US2979591A

US2979591A - Circuit interrupters

Info

Publication number: US2979591A
Application number: US762027A
Authority: US
Inventors: Robert E Friedrich
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1958-09-19
Filing date: 1958-09-19
Publication date: 1961-04-11
Anticipated expiration: 1978-04-11
Also published as: CH379601A; DE1134133B

Description

April 11, 1961 R. E. FRIEDRICH CIRCUIT INTERRUPTERS 3 Sheets-Sheet 1 Filed Sept. 19. 1958 April l, 1961 R. E. FRIEDRICH CIRCUIT INTERRUPTERS 3 Sheets-Sheet 3 Filed Sept. 19, 1958 me\ NO United States Patent O f CIRCUIT IN TERRUPTERS Robert E. Friedrich, Baldwin Borough, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 19, 1958, Ser. No. 762,027

17 Claims. (Cl. 200-148) This invention relates to circuit interrupters in general, and, more particularly, to arc-extinguishing structures for circuit interrupters and mounting arrangements therefor.

A general object of the invention is to provide an improved circuit nterrupter, which will be more effective than circuit interrupters heretofore employed in the industry.

A more specific object of the present invention is to provide an improved circuit nterrupter of the fluid-blast type, in which an arc-extinguishing fiuid may be ejected into the arc stream to rapidly effect the extinction thereof.

Another object of the invention is to provide an improved single-bushing type of circuit nterrupter, in which one or more modular units, or building block" units may be stacked upon one another in end-to-end relation to effect thereby a resultant circuit nterrupter adaptable for the interruption of high-value kva. circuits.

Still a further object of the present invention is to provide a complete line of circuit nterrupters adaptable for high or low voltage and for high or low kva. rating, in which the individual circuit interrupters are constructed from one or more building block" units, and such building block units are very adaptable for rapid production-line techniques.

Another object of the invention is to provide improved mounting arrangements for one or a plurality of singlebushing type circuit interrupters, so that a minimum of space is employed, and the Operating mechanism for operating two such interruptin g units is relatively simple.

Yet a further object of the present invention is to provide an improved mounting construction for a pair of single-bushing type circuit interrupters, in which improved piston means is associated with the Operating mechanism for the movable contact structures, so that the resulting combination is of minimum size and of sturdy Construction.

A further object of the'present invention is to provide "building block" units, or modular arc-extinguishing units of simple Construction and of a type such, that following assemblage, maintenance may readily be achieved whereby the Component parts of any such modularunit may quickly be inspected, without necessitating a disassembly of one or more adjacently disposed modular units.

Another object of the invention is to provide an im- I proved circuit nterrupter, which is highly effective, and

In United States patent application' filed December 20; 1956, Serial No. 629,604` now United States Patent 2,866, 045,' issued December 23, 1958, to Winthrop M; Leeds, i and assigned to the assignee of the instant application;

there isillustrated and described circuit interrupters' of the single-bushing type, which are' adaptable for use with highly effective arc-extinguishing meduns, .such as sul fur hexafluoride (SP 'or selenium hexauoride (SeF or for use with a mixture of one or both of the aforesaid gases with one or more of the following gases: air, carbon dioxide, argon, nitrogen, or helium. The nterrupter illustrated in the Leeds patent utilizes a puffer, or blast-producng Operating cylinder, which slides over a relatively stationary piston, and an orifice and a movable contact are moved with the aforesaid Operating cylinder. During the opening operation, the movable operating cylinder, in sliding over the relatively statonary piston, forces fluid, such as one of the aforesaid gases, through a movable orifice structure into the established arc to rapidly effect the extinction thereof. To render the interrupting device substantially friction-free, and to readily transmit current therethrough, a contact-roller arrangement is employed, which is illustrated and claimed in the aforesaid Leeds patent.

It is a further object of the present invention to improve upon the constructional features of the aforesaid Leeds patent, to render the same suitable for various voltage and kva. requirements for the particular applications to be encountered.

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 fragmentary, vertical sectional view taken through a single-bushing type of circuit nterrupter constructed in accordance with the principles of the present invention, with the contact structure being llustrated in the closed-circuit position;

Figure 2 is an enlarged, fragmentary, sectional View taken substantially along the line II-II of Figure 1 looking in the direction of the arrows;

'Figure 3 illustrates a mounting arrangement for a pair of single-bushing, interrupting structures for relatively low voltage requirements; A

Figure 4 illustrates a mounting arrangement similar to that illustrated in Figure 3, but adaptable for higher kva. and higher kv. requirements, wherein a multiplicity' of building blocks are employed in series relation;

Figure 5 illustrates a different type of mounting arrangement, in which the single-bushing interrupters are inverted, as Compared with the Figure 3 and 4 Constructions, again a common Operating mechanism being emp y Figure 6 illustrates another possible mounting arrangement involving a pair of single-bushing interrupting structures, which are tilted toward each other and utilize a common Operating mechanism;

Figure 7 illustrates a mounting arrangem'ent somewhat similar to that of Figure 6, but employing a common piston Construction disposed interiorly within the interconnecting common base casting; a

Figure 8 is an enlarged vertical sectional view through the circuit interrupting structure of Figur 7, illustrating the internal constructural features, and the method of Operating the common piston for both single bushing structures;

Fig. 9 illustrates a mounting constructionpossible for a single-bushing unit, adaptable for relatively low voltage requirements; e v

Fig. 10 is a sectional viw taken along the line'X--X of Fig. 1; and v v Fig. 11 is a sectional View taken along the line XI--XI of Fig. 1.

` Referring to the drawings, and more particularly to' -Fg. 1 thereof, the reference numeral lgenerally designates a single-bushing type of circuit nterrupter, which utilizes a pluralityof elementalgf'building block," arcextinguishing units 2 3. 'It'will be noted-that the figure 'is :broken at'the lines 4, 6"for clarity', y'e't`the structure' i L is intended to include an arrangement, in which as man Generally, it will be noted that each modular unit 2' may include a bar-shaped stationary contact support 7 (Fig. having a stationary contact 8 depending therefrom. Cooperating with the rod-shaped stationary contact 8 is a movable contact 9, preferably constructed of a plurality of resilient ngers 10. The fingers 10 may be formed by slotting a tube lengthwise. Such a tube 12 is secured to a movable Operating cylinder 13, the letter sliding over a relatively fixed piston 14. This piston 14 for the lowermost modular unit 3 has an adapter casting portion 15, which is adaptable for fixed, clamping engagement with the upper threaded end 16 of the terminal stud 17, which passes interiorly through the terminal bushing generally designated by the reference numeral 18.

