US3075060A

US3075060A - Circuit interrupters

Info

Publication number: US3075060A
Application number: US693309A
Authority: US
Inventors: Albert P Strom
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1957-10-30
Filing date: 1957-10-30
Publication date: 1963-01-22
Anticipated expiration: 1980-01-22
Also published as: GB860246A; FR1214300A; DE1199368B; CH366082A

Description

Jan. 22, 1963 A. P. STROM 3,075,060

' CIRCUIT INTERRUPTERS Filed Oct. 30, 1957 5 Sheets-Sheet 1 WITNESSES= INVENTOR KMMQ K Y BYAlbert I? Strorn WWflMW. WE

ATTO RNEY Jan. 22, 1963 A; P. STROM 3,075,060

CIRCUIT INTERRUPTERS Filed Oct. 50, 1957 5 Sheets-Sheet 2' Fig.6.

Sump Hi h Pressure Jan. P. STROM CIRCUIT INTERRUPTERS 4 Filed Oct. -50, 1957 I 5 Sheets-Sheet 3 3 9% 1: I age NI era- Jan. 22, 1963 A. P. STROM CIRCUIT INTERRUPTERS Filed Oct. 30. 1957 5 Sheets-Sheet 5 Now om. my 7 mt my 5. \U m m DE mm: 5 8. 1 N: we um. mm. .n o h E f mm. 50 8 m9 2.. m! mt mm mm. fimi 4 w 2.. $1 N: a C E .5 v w mm- MM This invention relates to circuit interrupters in general and, more particularly, to circuit interrupters utilizing a hydraulic operating mechanism.

A general object of the present invention is to provide an improved circuit interrupter, which will more effectively and rapidly interrupt the circuit therethrough, than has been achieved heretofore.

Another object of the present invent on is to provide an improved hydraulic operating mechanism for a circuit interrupter, which will function efliciently and rapidly to bring about quick separation of the contact structure. in this connection, the invention has particular advantage, when puller-type interrupters are employed, which create considerable variable back-pressure forces.

Another object of the invention is to provide an improved gas-blast circuit interrupter employing a hydraulic operating mechanism to forcibly effect contact separation and piston movement, regardless of the backpressure forces, which may be created during the interrupting operation by the arc-heated gases.

Yet a further object or" the present invention is to provide a circuit interrupter particularly adaptable for highvoltage application, in which the accumulator for the hydraulic operating mechanism may be disposed at high potential, and preferably immediately adjacent to the operating cylinders, the latter conjunction with pistons effecting contact separating movement.

A further object oi the invention is to provide an improved gas-blast circuit interrupter utilizing an effective arc-extinguishing gas, such as sulfur iexafiuoride SP or selenium hexailuoride SEE which gases have a highielectric strength, in which the arc-extinguishing gas is fed from ground potential up through a hollow, upstandiug, insulating pedestal, the latter being employed to vertically support the arc-extinguishing assembly for the circuit interrupter.

in gas-blast circuit interrupters, particularly those enploying putter-type interrupters, it is very desirable to have a powerful mechanism, that can start to open the breaker without delay, when a short circuit occurs, and has suliicient power to carry the mechanism through the opening stroke at essentially constant velocity, even though high-stopping forces are generated by the rapidly expanding gases in the are. The present invention is particularly concerned with a hydraulic type of mechanism, which can be used in a sulfur hexafluoride SP breaker, or breakers employing other gases, to obtain breaker operation with minimum delay and essentially constant velocity.

An important feature of the present invention is the mounting of the hydraulic cylinders, accumulator and valves at high potential, adjacent to the interrupting chambers themselves, so that the operating cylinders can thus be connected directly to the breaker contacts, or the puller piston (if such is used), and operated through the pipe connections from the accumulator so as to give maximum speed of operation.

Another important feature of the present invention is the utilization of a high-pressure pump at ground potential, with a hydraulic connection by means of a smallbore insulating tube extending upwardly through the hollow supporting porcelain insulator from the pump to accumulator at high potential. The hydraulic fluid such 1 the as oil may then be discharged from the operating cylin- 3,975,,hdh

Patented Jan. 22, 1953 ice ders, and carried down, by means of a relatively largebore insulating tube at low pressure, to the pump sump. As a result, operation of the breaker contacts and puffer pistons (when they are used) may be achieved from ground potential by means of an insulating rod actuated from the ground end by a solenoid spring, or other means, such as a hydraulic fluid forced through a pilot duct may be used. In the latter case a high-pressure hydraulic control pipe of insulating material extends down to a pilot valve at ground potential from an elevated master valve, and is employed to eifect the operation of the master control valve at high potential adjacent the accumulator and operating cylinders.

Yet a further object of the invention is to provide an improved impedance shunting contact assembly, having separable contacts for high-power circuit interruption, which shunting impedance assembly may be hydraulically actuated in a similar manner to the actuation of the main movable contact assembly.

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

FEGURE 1 is a fragmentary, side elevational view of a hydraulically actuated compressed-gas circuit interrupter, with a portion broken away to reduce the vertical height, and embodying the principles of the present invention, with the contact structure being indicated in the closed-circuit position;

FIG. 2 is a fragmentary, end elevational view of the complete circuit interrupter assembly of FIG. 1;

FIG. 3 is a considerably enlarged, vertical sectional view taken through the left-hand arc-extinguishing unit of the circuit interrupter of FIG. 1, showing the hydraulic actuating mechanism therefor, and the contact structure being illustrated in the closed-circuit position;

PEG. 4 is a diagrammatic View, considerably simplified, of the general hydraulic operating mechanism illustrated in FIGS. 1-3, with the contact structure being shown fragmentarily in the closed-circuit position;

FIG. 5 is a fragmentary, vertical sectional view taken through a modified type of circuit interrupter employing a shunting impedance assembly having movable contact structure, with the modified type of circuit interrupter being illustrated in the closed-circuit position; and

FIG. 6 is a considerably enlarged View, in vertical section, of one of the valve assemblies utilized in the modilied type of circuit interrupter of FIG. 5.

Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral 1 generally designates a circuit interrupter assembly particularly suitable for high-voltage and hi h-current applications. Although for purposes of illustration the present invention will be described as applied to a high-voltage, highpower circuit interrupter, such as one suitable for interrupting 16,000,900 kva. at 138 kv., it is to be understood that certain features of the invention are suitable for use on circuit interrupters of lower voltage and current rating, or, indeed, for circuit interrupters of considerably higher ratin The 138 liV. circuit interrupter illustrated in FIG. 1 includes a pair of laterally projecting, arc-extinguishing structures 2, enclosed within porcelain, weatherproof, hollow casings 3 and secured to the opposite sides of a mechanism compartment or housing 4. The mechanism housin 4 may consist of heavy, high-strength, steel plates welded together and forming a rugged support for carrying the laterally jutting arc-extinguishing structures 2, as well as supporting internally thereof suitable hydraulic operating cylinders and an accumulator, more particularly described hereinafter.

The mechanism housing 4 is supported at the upper end of an upstanding insulating pedestal 5, which, in this particular instance, maybe formed of porcelain. The upstanding pedestal 5 is shown broken in FIGS. 1 and 2, but in practice may extend a considerable distance upwardly depending upon the voltage encountered.

The lower end 6 of the insulatingpedestal 5 is supported, in turn, upon an angle-iron framework, generally designated by the reference numeral '7 and serving to support a reservoir or sump 3 and a lower control com partment 9. The framework '7 itself may rest upon a suitable base it), say formed from structural concrete.

With particular reference to H6. 3, it will be noted that the arc-extenguishing structure 2 includes a relatively stationary, rod-shaped contact 11, which may be threadedly secured and clamped, as at 12, to a spidershaped conducting support 13. The spider support 15 may be secured, as by mounting bolts lid, to a ring-shaped terminal plate 15 having a terminal pad 16. The terminal pad 16 may have apertures 17 thcrethrough to accommodate bolts for making a fixed connection to a high-voltage transmission line, not shown.

Extending over the spider support 13 is an end cap 18. The end enclosing cap lganay be secured by a plurality of bolts 19 to the ring-shaped terminal plate The end cap 18 may carry a rupture disc 2% (FIG. 3) adaptable to break, upon the occurrence of excessive pressure, and a basket'21 containing a material, such as activated alumina, to absorb products of decomposition from the arced gas.

It is to be noted that there is provided within the region 22 Within porcelain casing .3 a suitable arc-extinguishing, and high-dielectric strength gas, such as sulfur hexafluoride SE; at a pressure, say of 60 psi. Although SE; is mentioned, by way of example, it will be Obvious from the following description that other gases, or even compressed. air may be employed to advantage.

As shown in FIG. 3, the hollow porcelain casing 3 has a ring-shaped flange 23 secured thereto, as by cement 24, and the ring-shaped mounting flange 23 may be secured, as by bolts 19, to the terminal plate 15.

It will be observed that the contacting end of rodshapcd stationary contact 11 is bored out, as at 26, with side apertures, as at 27, to accommodate the entrance of a movable rod contact 28, the latter having an arc-resist; ing tip 29 composed of any suitable arc-resisting material, such as a tungsten-silver alloy.

The movable contact 23 is secured to a finger support 3! as by a threaded connection 31. The finger support 3d has a plurality of spaced fingers 32, which engage the external'surface of the stationary contact llll, as shown in FIG. 3, in the closed-circuit position of the interrupter.

Surrounding the contacts 11, 28 is an insulating orifice structure, generally designated by the reference numeral- 33, and, in this particular instance, being composed of polytetrafiuoroethylene. This material has been found especially suitable for resisting the action of arced sulfur hexafluoride gas, as set out more in detail in US. Patent 2,757,261, issued July 31, 1956, to Harry I. Lingal, Thomas E. Browne, Jr. and Albert P. Strom and assigned to the assignee of the instant application.

Clamping the orifice structure 33 to a movable puffer cylinder, generally designated by the reference numeral 34, is a support 35, the latter being secured to a cylinder end 36 by any suitable means, not shown. The puffer cylinder 34'includes the cylinder end 36 and a hollow puffer cylinder section 37, the latter sliding over resilient contact fingers 38, mounted in a ring-shaped contact support 39 constituting part of a stationary piston. The contact support 39 is secured, as by bolts as, to a support casting 41', which is secured, by bolts 42, to a heavy and plate 43 formed from steel plate and constituting, a portion of the mechanism housing 4-.

A piston rod 44 is clamped, by a nut 45, to the cylinder end 36 andefiects the actuation thereof, carrying with it the entire movable orificestructure 33, movable contact 28, finger support 30 and the fingers 32 thereof, all conistituting a movable contact assemblage, back over the support casting 41 in a manner, which will be obvious upon an inspection of PEG. 3. The flexible contact fingers 3t biased radially outwardly by compression springs i maintain good contacting engagement with the conducting cylinder .37 during this movement.

The right-hand end of the piston rod is fixedly secured to a piston 47, movable within an operating cylinder Asnoted in FIG. 3, there is always present high-pressure hydraulic fluid acting upon the left-hand, opening face 49 of the piston 47, as fed by a high-pressure conduit fill, tending to move the movable contact 23 toward the right, into the open-circuit position. it is one of the important features or" the invention that his high pressure exists at all times tending to force the hydraulic piston 47 open, and only by a. reduction of the pressure within the region 51 within operating cylinder it is possible to permit'such opening action to occur. it will be noted that if the pressure within region Si is the same as the pressure within region 52, to the left of piston 47, then the piston will nevertheless move to its closed position because of the fact that the cross-sectional area of piston rod moves through opening 53 out of the 036iating cylinder 43. Equalization of pressure, therefore, within

regions

51, 52, will effect closing of the interrupter, whereas a reduction of pressure within region 511, as more fully described hereinafter, will permit the constant high pressure within region 52 to effect a rapid.

opening stroke of the'movable contact 28 and orifice structure 33, compressing the sulfur hexafluoride gas within region 54', within puller cylinder and forcing it to flow out through the orifice 55', provided by orifice structure 33, to effect extinction of the are drawn therethrough.

