US3566054A

US3566054A - High voltage circuit breaker comprising a mechanical linkage interconnecting its components for synchronized operation thereof

Info

Publication number: US3566054A
Application number: US705044A
Authority: US
Inventors: Philip Barkan; Edward J Tuohy; Philip Sciscione
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1968-02-13
Filing date: 1968-02-13
Publication date: 1971-02-23
Anticipated expiration: 1988-02-23

Abstract

A circuit breaker comprising spaced-apart, high voltage enclosures respectively mounted atop spaced-apart insulators, circuit interrupters within the enclosures, and control valves respectively associated with the interrupters for controlling their operation. The control valves are interconnected by a mechanical linkage for simultaneously operating the control valves. The linkage comprises a force-equalizing coupling, the parts of which can change position slightly in response to minor shifting of one enclosure relative to another without imparting motion through said linkage to any of said control valves.

Description

United States Patent [72] Inventors PhilipBarkan Media; Philip Sciscione, Havertown; Edward J. Tuohy, Swarthmore, Pa.

[21] Appl. No. 705,044

[22] Filed Feb. 13, 1968 [45] Patented Feb. 23, 1971 [73] Assignee General Electric Company [54] HIGH VOLTAGE CIRCUIT BREAKER COMPRISING A MECHANICAL LINKAGE INTERCONNECTING ITS COMPONENTS FOR SYNCHRONIZED OPERATION THEREOF 17 Claims, 8 Drawing Figs.

[52] U.S. Cl 200/48, 200/145, 200/153, 200/148' [51] Int. Cl. ..H0lh 33/02, H01h 33/30 [50] Field of Search 200/ 148.6, 153.7, 153.8, 145, 148, 144.2 (Cursory), 48 (Cursory) [56] References Cited UNITED STATES PATENTS 3,167,630 I/ 1965 Alderman et al. 200/48 CIRCUIT BREAKER 2,783,338 2/1957 Beatty 200/148 2,979,591 4/1961 Friedrich 200/145X 3,300,609 1/1967 Flurscheim et a1. 200/ 145 3,333,071 7/1967 Oppel et al. 200/148X 3,418,439 12/1968 Casey et al.... ZOO/145x FOREIGN PATENTS 1,225,268 9/1966 Germany 200/ 148 1,247,452 10/1960 France ZOO/148(6) Primary Examiner-Robert K. Schaefer Assistant ExaminerRobert A. Vanderhye Attorneys-J. Wesley Haubner, William Freedman, Frank L.

Neuhauser and Oscar B. Waddell ABSTRACT: A circuit breaker comprising spaced-apart, high voltage enclosures respectively mounted atop spaced-apart insulators, circuit interrupters within the enclosures, and control valves respectively associated with the interrupters for controlling their operation. The control valves are interconnected by a mechanical linkage for simultaneously operating the control valves. The linkage comprises a force-equalizing coupling, the parts of which can change position slightly in response to minor shifting of one enclosure relative to another without imparting motion through said linkage to any of said control valves.

PATENTED FEB2 3197:

SHEET 5 OF 5 INVENTORS PHIL/P dc/sc/o/v PHIL/P BAR/(AN,

EDWARD J 700/,

ATTOR/VL'Y BACKGROUND OF THE INVENTION This invention relates to an electric circuit breaker of the type which comprises a plurality of widely spaced interrupting units and, more particularly, relates to means for effecting substantially simultaneous operation of said interrupting units.

An example of the type of circuit breaker we are concerned with is disclosed and claimed in US. Pat. No. 2,783,338 to Beatty, assigned to the assignee of the present invention. This circuit breaker comprises an enclosure at a high voltage with respect to ground, an interrupting unit within the enclosure, and a two-position control valve within the enclosure that can be operated from one position to its other position to effect opening of the interrupting unitand can be returned to said one position to effect closing of the interrupting unit. A complete circuit breaker typically comprises a plurality of such interrupting units, each within its own enclosure and each provided with its own control valve. Typically, the individual interrupting units with their associated control valves are widely spaced from each other.

In many circuit breaker applications, the individual interrupting units are required to operate substantially simultaneously. One way of effecting such simultaneous operation is by coupling all the control valves together with a long mechanical linkage extending between the widely spaced control valve locations. A problem encountered when such a linkage is used is that a minor change in the position'of one enclosure with respect to another tends to produce undesired operation of the interconnected control valves. Such minor changes in enclosure position can result from wind loads, thermal expansion, or unequal settling. This same problem of erroneous operation can result from a change in the effective length of the linkage, due, for example, to' thermal expansion or contraction. Reference may be had to US. Pat. No. 3,350,519 to Badsy et al., assigned to the assignee of the present invention, for a further discussion of this problem.

SUMMARY An object of our invention is to construct the interconnecting linkage in such a manner that undesired control valve operation is prevented despite minor changes in the relative positions of the enclosures and despite minor changes in the effective length of the linkage. I

Another object is to assure that an operating force applied to the linkage will operate the control valves substantially simultaneously despite prior minor changes in the effective length of the interconnecting linkage and despite prior minor changes in the relative positions of the enclosures.

Still another object is to maintainthe control valve ends of the linkage in precise positions despite changes in the effective length of the linkage, yet without introducing lost motion into the linkage and without causing the linkage to deform to accommodate the changes in length. Avoiding such lost motion and deformation is important if substantially simultaneous operation of the control valves is to be'achieve Still another object is to locate the control valve ends of the linkage in precise positions without requiring a high degree of precision in assembling the linkage and in locating the enclosures.

Still another object is to construct the linkage in such a manner that an operating force applied to its driving end will be distributed substantially equally between the control valves, despite prior compensatory action of the linkage to accommodate changes in effective length.