Certain features of the orfice construction are set forth and claimed in United States patent application filed October 30, 1957, Serial No. 693,309 by Albert P. Strom, and assigned to the assignee of the instant application.

Generally, the terminal bushing 18 has a substantially standard construction involving a lower porcelain casing, or shell 19, enclosing a condenser body 229. The condenser body 20, which, as well known by those skillcd in the art, surrounds the terminal stud 17, comprises a plurality of paper wrappings, having interspersed therewithin condenser layers so as to have a substantially uniform voltage gradient directed radially inwardly into the condenser body 20.

surrounding the condenser body 20 is a grounding sleeve 21 and an upper tapered porcelain shell 22. The grounding sleeve 21 extends through a mechanism housing 23, through which extends a crank shaft 24. Preferably.

a gas-tight seal 26 (Figure 2) is employed so that there will be no leakage of arc-extinguishing gas, which may be employed in connection with the operation of t"e circuit nterrupter 1. The crank shaft 24 is actuated externally of the mechanism housing 23 by a crank arm 27. Fixedly Secured to the interior end of the crank shah 24 is a crank arm 28 having a bifurcated end 29 to which is pivotally connected, as at 30, a link 31. The link 31 is pivotally connected, as at 32, to a crank arm 34 the latter effecting the rotation of a crank shaft 35, extending transversely' across the nterior of the mechanism housing 23, and having its ends journaled within interiorly extending journal boxes 33 associated with the mechanism housing 23. V

Fixedly secured adjacent the ends of the crank shaft 35 is a pair of crank arms 36, which straddle the groundng sleeve 21, and have pinned to their outer extrem ties, as at 37, longitudinally extending insulating Operating rods, generally designated by the reference numeral 38, for eifecting axial, reciprocating motion of the several Operating cylinders 13. As shown more clearly in Figure ll, the Operating rod 38 comprises a plurality of capped insulating rods 38a pinned together and easily detached from each other. v

From the foregoing description, it will be apparent that rotation of the externally situated crank arm 27 efiects rotative movement of the crank shaft 24, which, through the crank arm 28 and link 31, effects rotative movement of the interiorly disposed crank shaft 35. This will effect, through the crank arms 36. longitudinal movement of the insulating Operating rods 38, to not only eect opening and closing of the several serially related contact structures, but also movement of the several operating cylinders 13 over the stationary pistons 14 to etfect` gas flow through the ,orifices 39, as indicated by the arrows. r

cylinder 13 has a pair of supporting cars 40, which are pinned, as at 42, to the longitudinally extendirg insulati'ng Operating rod sections 38a, as shown more clearly in Fig-` `ure11..{

To facilitate movement of the Operating cylinders 13, and to bring about a friction-free guiding thereof, together with current transfer along the serially arranged modular arc-extinguishing units 2, 3, a contact roller assembly 43 is employed with each movable Operating cylinder 13. The contact roller assembly 43 follows the teachings set forth in the aforesaid Leeds patent, and briefiy includes on each side of the Operating cylinder 13 a movable guide i i It will be noted that each pufler, or movable Operating rail 44, which is bolted, as at 45, to the side ot' the operating cylinder 13. The movable guide rail 44 is interposed between two sets of contact rollers 46, each contact roller assembly 46 including a plurality of pairs of contact rollers 47 mounted on pins 48, which extend through four openings provided in a mounting plate 49. Thus, the movable guide rail 44, fixedly Secured to the movable Operating cylinder 13, freely rolls between the two sets of contact rollers 46 and enables current transfer therebetween. e

The contact rollers 47 roll and bear outwardly against a pair of fixed guide rails 51. The guide rails 51, associated with the lowermost elemental are-extinguishing unit 3, are fixedly bolted to a plate 50-, which extends laterally from the clamping portion 15 integrally formed with the stationary piston 14.

The fixed guide rails 51 associated with the upper' modul ar units, such as the unit 2 of Figure l, have their lower ends fixedly Secured to a laterally extending plate portion 60 of the piston support 52, the plate portion 60 being bolted to the intermediate inspection housing 53; The inspection housings 53 comprise a circular cylindrical portion 54, to which is secured, such as by welding,

upper and lower annular plate members 55, 56. Also it is apparent that the inspection housing 53 could be cast in one piece. The piston support 52 of the upper stationary piston 14, together with the guide rails 51, `are bolted to the upper plate 55 of the intermediate inspection housing 53.

To measure the current passing through the interrupter 1, preferably a pair of

current transformers

57, 58 are employed. The

current transformers

57, 58 may have a construction. such as set out in United States patent application filed March 31, 1958, Serial No. 725,286 by Benjamin P. Baker and Robert F. Karlicek, and assigned to the assignee of the instant application. As disclosed in the aforesaid Baker and Karlicek application, differential relaying is possible by such a mounting construction of the

current transformers

57, 53.

It will be noted that with the modular arc-extinguishing unit construction shown that each building block unit may include the same length of porcelain casing 59 (Fig. 4).' Annular flange mounting rings 61 are cemented to the'upper an'd lower ends of each porcelain casing 59. Also, the movable Operating cylinder 13 for each modular unit is identical to that for every other unit, all such Operating ,cylinders being pinned, as at 42 to the insulatiug Operating rods 38a. The orifice structures 39 and the movable contact structures 9 are likewise identical for all of the modular units 2, 3. The stationary Contacts 8 are .likewse identical for all the units.

As will be obvious, certain modifications must be made at the upper and lower ends of the interrupter 1 in connection with the upper and lower modular units 2, 3. Thus, a closure cap 62 is preferably bolted to the upper mounting flange 61 of the casing 59 for the uppermost unit 2. Also, the stationary piston 14 of the lowermost unit 3 must have a clamping adapter so as to be clamped to the upper threaded end 16 of the terminal stud 17. In

addition, althoughthe guide rails 51 and the piston supports 52 of the upper units are bolted to the upper annuof the terminal stud 17.

