US3071670A - Circuit interrupters - Google Patents

Description

1., 1963 R. N. YECKLEY ETAL 3,07

CIRCUIT INTERRUPTERS 2 Sheets-Sheefl Filed July 1, 1959 4 I E m.2151:5555

ee Ha Y flue E M m W m NW FM 2 Sheets-Sheet 2 Fig.7.

CIRCUIT INTERRUPTERS R. N. YECKLEY ET AL Fig .5.

Fig.6.

Jan. 1, 1963 Filed July 1, 1959 Patented Jan. 1, E963 lice 3,d73l,d7il CRECUIT ENTERRUPTERES Russell N. Yeelriey, Monroeville, and Frank L. Reese,

Wilkinshurg, Pa, assignars to Westinghouse Electric Qorporation, East iittsburgh, Pa, a corporation of Pennsylvania Filed July 1, 1959, Ser. No. $245M 4 Claims. (Ci. Eli-345) This invention relates to circuit interrupters in general, and more particularly to arc-extinguishing structures therefor.

A general object of the present invention is to provide an improved circuit interrupter, which will be of simple and highly effective construction, and which will also cover a Wide voltage range in interrupting ratings.

A more specific object of the present invention is to provide an improved circuit interrupter employing an improved pumping means for pumping arc-extinguishing fluid into the are to be interrupted.

A further object of the present invention is to provide an improved, dead-tank-type of circuit interrupter, in which a fluid-driving pump is associated with the one or more arc-extinguishing units to effectively bring about circuit interruption.

Although the invention has applicability when employed with any arc-extinguishing medium such as a suitable liquid, for instance circuit-breaker oil, and to a gaseous arc-extinguishing medium, such as air, the invention has particular applicability when employed in a sealedtank construction, employing a highly effective arc-extinguishing gaseous medium, such as sulfur hexafluoride (SF or selenium hexafluoride (SeF or mixtures of the aforesaid two gases, or mixtures of such gases with carbon dioxide, helium, nitrogen, argon and hydrogen.

Up to the present time, the present commercially-available, sulfur-hexafluoride (SP gas, circuit interrupters have utilized a self-pressure-generating type of circuit interrupter, such as, for instance as disclosed in US. Patent 2,979,589, issued April 11, 1961, to Benjamin F. Baker, and assigned to the assignee of the instant application. With reference to the aforesaid Baker interrupting structure, an upstanding porcelain casing was employed to house the interiorly disposed interrupting units. Each interrupting unit in the Baker structure included a contact structure operable to establish a pressure-generating arc and a serially-related interrupting are. A substantiai' ly closed interrupting unit was employed to effectively direct the gas flow.

it isa further object of the present invention to improve upon the individual, porcelain-clad pole-units of the aforesaid Baker interrupting structure, so as to provide an improved type of circuit interrupter, utilizing a puifertype of interrupting structure, preferably with the. three phases contained within a single dead-tank type of circuit interrupter. Where the ratings are higher, it may not be possible to position the three phases within a single dead-tank, and separate tank structures will, in this event, be preferable.

Yet a further object of the present invention is to provide an improved, simplified, puffer-type of circuit interrupter, in which a single piston and cylinder arrangement is operable to force fluid simultaneously into a plurality of interrupting structures. The interrupting structures may be adjacent pole units in the other phases of the circuit interrupter, or, in the high-voltage ratings, the interrupting structures may be associated with a singlepole unit, involving only a single phase of the circuit interrupter.

An auxiliary object of the invention is to provide a simplified, dead-tank-type of circuit interrupter, in which the number of gasketed joints for the tank structure is and a minimum. This obviously has particular advantage, when an expensive gaseous-type of arc-extinguishing medium is employed, such as sulfur hexafluoride (SF gas.

