US 3846601 A
A high-voltage compressed-gas circuit interrupter is provided including a tank structure, and a terminal bushing extending therein supporting an arc-extinguishing unit. A high-pressure gas-reservoir chamber is disposed adjacent the inner end of the terminal bushing for close proximity to the separable contact structure of the arc-extinguishing unit.
Description (OCR text may contain errors)
[ Nov. 5, 1974 Primary ExaminerRobert S. Macon INTERRUPTER Attorney, Agent, or FirmW. R. Crout Inventor: Winthrop M. Leeds, Pittsburgh, Pa. Assignee: Westinghouse Electric Corporation,  ABSTRACT Pittsburgh, Pa. A high-voltage compressed-gas circuit interrupter is Filed Mar 31 1972 provided including a tank structure, and a terminal bushing extending therein supporting an arc- Appl. No.: 240,144 extinguishing unit. A high-pressure gas-reservoir chamber is disposed adjacent the inner end of the ter- US Cl 200/148 B 200/145 200/148 F minal bushing for close proximity to the separable  i 33/82 contact structure of the arc-extinguishing unit.
200 14 11 143 3 143 H, Additional features include a blast-valve means, 200 143 F disposed in close proximity to the stationary contact structure, and the partial storage of high-pressure gas References Cited within the hollow stud of the terminal bushing to UNITED STATES PATENTS prevent liquefaction of a liquefiable gas under low-ambient temperature conditions Another feature of the invention includes a rotating United States Patent  Leeds COMPRESSED-GAS CIRCUIT  Field of Search........
21 Claims, 3 Drawing Figures operating rod for low inertia, and the pilot-valve operation of the blast-valve mechanism by a cam interconnection between the pilot-rod linkage and the 940 Thieme.........................
Strom..... Leeds et al........... Colclaser, Jr. et al.......... Leeds et PATENTEUNHV s 1974 :3. 848,601
' sum m 2 l COMPRESSED-GAS CIRCUIT INTERRUPT ER BACKGROUND OF THE INVENTION High-voltage gas-type circuit breakers are needed which are capable of interrupting fault currents within two cycles (at a 60-cycle frequency) after energizing the trip coil. It is a particular purpose of the present invention to provide particular constructional features to speed up the opening operation of a compressed-gas circuit interrupter to attempt to achieve this rating. In accordance with one aspect of the present invention, a high-pressure gas reservoir is located at the interior end of each of two terminal bushings extending within a circuit-interrupter tank structure, so as to provide a readily available supply of high-pressure arcextinguishing gas for effecting arc extinction. In addition in accordance with another apsect of the instant invention, a rotating insulating operating tube is provided to eliminate inertia effects, and also to provide a desired correlation between opening the movable contact structure and opening of the movable blastvalve structure. As a result of this tubular insulating operating-rod structure, the annular volume between the supporting insulating column and the outer wall of the rotating insulating operating rod is at a minimum, to thereby eliminate the hazard of injury to operating personnel from fracture of the insulating column, such as a porcelain column, should it occur due to earthquake shock, lightning strokes, etc.
In US. Pat. No. 3,214,546, issued Oct. 26, 1965, to Winthrop M. Leeds, and assigned to the assignee of the instant application, there is illustrated and describeda modular type of compressed-gas circuit interrupter, which contains high-pressure reservoir tanks disposed interiorly within a live metallic circuit-breaker tank. It is a further object of the present invention to improve upon the circuit-interrupter structure of the aforesaid patent rendering it more high speed in operation, and of simplified structure.
SUMMARY OF THE INVENTION According to a preferred embodiment of the present application, there is provided a tank structure, including a terminal bushing extending therewithin, at least partially supporting an arc-extinguishing unit adjacent the interior end of the terminal bushing. Preferably, a high-pressure reservoir tank is supported adjacent the inner end of the terminal bushing and in close proximity to the arc-extinguishing unit. A blast-valve structure is linked with the operating rod of the circuit breaker, which is preferably rotatable. The linkage for the separable contact structure of the arc-extinguishing unit is connected to the upper end of the rotatable operating rod of the interrupter.
In addition, desirable features of the invention include a plate electrically interconnecting the two stationary contact structures of the device, when it is of the double-break construction, so as to transfer the heat to the outer metallic walls of the surrounding tank structure.