Many advantages will be apparent from the construc-` tion disclosed. For" example, since the porcelain casings,

or shells '59, are the same length, they may be inexpensively manufactured utilizing rapid production-line .techniques. The same thing is true with the other Components with each modular unit, for example, the stationary and

movable contacts

8, 9, the Operating cylinders 13, and the relatively stationary pistons 14. The relatively stationary contact support bars 7 may be dentical. The uppermost contact support bar 7 may be bolted to an annular plate 63, whereas the other contact support bars 7 may be bolted to the lower annular plate 56 associated with each intermediate inspection housing 53. Depending upon the kva. and voltage requirements, a multiplicity of such modular building block" units may be employed. Since each modular unit has ,Component parts, which are substantially duplicates of those of the other modular units, considerable savings are realized in the construction of the circuit interrupter 1.

Figures 3-7 and 9 illustrate various possible mounting arrangements, which may be employed in connection with the circuit interrupter 1 disclosed in Figures 1 and 2. For example, in Figure 3 two single-bushing structures 64 are employed. It will be noted that each interrupting structure 64 has only a single intermediate inspection housing 53, so that each interrupting structure 64 has a pair of modular units 2, 3. The interrupting structures 64 may, for example, be supported upon a tubular crosssupport 65, through which extends a rotatable shaft, not shown, which may be employed to effect rotation of the crank shaft 24 of each interrupting structure 64.

The Operating shaft could, of course, rotate or reciprocate externally of the support 6 5. The cross-support 65 extends laterally from a common, grounded, mechanism housing 67, which, for example, may be located at the upper end of a support pedestal 68. As will be obvious, the mechanism housing 67, enclosiug the Operating mechanism may be situated at the lower end of support perlestal 68 and a suitable linkage employed. As will be ob- -vious to those skilled in the art, various types of Operating mechanisns, such as compressed-air, solenoid or hydraulic, may be employed. This mechanism is preferably disposed within the mechanism housing 67, and is employed to eifect simultaneous operation of both interrupting structures 64. As mentioned, such mechanism may efect rotation of the interiorly disposed shafts, not shown, extending through the tubular cross-supports 65, which support the interrupting structures 64 or, other connecting linkages may be employed. Preferably, an electrical connector 69 is employed to effect connection of the structures 64 in serially-related manner.

Other line connectors

70, 71 may be connected to the terminal studs 17 extending through each terminal bushing 18.

Figure 4 shows a structure generally similar to that previously described in connection with Figure 3, but adaptable for higher voltage and higher kva. ratings. It will he noted that here, each interrupting structure 72 has a pair of intermediate inspection housngs 53; consequently, each interrupting structure 72 has three modular arc-extinguishing units. The tubular cross-support 65 may be the same as in Figure 3, and a Connector 69, as before, may electrically connect the two interrupting structures 72 in series.

In the mounting arrangement illustrated in Figure 5, the interrupting structures 64 may be identical to the interrupting structure 64 of Figure 3, but, as shown in Figure 5, they extend downwardly, being electrically 'int rconnected by a Connector 73. In this case, however, the Connector 73 must be insulated from the supporting pedestal 68, since the Connector 73 is at high potential. Leads 74 and 75 connect to the external ends of the terminal bushings 18. The mounting Construction illustrated in Figure 5 has the advantage that the contact structures are more readily exposed, since the casings may be dropped vertically downwardly following unbolting of the connections.

,A Figure 6 illustrats ,another mounting arrangement, in

which interrupting structures 77 are generally of the type, as shown in Figures 3 and 5, but they are provided with a common base casting' 78, which gives additional rigidity to the mounting arrangement. Again a tubular cross-support 65 may bra-employed, surrounding a rotatable drive shaft, as was the case in Figures 3-5 or, as is obvious, an equivalent linkage externally of the support '65 may be used.

Figures 7 and 8 collectively illustrate still a further mounting arrangement, which follows generally the teachings of Figure 6, but are instead of each interrupting structure 80 having a pair of interiorly disposed operating rods, such as the rods 38 of Figure l, instead, as shown in Figure 8, a single piston 81 is employed. The piston 81 is actuated by means of an insulating rod 82, which extends downwardly within a weather-proof casing 83. Since the interrupting structures 80 do not need to accommodate internally disposed Operating rods of the type indicated at 38 in Figure l, they may be constructed with a smaller external diameter, as shown in Figure 8. The orifice structures 82a may, in this instance, be associated with the common piston housing 85. Also, the movable contacts 86 may be actuated by cranks 87, stationarily pivoted, as at 88, to fixed support brackets 89. Preferably, a link 90 is pivoted at 92 to one arm of the bell crank 87, and the upper end of link 90 is pivoted at 93 to the rod-shaped movable contact 86. As shown, one arm of the bell crank 87 is pivotally connected at 95 to a link 96. The inner end of link 96 is pivotally connected, as at 97, to a second bell crank 98 pivotally mounted at a stationary pivot 99.

The insulating Operating rod 82, movable reciprocally vertically, preferably has an actuating pin 100` which movestin slots formed in the lower legs 102 of the second bell cranks 98 to efiect their rotation, Also, the insulating Operating rod 82 has fixed thereto a spring-base plate 103, which serves as the lower seat for an accelerating compression spring 104. t

During the opening operation, the insulating Operating rod 82 is unlatched by means, not shown, disposed within the mechanism housing 105, so that the accelerating compression spring 104 is free to move the spring base 103 and hence the Operating rod 82 downwardly. The downward motion of the Operating rod 82 effects corresponding downward movement of the piston 81, disposed within the piston cylinder 106, and forces fluid, such as SF gas, through orifices 107 associated with the stationary contacts 108.

The downward motion of the Operating rod 82 not only effects piston travel, but also, through the two bell cranks 87, 98, eflects retraction of the two links 90 associated with the interrupting structures 80 to elfect thereby separation between the movable contacts 86 and the stationary contacts 108 within the insulating orifice structure 82a.

The blast of gas, as indicated by the arrows 109, quickly effects extinction of the arcs drawn through the insulating orifices 82a, and the circuit istinterrupted.

If desired, current transformers 110 may be employed surrounding the condenser body 111 associated with each r terminal bushing 112.