FIG. 4 shows more clearly, in diagrammatic form, the essential parts of the hydraulic operating mechanism of the present invention. The high-pressure conduit 5b, which leads to the region 52 on the opening side of the piston 47, also communicates with a high-pressure accumulator 56, disposed at high potential within the mechanism housing 4. As shown in FIG. 4, nitrogen gas at, say 2,000 p.s.i., is disposed in the region 5'7 above a.

movable piston or diaphragm 58, movable within the accumulator 56 and maintaining the hydraulic fluid, such as oil 59, under the same high pressure. pressure oil 5% not only communicates by means of highpressure conduits 56 to the two operating cylinders 43 of both arc-extinguishing structures 2, but also it connects by way of a conduit on to a master control valve, generally designated by the reference numeral 61 in FIG. 4. Further, the conduit 6t has a branch connection 62, which passes down through the hollow pedestal 5 to an auxiliary accumulator, designated by the reference numeral 63, and disposed at ground potential within the control compartment 9 (FIG. 1). Naturally the portion of the conduit 62 passing downwardly through insulating pedestal 5 is formed of insulating tubing.

A hydraulic pump 64, driven by a motor 65, is employed to draw hydraulic fluid 59 from the reservoir or sump 8 (FIG. 4) through a feed pipe as and force it under high pressure through a check valve 67 and through a conduit 63 into the auxiliary accumulator 6.3 at ground potential. A suitable gas, such as nitrogen N may be employed Within auxiliary accumulator 63 to the right of piston or diaphragm 69 therein under a suitable pressure, such as 2,000 psi. A branch conduit '76, leading from feed conduit 68, enters a port of a pilot valve, generally designated by the reference numeral 71. A valve spindle 72, movable within pilot valve 71, is biased by a compression spring 73 in a direction to permit high-pressure oil to pass through a region 74 of pilot valve '71 and upwardly through a control conduit 7d to the lower side ofa piston 76, reciprocably movable within master control valve 61. Thus, as shown in FIG. 4, the pilot valve 71 The highnoid 77 to eifect unlatching of a latch '78, to permit the compression spring 73 to move the valve control spindle 72 of pilot valve '71 to the right, thereby permitting flow of high-pressure oil upwardly through control pipe '75 to act upon the lower side of piston 76. FIG. 4 shows piston 76 of master valve 61 in the breaker closed position prior to its being moved upwardly to a breaker open position by the aforesaid tripping of pilot valve '71.

The piston 76 of master control valve 61 has a spidershaped connection 7Q with a sleeve valve 84}, the latter moving with piston 76 and controlling the flow of highpressure oil 59 downwardly through passages 81 within valve casing 82. As shown in FIG. 4, the master control valve 61 is in the breaker closed position, allowing highpressure oil 59 to pass across the upper edge 83 of sleeve valve and through ports 84 provided therein, to communicate through conduits 85 to the closing sides of hydraulic pistons 47.

Upon energization of a closing solenoid 86, the armature 87 thereof will strike a protruding end 33 of control spindle 72, forcing the latter to the left, as viewed in FIG. 4, compressing spring 73, eflecting the relatching of tripping latch 78, and placing the control pipe 75 in communication with an exhaust pipe 89 to the sump 3. This will permit compression spring 90 to move sleeve valve 89 downwardly, opening up the passages 81 and closing the lower end 91 of sleeve valve. This will eflect closing of the pistons 47 and hence closing of the movable contact structure 11, 28 in an obvious manner.

The lower end of the master control valve 61 communicates by means of a passage 92 to an insulating exhaust pipe 93 leading to the reservoir, or sump 8. Preferably the region. 94 above the liquid level '95 of sump S is filled with sulfur hexafluoride SP gas at the aforesaid 60 p.s.i., that is, at the same pressure as exists within the region 22 within hollow casings 3. It will be observed that a pipe as interconnects the region 94- within sump 8 with the region '97 within hollow upstanding pedestal support 5 to increase the voltage withstanding ability of the pedestal support This has the further advantage that an opening @8 is provided in support plate 99 (HQ. 3) at the upper end of porcelain casing 5 to communicate by Way of a pipe connection ltlll with the region 22 within casing 3, as shown in HS. 3.

It will be apparent that in the closed-circuit position of the interrupter l, as shown in FIG. 3, the electrical circuit therethrough includes terminal pad 16, ring-shaped terminal plate 15, spider support 13, stationary contact ll, movable contact 28, conducting cylinder head 36, conducting puiier cylinder 37, finger contacts 38, support casting 41, through the conducting mechanism housing 4, and through the right-hand arc-extinguishing structure 7; of FIG. 1 in a similar manner to the right-hand terminal pad to (PEG. 1).

In this closed-circuit position, the hydraulic mechanism will be in the position as shown in FIG. 3, and as shown in FIG. 4, with the exception that in FIG. 4 the pilot valve spindle '72 will be latched by the tripping latch 73 and will not be in the tripped position, as actually shown in FIG, 4.

When it is desired to effect the opening of the circuit interrupter 1, suitable means, not shown, eitects the energization of tripping solenoid 77. This action unlatches the tripping latch '78, against the tension spring 101, and rotates the nose 192 of the tripping latch 78 from under the shoulder 163 of pilot valve spindle 72.

The pilot valve spindle 72 (FIG. 4) will immediately be moved to the right, as actually shown in FIG. 4, by the compression spring 73', so that high-pressure oil will move through region 74- of pilot valve '71, through control pipe 75 to act upwardly upon the lower face of piston '76 of master control valve 61.

This will move sleeve valve till upwardly to close oh the passages 81, and to open up the passages 92 to pipes 85, so that the latter may exhaust high-pressure oil from regions 51 within cylinders 43 down through the exhaust pipe 93 to the sump ll.

Since high-pressure oil 59 continues to exist within the regions 52 of operating cylinders 48, the pistons 47 will move toward each other in an opening direction, causing separation of the contacts ill, 23, and efiecting compression of gas within regions 54 within cylinders 37 (FIG. 3). This forces compressed gas out through orifices 55 to effect extinction of the two serially related arcs drawn within the arc-extinguishing structures 2.