Accordingly, it is a general object of the present invention to provide an improved and highlyeffective compressed-gas circuit interrupter, which will be extremely high-speed in operation.
A more specific object of the present invention is to provide an improved compressed-gas circuit interrupter of the live tank type, that is, the type including a metallic tank supported up in the air by an insulating column, and at line voltage in the closed-circuit position of the interrupter.
Another object of the present invention is the provision of an improved compressed-gas circuit interrupter in which a pair of terminal bushings extend interiorly within an enclosed metallic tank, and carry stationary contact structures adjacent their interior ends. It is an important feature of the present invention to associate with said relatively stationary contact structures highpressure reservoir tanks also disposed adjacent the interior ends of the terminal bushings, and so arranged as to quickly force high-pressure blasts of gas into the established arcs.
Still a further object of the present invention is the provision of an improved operating arrangement for a compressed-gas circuit interrupter. Preferably, this assumes the form of a rotating insulating operating tube extending upwardly through a supporting column structure.
Yet a further object of the present invention is the provision of an improved double-break compressed-gas circuit interrupter of a type adapted for multiple use, that is, each unit being of modular construction, and adapted for series arrangement for the higher-voltages.
Still a further object of the present invention is the provision of an improved compressed-gas circuit interrupter in which liquefaction of the arc-extinguishing gas, during low ambient temperature conditions, is prevented by associating the high-pressure reservoir tanks with the terminal bushings, whereby the current flow through the terminal bushings effects a desired heating effect upon the high-pressure arc-extinguishing gas preventing the liquefaction thereof.
Yet a further object of the present invention is the provision of an improved compressed-gas circuit interrupter in which a conducting supporting plate structure is provided within the circuit-interrupter tank, which not only serves the function of transmitting current flow between the two serially related arc-extinguishing units, but also provides a desired supporting structure for the movable operating linkage of the circuit interrupter.
Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view, partially in vertical section, of a compressed-gas circuit interrupter embodying features of the present invention, the contact structure being illustrated in the closed-circuit position;
FIG. 2 is a fragmentary vertical cross-sectional view taken through the upper portion of the circuitinterrupter structure of FIG. 1, the contact structure, however, being illustrated in the partially open-circuit position; and,
FIG. 3 is a fragmentary detailed view showing, to an enlarged scale, the pilot exhaust-valve structure for the blast valves.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designatesa compressed-gas circuit interrupter. As shown, the circuit-interrupting structure 1 includes a live spherical metallic circuit-interrupter tank 2 disposed at the upper end of an insulating column 3, the latter being formed of any suitable material, such as prcelain, for example, so as to take advantage of its weathering characteristics.
Extending downwardly interiorly within the metallic tank 2 is a pair of terminal bushings 4, 5 to the lower ends of which are appended stationary contact structures 6. Cooperating with the relatively stationary contact structures 6, are movable contact structures 8, 9, which are simultaneously actuated in the opening and closing directions by a pair of straight-line linkages 10, ll.
It will be noted that surrounding the rearward side of each relatively stationary contact structure 6, is a highpressure reservoir 12, 13, which may assume either a spherical configuration, or a generally horizontally disposed cylindrical configuration. The purpose for each compressed-gas reservoir 12, 13 is to provide a ready supply of high-pressure arc-extinguishing gas, such as (SP gas, for the arc-extinguishing operation, as more fully described hereinafter.
It will be noted that in communication with the highpressure reservoirs 12, 13 are the hollow terminal studs 14, which extend axially through the terminal bushings 4, 5. This has the important advantage that during the closed-circuit condition of the interrupter, current flow through the hollow terminal studs 14 will heat the highpressure gas 7, and prevent the liquefaction thereof. In other words, as well known by those skilled in the art, when certain highly efficient are-extinguishing gases, such as sulfur hexafluoride (SF gas, are used at high pressure, the liquefaction point of such a gas may be relatively high. so that the situation is encountered that during low-ambient temperature conditions, such as in neighborhood of 40F, liquefaction of the aforesaid (SP gas may occur. Such liquefaction will drop the gaspressure, and so prevent the use of the (SF,,) gas at an-adequate pressure level during the arc-interrupting operation. By utilizing the heating effect of the current passing through the hollow terminal studs 14, which are in communication with the high-pressure reservoirs 12, 13, the (SP gas is maintained above its liquefaction point, and the requisite blast pressure is available at all times for proper interrupting action. When the breaker is open, or lightly loaded for long periods in cold weather, a supplementary heater 15 in the reservoir at the base of the breaker is turned on by thermostatic control to keep the SP gas vaporized.