Thus, in retrospect, it will be apparent that the novel circuit interrupter 115 of

Figu'res

7 and 8 comprises two single-bushing types of uid-blast interrupting structures 80 having their ends joinecl in a common piston housing 85 and simultaneously actuated by a linkage, which functions to not only eflect a double-break contact separav 7 the ends of the interrupting structures 80 to a common piston housing 85.

Certain broad features of the interrupting structure of Figs. 7 and 8 are described and claimed in United States patent application filed concurrently herewith, Serial Number 762,()26, by Benjamin P. Baker, and assigned to the assignee of the instant application.

From the foregoing description of the invention it will be apparent that there is provided a novel circuit interrupter readily adaptable for various voltage and kva. ratings. Thus, the number of modular arc-extinguishing units 2, 3 of Figure 1 may be determined by the operating requirements of the interrupter. Only slight modifications are required at the end of an assemblage of superimposed or end-to-end modular arc-extinguishing units. More irnportantly, practically all of the Component parts of each modular arc-extinguishing unit are identical to those of the adjacently disposed units, and consequently may be inexpensively manufactured by production-line techniques.

During the time that the interrupter 1 is in service, it may be readily inspected and maintained. For example, should it be desired to inspect the uppermost modular arc-extinguishing unit 2 of Figure 1, it is merely necessary to remove the top closure cap 62. One may then look through the annular support ring 63 and inspect unit 2. Unbolting contact support bar 7 from annular support ring 63, at the top of the assemblage will permit removal and inspection of the uppermost stationary contact 8. Moreover, it is then possible to view the condition of the uppermost orifice 39 and the top movable contact 9.

Should, however, it be desired to inspect an intermediate modular arc-extinguishing unit, say, for example, the lowermost unit 3 of Figure 1, it is then merely necessary to unbolt the inspection doors 118, which cover fianged openings 119 associated with the cylindrical portion 54. It will be noted that there are two such doors 119 disposed`diametrically on opposite sides of cylindrical portion 54 as shown in Fig. 10. Visual inspection is thus possible.

One may reach through either opening 119 and unpin the couplings 42 where a more thorough inspection is desired. Then, by unbolting bolts 120 (Fig. 1), the entire assemblage including annular plate 55 may be removed from the remainder of the structure. This procedure may also be followed at any intermediate inspection housing 53, when there are a plurality of such housings employed with a multiple-unit Construction.

By unpinning the pins 37 within mechanism housing 23, one may pull Operating cylinder 13 of lower unit 3 out of the interrupter.

The doors 118 are large enough to remove contact bars 7 therethrough. Also to remove any Operating cylinder 13, the units above may be removed in the above manner and their pins 42 removed by opening a lower door 118. Following this, the particular Operating cylinder 13 may be removed through the aunular plate 55 of the particular inspection housing 53.

Thus, the elongated arc-extinguishing assemblage 1 may be broken at any intermediate inspection housing 53, and the contguously disposed, modular, ar'c-extinguishing units examined for wear and possible replaceinent of parts.

There has also been disclosed a plurality of possible mounting arrangements involvirg such single-bushing types of structures, which may contain sulfur hexauoride (SF or other good interrupting media, which lend themselves to a complete line of breakers, for both high and low voltage and kva. rating.

The attendant advantages of provision for current transformers and the relatively low-Volume of gas required are obvious. The arrangements of Figures 3 and 4 would, for example, be suitable for interrupting 8 requirements of 230 and 345 kv., respectively. As shown, the cross-arm afiixed to the mounting tower Construction may be employed to accommodate or support the operating shaft from a common mechanism. i

It has been mentioned that for light duty, where half the number of units will be sufiicient, that a structure similar to that disclosed in Fg. 9, involving only a single interrupting structure, may be employed. The mounting arrangements of Figs. 6 and 7, involving interrupting structures tilted toward each other, aord an extra measure of mechanical rigidity.

From the foregoing description of the invention it will be obvious that the arrangements described provide a consistent line of both high and low voltage and kva. rating breakers obtained merely by varying the number of modular components and the size of the bushing. Overlapping protection is provided for the high kva. breakers, and in all cases current transformers are an integral part of the breaker, as in the case of oil, deadtank circuit interrupters.

When a very effective arc-extinguishing medium, such as sulfur hexafluoride (SP is employed, it has been demonstrated in the laboratory, and in commercial structures, that the type of pumping unit, such as employed in the modular units 2 and 3 of Fig. l, is most eifective, and is highly eficient in blasting the sulfur-hexafiuoride gas through the interrupting orifice structure to bring about rapid and efiicient arc extinction. consequently, very high voltage and kva. ratings may be obtained when a number of such modular pumping units are employed in series with a highly efiicient arc-extinguishing medium, such as sulfur hexafiuoride. A liquid arc-extinguishing medium may, of course, be employed as Well as gas.

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

I claim as my invention:

1. A uid-blast circut interrupter including an elongated arc-extinguishing assemblage, the arc-extinguishing assemblage including a plurality of serally related modular pump-type arc-extinguishing units, each of the plurality of arc-extinguishing units including a rod-shaped relatively stationary contact and a movable pumping structure carrying a movable contact, the movable contact of each arc-extinguishing unit separating from its respective rod-shaped relatively stationary contact to establish an arc longitudinally of the assemblage, the movable pumpng structure including a relatively movable Operating cylinder and a piston positioned therein, a' movable insulating orifice movable with the movable contact for directing a fluid-blast longitudinally of said established arc, Operating rod means extending longitudinally of the elongated assemblage and connected to the plurality of pumping structures for simultaneous movement, elongated casing means surrounding said elongated arc-extinguishing assemblage and including an insulating cylindrical casing for each arc-extinguishing unit, one or more metallie support couplings for coupling at least a pair of contguously disposed insulating casings together, means supporting at least one rodshaped relatively stationary contact for one arc-extinguishing unit from adjacent one end of a metallic support coupling, means supporting a portion of the movable pumping structure for the next serally-related are-extinguishing unit from adjacent the opposite end of said metallic support ooupling, means for etfecting longitudinal motion of said Operating' rod means, and the lougitudinal motion of the Operating rod means efiecting arc drawal and pumping action of fluid through the oritices in the plurality of modular arc-extinguishing units.