In carrying out our invention in one form, we provide a plurality of spaced-apart high voltage enclosures respectively cuit interrupters are respectively located within said enclosures, and a plurality of control valves respectively located adjacent said plurality of circuit interrupters are provided for controlling their operation. Common to said control valves 5 and located in a position therebetween, we provide a force- 7 FIG. 6.

equalizing member which is mechanically connected to the control valves through linkage means. The force-equalizing member is so mounted that its position can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control valves. An operating rod is mechanically connected at one end of said force-equalizing member and at its other end to motive means capable of applying an operating force thereto. The motive means permits minor longitudinal movement of the rod in response to a slight change in the position of said force-equalizing member. The connection between the operating rod and the force-equalizing member is at a central location on the force-equalizing member spaced substantially equidistant from the points at which said linkage means are connected to said force-equalizing member.

BRIEF DESCRIPTION OF DRAWINGS For a better understanding of the invention, reference may be had to the following description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of a circuit breaker assembly embodying one form of our invention.

FIG. la is a schematic illustration 'of part of the circuit breaker of FIG. 1 including as a portion a sectional view along the line la -la of FIG. 1. In this FIG. the circuit breaker is shown in its open position.

FIG. 2 comprises a similar sectional view of the circuit breaker of FIG. I but showing the circuit breaker in its closed position. FIG. 2 additionally comprises a sectional view of a portion of the circuit breaker of FIG. 1 taken in a plane parallel to the paper in FIG. 1.

FIG. 3 is a side elevational view of a circuit breaker assembly embodying a modified form of our invention.

FIG. 4 is a side elevational view partly in section of the circuit breaker of FIG. 3.

FIG. 5 is a sectional view along the line 5-5 of FIG. 4.

FIG. 6 is a perspective view of a portion of the linkage shown in FIGS. 4 and 5.

FIG. 7 is a diagrammatic plan view of the linkage portion of DESCRIPTION OF PREFERRED EMBODIMENTS Two-Control-Valve Embodiment of FIGS. 1-2

Referring now to FIG. 1, there is shown a high voltage circuit breaker comprising two substantially identical circuit breaker units 11a and 11b connected in series in a power circuit 25. Each circuit breaker unit comprises a metal tank 14 at a high voltage with respect to ground and an insulating column 15 supporting the metal tank and electrically isolating it from ground. A flexible conductor 25a electrically interconnects mounted on spaced-apart insulators in such a manner as to the two circuit breaker units Ila and 11b and does not interfere with the above-described minor shifting of one circuit breaker unit relative to the other in'response to such factors as wind loads or unequal settling. Disposed within each tank 14 is a an interrupting unit of any suitable type, for example, of the type shown and claimed in the aforesaid U.S. Pat. No. 2,783,338 to Beany: Since the details of the interrupting unit form no part of the present invention, most of them are not shown. In FIG. la and 2, a block 20 has been used to denote the operating mechanism of the illustrated interrupting unit.

Each interrupting unit comprises two pairs of relatively

movable contacts

21, 22 and 23, 24 connected in series in power circuit 25 extending therethrough. The stationary contact of each pair of contacts is supported on the conductive stud of a terminal bushing 26 projecting into tank 14. The bushing electrically isolates the stationary contact from the tank 14 when the contacts are opened, as shown in FIG. 1. The movable contact of these pairs of contacts is connected to the common operating mechanism by links schematically designated 27 in FIG. in. when operating mechanism 20 operates during a closing operation, it drives

movable contacts

21 and 23 into closed position substantially simultaneously. During an opening operation, mechanism 20

drives contacts

21 and 23 into their open positionsubstantially simultaneously.

Tank 14 contains a high pressure gas, and this is used for operating the mechanism 20. For controlling mechanism 20, a control valve 30, shown in simplified schematic form in FIGS. la and 2, is provided in a control conduit32 interconnecting the pressurized interior of tank 14and operating mechanism 20. This control valve 30 comprises amovable valve element 34 that is movable between two positions, one of which is shown in FIG. la and the other in FIG. 2; When in the position of FIG. 1a, the valve element .34 permits communication between the interior of tank 14 and conduit 32 via an inlet port 33 in the valve housing 36. In the position of FIG. la, the movable valve element 34 also abuts against a seat 37 at the upper end of the valve housing and thus prevents pressurized fluid from flowing into a vent passage38 from either the tank 14 or operating mechanism 20. When movable valve element 34 is operated into its position of FIG. 2, it abuts against the seal 39 and thus blocks communication between the interior tank 14 and operating mechanism 20. When valve element 34 is in this position of FIG. 2, a vent port 41 affords communication between vent passage 38 and control conduit 32,- thus venting operating mechanism 20.

When control valve 30 is in its'open position of FIG. 1a, operating mechanism 20 is under pressure and thus holds the contacts open in the manner shown inthe aforesaid Beatty patent. When control valve 30 is operated to its position of FIG. 2, operating mechanism 20 is vented, and suitable biasing means operates the contacts to their. closed position in the manner disclosed in the aforesaid Bea'tty patent.

As pointed out hereinabove, we are concerned with the type of circuit breaker in which widely spaced interruptingunits are required to operate substantially simultaneously. For example in the illustrated circuit breaker, ,the interrupting units in the series-connected circuit breaker units 11a and 11b are required to operate substantially simultaneously, both during circuit-breaker-opening and during. J'circuit-breakereclosing.

For effecting the desired simultaneous operation of the operating units, we interconnect the movable control valve elements 34 by means of a linkage 40.. This linkage 40 comprises four basic portions: l a linkage portion 40a connected the control valve in circuit breaker unitl Ia and extending between this control valve and a centrally-disposed casing 42;

(2) a substantially identical linkageportion 40b connected to the control valve in circuit breaker unit llb and extending between this control valve and a centrally-disposed casing 42;

(3) a force-equalizing coupling 44 joining linkage portions 40a and 40b together; and (4) a vertically-extending operating rod 46 extending between the force-equalizing coupling 44 and a fluid motor 48 at the lower end of the operating rod.