To effect the opening and closing operations of the straight-line linkages 10, 11, preferably a rotating insulating tube 16 is utilized, having connections 17, 18 to the aforesaid straight-line linkages 10, 11. A ringshaped guide 16a of polytetrafluoroethylene, for example, may be utilized for close friction-free guiding action. As shown, each straight-line linkage 10, 11 com prises a bracket 20, a connecting link 21, an actuating bell-crank 22, and an operating link 23. The operating links 23 are preferably connected to diametrically opposite sides of the rotating operating tube 16.
As set forth above, high-pressure (SF.,) gas is utilized to effect extinction of the arcs 25 (FIG. 2), which are established between the stationary contact fingers 6 and the upper ends of the movable tubular contacts 8,
9. To effect this end, blast-valve structures are employed, being actuated by exhaust pilot valves 34, 35. The exhaust pilot valves 34, are connected by floating insulating links 36, 37 to operating levers 38, 39, which, in turn, have their inner ends pivotally connected to an upstanding operating rod 40. The lower end of the pilot-valve operating rod 40 is guided by a stationary guide 40a. Also, it has a cam follower roller 40b actuated by a cam structure 43, which is formed at the upper periphery of the rotating insulating operating tube 16.
As a result of the aforesaid construction, during the opening operation, rotation of the insulating operating tube 16 not only effects, through the straight-line linkages 10, 11 downward opening movement of the movable tubular contacts 8, 9 to draw the arcs 25, but, in addition, the pressure is exhausted on the rear sides of the blast-valve pistons within operating cylinders 51 to effect thereby opening of the blast valves 30, thereby permitting the blasting of high-pressure (SF gas from the chambers 12, 13 downwardly through the orifice structures 55 and through the interiors 8a, 9a of the movable tubular contacts 8, 9, respectively. At the end of the opening stroke, the cam rod 40 is lifted to close the valve 34 so that the bias spring 30a can reclose the blast-valve 30.
U. S. Pat. No. 3,l54,658, issued Oct. 27, 1964 to R0- bert G. Colclaser and Russell N. Yeckley, and assigned to the assignee of the instant application, describes in detail the manner of arc interruption by the exhausting of the (SP gas downwardly through the interiors 8a, 9a of the movable tubular contacts 8, 9.
During the closing operation, the rotating insulating tube 16 is rotated in the opposite direction to thereby effect contact closure. The blast valves 30 may be operated during the closing operation, or suitable linkage, not shown, may be employed to effect a one-way actuation of the blast-valve structures 30 so that the blast effect is eliminated during the closing stroke of the circuit interrupter 1.
With reference to FIG. 2, it will be noted that the straight-line linkages 10, 11 are supported by, and the movable tubular contact structures 8, 9 are guided by, fingers 58 affixed to a generally horizontally extending conducting plate structure 60. Very high continuous current ratings for the contacts 8, 9 are obtained by directing the current flow from the moving contacts 8, 9 through the fingers 58 and into the current-carrying plate structure 60, which is secured, as by welding, for
example, at each end to the main tank 2, which acts as a radiator of heat generated in the contacts 8, 9.
A high-pressure insulating supply tube may be situated generally axially of the rotating insulating operating tube 16, and serves to maintain the pressure within the pressure chambers 12, 13 at an adequate pressure level necessary for efficient arc interruption. As shown in FIG. 1, a suitable compressor 74 may be utilized, in conjunction with a grounded high-pressure reservoir 76, to supply the (SP gas at the requisite pressure level. The gas, to be taken by the inlet side 74a of the compressor 74, may be extracted from the lower end of the supporting column 3. Suitable operating mechanism, which forms no part of the present invention, may be disposed within a mechanism compartment to effect opening and closing rotative action of the insulating operating tube 16.