2. A single-bushing type of fluid-blast circuit interrupter including a terminal bushing having a terminal stud extending axially therethrough, a circuit terminal disposed at one extremity of the terminal stud, grounded means for supporting said terminal bushing intermediate the ends thereof adjacent the mid-portion thereof, elongated casing means having a second circuit terminal disposed adjacent one end thereof, the other extremity of the terminal stud extending interorly within the other end of the elongated casing means, an elongated arcextinguishing assemblage disposed interiorly within said caing means and Situated between said other extremity of the terminal stud and said second circuit terminal, the arc-extinguishing assemblage including a plurality of serially related modular pump-type arc-extinguishing units, each of the plurality of arc-extinguishing units including a rod-shaped relatively stationary contact and a movable pumping structure carrying a movable contact, the movable contact of each arc-extinguishing unit separating from its respective rod-shaped relatively stationary contact to establish an arc longitudinally of the assemblage, the movable pumping structure including a relatively movable Operating cylinder and a piston positioned therein, a movable insulating orifice movable With the movable contact for directing a fluid-blast longitudinally of said established arc, Operating rod means extending longitudinally of the elongated assemblage and connected to the plurality of pumping structures for simultaneous movement, said elongated casing means including an insulating cylindrical casing for each are-extinguishing unit, one or more metallic support couplings for coupling at least a pair of contiguously disposed insulating casings together, means supporting at least one r'od-shaped relatively stationary contact for one are-extinguishing unit from adjacent one end of a metal-lic support coupling, means supporting'a portion of the movable pumping structure for the next serially-related arc-extinguishing unit from adjacent the opposite end of said metallc support coupling, crank means disposed adjacent said mid-porton of the terminal bushing for effecting longitudinal motion of said Operating rod means, and the longitudinal motion of the Operating rod means eecting arc drawal and pumping action of fluid through the orifices in the plurality of modular arc-extinguishing units.

3. A fluid blast circuit interrupter including an elongated arc-extinguishing assemblage, said arc-extinguishing assemblage including a plurality of modular arc-extinguishing units disposed in end-to-end relationship and externally disposed casing means, a boX-shaped intermediate inspection housing disposed between contiguous modular arc-extinguishing units and constituting a portion of said externally disposed casing means, said boxshaped intermediate inspection housing including end plates and a cylindrical body portion, at least one inspection door associated with each inspection housing for obtaining access therewithin, a relatively stationary piston Secured to one end plate of said inspection housing, a relatively stationary contact Secured to the other end plate of said inspection housing, an operating cylinder associated with one modular are-extinguishing unit and slidable over said relatively stationary piston, a movable contact and a second piston structure associated with said relatively stationary contact and forming in part another contiguously disposed modular are-extin'guishing unit, and means extending lengthwise of said arc-extinguishing assemblage for eecting simultaneous piston action of all the modular arc-extinguishing units.

4. A single-bushing type of fluid-blast circuit interrupter including a terminal bushing having a terminal stud extending' aXially therethrough, a circuit terminal disposed at one extremity of the terminal stud, grounded means for supporting said terminal bushing intermediate the ends thereof adjacent the mid-portion thereof, elongat'ed casing means having a seconds-circuit terminal end of the 'elongated casing means, an elongated arcextinguishing 'assemblage disposed interiorly within said casing means and `situated between said other extremity of the-terminal stud and said second circuit terminal, the arc-extinguishing assemblage including a plurality of serially-related modular pump-type 'arc-extinguishing units, each of the plurality of arc-extinguishing units including a rod-shaped relatively stationary contact and a movable -pumping cylinder carrying a cooperable movable contact, said movable pumping cylinder also carrying a movable orifice for directing a fluid blast longitudinally of the arc established between the relatively stationary and movable contacts, a relatively stationary piston positioned within each movable p umping cylinder, a pair of operating lugs for each movable pumping cylinder, a pair of Operating rods movable longitudinally on opposite sides of the assemblage and connected to the pairs of Operating lugs for the movable pumping cylinders for simultaneous motion of the movable contacts and pumping cylinders, said elongated casing means including an insulating cylindrical casing element for each arc-extinguishing unit, one or more metallic substantially cylindrical inspection housings for coupling at least a pair of contiguously disposed insulating casings together, each substantially cylindrical inspection housing having inwardly extending plate port'ions at opposite ends thereof, eachinspection housinghaving at least one inspection door associated therewith, means supporting at least one rod-shaped relatively stationary contact for one arc-extinguishing unit from one plate portion of one inspection housing, means supporting a relatively stationary piston for the next serially related arc-extinguishing unit from the opposite plate portion of said one inspection housing, and Operating crank means mounted adjacent the mid-portion of the terminal bushing which, are connected to said pair of Operating rods for efi ectng recprocal movement of said pair of Operating rods for effectng the drawing of a plurality of serially related arcs and simultaneous pumping action for effecting the cxtinction of said serially related arcs.

5. A single-bushing fluid blast circuit interrupter including a single terminal bushing, means for supporting said terminal bushing intermediate the ends thereof, an elongat'ed -arc-extinguishing assemblage including external casing means disposed adjacent one end of said terminal bushing, said arc-extinguishing assemblage including a plurality of modular arc-extnguishing units disposed in end-to-end relations-hip, a box-shaped intermediate inspection housing disposed between contiguous modular arc-extinguishing units and constituting a portion of said external casing means, said box-shaped intermediate inspection housing including end plates and a cylindrical body portion, a relatively stationary piston secured to one end plate of said inspection housing, a relatively stationary contact Secured to the other end plate of said inspection housing, an Operating cylinder assocated with one modular arc-extinguishing unit and slidable over said relatively stationary piston, a movable contact and a second piston structure associated with said relatively stationary contact and forming in part another contiguously disposed modular. arc-extinguishing unit, and means extending lengt'hwise of said arc-extinguishing assemblage for efiecting simultaneous piston 'action of all the modular arc-extinguishing units.

6. A fluid-blast circuit interrupter including a pair of inclined single-bushing-type elongated interrupting structures, each single-bushing-type interrupting structure including a single terminal bushing having a terminal stud` extending axially therethrough, a circuit terminal disposed at one outer extremity of each terminal stud, an arcextinguishing unit disposed adjacent the other inner extremity of each terminal stud, means supporting each terminal bushing intermediatethe ends thereof, insulating elongated hollow'casing means enclosing the arc-extin li guishing unit and the inner extremity of the terminal stud for each single-bushing-type interrupting structure, each insulating elongated hollow casing means havng one end thereof abutting the supporting means for the v respective interrupting structure, a common metallc piston housing interconnecting the other converging ends of the two casing means which are disposed adjacently to each other, relatively stationa-y contact means for each arc-extinguishing unit supported by and electrically connected with said common metallc piston housing, a cooperable movable contact means for each unit movable toward the nner extremity of the respective terminal stud v during the opening operation, and a common piston operable within the common piston housing to force fluid against the establshed arcs drawn within the two arc-extinguishing units to effect their extinction.