Referring to FIG. 2, this linkageis enclosed by a T- shaped housing 47 which comprises major components of insulating material. This T-shaped housing 47 comprises a vertically extending tubular insulating column 148 surrounding vertical operating rod 46 and a metal casing 42 mounted atop column 148. Projecting horizontally-from casing 42 are two tubular subhousings 49a and 49b, primarily of insulating material, which surround linkage portions 40a and 40b, respectively. Each of these tubular subhousings communicates at one end with the central casing 42 and at its other end with the interior of associated tank 14. The interior of the T-shaped housing 47 is therefore filled with gas at the same pressure as the gas inside tanks 14. Certain features of this housing 47 are described in more detail and claimed in application Ser. No.

705,040 of Sciscione, filed Feb. 15, 1968, now U.S.Pat. No.

Referring to FIGS. la and 2, the linkage portion 400 comprises a value actuating rod 50a, a first bellcrank 510, an insulating tie rod 52a, a second bellcrank 54a, and a tie link 55a. The first bellcrank 51a is mounted on a stationary pivot 53a carried by tank 14 and a second bellcrank 54a is mounted on a stationary pivot 56a carried by central casing 42. The valve actuating rod 501: is suitably connectedjat one of its ends to the movable valve element 34 and at its other end to one arm of the first bellcrank 51a. Insulating tie rod 52a is pivotally connected at its respective opposite ends to the other end of the first bellcrank 51a and to one arm of second bellcrank 54a. The other arm of bellcrank 54a is pivotally connected to the upper end oftie link 55a.

Since the other linkage portion 40b is substantially identical to 40a, it will not be described; but corresponding parts thereof are designated with reference numerals corresponding to those used on linkage 40a, except with the suffix b instead of a. I

As shown in FIG. 2, the two linkage portions 40a and 40b are connected together by means .of a force-equalizing coupling 44. This coupling comprises'a floating force-equalizing member 60 to which the vertical operating rod 46 is pivotally connected at a centrally-disposed location 61. The linkage portions 40a and 40b are pivotally connected to the force-equalizing member 60 at

points

62 and 64 spaced equidistant from the operating ro'd connection at 61. The operation of force-equalizing coupling 44 is explained in greater detail hereinatter, and it will be apparent from such explanation that the force-equalizing member 60 is a rigid member that during circuit breaker operation maintains a fixed spacing between

points

62 and 64.

Vertical operating rod 46 extends between force-equalizing coupling 44 and a fluid motor 48 at its lower end. This operatingrod 46 is, for the most part, form'edof a high strength insulating material.

Fluid motor 48 comprises a piston 70fixed to the lower end 'of operating rod 46 and slidably mounted in an operating rod 74 extending downwardly therefrom through an opening 75 in the lower end wall of cylinder 72. Extension rod'74 is slidably mounted in opening 75, and a suitable seal surrounds rod 74 to prevent leakage through opening 75. Extension 74 is exposed to the surrounding atmosphere at its lower end, thus reducing the effective area of the lowerface of piston 70 by an amount equal to the cross-sectional area of opening 75.

Since T-shaped housing 47 is filled with pressurized gas, it

will be apparent that there is always a fluid pressure force acting downwardly on piston 70. This downward force is present even if equal pressures are presenton opposite sides of piston 70 in view of the piston's smaller effective area on its lower face than on its upper face. I

For controlling the position of piston 70, a 3way main con trol valve (FIG. 2) is provided. When the circuit breaker is in its closed position of FIG. 2, the-space beneath piston 70 is vented to atmosphere through valve 80.. But when-valve 80 is operated into its dotted line position, thevent to atmosphere is closed, and high pressure gas flows through a supply line 82 into the cylinder space beneath piston 70. Preferably, this pressurized gas is obtained from a source that is at the same pressure as the gas in housing 47.

cmcurr BREAKER OPENING A circuit-breaker-opening operation is initiated by operating main control valve 80 from itssolid line to its dotted line the high pressure gas in tank 14 acting against the lower surface 83 of the movable valve element 34. This force urges movable valve element 34 toward its position of FIG. la, but such motion is prevented when the circuit breaker is closed by the downward force normally acting on piston 70. When this downward downward is reduced, as above-described, the fluid pressure force on the movable valve elements 34 is able to predominate and drive the'movable elements. 34 from their position of FIG. 2 to that of FIG. lag-This opens the circuit breaker as was described hereinabove.

cmcurr BREAKER ctosmo Circuit-breaker closing from the open position of FIG. 1a is effected by reversely operating main control valve 80 to vent the space beneath piston 70. This rapidly increases the net force acting downwardly on piston 70, thereby driving piston 70 and operating rod 46 downwardly. Thismotion is transmitted through force-equalizing member 60 and linkages 40a, 40b to movable control valve elements 34. This drives movable valve elements 34 downwardly from the position of FIG. In to the position of FIG. 2. This valve movement vents the operating mechanism 20, as previously explained, thus causing it to close the

contacts

21, 23, as desired.

EQUAL DISTRIBUTION OF CLOSlNG CONTROL FORCE BETWEEN VALVE ELEMENTS We are able to achieve closely. synchronized movement of the movable valve elements 34 downwardly through their circuit-breaker-closing control stroke because we distribute the operating from the fluid motor 48 substantially equally to the movable valve elements 34. Coupling 44 is able to distribute the downward force from fluid motor-48 substantially equally between the two connecting linkages40a and 40b because, referring to the force-equalizing member 60, the effective distance between

points

61 and 62 is substantially equal to the effective distance between

points

61 and 64. The force imparted to each linkage 4011 or 40b through the common vertical operating rod 46 is directly proportional to the effective distance between the point 61 (at which the operating rod is connected to force-equalizing member 60) and the

points

62 or 64, as the case may be, at which the particular'linkage is connected to the force-equalizing member 60. By making these effective distances equal, we areable to distribute the force from the downwardly-moving operating rod 46 substantially equally between the two linkages, and thus substantially equally between the two movable valve elements 34.

