US3433913A

US3433913A - Gas-blast circuit interrupter

Info

Publication number: US3433913A
Application number: US475440A
Authority: US
Inventors: Winthrop M Leeds
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1965-07-28
Filing date: 1965-07-28
Publication date: 1969-03-18
Anticipated expiration: 1986-03-18
Also published as: BE684755A; GB1125506A

Description

March 18,1969

w. M. LEEDS GAS -BLAST CIRCUIT INTERRUPTER Filed July 28, 1965 Sheet FIG. I.

March 18, 1969 w. M, LE D 3,433,913

GAS -BLAS T CIRCUIT INTERRUPTER United States Patent 3,433,913 GAS-BLAST CIRCUIT INTERRUPTER Winthrop M. Leeds, Forest Hills, Pittsburgh, Pa.,-assignor to Westinghouse Electric Corporation, Pittsburgh, Pa.,

a corporation of Pennsylvania l 7 Filed July 28, 1965, Ser. No. 475,440 US. Cl. 200-148 Claims Int. Cl. H01h 33/82, 9/40, 33/14 ABSTRACT OF THE DISCLOSURE A gas-blast circuit interrupter is provided with a pair of separable main contacts shunted by the combmatron of a pair of separable impedance contacts 1n ser es with a resistance. A single blast valve serves umtarlly as an upstream blast valve for controlling the gas flow at the main contacts, and at the same time, as a downstream blast valve for controlling the gas flow at the separable impedance contacts. A time delay is provided to separate the main contacts prior to separation of the separable impedance contacts.

This invention relates, generally, to gas-blast circuit interrupters and, more particularly, to gas-blast c1rcu1t interrupters adaptable for heavy-power duty A general object of the present invent1on 1s to provide an improved compressed-gas circuit interrupter of simplified construction and capable of interrupting heavy-power circuits.

Another object of the present invention is to provide an improved compressed-gas circuit interrupter suitable for high-voltage application, and particularly adaptable. for operation using 7 a highly-efiicient arcextinguishing gas, such as sulfur-hexafluoride (SP gas, and in which improved extinguishing efiectiveness is obtained.

Another object of the present invention is to provide an improved circuit interrupterhaving a pair of separable rnain contacts using an upstream blast valve, and an electrically-parallel shunting pair of resistance con tacts using a downstream blast valve, in which the 1mproved blast valve of the instant application unltarlly performs both blast-valve functions.

Still a further object of the pesent invention 1s to provide an improved compressed-gas circuit interrupter of the rotating-arm type, in which the passage means for conducting gas through the one or "more hollow rotating arms provides, additionally, an exhaust passage for downstream blast-valve action exerted on a shunting pair of resistance contacts. e

" Another object of the present invention is to provlde an improved compressed-gas circuit interrupter of the type set forth in United States patent application filed Feb. 26, 1965, Ser. No. 435,560, now US. Patent 3,371,176, issued Feb. 27, 1968 to Winthrop M. Leeds, entitled High-Voltage Circuit Interrupter With a Pair of Fluid-Conducting Pivotally-Mounted Contact Arms, and assigned to the assignee of the instant application. More particularly, it is a distinct purpose of the present invention to simplify the resistance-interrupting operation of the aforesaid patent rendering it more simple and of compact arrangement. l l

Still a further object of the present invention is to providean improved compressed-gas circuit interrupter 3,433,913 Patented lylar. 18, 1969 ice modules is considerably increased to thereby cut down on the number of modules for the higher-voltage applications.

Further objects and advantages will readily become apparent upon reading the following specification, taken in-conjunction with the drawings, in which:

-' FIGURE 1 is a side elevational view of one pole-unit of a three-phase circuit interrupting structure;

FIG. 2. is a diagrammatic view of the main and resistance contact structure for one of the interrupting modules of the circuit interrupter illustrated in FIGURE 1, the contact structure-being shown in the partially open-circuit position; 1

IFIG. 3 is an enlarged fragmentary view showing in more detail one of the arc-extinguishing units, the contact 'structure being illustrated in the closed-circuit position; FIG. 4 is a plan view, in section, taken substantially along the line IV-IV of FIG. 3 with the rotating arms, however, in longitudinal section, and also showing the blast-valve operating mechanism;

FIG. 5 is a perspective view of the bridging resistance contact assemblage of thepresent invention;

FIG. 6 is a fragmentary enlarged detail view showing the lost-motion connection between the main and resistance contacts; and,

--FIG. 7 isa-simplified diagrammatic view indicating the impedance, or resistance contacts, and their relationship with the main contacts present in one of the interrupting-modules of the circuit-interrupting arrangement of FIG-URE'I.