7. A fluid-blast circuit interrupter including an upstanding support pedestal, a pair of oppositely extendng support arms extending laterally outwardly' from said upstanding support pedestal, a pair of inclined single-bushing-type elongated interrupting structures, each singlebushing-type interrupting structure including a single terminal bushing having a terminal stud extending axially therethrough, a circuit terminal disposed at one outer extremity of each terminal stud, an arc-extingushing unit disposed adjacent the other inner extremity of each terminal stud, the outer ends of said laterally extending support arms supporting the pair of terminal bushings intermediate the ends thereof, insulating elongated hollow casing means enclosing the arc-extinguishing unit and the inner extremity of the terminal stud for each single-bushing-type interrupting structure, each insulating elongated hollow casing means having one end thereof disposed adjacent the outeend of one support arm, a common metallc piston housing interconnecting the other converging ends of the two casing means which are disposed adjacently to each other, each arc-extinguishing unit having separable contact means associated therewith to establish an arc, and a common piston operable within the common piston housing to force fluid against the established arcs drawn within the two arc-extinguishing units to eect their extinction.

8. A circuit interrupter including an upstanding 'support tower at ground potential, a transverse support at ground potential extending laterally from said upstanding support tower, a pair of inclined single-bushing-type elongated interrupting structures, each single-bushing-type interrupting structure including a single terminal bushing having a terminal stud extending aXially therethrough, a circuit terminal disposed at one outer extremity of each terminal stud, an arc-extinguishing unit disposed adjacent the other iuner extremity of each terminal stud, the outer ends of said grounded transverse support holding each terminal bushing in place intermediate the ends thereof, insulating stationary elongated hollow casing means enclosing the arc-extinguishing unit and the inner extremity of the terminal stud for each single-bushing-type interrupting structure, a common stationary interconnecting housing bridging the inner ends of the two hollow casing means for rigidity and support, and said common interconnecting stationary housing electrically interconnecting the arc-extinguishing units in series relation.

9. The combination in a circuit interrupter of an upstanding support pedestal at ground potential, a pair of grounded arms extending laterally from said grounded support pedestal, a pair of single-bushing-type elongated interrupting structures, each single-bushing-type interrupting structure including a single terminal bushing having a terminal stud extending axially therethrough, a circuit terminal disposed at one extremity of each terminal stud, an are-extinguishing unit including separable contact means disposed adjacent the other extremity of each terminal'stud, supporting means including the\ outer ends of said grounded arms for supporting the two terminal bushings intermediate the ends thereof, insulating elongated hollow casing means enclosing the arc-extinguishing unit for each terminal bushing and abutting at one end thereof against said supporting means, closure-cap means closing the other end of each elongatedinsulating hollow casing means, the arc-extinguishing unit being electrically connected between said closure-cap means and said other extremity of each terminal stud, and Operating means extending along said grounded arms for affecting the actuation of said single-terminal-bushing intcrrupting structures.

10. The combination in a circuit interrupter of an upstanding support pedestal at ground potential, a pair of grounded arms extending .laterally from said grounded support pedestal, a pair of upright single-bushing-type elongated interrupting structures, each single-bushing-type interrupting structure including a single terminal bushing having a terminal stud extending axially therethrough, a circuit terminal disposed at one lower extremity of each terminal stud, an arc-extinguishing unit including separable contact means disposed adjacent the other extremity of each terminal stud, supporting means including the outer ends of said grounded arms for supporting the two terminal bushings intermediate 'the ends thereof, insulating elongated hollow casing means enclosing 'the are-extinguishng unit for each terminal bushing and abutting at one end thereof against said supporting means, upper closure-cap means closing the other end of each elongated insulating hollow casing means, the arc-extinguishing unit being electrically connected between said closure-cap means and said other extremity of each terminal stud, Operating means extending along said grounded arms for eecting the actuation of said single-terminal-bushing interrupting structures, and means electrically connecting the two upper closure-cap means in electrical series.

11. The combination in a circuit interrupter of an upstanding support pedestal at ground potential, a pair of grounded arms extending laterally from said grounded support pedestal, a pair of upright single-bushing-type elongated interrupting structures, each single-bushing-type interrupting structure including a single terminal bushing having a terminal stud extending axially therethrough, a -circuit terminal disposed at one upper extremity of each terminal stud, an arc-extinguishing unit including separable contact means disposed adjacent the other lower eX- tremity of each terminal stud, supporting means including the outer ends of said grounded arms for supporting the two terminal bushings intermediate the ends thereof, insulating elongated hollow casing means enclosing the arcextinguishing unit for each terminal bushing and abutting at one end thereof against said supporting means, lower closure-cap means closing the other end of each elongated insulating hollow casing means, the arc-extinguishing unit being electrically connected between said closure-cap means and said other extremity of each terminal stud, Operating means extending along said grounded arms for effecting the actuation of said single-terminal-bushing interrupting structures, and means electrically connecting the two lower closure-cap means in electrical series.

12. A fluid-blast circuit interrupter including an elongated arc-extinguishing assemblage, the arc-extinguishing assemblage including a plurality of serially-related modular pump-typearc-extinguishing units, each of the plurality of arc-extinguishing units including a rod-shaped relatively stationary contact and a movable pumping cylinder carrying a cooperable movable contact, said movable pumping cylinder also carrying a movable orifice for directing a fluid blast longitudinally of the are established 'between the relatively stationary and movable Contacts,

a relatively stationarypiston positioned within each movable pumpingrcylinder, a pair of Operating lugs for each movablepumping cylinder, a pair of Operating rods mov able longitudinally on opposite sides of the assemblage and connected to the pairs of Operating lugs for the movable pumping cylinders for simultaneous motion of the movable contacts and pumping cylinders, elongated casing means closely surrounding said elongated arc-extinguishing assemblage and including an insulating cylindrical casing for each arc-extinguishing unit, one or more metallic substantially cylindrical inspection housings for coupling at least a pair of contiguously disposed insulating casings together, each substantially cylindrical inspection housing having inwardly extending plate portions at opposite ends thereof, each inspection housing at least one ,inspection door associated therewith, means supporting at least one rod-shaped relatively stationary contact for one arc-extinguishing unit from one plate portion of one inspection housing, means supporting a relatively stationary piston for the next serially related arc-extinguishing unit from the opposite plate portion of said one inspection housing, and Operating means for efiecting reciprocal movement of said pair of Operating rods for eifecting the drawing of a plurality of serially related arcs and simultaneous pumping action for eflecting the extinction of said serially related arcs.