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 vertical sectional view taken through the center pole-unit of the three-phase circuit interrupter illustrated in FIG. 2, taken substantially along the line II of FIG. 2, with the contact structure being illustrated in the partially open-circuit position;

PEG. 2 is a plan View of the three-phase circuit interrupter of FIG. 1, with a portion of the cover plate broken away to disclose the single internally disposed puffer structure;

FIG. 3 is a considerably enlarged, plan view in section taken substantially along the line III-III of FIG. 4-;

FIG. 4 illustrates, in an enlarged fashion, the single puffer structure directing fluid into one of three interrupting structures, the contact structure being illustrated in the partially open-circuit position, and the view being taken substantially along the line IVIV of FIG. 3. It will be noted that the view of FIG. 4 is taken from the opposite side of the puffer structure than that shown in FIG. 1;

FIG. 4A illustrates, fragmentarily, a modified type of interrupting unit, which may be substituted for the interrupting unit of FIG. 4;

FIG. 5 illustrates a modified type of circuit interrupter, in which a single puffer structure is utilized for each of the three phases, the contact structure being shown in the closed-circuit position, and the sectional view being taken substantially along the line VV of FIG. 6;

FIG. 6 is a plan viewof the three-phase circuit interrupter of FIG. 5, with a portion of the cover plate being broken away to disclose the internal interrupting structure;

FIG. 7 illustrates a vertical sectional view taken through still another modified type of three-phase circuit interrupter, again the contact structure being shown in the closed-circuit position, the sectional view being taken substantially along the line VIIVII of FIG. 8; and

FIG. 8 is a plan view of the circuit interrupter of FIG. 7, with a portion of the cover plate broken away to illustrate more clearly the internal interrupting arrangement.

Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designates a three-phase circuit interrupter, wherein the three phases are disposed within a generally cylindrical tank 2. As shown. the tank 2 has a cover plate 3, which is secured, by mounting bolts 4 and associated nuts 5, to a mounting flange portion 6 of the tank 2.

Extending downwardly internally into the cover 3, and secured thereto, are three pairs of terminal bushings 7, 8, 9, id, 11, 12. As is known by those skilled in the art, the cover plate 3 would be provided with cylindrical flange supporting structures, not shown, to support the grounded mounting flange of each terminal bushing. Extending longitudinally through each terminal bushing is the respective terminal stud therefor, such as stud 7A, 3A, 9A, 10A, 11A, or 12A.

As more clearly illustrated in FIG. 2, wherein a portion of the top cover plate 3 is broken away, there is provided a single pumping means, generally designated by the reference numeral 13, and including an operating cylinder 14, within which reciprocally moves a fluiddriving piston 15.

FIG. 4 more clearly shows, to an enlarged scale, the construction of the pumping means 13. The piston 15 has a piston ring 15A to provide a close fit with the internal Wall 14A of the operating cylinder 14. A compresact 1,

sion spring 16 is disposed between the top surface 17 of the piston and the closure plate 18, which closes the upper end of the operating cylinder 14. Extending with a sliding fit through an aperture 19, provided in the piston 15, is a lift rod 2t formed of insulating material. As shown in FIG. 4, the lower end of the lift rod 2t) has a threaded connection, as at 21, with a bifurcated rod-end 22, which is pivotally connected, as at 23, to a hookshaped contact arm 24, the latter being pivotally mounted, as at (FIG. 1), to a contact foot 26 secured to the lower end of the terminal stud 1 3A.

As shown in FIG. 4, the movable contact end 27 of the rotatable contact arm 24 makes separable engagement with a relatively stationary contact 28, which is resiliently supported, by a contact compression spring 29, to the u per Wall St) of an interrupting unit, generally designated by the reference numeral 31. An orifice structure 32, including a sleeve-like orifice member 33, is fixedly secured to the bottom wall 34 of the arc-extinguishing unit 31.