Referring to the drawings, and more particularly to FIGUREl thereof, the reference numeral 10 generally designates a three-phase circuit-interrupting assemblage. 1 only illustrates a side elevational view of one of the pole-units of the three pole-units utilized in such athree-phase operating arrangement. It is to be under stood that there are, intact, three such pole-units in alignment, and FIGURE 1' only shows a side elevational view of one such pole-unit.

It will be observed that, generally, there are provided three interrupting modules 12, each of which is supported in"an upstanding manner, as shown in FIGURE 1, by a hollow insulating supporting column construction 14. With reference to FIG. 2, extending upwardly interiorly of each hollow insulating supporting column construction 14 is a high-pressure supply pipe 16, which supplies highpressure arc-extinguishing gas to a high-pressure reservoir 18-, the latter disposed interiorly of a live metallic lowpr'essure housing 20. K l

As illustrated'in FIG. 2, it will be observed that each metallic relatively low-pressure housing 20 has extending therewithin a pair of terminal bushings 22, to the interior ends of which are fixedly secured tubular relatively stationary contact structures 24. As shown in more detail inPIG. 3 of the drawings, each tubular relatively stationary contact 24 makes'contacting engagement with a plurality of resiliently-biased finger contacts 26, the latter-being carried adjacent the free extremities of a rotating-arm movable contact assemblage, generally designated by the reference numeral 30.

i In more detail, each rotatable movable contact assemblage 30 includes a pair of movable arc-extinguishing units 32., which direct gas flow obtained from a flow of high-pressure gas through the hollow interior 30a of the rotating movable contact assemblage 30.

V With reference to FIG. 4 of the drawings, it will be noted that the interior'30a of each movable rotatable contact assemblage 30 may, at times, be communicated through a reciprocally-movable blast-valve structure 40 tOa-higlrpressure region, generallydesignated by the reference numeral 50, and communicating through auxiliary upstream orifice apertures 52 to the general interior 49 of the high-pressure reservoir tank 18. It will, therefore, be apparent that upon leftward opening movement of the blast valve 40, apertures a will become aligned with the openings 30b provided at the inner extremities of the rotating movable arms of the contact assemblage 30 and will provide an outwardly flowing blast of gas through the hollow arm portions of the rotating movable assemblage 30; and this gas blast will be directed by the insulating gas directing orifices in opposite directions through the movable tubular stationary contact 24 and also through the tubular movable contact assemblage, generally designated by the reference numeral 58, as shown in FIG. 3 of the drawings, although FIG. 3 shows the closed-circuit position of the contact structure.

As shown in more detail in FIG. 3 of the drawings, each movable contact assemblage 58 comprises a movable tubular arc horn 58a and the surrounding inwardlybiased resilient finger contacts 26, the latter making engagement with the external surfaces of the stationary contacts 24.

With reference to FIG. 4 of the drawings, it will be noted that the high-pressure reservoir housing 18 in cludes an inwardly-projecting strut 18a, which fixedly supports into position the tubular bearing sleeve 18b, the latter serving to support a movable resistance bridging contact assemblage, generally designated by the reference numeral in FIG. 5, and comprising a metallic rotatable bearing sleeve 62 having an outwardly-jutting arm 64.

The arm 64 has an axially-extending nose portion 64a, which projects into a recess provided by a casting hub portion 72 constituting a part of the movable rotatable contact assemblage 30. Accordingly, there is provided a lost-motion connection between the movement of the main rotating hollow contact assemblage 30 and the sleeve-like movable resistance contact assemblage 60, as shown more clearly in FIG. 6 of the drawings.