The above-described equal speed relationship of the two movable valve elements 34 can beaffected by the presence of unequal frictional opposing forces on the two valve elements, but we are able to largely eliminate this effect by making the accelerating, or operating, forces large with respect to the frictional forces. Moreover, in our linkage the main frictional opposing force is the friction betweenoperating piston 70 and cylinder 72; and this force, since it is associated with the common operating piston 70, is common to both movable valve elements 34 and does not contribute to any force inequalities capable of affecting the relative speeds of the valve elements.

EQUAL DISTRIBUTION OF OPENING CONTROL FORCES BETWEEN VALVE ELEMENTS The force-equalizing coupling 44 also enables us to achieve 1 closely synchronized movement of the movable valve elements when they move upwardly through their circuit breaker opening-initiating strokes. Recall in this regard that the operating force on the movable valve elements for this motion is derived from the gas pressure in tanks 14 acting onbottom surfaces 83 of movable valve elements 34. Since these valve elements 34 have equal operating areas and since the pressures in tanks 14 are equal (due to communication between the tanks), equal operating forces are acting on the movable valve elements 34 tending to drive them upwardly. The restraining force opposing these operating forces on the valve elements results primarily from high pressure gas above main piston and the vented space beneath piston 70. This restraining force is transmitted equally to the two movable valve elements 34 due to the force-equalizing coupling 44. When pressurized gas is admitted to the space beneath piston 70 to initiate circuit breaker opening, the net restraining force from the pressure on piston 70 decreases as the gas pressure rapidly builds up. At any given instant, this net restraining force is transmitted substantially equally to the movable valve elements 34 through force-equalizing coupling 44, and hence the two valve elements are subjected to substantially equal restraining forces at any given instant. This relationship combined with the equal operating forces on the two movable valve elements 34 results in their moving upwardly substantially simultaneously at substantially the same speed. The operating forces during this movement are large compared to any frictional opposing forces, and hence these frictional forces have little effect on the desired synchronization. The main frictional opposing force is the friction between main piston 70 and cylinder 72, and this force does not affect the equal speed relationship because it is divided substantially equally between the two valve elements by the force-equalizing coupling 44. 1

The time required for a given movable control valve element 34 to move through its stroke will also be dependent upon the mass of the movable valve element and the mass of the linkage between valve element 34 and the forceequalizing member 60. But by making this substantially equal for the two valve elements 34, we can minimize speed inequalities due to this factor. Since the two valve elements are the same and the linkage portion 40a is substantially identical to 40b, it will be apparent that these masses are substantially equal.

COMPENSATION FOR ENCLOSURE SI-IIFIING. THERMAL EXPANSION, AND IMPRECISE ASSEMBLY As pointed out hereinabove, there is a chance that circuit breaker unit 11b will shift slightly with respect to unit 11a due to wind loads or'unequal settling. If a conventional linkage were connected between the control valves 30, this shifting of one circuit breaker unit with respect to the other would tend to cause one or both of the movable elements 34 to move off its seat 37, assuming the circuit breaker is then open, or off its other seat 39, assuming the circuit breaker is then closed. Such movement of the control valve element 34 off its seat 37 or 39 is highly undesirable since it would cause unintended operation of the circuit breaker. Similarly, if a conventional linkage were connected between the movable valve elements 34 and the effective length of the linkage changed due to thermal expansion or contraction, there would be an undesirable tendency to move the movable control valve elements off their seat 37 or 39, as the case may be.

We are able to overcome these problems with our linkage 40 because it is able to compensate forthese changes in effective linkage length or position of the circuit breaker units. In this respect, the floating, force-equalizing member 60 simply shifts in an appropriate direction to accommodate the abovedescribed changes. For example, assume that circuit breaker unit 11b of FIG. 1 shifts slightly ina direction away from circuit breaker unit 11a when the circuit breaker is in its closed position of FIG. 2. The seating force on the movable valve elements 34, which is derived from fluid motor 48, would maintain the valve members seated against the seat 39. But the tie 7 thought-of as being inactive during this period of compensation. The above-described counterclockwise motion of forceequalizing member 60 against the downwardly acting force on piston 70 and operating rod 46 produces a downward reaction on pivot 62 which applies additional force to linkage 40a tending to hold the valve member 34 of unit 11a on its seat 39.

A slight shift in the position of force-equalizing member 60 to compensate for the above-described conditions has no substantial effect on the ability of coupling 44 to distribute forces equally between the two linkages40a and 40b. Despite this slight shift in position, the effective distance between

pints

61 and 62 remains substantially equal to the effective distance between

points

61 and 64, and this enables coupling 44 to retain its force-equalizing ability.

- Whether the linkages 40a, 40b have unequal effective lengths due to thermal causes, as above-described, or due to a lack of precision in assembling them, the force-equalizing coupling 40 will still function inthe' same way to provide for precise location of the control valves 34 on their seats. Similarly, whether the lack of precisene'ss in locating the circuit breaker units 11a and 11b is due-to the above-described causes (e.g., wind loads or settling) or is due to a failure of the assembler to locate the units exactly, the force-equalizing coupling 40 will still function in the same way to provide for precise location of the control valves 34 on their seats.

THREE-CONTROL-VALVE EMBODIMENT or FIGS.

- tially identical circuit breaker units 11a, 11b and 11c electrically connected in series in powercirc uit25. Each of these circuit breaker units comprises a metalltankj 14 at a high voltage with respect to ground and an insulatingcolumn 15 supporting the tank and effectively isolating it from ground. The interrupter units within the tanks are the same; as in FIGS. l--2.

Adjacent to metal tank 14 of the central circuit breaker unit 11c, there is a casing 42 in which the force-equalizing coupling member 60 is mounted. The force-equalizing member 60 is connected to the control valves in the outer two circuitbreaker units 11a and 11b by linkages 40a and 40b which are substantially the same as linkages 40ojand 40b of FIGS 1-2. The force equalizing member 60 is connected to the control valve of the center circuit breaker irnit 110 by a linkage 40c, best seen in FIG. 5. This linkage comprises a valve actuating. rod 500', bellcrank 54c, and tie'link 55c. Bellcrank 54c is mounted on a stationary pivot 56c. Valve-actuating rod 500 is pivotally connected at one end to the movable valve element (not shown) of the central circuit'breaker unit and at its other end'to one arm of bellcrank 54:. The other end of bellcrank 54c is pivotally connected to a tie link 55c.