13. A single-bushing type of fiuid-blastcircuit interrupter including a terminal bushing having a terminal stud extending `axially therethrough, a crcuit terminal disposed at one extremityof the terminal stud, grounded means for supporting said terminal bushing intermediate the ends thereof adjacent the miti-portion thereof, elongated casing means having a second crcuit terminal disposed adjacent one end thereof, the other extremity of the terminal stud extending interiorly within the other end of the elongated casing means, an elongated arc-extinguishing assemblage disposed interiorly within said casing means and Situated between said other extremity of the terminal` stud and said second crcuit terminal, the arc-extinguishing assemblage including a plurality' of serially-related modular pump-type arc-extinguishing units, each of the plurality of arc-extinguishing units including a rod-shaped relatively stationary contact and a movable pumping cylinder carrying a cooperable movable contact, said movable pumping cylinder also carrying a movable orifice for directing a fiuidblast longitudinally of the arc established between the relatively stationary and movable contacts; a relatively stationary' piston positioned within each movable pumpingcylinder, a pair of operatng lugs for each movable pumping cylinder, a pair of Operating rods movable` longitudinally on opposite sides of the assemblage and connected to the pairs of operating lugs for the movable pumping cylinders for simul- 'taneous motion of the 'movable contacts and pumping cylinders, said elongated casing means including an insulating cylindrical casing element for each arcextinguishing unit, one, or more metallic substantially cylindrical inspection `housings for coupling at least 'a pair of contiguously disposed insulating casings together, each substantially cylindrical inspection housing having inwardlyv extending plate portions at opposite ends thereof,

. each inspection housing having at least one inspection door 'associated therewith, means supportingat' least one rod-shaped relatively stationary contact for one are-extinguishing unit from one plate portion of oneinspection housing, means supporting a relatively stationary piston for the next" serially related arc-extinguishingunitllfrom the opposite plate portion'of 'said one inspection housing, operatingfcrank means mounted adjacent'the midportion of the terminal bushing which are connectedflto said 'pair of Operating rods for effecting reciprocal move'- ment of said pair of Operating rods for efifecting the drawing of a plurality of serially related arcs and simultaneous i ride gas 'forhigh diele'ctric strength andoutstandinginterrupting performance.

14. A gas-blast type of crcuit interrupter for highpower and high-voltage service including a condensertype terminal bushing having a terminal stud extending axially therethrough, a first crcuit terminal Situated at one end of said terminal stud, a relatively stationary piston secured to the other end of said terminal stud, a mechanism housing positioned intermediate the ends of said condenser-type terminal bushing and at ground potential, an Operating shaft extending through said mechanism housing and adapted for rotative opening and closing movement, crank means straddling said terminal bushing and secured to said rotatable Operating shatt, elongated casing means at least partially of insulating material enclosing said other end of the terminal stud and abutting said mechanism housing at one end thereof, a'ciosure-cap disposed at the other end of said casing means, a second circuit terminal supported by said closure-cap, said elongated casing means and said terminal bushing being in substantial alignment, an elongated arc-extinguishing assemblage disposed axially along said elongated casing means and positioned between said other end of the terminal stud and said closure-cap, the arc-extinguishing assemblage including a plurality of se,- rially-related modul-ar pump-type arc-extinguishing units, each of the plurality of arc-extinguishin g units including a rod-shaped relatively stationary contact and a movable pumping cylinder carrying a cooperable movable contact, said movable pumping cylinder also carrying a movable orifice for dlrecting a fluid blast longitudinally of the arc established between the relatively stationary and movable contacts, a relatively stationary piston positioned within each movable pumping cylinder, a pair of Operating lugs for each movable pumping cylinder, a pair of Operating rods movable longitudinally' on opposite sides of the assemblage and connected to the pairs of Operating lugs for the movable pumping cylinders for simultaneous motion of the movable contacts and pumping cylinders, said elongated casing means including a weatherproof insulating cylindrical casing for each arc-extinguishing unit, one or more metaliic `substantially cylindrical inspection housings for coupling at least a pair of' contiguously disposed insulating casings together, each substantially cylindrical inspection `housing having inwardly extending plate portions at opposite ends thereof, each inspection housing having at least one inspection'door V associated therewith', means supporting at least one rodshaped relatively stationary contact for one arc-extinguishing unit from one plate portion of one inspection housing, means supporting a relatively stationary piston for the next serially related arc-extinguishing unit from the opposite plate portion of said one inspection housing,`said closure-cap supporting the rod-shaped relatively stationary contact of the outermost arc-extinguishing unit, and means connecting said crank means with said pair of Operating rods for longitudinal reciprocal movement thereof, whereby simultaneous contact separation and simultaneous pumping action for all the units occurs for rapid crcuit interruption. i

15. A gas-blast type of crcuit interrupter for highpower and high-voltage service including a condensertype terminal bushing having a terminal stud extendng aXially therethrough, a first crcuit' terminal situatedat one end of said terminal stud, 'a relatively stationary piston secured to the other end of said terminal stud, a

elongated 'casing means at least ,partially 'ofin sulating i material enclosing said other end of the terminal stud andfabutting said mechanism housing at one nd thereof,