Generally, the operation of my improved modular type arc-extinguishing assemblage 12 is such as to effect release of the operating mechanism, the latter being disposed within a mechanism compartment (FIG. 1) disposed at the lower end of the framework 87 supporting each pole-unit 10, and thereby permit counterclockwise opening rotative movement of the movable contact assemblage 30, as indicated by the arrows 31 in FIG. 2 of the drawings. This will effect through a blast-valve operating mechanism 33 (FIG 4) inward opening movement of the blast valve 40, thereby permitting a blast of gas to flow radially outwardly through the two passages 30a associated with the rotating movable contact assemblage 30, as shown in FIG. 4. Extinction will occur at the main arcs established within the interrupting units 32, but the circuit will be maintained through impedance, or resistance sections 90, which are electrically connected between the inner ends of the terminal bushings 22 and fixed resistance contacts 94, which are supported by insulating bushings 96 extending through the side walls of the high-pressure reservoir 18, in a manner more clearly indicated in FIGS. 3 and 4 of the drawings.

As a result of the foregoing construction, following takeup of the lost motion 80, the rotatable bridging sleeve 62, carrying the movable bridging resistance contacts 98, will separate from the stationary resistance contacts 94 and the orifice contacts 52 and draw a pair of serially-related impedance, or resistance arcs 97 to be acted upon by an inwardly flow of compressed gas, as indicated by the arrows in FIG. 4. As shown in FIG. 4, the inner ends of the resistance arcs 97 terminate at arc-horn portions 97a supported by a T-shaped bracket 19.

Extinction of the resistance-current arcs 97 is thereby achieved by the extinguishing gas flow through the stationary orifice contacts 52 and continued rotative movement introduces two isolating gaps into the circuit, as

well understood by those skilled in the art. To maintain the maximum angular displacement between the rotative movable contact assemblage 30 and the rotatable supporting resistance bridging sleeve 62, there is preferably provided a compression spring (FIG. 6) situated in the lost-motion cavity 70 provided in the hub portion 72 of the main rotative movable contact assemblage 30. This biasing action, as supplied by the compression spring 110, will insure that during the closing operation the

resistance contacts

94, 98 and 52 will close prior to the closing of the main moving contacts 58 into engagement with the main stationary contacts 24.

FIG. 7 diagrammatically illustrates the impedance, or resistance shunts in a simplified manner. It will be obvious that the utilization of the resistance sections 90 will facilitate interruption at the main contacts 24, 5'8, and will improve the power factor of the circuit thereby facilitating subsequent interruption of the resistance arcs 97. The extinguishment of the resistance arcs 97 (FIG. 7), which are drawn through the orifice openings 52 (FIG. 4) is thus a relatively easy task. Also, it will be noted that the movement of the reciprocally-operable main blast valve 40 not only serves as a downstream blast valve for the

resistance contacts

52, 94 but also as an upstream blast valve for the extinguishing action exerted on the

main contacts

24, 58 associated with each arc-extinguishing unit 32.

To effect proper opening motion of the blast valve 40, there is provided a linkage, which is similar to that set forth in the aforesaid patent application Ser. No. 435,560. As described in detail in the aforesaid patent application, there is provided at the end of the reciprocally movable blast valve 40 a generally conical portion 100 extending inwardly to deflect gas through openings or ports 40a in the side wall of the valve 40. The valve 40 has a stem 40b which extends through a guide portion 400 on the outer end of the hollow bearing support 1 8d. A valve spring 40c surrounding the valve stem 40b between the end 180 of the bearing support 18d and a washer 40d on the valve stem 40b biases the valve 40 to the closed position. A pin 40c retains the washer 40d on the valve stem 400.

The valve 40 may be opened by a cam 43 rotatably mounted on a pin 44. The cam 43 has teeth 45 thereon engaged by a pawl 46 carried by an arm 47 pivotally mounted on the pin 44. The arm 47 is actuated by a link 48 which, in turn, is actuated by a bell-crank 49. The bellcrank 49 is rotated by an insulating operating rod 51 extending downwardly interiorly of the insulating hollow column 14 and pivotally connected to the rotating assemblage 30 as shown in FIG. 3.