Linkage portions

40a, 40b, and 40c are'connected together by means of forceequalizing coupling 44. This coupling 44 comprises the force-equalizing member 60, to which vertical operating rod 46 is connected by means ofa universal joint 61. Referring to FIG. 6, the

linkage portions

40a, 40b, and 40c are connected to force-equalizing member. 60 by

universal joints

62, 64 and 65, respectively. These; three a universal joints respectively interconnect the force-equalizing member 60 and

tie links

55a, 55b and 550. t

Referring to FIG. 7, the

universal joints

62, 64, and 65 may be thought of as being located at the corners of an equilateral triangle, indicated by

dotted lines

90, 91, 92. The universal joint 6i may be thought of as being located at the center of this triangle, spaced equidistantly from the centers of the three universal joints. The operation of the force-equalizing coupling 44 is explained in greater detail hereinafter.

Vertical operating rod 46 extends between force-equalizing coupling 44 and a fluid motor 48 at, its lower end. This fluid motor 48 is substantially the same as fluid motor 48 of FIGS. 12 and is therefore not explained in detail. A control valve 80 controls the operation of fluid motor 48 in the same manner as described hereinabove with respect to FIGS. 1-2.

Circuit breaker opening is effected in essentially the same manner as explained with respect to FIGS. 1-2. That is, high pressure gas is admitted to the lower side of piston 70 to reduce the downward or restraining force acting thereon. This allows the fluid pressure force acting on the movable control valve elements 34 in the tanks to predominate and drive the movable valve elements 34 from their circuit-breaker-closed position to their circuit-breaker-open position.

Circuit breaker closing is effected by venting the pressurized space beneath piston 70, thus allowing the piston to be driven downwardly from its elevated circuit break open position. This motion is transmitted through force-equalizing member 60 and

linkages

40a, 40b, and 40c to the movable control valve elements 34. This drives the movable valve elements 34 from their circuit breaker open positions to their circuit breaker closed positions, thus effecting circuit breaker closing in the manner previously described.

We are able to achieve closely synchronized movement of the movable valve elements 34 through their circuit breaker closing stroke because we distribute the operating force from fluid motor 48 substantially equally between the movable valve elements 34. This equal force distribution is made possible because the effective distances between the central universal joint 61 and each of the three other

universal joints

62, 64, 65 are substantially equal. The force imparted to each

linkage portion

40a, 40b, or 40c is directly proportional to the effective distance between its universal joint and the central universal joint 61; and by making these effective distances equal, we distribute the force from the downward moving operating rod substantially equally between the three linkages and thus substantially equally between the three valve elements 34.

The force-equalizing coupling 44 also provides for closely Q. synchronized movement of the movable valve elements when they move through an opening initiating stroke. Recall that the force for such opening initiating stroke is derived from the fluid pressure in tanks 14 acting on movable valve elements 34. These forces. are substantiallyv equal, as explained with respect to FIGS. 1--2. The restraining force opposing these operating forces on the valve elements results primarily from high pressure gasabove main piston 70 and the vented space beneath piston 70. When pressurizedgas is admitted to the space beneath piston 70 to initiate circuit breaker opening, the net restraining force from the pressure on piston 70 decreases as the gas pressure builds up. At any given instant, this net restraining force is transmitted substantially equally to the three valve elements 34 through force-equalizing coupling 44, and hence the three valve elements see substantially equal restraining forces at any given insta'nL'This relationship com bined with the equal operating forces on the three movable valve elements 34, results in their moving upwardly substantially simultaneously at substantially the same speed.

Although the three movable control valve elements 34 are identical, the linkage portion 40c is shorter than linkages 40a and 40b, and this makes the mass associated with the control valve 34 of the center unit slightly-less than the mass associated with the control valves of the other two units 11a and 1111. It has been found that this difference in the eflective masses has only a small effect on synchronization of the three valve elements. But we can reduce even this small effect by adding'a suitable weight (not shown) to the linkage 400 to make its mass substantially the same as that of the other two linkages.

As pointed out hereinabove, there is a possibility that one circuit breaker unit will shift slightly with respect to the others due to winds or unequal settling or the like. Also, the effective and scope of our invention.

v Q length of linkages 40a, 40b, and 400 may change slightly due to thermal expansion or contraction. Either of these conditions tends to cause undesired operation of the control valves. The linkages of FIGS. 3-7 can compensate for either of these two conditions in substantially the same manner as described with respect to FIGS. 1-2 to thereby prevent undesired control valve operation. in this respect, the floating force-equalizingmember 60 simply shifts in an appropriate direction to accommodate the abovedescribed changes. Despite the shift, the movable control valve elements 34 remain in the seated position they are then occupying, being held in their circuitbreaker-closed position (corresponding to that of FIG. 2) by force from fluid motor 48. The

universal joints

62, 64, 65 between the three linkage portions and the force-equalizing member and the universal joint 61 between the operating rod and the force-equalizing member permit the force-equalizing member 60 to shift in any direction needed to accommodate these changes. For example, assume that the tank 14 of the center circuit breaker unit lie, for, some reason, shifts slightly transverse to the plane of the paper in FIG. 3 away from the viewer. This would cause the force equalizing member 60 to rock slightly in a counterclockwise direction about its axis X-X as seen in FIG. 6, concurrently lifting the operating rod 46 slightly. This axis X-X extends through the centers of

universal joints

64 and 62. The universal joint 6! permits this rocking movement to occur without blockage from the operating rod 46; and

universal joints

62, 64, 65 permit this rocking movement to occur without blockage from the linkages 40a, 40b, 400, respectively connected thereto.