To obtain substantially equal voltage division between the two breaks during this interruptin operation, preferably impedance tubes 1% are employed shunting the contacts 11, 2d and providing substantially equal voltage division between the two extinguishing structures 2.

In the fully open circuit position of the interrupter, the pistons 47 (FIG. 4) will be disposed at the inner ends of the operating cylinders 48, close to each other, and valve sleeve till will be in its upper closed position, with the pilot valve assembly '71 in the position as it is actually shown in FIG. 4.

To effect the closing operation of the interrupter l, suitable means, not shown, effects the energization of the closing solenoid 86. This will move armature 87 thereof to the left, as viewed in FIG. 4, moving pilot valve spindle 72 to the left, and relieving the oil pressure in control pipe '75. Tue nose ltlZ of tripping latch '78 will latch under the shoulder 163 of spindle 72, and valve sleeve of master control valve 51 will be moved downwardly by the compression spring High-pressure oil will pass from accumulator 56 through passages 81 over the top 83 of valve sleeve 8%, through ports and through conduits 85 to act within regions 51, thereby moving actuating pistons d7 outwardly, away from each other, in the closing direction. This will effect closing of the contact structure ll, 23 (Phil. 3) in an obvious manner.

To prevent the leakage of hi h pressure oil along the opening 53, as shown in PEG. 3, a drain connection 1 5;? is provided leading to a collecting can with the upper end of the can having a gas connection, through a pipe M7, to the region 22 within hollow casing 3. This structure is set out and claimed in US. patent application filed Gctober 30, 1957, Serial No. 693,306 by Winthrop lvi. Leeds, and assigned to the assignee of the instant application. This application also covers the use of gas, such as S3,, wi rin hollow pedestal 5.

Preferably a pair of windows (FIG. 1) are provided in a side plate ill? of mechanism housing 4 to permit observation of a pair of indicating pointers lltl, which are pivotally mounted, are spring-biased to the closed position by suitable biasing means not shown. The upper ends of the indicating pointers (FIG. 3) have abutments lll secured thereto, which are struck by the pistons 47 when the latter reach the extremity of their opening stroke. Thus, an accurate indication is provided, as to the contact condition, of each arc-extinguishing structure 2, since the indicator pointer ll? will constantly indicate the closed position, unless and until it is actually struck by a portion of the operating piston 4-7.

With attention being directed to H6. 1, it will be observed that a gauge 112; indicates the pressure of the SP above the liquid level @5 (FIG. 4) within sump 3. Also a glass-tube gauge 113 is employed to note the level $5 of the hydraulic oil 5& within the sump S. A drain pipe is connected to the bottom of the sump it for drainage purposes. The control pipe 75 and the feed pipe to the upper accumulator ss are indicated in FIG. 1, as is also the pipe leading from the pilot valve '71 within compartment 9 to the sump El. Handles 115 are provided to open the doors of compartment 9, permitting access to the various pressure switches and to the control panel therein. A manually operable valve 2th; for filling the sump with oil through a line Edda is shown in With further reference to FIGS. 1 and 2, it will be noted that a pipe 116 is provided, connectedto the upper end of sump ti and permitting'SF gas to be fed from an external supply tank, not shown, through hand" valve llllec to the region 94 (FIG. 4) within the upper end of sump ii. The connection Q6, leading from pipe 1116, connects the region 94 within sump 8 to the region h! (FIG. 3) within casing 5. A lifting eye ll? may be welded to the mechanism housing 3 for enabling-transportation of the entire interrupter l. p

The hand operation for inching of the breaker contacts by the use of the control valves M8, 119 will now be described. This is done for maintenance purposes with power removed from the interrupter l by opening suitable disconnect switches, not shown. Hand operation may be accomplished by means of two valves llltl, 119 just inside or" a front metallic cover plate 120 (FIG. 1). The left-hand valve lid, as viewed in PKG. 3, is in the conduit 62 leading from the lower accumulator 63 to the upper accumulator'b, and this hand valve 118 is normally open. The right-hand valve 119 is in aline 121 that connects the upper accumulator 56 to the sump 8 by way of the master control valve 61, and is normally closed. For hand operation, with the power oil the breaker, it is merely necessary to close the left-hand valve 118, shutting olf lower accumulator 63 and open the right-hand valve 119 to reduce the upper accumulator pressure to zero. Valve 119 is thenreclosed, If the breaker l is now closed, and it is decided to open it, the pilot valve 71 is actuated to the open position. This puts pressure from the lower accumulator 63 on the small piston is under the large operating sleeve valve so, moving it to the breaker open position. However, since there is no pressure on the opening faces 49 of pistons 47 within the contact operating cylinders 48, the movable contacts 28 will not move open until the left-hand valve 118 (FIG. 3) is cracked open, thereby admitting oil at a slow rate from the lower accumulator 63. By this means the movable contacts 28 may be inched open and stoppedat any point during such an inspecting operation.

Similarly, to inch the movable contacts 23 closed, it is merely necessary to reset the pilot valve 71 to the closed position, allowing the large valve 61 to move to closing position. Then the movable contacts 28 may be inched closed by cracking the left-hand valve lllil open.

inere is a particular advantage of pressurizing the sump 8, as was disclosed and claimed in the aforesaid Leeds application. If the sump 3 is not pressurized, the sump return line 93 (FIG. 4) at the bottom of the large master valve 61 is at a pressure below atmospheric,.by the pressure of the column of oil from this point to the sump t This is also true of the line '75 leading to the small piston 76 that opens the main master control valve at when this valve or is closed. This small differential pressure is more likely to leak at the 0 ring seal about these lines than a higher pressure, and if it does, an air bubble would enter the sump lines 75, 93. This would be particularly bad in the line 75 leading to the small piston 76 that operates the master control valve 61, since this line 75 alternates between sump pressure and high pressure. If air got into this line 75, it would have to be compressed before the valve would open, which might cause a delay of several times normal operating time.

With the sump 8 at a positive pressure, as provided by the SP at 60 psi. in region 94 (FIG. 4-), the air cannot leak in the sump lines 75', 93, and such leakage troubles cannot occur.