The pawl 46 is biased into engagement with the teeth 45 by a spring 53 disposed between one end 46a of the pawl 46 and a projection 47a on the arm 47. When the link 48 is moved to the left, as shown in FIG. 4, the cam 43 is rotated counterclockwise to open the valve 40. At the end of the opening movement, the end 46a of the pawl 46 engages a pin 57 to disengage the pawl from the teeth 45, thereby permiting a spring "59 to return the cam 43 to the closed position. The valve spring 40b then recloses the valve 40. The arm 47 is returned to the nonactuating position when the breaker is reclosed.

From the foregoing description it will be apparent that there has been provided an improved compressed-gas circuit interrupter in which a single blast valve 40 serves as an upstream blast valve for the main arcing contacts, and also as a downstream blast valve for the shunting resistance contacts. There results a simplified and compact construction. As used in the specification and also in the claims, a valve is designated as upstream or downstream with reference to a contact structure, if it is physically located (in the upstream case) between the high-pressure source and the contacts, or, alternatively (in the downstream case), the contacts are 10- cated -between the blast valve and the high-pressure source.f

t The present invention makes possible a 345 km, 25,000 mva. circuit-breaker rating in a single'colilmn of two main breaks for each pole-unit, using shunting impedances, such as resistors and separate residual current interrupters. With two'taller:columns and four main breaks the rating would be 700 kv,, 50,000, mva., while with three still taller columns and six main breaksthe .rating would be 1000 kv., 75,000 mva. Moreover, and very importantly, such improved construction is'lower-in cost than present commercial designstof this particular type.

Although there has been illustratedand described a specific structure, it is to be clearly understood that the same was merely forthe 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 as my invention:

1. A gasblast type of circuit interrupter including a pair of separable main arcing contacts, impedance means and serially-connected impedance arcing contacts disposed in shunting relationship to said pair of separable main arcing contacts, means defining a high-pressure reservoir, means for separating the main arcing contacts before the separation of the impedance arcing contacts, and single blast-valve means for serving as an upstream blast valve for gas flow at the main contacts and also as a downstream blast valve for gas flow at the impedance contacts.

2. In combination, a high-pressure reservoir containing high-pressure gas under pressure and providing a hollow bearing support, at least a hollow rotary main contact arm pivotally mounted on said hollow bearing support and carrying a movable main arcing contact, a stationary main arcing contact cooperable with the movable main arcing contact to establish a main-current arc, a movable blast valve for controlling a flow of high-pressure gas through said hollow bearing support and through the hollow main contact arm to effect extinction of the maincurrent arc, a shunting impedance and separable impedance contacts, at least one of said impedance contacts being disposed interiorly of said high-pressure reservoir, movable contact bridging means supporting a companion impedance contact and having a lost-motion connection with said hollow rotating main contact arm, and orifice contact means disposed in the hollow bearing support for providing a downstream blast of gas to extinguish the residual current are.

3. In combination, means defining a high-pressure reservoir containing high-pressure gas under pressure and providing a hollow bearing support, a rotating main contact assemblage pivotally mounted upon said hollow bearing support and having two hollow outwardly-extending movable contact arms, each of said movable contact arms carrying a movable main contact, a relatively stationary main contact cooperable with each movable main contact, a movable blast valve for controlling a flow of highpressure gas through said hollow bearing support and radially outwardly through the two hollow contact arms to effect extinction of the two main current arcs, a shunting impedance and separable impedance contacts associated with each main movable contact, at least one of the impedance contacts of each set of impedance contacts being disposed interiorly of said high-pressure reservo r, movable bridging contact means supporting a movable bridging impedance contact and having a lost-motion connection with the main rotating contact arm, and stationary orifice contact means disposed in the hollow bearing support for providing a downstream blast of gas to extinguish the two residual current arcs.