Similarly, should the tank of circuit breaker unit 110 shift slightly away from the other tanks, there will be a tendency for linkage 40a to rotate its crank 54a slightly counterclockwise. As viewed in FIG. 6, this rocks the force-equalizing member 60 slightly in a clockwise direction about an axis Y-Y connecting the centers of

universal joints

64 and 65, concurrently lifting operating rod 46 slightly. The various universal joints permit this movement of the force-equalizing member 60 to occur without binding or blockage from the parts connnected therethrough to the force-equalizing member.

Similarly in the event that a shifting of circuit breaker unit llb occurs, crank 5411 will pivot slightly, rocking force equalizing member 60 about axis Z-Z connecting

universal joints

62 and 65. This provides the same type of compensatory action as described hereinabove to maintain the movable control valve elements 34 seated. The force-equalizing member 60 is, of course, able to rock suitablytof accommodate any combination of these pivoting actions of

cranks

54a, 54b, and 54c.

GENERAL COMMENTS ln practicing our invention in its broader aspects, other forms of forceequalizing couplings can be used in place of the specifically illustrated force-equalizing couplings 60. We prefer however that the coupling be of a symmetrical design that provides for substantially equal force distribution to the control valves under both static and'dynamic conditions.

While we have shown and described particular embodiments of our invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from our invention in its broader aspects; and we, therefore, intend in the appended claims to cover all such changes and modifications as fall within the true spirit We claim: i

l. A high voltage circuit breaker comprising:

a. a plurality of spaced-apart enclosures at a high voltage with respect to ground;

b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure I relative to another; v

c. a plurality of circuit interrupting mearm respectively located within said plurality of enclosures;

d. a plurality of control valves respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means;

e. a force-equalizing member common to said control valves located in a position between said control valves;

f. a plurality of linkage means respectively mechanically connecting said control valves'to said force-equalizing member;

g. an operating rod pivotally connected at one end to said force-equalizing member;

h. means for so mounting said force-equalizing member that its position can change slightly in' response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control valves;

i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means while inactive permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member;

j. said operating rod being pivotally connected to said forceequalizing member at a central point spaced substantially equidistant from the points at which said linkage means are respectively connected. to said force-equalizing member; and

k. said force-equalizing member being a rigid member that during circuit breaker operation maintains a fixed spacing between said points at which said plurality of linkage means are respectively connected thereto.

2. The circuit breaker of claim 1 in which said forceequalizing member acts to distribute a force applied to said other end of said operating rod substantially equally between said control valves despite slight changes in the position of said force-equalizing member in response to enclosure shiftmg.

3. The circuit breaker of claim 1 in combination with:

a. valve-operating means located at each enclosure for providing a force for operating the associated control valve against a restraining force applied to said other end of said operating rod; and

b. said force-equalizing member acting to distribute said restraining force substantially equally between said control valves, thereby to promote synchronized motion of said control valves. v

4. The circuit breaker of claim 3in which each of said valveoperating means applies an operating force to said forceequalizing member which is directed generally vertically at the points where said linkage means are connected to said forceequalizing member, said operating forces acting in substantially the same vertical direction, said restraining force being applied to said force-equalizing member in a vertically opposite direction at the point where said operating rod is connected to said force-equalizing member.

5. A high voltage circuit breaker comprising:

a. a plurality. of spaced-apart enclosures at a high voltage with respect to ground;

b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner. which permits minor'shifting of one enclosure relative to another;

' c. a plurality of circuit interrupting means respectively located within said plurality of enclosures;

f. linkage means mechanically connecting said control valves to said force-equalizing member;

g. an operating rod mechanically connected at one end to said force-equalizing member;

h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without k. said circuit breaker comprising three of said enclosures,

. said operating rod being connected to said force-equalizsaid force-equalizing member beingconnected to said imparting motion through said linkage-means to any of said control valves;

means for actuating said operating rod comprising motive means for applying an operating forceto the other end of said operating rod, said motive means permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member;

ing member at a central point spaced substantially equidistant from the points at which. said linkage means are connected to said force-equalizing member;

three of said interrupting means, three of said control 15 valves, and three of said linkage means mechanically interconnecting said control valves and said force-equali2 ing member, I

three linkage means through three universal oints respectively located at the corners of a substantially equilateral reference triangle; and t in. said operating rod being connected to said force-equalizing member at a central point on said triangle substantially equidistant from said corners. i

1 j. said operating rod being connected to said force-equaliz ing member at a central point spaced substantially equidistant from the points at which said linkage means are connected to said force-equalizing member; and

it. said force-equalizingmember being a rigid member that during circuit breaker operation maintains a fixed spacing between said points at which said plurality of linkage means are respectively connected thereto. 10. The circuit breaker of claim 9 in which said forceequalizing member acts to distribute a force applied to said other end of said operating rod substantially equally between said control elements despite slight changes in the position of said force-equalizing member in response to a shift of one enclosure relative to another.

6. The circuit breaker of claim 5 in which said operating rod is connected to said force-equalizing member through a universal joint between the operating rod and said forceequalizing member. v

11. The circuit breaker of claim 1 in which: a. said control valves have predetermined seats against which they respectively bear when said circuit breaker is 3 closed;