As illustrated in FIG. 2, all three poles of the threephase circuit interrupter are disposed within a single tank 2. A horizontally extending main operating shaft 35 extends through a single gas-tight seal into the interior 37 of the tank 2. This rotatable operating shaft 35 has three crankarrns 33-40 clamped thereto. The end crank arms 3S and 4%) are pivotally mounted as at 33A, 4tlA to insulating lift rods 41, 42, which have their lower ends pivotally connected to the adjacent contact arms 24. The center crank arm 39 is pivotally connected, at 43, through a link 29A, to the insulating lift rod 20. Thus, rotatable opening and closing movements of the main shaft 35 will simultaneously effect opening and closing rotatable movement of the three contact arms 24.

As shown in FIG. 2, the other end 44 of the main operating shaft 35 is located within an internally disposed boss portion 45, which may be welded to the inner side wall of the tank 2, so that only a single gas-tight seal 36 is required for the main operating shaft 35.

FIG. 1 also shows current transformers 46, encircling the terminal bushings, for protective relaying functions, as well known by those skilled in the art.

From the foregoing description, it will be obvious as to the manner of operation of the circuit interrupter 1. However, by way of recapitulation, during the opening operation, the rotatable main shaft 35 is rotated, by any suitable external operating mechanism, not shown, in a counterclockwise direction, as indicated by the arrow 47 in FIG. 1. This will effect through the three crank-arms 3341i downward movement of the three insulating liftrods 2%, 41, 42, to effect, through the pivotal connections 23, opening rotatable movement of the three contact arms 24. It will be noted, with reference to FIG. 2, that the middle contact arm 24 is hinged, as at 25, to the contact foot 26, which is disposed to the right of the center line 48 of FIG. 2. The outer two contact arms 24, however, are hinged to the contact feet 49, 59 disposed to the left of the center line 43 of FIG. 2. This provides a more compact construction, and, more importantly, permits a symmetrical location of the three exhaust outlets 51 associated with the single pump means 13, which lead to the three interrupting units 31. Thus, the three passages 51 provide a centrally-located, symmetrical Y-shaped fluid inlet conduit structure for substantially balancing the fluid reaction forces in the injecting operation.

Due to the sliding lost-motion connection of the operating rod 20, as at 19, with the piston 15, the operating rod 20 and rod end 2 2 may move freely downwardly, independently of following movement of the piston 15, the latter being biased downward by its own compression spring 1e. As a result, contact separating movement is rapidly obtained entirely independently of relatively slow operation of the pumping means 13. Arcs 52, shown more clearly in FIG. 4, are drawn within each of the three interrupting units 31. Fluid flow is forced, by

downward movement of the piston 15, out through the exhaust outlet 51 and into the arc-extinguishing units 31. Thus, fiuid, such as a sulfur hexafluoride (SF gas, is forced out of the operating cylinder 14, as indicated by the arrows 53, tirough the exhaust outlets 51, into the established are 52, and out through the orifice restriction 54, as provided by the orifice sleeve 33. As a result, the arc-extinguishing gas is directed longitudinally of each are 52 through the orifice structure 32 to quickly bring about its extinction.

During the closing operation, the main operating shaft 35 is rotated, by the external mechanism, in a clockwise direction, as viewed in FIG. 1. This will effect, through the three crankarms 38-4 upward movement of the three lift- rods 29, 41, 32 and reclosing of the several contact structures. Spring-biased normally open valves 61 assist in filling the piston chamber with fluid. During the interrupting operation, these valves 61, of course, are closed, as indicated in FIG. 4.

Because of the provision of a shoulder 55 (FIG. 4) on the rod-end 22, the fiuid-driving piston 15 will be picked up by this shoulder during the closing stroke, to eifect the charging of the piston biasing spring 16. In the fully closed-circuit position of the interrupter, only partially indicated in FIG. 1, it will be noted that the several lift rods 2), 41, 4 2 and the crank arms 38-49 form substantially toggle linkages, which are almost on center, to thereby reduce the tension exerted upon the crank arms FIG. 4A illustrates a modified type of arc-extinguishing unit 31A, in which lateral flow of the fluid from piston 15 takes place, as indicated by the arrows. Insulat ing splitters assist in effecting arc extinction.