4. A compressed-gas type of circuit interrupter including a relatively low-pressure metallic housing, a pair of terminal bushings extending interiorly within said housing and carrying a pair of relatively stationary main arcing contacts at the interior ends thereof, a high-pressure reservoir disposed within said housing and containing highpressure gas under pressure and providing a hollow bearing support, a hollow rotating main contact-arm assemblage pivotally mounted on said hollow bearing support and carrying a pair of movable main arcing contacts at the outer extremities thereof, each main arcing contact being cooperable with a respective relatively stationary main arcing contact, a movable blast valve for controlling a flow of high-pressure gas through said hollow bearing support and through the radially-outwardly extending hollow, main contact arms to effect extinction of the main current arcs, a resistance section disposed adjacent the interior end of each terminal bushing and having a resistance bushing connected therethrough extending interiorly within the high-pressure reservoir, a stationary impedance contact situated at the interior end of each resistance bushing, a movable bridging contact sleeve carrying a pair of serially-related movable bridging contacts and rotatable upon said hollow bearing support, means defining a lost-motion connection between said movable bridging contact sleeve and the rotating main hollow contact assemblage, and stationary orifice contact means disposed in the hollow bearing support for providing a downstream blast of gas to extinguish the two residualcurrent arcs.

5. A gas-blast circuit interrupter including means defining a high-pressure gas reservoir, a pair of separable main arcing contacts, a stationary impedance contact disposed within said high-pressure gas reservoir, impedance means connected between one of said separable main contacts and said stationary impedance contact, gas blast conduit means connecting said reservoir with the space between the main arcing contacts when separated, a blast valve located in said gas-blast conduit means and openable to provide a blast of high-pressure gas to extinguish the main current are drawn between the separated main contacts, a cooperating impedance contact spaced from said first-mentioned impedance contact at least in the open position of the impedance contacts, means for establishing an impedance are between the two impedance contacts subsequent to the establishment of the main current are, said second-mentioned impedance contact being so located in said gas-blast conduit means that opening of the blast valve will cause an extinguishing flow of high-pressure gas along said conduit -means which will in addition extinguish the impedance are.

6. A compressed-gas circuit interrupter including a high-pressure gas reservoir tank, a pair of terminal bushings extending into said tank and carrying a pair of spaced impedance contacts at the inner ends thereof, two pairs of separable main arcing contacts, impedance means connected between said interiorly-disposed stationary impedance contacts and one of each pair of separable main contacts, gas-blast conduit means connecting said reservoir with the spaces between the two pairs of main arcing contacts when separated, a single blast valve located in said gas-blast conduit means and openable to provide a blast of high-pressure gas to extinguish the two seriallyrelated main current arcs drawn between the two pairs of separated main contacts, two stationary orifice contacts provided in said gas-blast conduit means, means for establishing an impedance current arc between each stationary impedance contact and its respective orifice impedance contact, means for establishing said two impedance current arcs after the establishment of the two main current arcs, and the gas blast passing toward the main current arcs in addition to passing through the two stationary orifice impedance contacts to effect extinction of the two impedance current arcs.

7. The combination as set forth in claim 6, wherein the gas-blast conduit means provides a hollow bearing portion, and the two movable main arcing contacts are disposed at the free extremities of a rotatable contact assemblage pivotally mounted upon said hollow bearing support.

8. The combination as set forth in claim 6, wherein the gas-blast conduit means provides a hollow bearing support for a movable rotatable contact assemblage carrying a pair of movable main contacts, and the blast valve reciprocally operates within said hollow bearing support.

9. A compressed-gas circuit interrupter including a pair of separable main arcing contacts, :means including an impedance and a serially-related pair of impedance contacts shunting said pair of separable main arcing contacts, means separating the pair of main arcing contacts before the separation of the pair of impedance contacts, high-pressure gas-conducting conduit means interconnecting the region adjacent the pair of impedance contacts with the region adjacent the pair of separable main arcing contacts, unitary blast-valve means disposed in said conduit means between the two pairs of contacts, whereby said unitary blast-valve means constitutes a downstream blast valve for the impedance contacts and an upstream blast valve for the main arcing contacts.

10. The combination according to claim 9, wherein the unitary blast-valve is a reciprocally operable sleeve valve operating axially of the gas-conducting conduit means.

References Cited UNITED STATES PATENTS 2,665,351 1/1954 Forwald.

2,977,446 3/ 1961 Baker.

3,014,111 12/ 1961 Forwald.

3,043,940 7/1962 Leeds.

3,093,717 6/ 19 63 Forwald.

3,291,947 12/ 1966 Van Sickle ROBERT S. MACON, Primary Examiner.

US. Cl. X.R.