- a'gas comprising sulfur hexa fluoride contained within said i elongated' casing means, a closure-cap disposedat the' other end of said casing means, a second circuit terminal supported by said closure-cap, said elongated casing means and said terminal bushing being in substantial alignment, an elongated arc-extingushing assemblage disposed aXially along said elongated casing means and positioned between said other end of the terminal stud and said closure-cap, the arc-extinguishing assemblage including a plurality of serially-related modular pumptype arc-extinguishing units, each of the plurality of arcextinguishing units including a rod-shapcd relatively stationary contact and a movable pumping cylinder carrying a cooperable movable contact, said movable pumping cylinder also carrying a movable orifice for directing a fluid blast longitudinally of the arc established between the relatively stationary and movable Contacts, a relatively stationary piston positioned within each movable pumping cylinder, a pair of Operating lugs for each movable pumping cylinder, a pair of Operating rods movable longitudinally on opposite sides of the assemblage and connected to the pairs of Operating lugs for the movable pumping cylinders for simultaneous motion of the movable contacts and pumping cylinders, said elongated casing means including a weatherproof insulating cylndrical casing for each arc-extinguishing unit, one or more rnetallic substantially cylndrical inspection housngs for coupling at least a pair of contiguously disposed insulating casings together, each substantially cylndrical inspection housing having inwardly extending plate portons at opposite ends thereof, each inspection housing having at least one inspection door associated therewith, means supporting at least one red-shaped relatively stationary contact for one arc-extinguishing unit from one plate portion of one inspection housing, means supporting a relatively stationary piston for the next serially related arc-extinguishing unit from the opposite plate portion of said one inspection housing, said closure-cap supporting the red-shaped relatively stationary contact of the outermost arc-extinguishing unit, and means connecting said crank means with said pair of operating rods for longitudinal rcciprocal movement thereof, whereby simultaneous contact separation and simultaneous pumpng action for all the units occurs for rapid circuit interruption.

16. A gas-blast circuit interrupter of the multi-gap axial-flow type adaptable for various voltages and k.v.a.

ratings by 'varying the number of gaps including an elongated multiple-unit arc-extinguishing assemblage, elongated casing means at least partially of insulation closely surrounding said elongated arc-extinguishing assemblage, the multiple-unit arc-extinguishing assemblage including a plurality of aXial-flow pufier-type arc-extinguishing units positioned in end-to-end relationship and serially connected into the circuit, theseveral parts of the units being substantially identical, each aXial-flow pufier-type arc-extinguishing unit including a red-shaped stationary contact and a movable puffer structure carrying a cooperable elongated movable contact, the movable contact separating from its respective stationary contact in a direction longitudinally of the assemblage to draw r a lengthening arc in an open space, the movable puffer structure for each arc-extinguishing unit including a stationary piston and a movable Operating cylinder, the

movable Operating cylinder carrying an insulating orifice concentric With the elongated movable contact for directto an intervening cylndrical casing portion, at least one' inspection door associated with each cylndrical casing portion, a transverse support bar for supporting the rodshaped stationary contact for one arc-extnguishing unit and supported by one of the two annular support plates of one inspection-housing coupling element, the stationary piston for the adjoining arc-extinguishing unit being supported by the other of the two annular support plates of said one inspection-housing coupling element, diametrically-positioned Operating lugs secured to each movable Operating cylinder, a pair of Operating rods largely of insulating material coupled to the several pairs of lugs for simultaneous contact and piston movement, and means for reciprocally moving the pair of Operating rods for opening and closing movements of the circuit interrupter.

17. A single-terminal-bushing type of gas-blast circuit interrupter including a single terminal bushing having a terminal stud extendng axially therethrough, a first circuit terminal disposed at one extremity of said terminal stud, a stationary piston secured to the other end of said terminal stud, elongated casing means enclosing said other end of the terminal stud, the elongated casing means having a rnetallic closure-cap supporting a second circuit terminal at one end thereof, groundcd support means for supporting said single terminal bushirg intermediate the ends thereof, the other end of said elongated casing means abutting said groundcd support means, an elongated multiple-unit aXial-flow arc-extinguishing assemblage disposed interiorly of said casing means and positioned between said other end of the terminal stud and said rnetallic closure-cap, the multiple-unit arc-extinguishing assemblage including a plurality of aXial-fiow pufier-type arc-extinguishing units positioned in end-to-end relationship and serially connected into the circuit, the several parts of the units being substantially identical, each axial-flow pufier-type arc-extinguishing unit including a rod-shaped stationary contact and a movable puer structure carrying a cooperable elongated movable contact, the movable contact separating from its respective stationary contact in a direction longitudinally of the assemblage to draw a lengthening arc in an open space, the movable puffer structure for each arc-extinguishing unit including a stationary piston 'and amovable Operating cylinder, the movable Operating cylinder carrying an insulating orifice concentric with the elongated movable contact for directing a gas blast' axially of the established arc and away from the inner wall of said casng means to avoid rogressive breakdown therealong, the orifice at least partially' enclosin'g said rodshaped stationary contact, said elongated ca'sing means including a plurality of identical insulatingweatherproof casi'ng elements, one for each unit, and cylindricallyshaped rnetallic inspection-housing coupling elements interposedbetween the casing elements, each inspectionhousing coupling element having two annular spaced support plates secured to an interveningcylindrical casing portion, at least one inspection door associated with each cylndrical casing portion,` a transverse support bar ,for

supportng the red-shaped stationary conta'ct"for one arcextingushing unit and supported by one of 'the two annular support plates of one inspection-housing coupling element, the stationary piston for the `adjoiningarc-extinguishng unit being supported by theother of the two annularsupport plates of ,said one inspection-housing coupling element, diametrically-positioned Operating lugs secured to each movable' Operating cylinder, a pair of Operating rods largely of insulating material coupled to the several pairs of lugs for simultaneous' contact and piston movement, and Operating crank means disposed adjacent said groundcd support means straddling the terminal'bushing and 'coupled to said pair'gf Operating rods forppening and closing movement of the interrupter.

(References on following page) l r References Cited in the file of this patent UNITED STATES PATENTS Ruppel Sept. 22, 1936 Howe Oct. 12, 1937 MacNeill June 20, 1939 Jansson Dec. 12, 1944 Amer Nov. 23, 1948 Van Sckle Apr. 19, 1949 Beatty May 29, 1951 Vogelsanger et al. Feb. 2, 1954 Forwald May 31, 1955 18 Flurschem et al. Oct. 9, Thommen Feb. 18, Prince Sept. 2, Leeds Dec. 23,

FOREIGN PATENTS Germany Nov. 5, France Sept. 4, France July 29, Great Britain Apr. 30, France Jan. 31, Germany Nov. 17,