With reference to FiGS. 5 and 6 of the drawings, it will be observed that there is disclosed a modified type of circuit interrupter, generally designated by the reference numeral 57, and including an elongated tank structure 58 having an elongated cover plate 59. The three pairs of bushings fill-d5 extend downwardly, in pairs, through the elongated cover plate 59. Respective terminal studs 643A A are associated with the terminal bushings rt 65. Current transformers 46 are again employed. In this case, however, due to the higher interrupting rating of the circuit interrupter 57, there is associated a single piston device 66 with each pole of the interrupter. In other words, with reference to FIG. 5, for each pole of the interrupter (FIG. 5 showing the middle pole) the piston device serves to force fluid into the adjacently disposed arc-extinguishing unit 67 in much the same manner, as was described in connection with FIG. 4 of the drawings.

Similarly to the construction employed in FIG. 1, again rotatable contact arms 68 are utilized. These may, however, in this instance be hinged by connections 69 to contact feet 7tl72 secured to the lower interior ends of the terminal studs 61A, 63A, 65A all to the right of the centerline 73 of the circuit interrupter 57. As a result, the three identical arc-extinguishing units 67 may all be disposed to the left of the center-line 73- of FIG. 6, all depending respectively from the lower ends of the terminal studs 69A, 62A and 64A. The lif eds 2013, which may be very similar to the insulating lift-rods 20 of FIG. 4, will be preferably interconnected by a horizontal extending isnulating yoke 74, which is vertically actuated by a single insulating lift-rod 75. The lift-rod 75 may extend externally through the top cover plate 59, and may be connected, as at 76, to a bell-crank 77, the latter being actuated by any suitable external mechanism, as well known by those skilled in the art.

Since the functioning of the arc-extinguishing units 57 is substantially identical with the functioning of the arc-extinguishing units 31, previously described in connection with FIG. 4, this description will not be repeated. Also, the actuation of the piston 15, associated with each piston device 66, is identical to the actuation of the piston 15 illustrated in FIG. 4.

From the foregoing description, it will be apparent that rotation of the bell-crank 77 will effect, through the pivotal connection 76, downward opening movement of the lift rod 75. This will permit the insulating yoke 74 to move downwardly, as biased downwardly by accelerating springs, not shown, and associated with the externally provided operating mechanism.

The downward opening movement of the insulating close yoke 74 will simultaneously efiiect downward movement of the three insulating lift-rods 263. This will permit independent contact separating movement free of the slower travel of the piston 15, as provided by the sliding connection 19 (FIG. 4) within the piston plates 15. The compression spring 16, in each piston device 66, Will effect downward driving motion of the piston 15, forcing fluid, such as sulfur hexafluoride gas, through the exhaust outlet 51 and into the arc-extinguishing units 67, where interruption occurs in the manner previously described.

For the higher interrupting ratings, it may be desirable to associate two interrupting units 67 with each pole of the interrupter, and FIGS. 7 and 8 show this slight variation over the interrupting structures illustrated in FIGS. 5 and 6. The operation is the same as described in connection with FIGS. 5 and 6, except that with respect to FIGS. 7 and 8, the piston devices 80 are operable to send fluid in opposite directions through the associated outlets 81, 82 into the two arc-extinguishing units 67, associated with each pole of the modified type circuit interrupter 33.

From the foregoing description, it will be apparent that there is described an improved interrupting structure employing novel pumping means, or puffer structures, associated in such a manner as to effectively direct fluid flow into the established arcs for efficient circuit interruption. Depending upon the interrupting ratings, a single pumping structure may be provided for the three phases, or, for the higher ratings, separate pumping structures may be provided for the different pole units. Where single breaks are adequate for the voltage and current ratings, only a single arc-extinguishing unit 31, 31A or 67 may be associated with each pole unit.

For the higher interrupting ratings, as indicated in FIGS. 7 and 8, pairs of arc-extinguishing units 67 may be employed, each having its own movable contact 84, the movable contacts being interconnected by a bridging cross-bar construction 85.