With particular reference to FIG. of the drawings, it will be observed that there is illustrated a modified type of circuit interrupter, generally designated by the reference numeral 122 and comprising a generally Y-shaped structure. The ll-shaped structure includes an upstanding, hollow, insulating pedestal 12.3, which is analogous to the pedestal 5 of the interrupter ll of FIG. 1;

Supported upon the top of the hollow supporting pedestal 123 isa mechanism housing, generally designated A mounting flange ring closing a pair of hydraulically actuated pistons 1129. Se-

cured, in threaded manner, to the actuating pistons 129 is atubular piston rod 13b, to the outer end of which is fixedly secured a movable contact 131, which makes contacting engagement with a relatively stationary contact 132.

The

separable contacts

131, 132 are disposed within a surrounding weatherproof casing 133, which is preferably formed from porcelain. The porcelain casingl33 has secured thereto at its lower end, by cement 134, a ring-shaped mounting flange 135, the latter being secured, as by bolts 136, to the upper slanting surface 143 of the mechanism housing 124,- as shown in FIG. 5

Secured, as by cement 137, to the outer end of the weatherproof casing 133 is a closure cap 138 having a line terminal connection 13?, as shown. Gaskets Mb, 1 1 may be employed to eifect a gastight seal, since sulfur hexafiuoride gas is disposed within the region 142 at a pressure of, say 60 psi. Secured, by suitable means, not shown, to the slanting surface 143 of the mechanism housing 124 is an operating cylinder 144. Slidable within the operating cylinder 144 is a piston 145, the latter being secured to and movable with the movable contact 131. Also movable-with the movable contact 131 is an insulating orifice member 146, the latter having an orifice restriction 147. As in the arrangement of FIG. 1, retraction of the piston 145 within operating cylinder 144 causes fluid, such as SP .to pass through the openings 148 in pistonl lti, through the orifice M7 and adjacent the established are drawn between

contacts

132, 131 to effect the extinction of the latter.

Extending into the tubular piston rod is a flexible rod-shaped contact 149, which is secured to the lower end of the operating cylinder 12% 7 During the opening movement the flexible rod contact 149 carries the current from the movable contact 133. to the conducting mechanism housing 124, and hence to the other arc-extinguishing unit 159 of the circuit interrupter 122.

Shouting each of the two identical arcrextinguishing units 15% is an impedance interrupter, generally designated by thereference numeral 151 and comprising a relatively stationary contact 152- cooperable with a movable contact 153. The movable contact .153 is fixedly secured to a piston 15d movable within an operating cylinder 155, being hydraulically actuated.

The

contacts

152, 153 separate within an orifice structure 155, movable with the movable contact 153 and with a piston 156. Thus sulfur hexafiuoride gas is compressed within the region 157 and is forced to flow through openings 158 through the orifice 159 and ad jlacent the impedance are drawn between 53.

The

contacts

152, 153 are separable within an en-.

closing, weatherproof casing, designated by the reference numeral 3 .60 and preferably formed of porcelain. A closure cap 161 is secured by any suitable means to the outer end of the weatherproof casing res and is e1ec-- trically connected by a connector 162 to the line-terminal connection 1390f closure cap 133.

In the closed-circuit position of the interrupter 122,

the electrical circuit therethrough in'cludes'line terminal to the right-hand operating cylinder 1.28, as viewed in- PlG. 5, and throughthe right-hand arc-extinguishing unit 15d in an identical manner.

contacts .152,

Naturally a shunt circuit exists about each of the arce-xtinguishing units 1561 through the impedance interrupter 151 by way of the connector 162, conducting cap 161, resistance blocks 164, stationary contact 152, movable contact 153, piston 1534-, operating cylinder 155, and to the mechanism housing 12d.

The hydraulic operatin mechanism, generally designated by the reference numeral 165, will now be described. As in the construction of the interrupter 1 of FIG. 1, an accumulator ass at high potential is employed. This accumulator 66 may have a construction identical to the accumulator 5'6 of FIG. 4, having nitrogen gas therein at 2000 psi. acting upon a diaphragm separating the nitrogen N and the oil 59. A high-pressure pipe 167 constantly connects the high-pressure end of the accumulator 166 to the upper opening face of each operating piston 129, thereby tending to bias the movable contacts 131 to their open-circuit position. Additional conduits 163 connect the high-pressure accumulator 1 56 to the opening side of the pistons 154, Within operating cylinders 155, also tending to bias the movable impedance contacts 153 to the open-circuit position. The construction is such that a suitable restriction is provided in conduit is dumping high-pressure oil out of cylinders 155, so that in fact, the movable contact 153 opens subsequently to the opening of the main movable con tact 131.

As shown in PEG. 5, the hydraulic mechanism 155' includes a closing hydraulic valve 169 and an opening hydraulic valve lliti. Each of the

hydraulic valves

169, 17% has a construction, as shown in FIG. 6 of the drawings. FIG. 6 shows, to an enlarged scale, the closing valve 169, but, as will be obvious hereinafter, the opening valve 171? may have a similar construction, the only difference being in the types of conduits leading into the valve casing 177.. Features of the opening valve 17% are set forth and claimed in United States patent application filed March 15, 1961, Serial No. 95,933, by Albert P. Strom and William H. Fischer and assigned to the assignee of the instant application.

In the case of the closing valve 169, the upper conduit 1725 leads directly from the high-pressure accumulator 166, whereas in the case of the opening valve 174), the upper conduit 173 is connected to the lower side of the operating pistons 129 through a common manifold 175. The outlet conduit 1%- leading from the closing hydraulic valve 169 leads to the common manifold 175, which in turn is connected to the lower end of each operating cylinder 123 by a pipe connection 176. The outlet conduit 177 of the opening valve 17% leads through an insulating tube 1'79 to a lower sump 8 (FIG. 4). An insulating operating rod 1% extends upwardly through the weatherproof pedestal 123, and through a bellows 181 to a double-armed bell-crank lever 182. The doublearmed belbcranlr lever 182 is pivotally mounted about a fixed axis 183 and is rotated thereabout by the operating rod 189. The operating rod 13%? may be manually or electromagnetically actuated from ground potential by any suitable means, not shown.