7. The circuit breaker of claim 5 in which:

a. said force-equalizing member is located at a level where the voltage with respect to ground is high and substantially the same as that of said enclosures when said circuit b. said motive means biases said operating rod in a direction to hold said control valves against their respective predetermined seats; and

c. while said circuit breaker is closed, any movement of said breaker is closed- 35 f 1 one-equalizing member in response to shifting of one sald .opemung. rod i 'elecmca} Insulating enclosure which moves said operating rod against the bias i f s mom's s. at Substantially groan of said motive means applies a reaction force to the coni an trol valve of another enclosure that acts in a direction to said lmmge means combmed with said hold said control valve against its predetermined seat. member extends between said enclosures in the high volt- 40 u A high voltage; circuit eak er comprising: of said and linkage means a. a plurality of spaced-apart enclosures at a high voltage being partially of electrical insulating material. with respfict to ground, is 2. g fi 2: d at leve where b. means comprising a plurality of spaced-apart insulating i Zmg em 6 1s 0 a structures respectively supporting said enclosures in a i voltage with respect ground hlgh m? manner which permits minor shifting of one enclosure tially the same as that of said enclosures when said circuit relative to another breaker is closed; b. said operating rod partially of electrical insulating g gz r mi gfifi ig ggfig rg respecuvely $2 ,3 2:; ald motive means is f ground d. a plurality of control elements respectively located adc. said linkage means combined with v 'd three-equalizing i223:- 3 13232 332g ggg iggggfi lg fizgg member extends between said enclosures m the high voltf g p be R 3 l of being partially of electrical insulat ng material. p 1 c e 9. A high voltage circuit breaker comprising: f m a an d l l a. a plurality of spaced-apart enclosures at a high voltage enigijggfffligfifi'Q y g s 531 Comm 9 with respect to ground; I .7 l r; b. means comprising 'a plurality of spaced-apart insulating 8- l opel'atmg l'f y connected at one end to structures respectively supporting said enclosures in a said f q g l i V manner which permits minor shifting of one enclosure 9* moummg sald f' l f l ti to h its position can change slightly'in response to minor shiftc. a plurality of circuit interrupting means respectivel of one of said enclosures relative to another without located within said plurality ofenclosures; mp g motion h ugh and linkage means to any of d. a plurality of control elements respectively located ad- Said col'lll'olelelllelllsi. I

jacent said plurality of circuit interrupting means for inmeans amalfng 831d p f g p s motive itiating operation of the associated interrupting means; pp y g p force other end of e. a force-equalizing member common to said control elesaid operating rod, said mot ve means permitting minor merits located in a position between said control elelongitudinal movement of said operating rod in response merits; to a slight change in the position of said force-equalizing f. a plurality of linkage means respectively mechanically member; I

connecting said control elements to said force-equalizing 3'. said operating rod being connected to said force-equalizmember; ing member at a central point spaced substantially I gain operating rod pivotally connected at one end to said equidistant from the points at which said linkage means force-equaliririg member; are connected to said forceequalizing member;

it. said circuit breaker comprising three of said interrupting means, three of said control elements,and three of sd said linkage means mechanically interconnecting said controi elements and said force-equalizing member;

l. said force-equalizing member being connected to said three linkage means through three universal joints respectively located at the corners of asubstantially equilateral reference triangle; and

in. said operating rod being connected to said force-equalizing member at a central point on said triangle substantially equidistant from said corners.

13. A high voltage circuit breaker comprising:

a. a plurality of spaced-apart enclosures at avhigh voltage with respect to ground;

b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures and permitting minor shifting of one enclosure relative to another;

c. a plurality of circuit interrupting means respectively located within said plurality of enclosures;

d. a plurality of control valves respectively located adjacent said plurality of circuit interruptingmeans for initiating operation of the associated interrupting means;

. a forceequalizing coupling "common to said control valves and located in a position between said control valves;

f. a plurality of linkage means respectively mechanically connecting said control valves to said force-equalizing coupling;

g. an operating rod pivotally connected at one end to said force-equalizing coupling;

. said force-equalizing coupling being so constructed that the position of its parts can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control valves;

. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod;

j. said motive means while inactive permitting minor longitudinal movement of said operating rod in response to a slight change in the position of the parts of said forceequalizing coupling; v

it. said linkage means and said force-equalizing coupling being substantially free of lost motion that would allow said motive means to operate without imparting motion to at least one of said control valves; and

I. said force-equalizing coupling comprising a substantially rigid force-equalizing member connected to said linkage means at spaced points and "pivotally connected to said operating rod at a point between said spaced points and maintaining a fixed spacing between said spaced points.

14. The circuit breaker of claim 13 in which said forceequalizing coupling acts to distribute a force applied to said other end of said operating rod substantially equally between said control valves despite slight changes in the position of the parts of said force-equalizing coupling.-

15. The circuit breaker of claim 14 in combination with:

b. said force-equalizing coupling acting to distribute said restraining force substantially equally between said control valves, thereby to promote synchronized motion of said control valves.

16. A high voltage circuit breaker comprising:

a. a plurality of spaced-apart enclosuresat a high voltage with respect to ground;

b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure relative to another;

d. a plurality of control valves respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means,

f. a plurality of linkage means respectively mechanically connecting said control valves to said forceequalizing member;

h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosuresrelative to another without imparting motion through said linkage means to any of said control valves;

. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member;

. said operating rod being connected to said force-equalizing member at a central point spaced substantially equidistant from the points at which plurality of said linkage means are respectively connected to said forceequalizing member,

. each of said enclosures containing high pressure fluid acting on the associated control valves therein with substantially equal force and urging said control valves toward predetermined positions of circuit breaker control;

. said motive means providing'a restraining force applied to said other end of said operating rod which normally restrains said control valves against movement toward said predetermined positions of circuit breaker control;

m. means for reducing said restraining force to permit said fluid pressure forces on said control valves to predominate and drive said control valves toward said predetermined positions; and

n. said force-equalizing member acting to distribute said restraining force at any given instant substantially equally between said control valves during their motion toward said predetermined positions of circuit breaker control.