From the foregoing description, it will be apparent that there is provided an improved high-voltage gastype circuit interrupter l capable of interrupting fault currents in an extremely short time, such as in the order of two cycles after energizing the trip coil. It will be noted that the live-tank construction, as described, has the following special features to speed up the interrupting operation: The high-pressure reservoirs 12, 13 are located on the interrupter end of each terminal bushing 4, 5 in the live-tank module 2. The blast valve 30 is disposed closely adjacent to each set of stationary contact fingers 6 for minimum delay in getting high-pressure (SF gas into the arcing zone. A low-inertia tubular insulating operating rod 16, in the supporting porcelain column 3, provides high-speed mechanical operation. This tube 16 rotates to move the straight-line linkages l0, 11 connected to the moving arcing contacts 8, 9.
An important special safety feature of the present invention is that only a small gas volume 3a is available between the rotating insulating operating rod 16 and the surrounding porcelain column 3 to propel fragments, in the event that the porcelain column 3 is fractured by an accident, or by earthquake conditions.
Another important feature of the present invention is the use of low-inertia small insulating rods 36, 37 to operate the pilot valves 34, 35, exhausting pressure behind the main blast-valve pistons 50 on each terminal 4, 5 to provide a fast blast-valve opening action. Finally, a very high continuous current rating for the contacts 8, 9 is obtained by the utilization of the contact fingers 58 transmitting the current flow through the generally horizontally extending conducting plate structure 60.
The condensation of high-pressure gas under loadcarrying conditions is avoided by allowing high: pressure SF gas, for example, to fill the hollow bushing terminals 14, which act as heaters for the (SF,,) gas when carrying load current.
Although there has been illustrated and described a specific structure, itis to be clearly understood that the same was 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 as my invention:
1. A compressed-gas circuit interrupter including a metallic tank and a terminal bushing extending therein, an arc-extinguishing unit including separable contact structure, at least, partically supported by the interior end of said terminal bushing, a high-pressure gasreservoir chamber also supported adjacent the inner end of the terminal bushing and supported thereby for close proximity to said separable contact structure, and the gas exhausting during arc interruption into the general region within said metallic tank.
2. The combination according to claim 1, wherein a pair of terminal bushings extend within the metallic tank, an arc-extinguishing unit including a pair of separable contacts is supported by the interior end of each terminal bushing, and a high-pressure gas-reservoir chamber is supported adjacent the interior end of each terminal bushing closely to each arc-extinguishing unit.
3. The combination according to claim 1, wherein the metallic tank is at high voltage and supported up in the air from ground potential by insulating supporting means.
4. The combination according to claim 2, wherein blastvalve means are associated with each of the arcextinguishing units, and piston means are utilized to actuate said blast-valve means.
5. The combination according to claim 4, wherein a pilot exhaust-valve means is associated with each blastvalve means, and a linkage means interconnects the pilot exhaust-valve of each arc-extinguishing unit with the movable contact of the respective unit. whereby a blast of arc extinguishing gas is forced to flow between the separated contact structure for are extinction.
6. The combination according to claim 2, wherein each terminal bushing supports an arc-extinguishing unit including separable contact structure and an associated high-pressure gas-reservoir chamber, a generally horizontally extending conducting plate structure is fixedly secured to the side walls of the tank structure and has sliding contact means associated therewith, each arc-extinguishing unit having a movable contact making sliding contacting engagement with said sliding contact means, whereby the generally horizontally extending plate structure provides a current-conducting path between the two arc-extinguishing units.
7. The combination according to claim 6, wherein the generally horizontally extending plate structure includes bracket means for structurally supporting the operating linkage for each movable contact.
8. The combination according to claim 1, wherein the metallic tank is at high voltage, insulating supporting means supports said high-voltage metallic tank up in the air above ground potential, and a rotating insulating operating tube extending upwardly through the insulating supporting means interconnects the operating means for the arc-extinguishing unit and the ground mechanism.
9. The combination according to claim 8, wherein there is present only a slight volume between the insulating supporting means and the outside surface of the rotating insulating operating rod for propelling fragments in the event of fracture of the insulating supporting means.