With attention again directed to FIG. 6, it will be observed that each of the hydraulic valves 169, 170 has a pilot-valve spindle 13d, biased by a spring 185, so that high-pressure oil 5% tends to pass from a pipe 186 into a region 137 to act upwardly upon a piston 183 movable within a piston casing 139. The piston 188, in turn, strikes a stem 1%, secured through a spider support 1% t the lower end of a main sleeve valve 192. The sleeve valve 192 reciprocally moves within the valve casing 171 and controls the flow of oil '9 through the valve.

The double-armed bell crank lever 182 is so arranged as to depress either one button 1% of the closing valve 169 or the button 193 of the opening valve 170. When the button 1% is depressed, this moves the pilot valve spindle 184 to the left, as viewed in PEG. 6, closing oil the highpressure oil inlet 186, and dumping the region 17% below lb piston 18% to the low sump pressure, through region 194 and low pressure outlet 195, leading to the sump 55.

Thus, when the button 193 of either

valve

169, 176 is untouched, the arrangement is such that high-pressure oil maintains the piston 188 and hence the sleeve valve 1&2 in its upper raised open position. On the other hand, when the button 193 is depressed, the converse situation arises, and the sleeve valve 192 is maintained at its lower closed position by the pressure of the oil within region 1%.

The operation of the modified type of interrupter 122 will now be explained. To effect the opening of the interrupter, from the closed-circuit position illustrated in FIG. 5, the operating rod 186 is moved upwardly so as to release the I utton 193 of opening valve 176 and to depress the button 193 of closing valve 169. As heretofore explained, the pilot valve spindles 18d of both valves will move to positions wherein the sleeve valve 192 of closing valve 169 will be closed, thereby shutting off high-pressure oil from accumulator 166 to the region 197 within operating cylinder 3.28, whereas the sleeve valve 152 of openin valve 171 will be raised to permit a dumping of highpressure oil out of the region of operating cylinders 128 through the manifold and through the exhaust pipe 379 to the sump 8 (FIG. 4).

Since there exists high-pressure oil at all times on the upper surfaces of tie pistons 129, and since the lower sides of the pistons 129 are now exposed to a reduced pressure, these pistons 129 will now move down, causing the opening of the movable contacts 131 away from the stationary contacts 132, drawing two serially related arcs within the orifices 147. The blast of gas passing through the orifices 147 in the manner previously described, will effect extinction of the main-current arcs drawn between contacts 231, 132.

At the same time, that the pressure is reduced within regions 197 of operating cylinders 123, the pressure will likewise be reduced in the regions Within operating cylinders 1.55 back of the pistons 15 in the impedance current interrupters 151. Because of the provision of suitable restrictions in the conduits 199, the opening of the impedance contacts 153 will be slightly delayed. This will give the main current are a chance to be interrupted at the main gaps 13-1, 132 so that only a small residual current are needs to be subsequently interrupted at the

impedance contacts

152, 153.

Since the resistance blocks 164- reduce the current, and improve the power factor, the residual current are passing etween the

contacts

152, 153 will quickly be extinguished by the puff of SE; gas out of the region 157 by retraction of the pistons 15 5. in the fully open-circuit position, the pistons 145, 156 are in their fully open positions, the

movable contact structures

131, 153 are opened, and current has therefore ceased to how through the interrupter 122.

To eilect the closing of the interrupter, the operating rod 13! is moved downwardly, releasing the button of closing valve 169 and engaging the button 1% of opening valve 170. In the manner heretofore explained, the sleeve valve 1% of closing valve 169 will he raised to its open position, thereby effecting intercommunication between the accumulator ildd and the manifold 175 and hence regions 197 in back of the pistons 129. The depression of the button 1% of opening valve 17% will effect the closing of the sleeve valve 1E2r associated therewith, thereby closing the connection between manifold 175 and the lower sump 8. Since the cross-sectional area of the tubular portion of tubular piston rod 13% moves out of the operating cylinder 128, this unbalanced pressure acting upon piston 129 efifects the rapid closing of contact structure 1M, 132. A similar action takes place in each impedance interrupter 151 and these close likewise. The interrupter is hence closed and current passes therethrough.

From the foregoing description of the two

circuit interrupters

1, 122, it will be observed that there has been 1 1 provided an improved hydraulically actuated circuit interrupter in which the accumulator as, 166 is at high potential and closely adjacent the operating

cylinders

48, 128. The pipe connections are therefore short, and since the operating

cylinders

48, 128 are immediately adjacent the movable contact structures 2%, 131, high-speed motion results with no delay whatsoever. Not only are the accumulators 5d, 166 at high potential immediately adjacent the contact structures, but also they need be of relatively small size because of the replenishment of highpressure hydraulic fluid therein by the feed pipes 62, The sulfur hexailuoride gas at the lower pressure can be fed upwardly through the pedestal 5 or upwardly through a pipe 2M (FIG. 5) to maintain the proper pressure within the arc-extinguishiug structures.

In both interrupters the tripping operation is initiated at ground potential, the tripping impulse being sent through the w-eartherproof pedestal 5, 1.23.

By having the accumulator at high potential and the hydraulic mechanism also at high potential, a high-speed circuit interrupter results in which no time delay whatsoever is encountered between the initiation of the tripping impulse and the initiation of the opening operation of the movable contact structure.

Although there have been shown 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 as my invention:

1. A circuit interrupter for interrupting high-voltage circuits of considerable power including an arc-extinguishing unit, insulating support means for supporting said arc-extinguishing unit an adequate distance from ground potential, said arc-extinguishing unit including a relatively stationary contact, a cooperable movable contact separable from the relatively stationary contact to establish an arc, hydraulic operating means disposed in immediate proximity to the contacts for actuating said movable contact including a hydraulic operating cylinder and a high-pressure accumulator, a master control valve for controlling the flow of hydraulic liquid into said cylinder, a hydraulic piston movable within said hydraulic operating cylinder, means connecting said hydraulic piston to said movable contact for the actuation thereof, and the hydraulic operating cylinder accumulator, master control valve and piston all being atthe same high potential as the movable contact.