Where a relative expensive gas, such as sulfur hexafiuoride (SP gas is employed, the disclosed construction has the advantage of employing only a single gas-tight seal for the operating shaft 35, or for the lift-rod 75.

As compared with the interrupting structure of the aforesaid Baker patent, it will be apparent that there are a number of advantages of the interrupting structure of our invention. These are:

(1) Use of the puffer makes possible an increased interrupting capacity.

(2) One puifer for the three phases reduces physical size and reduces costs over multiple piston designs.

(3) The single-tank construction reduces the number of gasketed joints for a three-phase circuit interrupter.

(4) The steel tank construction reduces the hazards and complications of all porcelain structures.

United States patent application, filed September 19, 1958, Serial No. 726,026, by Benjamin P. Baker, and assigned to the assignee of the instant application, covers broadly a single piston construction for forcing fluid into two adjacently disposed interrupting structures.

Also, United States patent application, filed September 27, 1957, Serial No. 686,775, now United States Patent 2,965,736, issued December. 20, 1960, to Thomas E. Browne, Jr., and Albert P. Strorn, and assigned to the assignee of the instant application, discloses and claims an SP dead-tank structure employing pistons charged by the contact structure.

Although there have been illustrated and described particular interrupting 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.

We claim as our invention:

1. A three-phase, fluid-blast circuit interrupter including a grounded dead tank, three pairs of terminal bushings extending into said grounded dead tank, three rotatable crank arms hinged in staggered relation to the interior ends of three of said terminal bushings, three relatively stationary contact structures in staggered arrangement associated with the interior ends of the remaining three terminal bushings, a single centrally located pumping device including an operating cylinder and a piston mov able therein, a centrally-located symmetrical Y-shaped fluid inlet conduit structure including three radially extending inlet conduits associated with said single pumping device and leading adjacent the three relatively stationary contact structures and the pumping device being operable during the opening operation to force fluid simultaneously through the three inlet conduits and radially outwardly toward the three relatively stationary contact structures for are interruption whereby to substantially balance the fluidflow reaction forces.

2. A three-phase, fluid-blast circuit interrupter including a grounded dead tank, three pairs of terminal bush ings extending into said grounded dead tank, three rotatable crank arms hinged in staggered relation to the interior ends of three of said terminal bushings, three relatively stationary contact structures in staggered relation associated with the interior ends of the remaining three terminal bushings, a single centrally located pumping device including an operating cylinder and a piston movable therein, a centrally-located symmetrical Y-shaped fluid inlet conduit structure including piston biasing means, three radially extending inlet conduits associated with said single pumping device and leading adjacent the three relatively stationary contact structures, an insulating lift rod associated with one of the rotatable crank arms, engaging means movable with said lift rod to charge said piston biasing means during the closing operation, and the pumping device being operable during the opening operation to force fluid simultaneously radially outwardly through the three inlet conduits and toward the three relatively stationary contact structures for are interruption whereby to substantially balance the fluid-flow reaction forces.

3. A three-phase fluid-blast circuit interrupter including a grounded tank, three pairs of terminal bushings extending into said grounded tank, three rotatable crank arms hinged in staggered relation to the interior ends of three of said terminal bushings, three relatively stationary contact structures in staggered arrangement associated with the interior ends of the remaining three terminal bushings, a single substantially centrally-located fluid-blast pumping device disposed within said grounded tank and including a relatively stationary operating cylinder and a piston movable therein, an operating rod for operating one of said rotatable crank arms and having a portion thereof composed of insulating material so that said operating rod does not conduct current, said operating rod being movable through said relatively stationary operating cylinder and having a lost-motion connection with said movable piston, a centrally-located symmetrical Y-shaped fluid inlet conduit structure including three radially extending inlet conduits associated with said single pumping device and leading toward said three relatively stationary contact structures, biasing means associated with said piston for moving the same relative to the operating cylinder for forcing fluid out of the operating cylinder through said three radially extending inlet conduits toward said relatively stationary contact structures for effecting extinction of the arcs drawn thereat whereby to substantially balance the fluid-flow reaction forces, the closing motion of said operating rod not only effecting closing motion of said one rotatable crank arm but also charging of said piston in opposition to said biasing means, and said lostrnotion connection being effective during the opening operation to permit unimpeded opening travel of said one rotatable crank arm independently of motion of the piston.