10. A compressed-gas circuit interrupter including an upstanding hollow insulating column, a rotatable insulating operating tube extending axially of said insulating column and having only slight clearance therebetween, means for guiding rotating movement of said insulating rotatable operating tube, a pair of terminal bushings extending within the live metallic tank and carrying arc-extinguishing units and high-pressure gasreservoir chambers at the interior ends thereof, blastvalve means associated with each high-pressure gasreservoir chamber, separable contact means associated with each arc-extinguishing unit, and operating means for the movable contact structure and the blast-valve means including a pilot-exhaust valve for each blastvalve means, whereby separation of the movable contact structure and actuation of the pilot-exhaust valve means permits a flow of high-pressure gas to blast between the separable contact structure for areextinguishing purposes.
11. The combination according to claim 10, wherein a rotatable hollow tubular operating rod extends upwardly through the insulating supporting column, a pair of reservoir chambers are disposed adjacent the inner ends of the pair of terminal bushings, and a generally Y-shaped supply pipe being in fluid communication with the aforesaid supply tube, and synchronizing means are provided for synchronizing opening of the separable contact structure and opening of the blastvalve means for the purpose of supplying a highpressure blast of gas at the are established in each arcextinguishing unit.
12. A high-voltage compressed-gas circuit interrupter including a base, an insulating column extending upwardly from said base and supporting a live metallic tank at the upper end thereof, a pair of terminal bushings extending into said live metallic tank and carrying a pair of arc-extinguishing units and a pair of highpressure gas reservoirs at the interior ends thereof, separable contact structure and blast-valve means associated with each arc-extinguishing unit, a generally horizontally extending conducting plate structure secured to the inner walls of said live metallic tank and having sliding contact fingers associated therewith, the movable contact of each arc-extinguishing unit making sliding engagement with said sliding contact fingers, whereby said horizontally extending conducting plate structure causes the transmission of current flow between the two arc-extinguishing units.
13. The combination according to claim 12, wherein a rotatable insulating operating tube extends upwardly through the insulating column and has cam means disposed at the upper end thereof for actuation of the pilot-exhaust valve means.
14. The combination according to claim 12, wherein a pair of insulating pilot exhaust-valve operating rods are connected together and cam actuated by the rotatable insulating tubular operating rod.
15. The combination, a high-voltage compressed-gas circuit interrupter including an upstanding insulating supporting column, a live metallic tank surmounted upon said insulating column and having a pair of terminal bushings extending therewithin, a pair of arc extinguishing units and a pair of high-pressure gas-reservoir chambers disposed at the interior ends of said pair of terminal bushings, a pair of separable contacts and piston-actuated blast-valve means associated with each arc-extinguishing units, and pilot exhaust valve means associated with each unit and simultaneously actuated for effecting a blast of high-pressure gas at the established arcs.
16. The combination according to claim 15, wherein the conducting stud of the terminal bushing is tubular and provides gas communication with the highpressure gas reservoir chamber.
17. The combination according to claim 2, wherein the conducting stud of each terminal bushing is tubular and provides gas communication with the respective high-pressure reservoir chamber.
18. The combination, a high-voltage compressed-gas circuit interrupter including an upstanding insulating column, a live metallic tank surmounted upon said column and having a pair of terminal bushings extending therewithin, each terminal bushing having a tubular terminal stud in gas communication with a supported high-pressure gas reservoir tank disposed at the interior end of each terminal bushing, each terminal bushing supporting an arc-extinguishing unit including separable contact structure, blast-valve means associated with each high-pressure gas reservoir, and means actuating the blast-valve structure in accordance with opening movement of the movable contact structure, whereby a blast of high-pressure gas is caused to flow toward the established arcing.
19. The combination according to claim 18, wherein there is provided a generally horizontally extending conducting plate structure, said plate structure having two pairs of sliding contact fingers, two movable contacts being in contacting engagement with said sliding contact fingers, operating means for the movable contact structure including a pair of bell-cranks pivotally supported on said horizontally extending conducting plate structure, and means for causing the actuation of said two bell-cranks.
20. The combination according to claim 19, wherein there is provided a rotatable insulating hollow operating tube extending upwardly interiorly of a hollow insulating column and having only slight clearance therewith.
21. The combination according to claim 19, wherein a pair of pilot-exhaust valves are associated with the pair of high-pressure gas-reservoir chambers and is mechanically connected so as to effect simultaneous blastvalve opening movement.