2. The combination in a high-voltage circuit interrupter of insulating support means for supporting a pair of serially related arc-extinguishing units a suflioient distance from ground potential, said pair of serially-related supported are-extinguishing units including two pairs of serially related contacts separable to establish at least two serially related arcs, said pairs of contacts including two movable contacts movable toward each other during the opening stroke, a pair of hydraulic operating cylinders having hydraulic pistons therein coupled to said movable contacts, a high-pressure accumulator positioned generally between said units for feeding hydraulic fluid into said hydraulic operating cylinders, and the two movable contacts, hydraulic operating cylinders, accumulator and pistons all being at substantially the same voltage.

3. A high-voltage circuit interrupter including a pair of separable main contacts and a pair of separable shunting impedance contacts, an impedance in series with said pair of impedance contacts, hydraulic operating means for sequentially opening first a movable main contact and subsequently a movable impedance contact, separate hydraulic operating cylinders and separate pistons for effecting the opening movement of said movable contacts, and the hydraulic operating cylinders being atsub'stantially the same high voltage as the movable contEtCtS'.

4-. A high-voltage circuit interrupter including a pair of separable main contacts and a pair of separable shunting impedance contacts, an impedance in series with said pair of impedance contacts, hydraulic operating means for sequentially opening first a movable main contact and subsequently a movable impedance contact, hydraulic operating cylinders and pistons for eiiecting the opening movement of said movable contacts, a highpressure accumulator for feeding hydraulic fluid into said hydraulic operating cylinders, and the hydraulic operating cylinders and accumulator being at substantially the same high voltage as the movable contacts.

5. A high-voltage circuit interrupter including an upstanding hollow insulating pedestal, an arc-extinguishing unit supported at the upper end of said upstanding pedestal an adequate distance above ground potential, said elevated arc-extinguishing unit including a pair of separable cooperable contacts, a hydraulic operating cylinder and a piston therein coupled to one of said contacts,

means including a high-pressure accumulator for feeding hydraulic fluid to the opening side of said piston for constantly maintaining high-pressure hydraulic operating fluid on the opening side of said hydraulic piston, hydraulic means including a master control valve for governing the hydraulic pressure on the closing side of said piston to effect opening and closing movement of said one contact, the accumulator and the hydraulic operating cylinder being at substantially the same high potential as said one contact, an auxiliary accumulator disposed at ground potential, and a feed conduit extending upwardly through said hollow pedestal and interconnecting the two accumt lators.

6. A high-voltage circuit interrupter including an arcextinguishing unit, an insulating pedestal for supporting said arc-extinguishing unit up in the air above ground potential, said unit having a movable contact associated the with, a hydraulic operating cylinder and a piston for moving said movable contact, a highrpressure accumulator at high potential supported by said pedestal, an auxiliary accumulator at ground potential, and an insulating feed conduit extending through said insulating pedestal and hydraulically interconnecting said two accumulators.

7. The combination in a high-voltage circuit interrupter of an elevated arc-extinguishing unit, an insulating hollow pedestal for supporting said elevated arc-extinguishing unit up in the air above ground potential, said unit including a movable contact, a hydraulic operating mech anism for moving said movable contact including a hydraulic operating cylinder, piston, master control valve, and accumulator all at high potential supported on said insulating pedestal, an auxiliary accumulator at ground potential, insulating conduit means interconnecting said two accumulators, and means extending upwardly through said hollow insulating pedestal for operating said master control valve at high potential.

8. A high-voltage circuit interrupter including an arcextinguishing unit, an insulating pedestal for supporting said arc-extinguishing unit up in the air above ground potential, said unit having a movable contact associated therewith, a hydraulic operating cylinder and a piston for moving said movable contact, a high-pressure accumulator at high potential supported by said pedestal, an auxiliary accumulator at ground potential, an insulating feed conduit extending through said insulating pedestal and hydraulically interconnecting said two accumulators, a master control valve at high potential, a manual inching valve in said feed conduit, a sump at ground potential, a second manual inching valve in a hydraulic connection from said high potential accumulator to said sump, whereby said manual inching valves may be used to inch the movable contact slowly for inspection purposes.

9. A circuit interrupter of the gas-blast type for interrupting high-potential circuits including an upstanding hollow insulating support pedestal for supporting an arcextiuguishing unit an adequate distanceabove ground potential, said supported arc-extinguishing unit including a relatively stationary contact, a cooper-able movable contact :cooperable with said relatively stationary contact to establish an arc, a relatively stationary operating cylinder, a movable puffer piston movable within said relatively stationary operating cylinder to blast gas through said are to effect the extinction thereof, a piston rod for said movable purier piston, hydraulic operating means at high potential and also supported by said hollow pedestal for elfecting opening motion of both said movable puffer piston and said movable contact including a hydraulic operating cylinder and a high-pressure accumulator, a hydraulic piston movable within said hydraulic operating cylinder, means connecting said hydraulic piston to said piston rod for efiectiug opening and closing motion of said putter piston, an auxiliary accumulator at ground potential, feed-pipe means interconnecting the two accumulators and extending through said hollow support pedestal, and the hydraulic operating cylinder, high-pressure accumulator and piston being at the same high potential as the movable contact.

10. The combination in a high-voltage gas-blast circuit interrupter for interrupting high-potential circuits of a generally T-shaped interrupting structure, a pair of relatively stationary contacts disposed adjacent the outer ends or the lateral arms of the generally T-shaped interrupting structure, a pair of relatively stationary operating cylinders in the arms of the generally T-shaped structure, a pair of putter pistons carrying movable contacts movable within said pair of relatively stationary operating cylinders toward each other during the opening operation, a hydraulic operating mechanism at high potential including at least one hydraulic operating cylinder and a pair of hydraulic pistons connected to said pair of puffer pistons, the hydraulic operating mechanism also including a high-pressure accumulator at high potential, an auxiliary accumulator at ground potential, and an insulating supply line extending through the central support of the generally T-shaped interrupting structure interconnecting the two accumulators.