4. The combination in a three-phase fluid-blast circuit interrupter of a grounded tank, three pairs of terminal bushings extending downwardly into said grounded tank, a rotatable main drive shaft extending laterally of said tank and disposed substantially horizontally, three rotatable crank arms hinged in staggered relation to the lower interior ends of three of said terminal bushings, three relatively stationary contact structures in staggered arrangement associated with the lower interior ends of the remaining three terminal bushings, a single substantially centrally-located fluid-blast pumping device disposed within said grounded tank and including a relatively station ary operating cylinder and a piston movable therein, three crank-arms secured to said rotatable main drive shaft, operating rod means interconnecting said three crankarms rotatable with the main drive shaft with said three hinged crank arms for effectingthe simultaneous opening and closing movements thereof in response to opening and closing rotatable movement of the main drive shaft, said operating rod means including an operating rod for operating the middle hinged cran; arm and having a portion thereof composed of insulating material so that said operating rod does not conduct current, said operating rod being movable through said relatively stationary operating cylinder and having a lost-motion connection with said movable piston, a centrally-located symmetrical Y-shaped fluid inlet conduit structure including three radially extending inlet conduits associated with said single pumping device and leading toward said three relatively stationary contact structures, biasing means associated with said piston for moving the same relative to the operating cylinder for forcing fluid out of the operating cylinder through said three radially extending inlet conduits toward said relatively stationary contact structures for effecting extinction of the arcs drawn thereat, whereby to substantially balance the fluid-flow reaction forces, the closing motion of said operating rod not only effecting closing motion of said one rotatable crank arm but also charging of said piston in opposition to said biasing means, and said lost-motion connection being effective during the opening operation to permit unimpeded opening travel of said one rotatable crank arm independently of motion of the piston.

References Cited in the file of this patent UNITED STATES PATENTS 2,095,441 Howe Oct. 12, 1937 2,098,801 Erben Nov. 9, 1937 2,221,720 Prince Nov. 12, 1940 2,381,592 Hilliard Aug. 7, 1945 2,760,033 MacNeill et al. Aug. 22, 1956 2,781,435 Heilmann et al Feb. 12,-1957 FOREIGN PATENTS 106,334 Australia Jan. 19, 1939 519,113 Great Britain Mar. 18, 1940 537,482. Great Britain June 24, 1941 850,075 France Aug. 28, 1929 940,814 France June 7, 1948

Claims (1)

1. A THREE-PHASE, FLUID-BLAST CIRCUIT INTERRUPTER INCLUDING A GROUNDED DEAD TANK, THREE PAIRS OF TERMINAL BUSHINGS EXTENDING INTO SAID GROUNDED DEAD TANK, THREE ROTATABLE CRANK ARMS HINGED IN STAGGERED RELATION TO THE INTERIOR ENDS OF THREE OF SAID TERMINAL BUSHINGS, THREE RELATIVELY STATIONARY CONTACT STRUCTURES IN STAGGERED ARRANGEMENT ASSOCIATED WITH THE INTERIOR ENDS OF THE REMAINING THREE TERMINAL BUSHINGS, A SINGLE CENTRALLY LOCATED PUMPING DEVICE INCLUDING AN OPERATING CYLINDER AND A PISTON MOVABLE THEREIN, A CENTRALLY-LOCATED SYMMETRICAL Y-SHAPED FLUID INLET CONDUIT STRUCTURE INCLUDING THREE RADIALLY EXTENDING INLET CONDUITS ASSOCIATED WITH SAID SINGLE PUMPING DEVICE

Images