcing contact 40 being subjected to a flow of gas, as indicated by the arrows 41 in FIG. 4 of the drawings. During this time, both primary and secondary blast valves 27, 23a, 23b are opened. When the are 38 has been extinguished, it is desirable to halt the further consumption of high-pressure gas, and to effect this end, closure of the secondary blast valves 23a, 23b is desirable. This closing motion of the secondary blast valves is achieved by a flange portion 10b secured to the movable contact 10, which compresses a compression spring 43 and following the overcoming of friction at the seal 44, the secondary movable blast valve 23a is closed up against its seat 45, as illustrated in FIG. 5, thereby halting the further flow of compressed gas. The right-hand secondary blast valve 23b, as illustrated in FIGS. 3-5 of the drawings is mechanically connected to the laddershaped operating linkage 21, and therefore moves simultaneously with the left-hand secondary blast valve 23a. In other words, both the moving contact 10 and the flange portion 10b thereof, and also the operating rod 46, together with its actuator portion 46a, causes compression of the compression spring 43a and corresponding closure of the right-hand secondary'blast valve 23b against its seat 45a. The breaker is now in the open-circuit position with the primary blast valve opened, and both secondary blast valves 23a, 23b closed, as shown in FIG. 5. The compression springs 43, 43a constitute a biasing means 13, tending to close the secondary blast-valves 23a, 2312, which is steadily compressed, or stressed, during the opening operation to mechanically cause the closing of the secondary blast-valves.

During the closing operation, the high-pressure gas is exhausted from the lower surface of the piston structure, not shown, and the high-pressure gas which is constantly present above the piston structures causes the downward closing motion thereof. This is communicated through the ladder-shaped linkage 21, and also through the operating rod 30 (FIG. 3) connected to the movable contact 10. As a result, the moving contact 10 moves downwardly, as viewed in FIG. 1 of the drawings, and the operating rod 19, being connected to the ladder-shaped linkage 21, also moves downwardly to thereby effect opening of the right-hand secondary blast valve 23b of. FIGS. 3-5. The circuit breaker is now in the closed-circuit position.

To enable the circuit breaker 1 to carry considerable current, there is provided the two pairs of stationary contact fingers 34, 48 each of which is supported by its contact holder 34a or 48a. The contact holders are, as readily apparent in FIG. 3, bolted to the plate portions 50, 51 constituting the ends of the low-pressureregions rearwardly of the stationary and movable contact structures 10, 11 reference being had to FIG. I in this connection.

From the foregoing description it will be apparent that there has been provided an improved high-speed compressed-gas circuit interrupter in which the contacts separate in a high-pressure atmosphere, or environment 8. The separation of the separable contacts not only causes opening of the primary blast valve 27 to result in a radial inward flow of the high-pressure fluid exhausting through the contacts, but continued opening motion effects a subsequent closure of the secondary blast valves 23a, 23b and a cessation of the exhaust ing gas flow occurring through both contacts. This results in the contacts being separated in a high-pressure region 8 while in the open circuit position, thereby taking advantage of the high-dielectric-strength of the high-pressure gas. As well known by those skilled in the art, this results in a minimum separation distance in the open-circuit position of the interrupter.

Certain features of the operating mechanism are set forth and claimed in US. Pat. application filed Sept. 25, 1968, Ser. No. 762,479, now US. Pat. No. 3,590,189, issued June 29, 1971 and assigned to the assignee of the instant application.

Certain other features relating to the general configuration of the circuit interrupting structure with the generally U-shape are set forth and claimed in US. Pat. application filed Dec. 9, 1968, Ser. No. 782,365, now US. Pat. No. 3,596,028, issued July 27, 1971, and likewise assigned to the assignee of the instant application.

Although there has been illustrated and described specific structures, it is to be clearly understood that the same were merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. A compressed-gas circuit interrupter comprising, in combination:

a. a pair of separable contacts at least one of which is tubular;

b. container means refining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position;

c. means defining a primary blast-valve located closely adjacent the point of separation of the separable contacts and preventing the inward flow of said high-pressure atmosphere through the tubular separable contact when in the closed-circuit position; means defining at least one downstream secondary blast-valve independently movable from the movable tubular contact, and pneumatically connected to the region internally of said one tubular contact to halt the continued flow of compressed gas through the tubular contact when the circuit-interrupter is in the open-circuit position;

e. reciprocal operating means for effecting the opening and closing movements of said one tubular venting contact;

f. biasing means provided to tend to close the secondary blast-valve;

a movable secondary blast-valve actuator responsive to the opening and closing movements of said reciprocal operating means for mechanically effecting the stressing of said biasin means during the opening operation and also e ecting the subsequent closing of the secondary blast-valve at a predetermined time during the opening operation to prevent thereby the further exhausting of compressed gas through the tubular venting contact at such time; and,

said movable secondary blast-valve actuator mechanically effecting the opening of the secondary blast-valve during the closing operation of said operating means to thereby exhaust the region within the tubular venting contact in the closedcontact position.

2. The compressed-gas circuit interrupter of claim 1, in which both separable contacts are tubular and two secondary blast-valves are provided.

3. The combination of claim ll, wherein the primary blast-valve is immediately adjacent the point of abutment of the separable contacts.

4. The combination of claim 1, wherein two spaced stationary sets of contacts fingers bear on said one tubular separable contact for increased current flow.

5. The combination of claim ll, wherein an inner arcing horn is associated with the other separable contact.

6. The combination of claim 5, wherein the inner arcing horn is tubular and exhausts gas therethrough.

Claims (6)

1. A compressed-gas circuit interrupter comprising, in combination: a. a pair of separable contacts at least one of which is tubular; b. container means refining a high-pressure atmosphere about said separable contacts when they are in the closed-circuit position; c. means defining a primary blast-valve located closely adjacent the point of separation of the separable contacts and preventing the inward flow of said high-pressure atmosphere through the tubular separable contact when in the closedcircuit position; d. means defining at least one downstream secondary blast-valve independently movable from the movable tubular contact, and pneumatically connected to the region internally of said one tubular contact to halt the continued flow of compressed gas through the tubular contact when the circuit-interrupter is in the open-circuit position; e. reciprocal operating means for effecting the opening and closing movements of said one tubular venting contact; f. biasing means provided to tend to close the secondary blastvalve; g. a movable secondary blast-valve actuator responsive to the opening and closing movements of said reciprocal operating means for mechanically effecting the stressing of said biasing means during the opening operation and also effecting the subsequent closing of the secondary blast-valve at a predetermined time during the opening operation to prevent thereby the further exhausting of compressed gas through the tubular venting contact at such time; and, h. said movable secondary blast-valve actuator mechanically effecting the opening of the secondary blast-valve during the closing operation of said operating means to thereby exhaust the region within the tubular venting contact in the closedcontact position.

2. The compressed-gas circuit interrupter of claim 1, in which both separable contacts are tubular and two secondary blast-valves are provided.

3. The combination of claim 1, wherein the primary blast-valve is immediately adjacent the point of abutment of the separable contacts.

4. The combination of claim 1, wherein two spaced stationary sets of contacts fingers bear on said one tubular separable contact for increased current flow.

5. The combination of claim 1, wherein an inner arcing horn is associated with the other separable contact.

6. The combination of claim 5, wherein the inner arcing horn is tubular and exhausts gas therethrough.

Images