11. A high-power gas-blast circuit interrupter including a pair of separable main contacts and a pair of separable shunting impedance contacts, an impedance in series with said pair of impedance contacts, a pair of gas-blast puffer structures. associated with said two pairs of separable contacts to effect the extinction of the main current arc and the residual current arc, a hydraulic operating mechanism for said puffer structures including a pair of hydraulic operating cylinders and a pair of hydraulic pistons movable therein, means for delaying the motion of the hydraulic piston associated with the impedance contacts relative to the motion of the hydraulic piston associated with the main contacts, and the hydraulic operating mechanism causing said putter structures to sequentially extinguish the main and residual current arcs.

12. A high-power gas-blast circuit interrupter including a pair of separable main contacts and a pair of separable shunting impedance contacts, an impedance in series with said pair of impedance contacts, a pair of gas-blast puffer structures associated with said two pairs of separable contacts to efiect the extinction of the main current are and the residual current arc, a hydraulic operating mechanism at the same potential as the movable contacts for said pufier structures including a pair of hydraulic operating cylinders and a pair of hydraulic pistons movable therein, means for delaying the motion of the hydraulic piston associated with the impedance contacts relative to the motion of the hydraulic piston associated with the main contacts, and the hydraulic operating mechanism causing said puffer structures to sequentially extinguish the main and residual current arcs.

13. A high-voltage fluid-blast circuit interrupter adaptable for interrupting high-potential circuits including an upstanding generally T-shaped interrupting structure having a hollow upstanding portion, a pair of line terminals disposed at the outer extremities of the laterally extending arms of the generally T-shaped interrupting structure, each arm including a laterally extending insulating casing, a pair of relatively stationary contacts disposed adjacent the outer ends of the lateral arms of the generally T-shaped interrupting structure and interiorly of the casings, a pair of movable contacts cooperable with said pair of relatively stationary contacts and movable toward each other during the opening operation, a fluid-blast puffer structure associated with each movable contact and movable therewith during the opening operation, a mechanism housing disposed at the upper end of the supporting column of the generally T-shaped interrupting structure and interposed between the two insulating casings, a hydraulic operating mechanism at high potential disposed at least partly within said mechanism housing, said mechanism housing being at high potential and at the potential of the movable contacts, said hydraulic operating mechanism including a pair of hydraulically operated pistons connected to the pair of movable contacts to effect the actuation thereof and a high-potential accumulator, an auxiliary accumulator at ground potential, and a feed conduit at least partly of insulating material interconnecting said two accumulators and extending through said hollow upstanding portion.

14. The high-voltage fluid-blast circuit interrupter according to claim 13, wherein a master control valve is at high potential and a hydraulic pilot line also extends upwardly through said hollow upstanding portion.

15. A high-voltage fluid-blast circuit interrupter including an upstanding generally Y-shaped interrupting structure, a pair of line terminals disposed at the outer ends of the outwardly extending arms of the generally Y-shaped interrupting structure, main contact means disposed within said outwardly extending arms of the generally Y-sha-ped interrupting structure, additional outwardly extending arms containing shunting impedance contacts, hydraulic means at high potential disposed at the upper end of the supporting column of the generally Y-shaped interrupting structure, means delaying opening of the impedance contacts until after arc extinction at the main contact means including said hydraulic means for sequentially operating the main contact means and the impedance contact means, and connecting means interconnecting the outer ends of the impedance arms with the outer ends of the first-mentioned arms.

References Cited in the file of this patent UNITED STATES PATENTS 1,653,086 Christensen et al Dec. 20, 1927 2,239,554 Duffing Apr. 22, 1941 2,290,320 Duffin'g July 21, 1942 2,445,529 Leeds July 20, 1948 2,459,599 Strom Jan. 18, 1949 2,604,562 Paul July 22,1952 2,662,133 Burmeister Dec. 8, 1953 2,665,351 Forwald Ian. 5, 1954 2,730,589 Perry et al Jan. 10, 1956 2,745,952 Cabanes et al May 15, 1956 2,748,226 MacNeill et al. May 29, 1956 2,781,435 Heilmann et al. Feb. 12, 1957 2,813,177 Eberhard et al Nov. 12, 1957 2,816,978 Lindell Dec. 17, 1957 2,933,575 Baker Apr. 19, 1960 FOREIGN PATENTS 72,321 Switzerland May 1, 1916 479,069 Great Britain Jan. 31, :1938 117,076 Australia June 4, 1943 599,966 Great Britain Mar. 25, 1948 5 France May 12, 1954 509,879 Italy Ian. 18, 1955 760,146 Great Britain Oct. 31, 1956 ,524 Great Britain Jan. 9, 1957

Claims

1. A CIRCUIT INTERRUPTER FOR INTERRUPTING HIGH-VOLTAGE CIRCUITS OF CONSIDERABLE POWER INCLUDING AN ARC-EXTINGUISHING UNIT, INSULATING SUPPORT MEANS FOR SUPPORTING SAID ARC-EXTINGUISHING UNIT AN ADEQUATE DISTANCE FROM GROUND POTENTIAL, SAID ARC-EXTINGUISHING UNIT INCLUDING A RELATIVELY STATIONARY CONTACT, A COOPERABLE MOVABLE CONTACT SEPARABLE FROM THE RELATIVELY STATIONARY CONTACT TO ESTABLISH AN ARC, HYDRAULIC OPERATING MEANS DISPOSED IN IMMEDIATE PROXIMITY TO THE CONTACTS FOR ACTUATING SAID MOVABLE CONTACT INCLUDING A HYDRAULIC OPERATING CYLINDER AND A HIGH-PRESSURE ACCUMULATOR, A MASTER CONTROL VALVE FOR CONTROLLING THE FLOW OF HYDRAULIC LIQUID INTO SAID CYLINDER, A HYDRAULIC PISTON MOVABLE WITHIN SAID HYDRAULIC OPERATING CYLINDER, MEANS CONNECTING SAID HYDRAULIC PISTON TO SAID MOVABLE CONTACT FOR THE ACTUATION THEREOF, AND THE HYDRAULIC OPERATING CYLINDER ACCUMULATOR, MASTER CONTROL VALVE AND PISTON ALL BEING AT THE SAME HIGH POTENTIAL AS THE MOVABLE CONTACT.