17. A high voltage circuit breaker-comprising:

f. a plurality of linkage means respectively mechanically connecting said control 'valves to said force-equalizing member;

h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without control valves; 1

i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member;

Q said operating rod being connected to said force-equalizing member at a central point-spaced substantially equidistant from the points at which plurality of said linkage means are respectively connected to said forceequalizing member;

k. said control valves having predetermined seats against which they respectively hear when said circuit breaker is closed;

i. said motive means biasing said operating rod in a direction l0 l6 I to hold said control vsvas against their respective predetermined seats; and

m. while said circuit breaker is closed, any movement of

Claims

1. A high voltage circuit breaker comprising: a. a plurality of spaced-apart enclosures at a high voltage with respect to ground; b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure relative to another; c. a plurality of circuit interrupting means respectively located within said plurality of enclosures; d. a plurality of control valves respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means; e. a force-equalizing member common to said control valves located in a position between said control valves; f. a plurality of linkage means respectively mechanically connecting said control valves to said force-equalizing member; g. an operating rod pivotally connected at one end to said foRce-equalizing member; h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control valves; i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means while inactive permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member; j. said operating rod being pivotally connected to said forceequalizing member at a central point spaced substantially equidistant from the points at which said linkage means are respectively connected to said force-equalizing member; and k. said force-equalizing member being a rigid member that during circuit breaker operation maintains a fixed spacing between said points at which said plurality of linkage means are respectively connected thereto.

2. The circuit breaker of claim 1 in which said force-equalizing member acts to distribute a force applied to said other end of said operating rod substantially equally between said control valves despite slight changes in the position of said force-equalizing member in response to enclosure shifting.

3. The circuit breaker of claim 1 in combination with: a. valve-operating means located at each enclosure for providing a force for operating the associated control valve against a restraining force applied to said other end of said operating rod; and b. said force-equalizing member acting to distribute said restraining force substantially equally between said control valves, thereby to promote synchronized motion of said control valves.

4. The circuit breaker of claim 3 in which each of said valve-operating means applies an operating force to said force-equalizing member which is directed generally vertically at the points where said linkage means are connected to said force-equalizing member, said operating forces acting in substantially the same vertical direction, said restraining force being applied to said force-equalizing member in a vertically opposite direction at the point where said operating rod is connected to said force-equalizing member.

5. A high voltage circuit breaker comprising: a. a plurality of spaced-apart enclosures at a high voltage with respect to ground; b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure relative to another; c. a plurality of circuit interrupting means respectively located within said plurality of enclosures; d. a plurality of control valves respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means; e. a force-equalizing member common to said control valves located in a position between said control valves; f. linkage means mechanically connecting said control valves to said force-equalizing member; g. an operating rod mechanically connected at one end to said force-equalizing member; h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control valves; i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member; j. said operating rod being connected to said force-equalizing member at a central point spaced substantially equidistant from the points at which said linkage means are connected to said force-equalizing memBer; k. said circuit breaker comprising three of said enclosures, three of said interrupting means, three of said control valves, and three of said linkage means mechanically interconnecting said control valves and said force-equalizing member, l. said force-equalizing member being connected to said three linkage means through three universal joints respectively located at the corners of a substantially equilateral reference triangle; and m. said operating rod being connected to said force-equalizing member at a central point on said triangle substantially equidistant from said corners.

6. The circuit breaker of claim 5 in which said operating rod is connected to said force-equalizing member through a universal joint between the operating rod and said force-equalizing member.

7. The circuit breaker of claim 5 in which: a. said force-equalizing member is located at a level where the voltage with respect to ground is high and substantially the same as that of said enclosures when said circuit breaker is closed; b. said operating rod is partially of electrical insulating material and said motive means is at substantially ground potential; and c. said linkage means combined with said force-equalizing member extends between said enclosures in the high voltage region of said circuit breaker, said linkage means being partially of electrical insulating material.

8. The circuit breaker of claim 1 in which: a. said force-equalizing member is located at a level where the voltage with respect to ground is high and substantially the same as that of said enclosures when said circuit breaker is closed; b. said operating rod is partially of electrical insulating material and said motive means is at substantially ground potential; and c. said linkage means combined with said force-equalizing member extends between said enclosures in the high voltage region of said circuit breaker, said linkage means being partially of electrical insulating material.

9. A high voltage circuit breaker comprising: a. a plurality of spaced-apart enclosures at a high voltage with respect to ground; b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure relative to another; c. a plurality of circuit interrupting means respectively located within said plurality of enclosures; d. a plurality of control elements respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means; e. a force-equalizing member common to said control elements located in a position between said control elements; f. a plurality of linkage means respectively mechanically connecting said control elements to said force-equalizing member; g. an operating rod pivotally connected at one end to said force-equalizing member; h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control elements; i. means for actuating said operating rod comprising motive means for applying an or operating force to the other end of said operating rod, said motive means while inactive permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member; j. said operating rod being connected to said force-equalizing member at a central point spaced substantially equidistant from the points at which said linkage means are connected to said force-equalizing member; and k. said force-equalizing member being a rigid member that during circuit breaker operation maintains a fixed spacing between said points at which said plurality of linkage means are respectively connected thereto.

10. The circuit breaker of claim 9 in which said foRce-equalizing member acts to distribute a force applied to said other end of said operating rod substantially equally between said control elements despite slight changes in the position of said force-equalizing member in response to a shift of one enclosure relative to another.

11. The circuit breaker of claim 1 in which: a. said control valves have predetermined seats against which they respectively bear when said circuit breaker is closed; b. said motive means biases said operating rod in a direction to hold said control valves against their respective predetermined seats; and c. while said circuit breaker is closed, any movement of said force-equalizing member in response to shifting of one enclosure which moves said operating rod against the bias of said motive means applies a reaction force to the control valve of another enclosure that acts in a direction to hold said control valve against its predetermined seat.

12. A high voltage circuit breaker comprising: a. a plurality of spaced-apart enclosures at a high voltage with respect to ground; b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure relative to another; c. a plurality of circuit interrupting means respectively located within said plurality of enclosures; d. a plurality of control elements respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means; e. a force-equalizing member common to said control elements located in a position between said control elements; f. linkage means mechanically connecting said control elements to said force-equalizing member; g. an operating rod mechanically connected at one end to said force-equalizing member; h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control elements; i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member; j. said operating rod being connected to said force-equalizing member at a central point spaced substantially equidistant from the points at which said linkage means are connected to said force-equalizing member; k. said circuit breaker comprising three of said interrupting means, three of said control elements, and three of sd said linkage means mechanically interconnecting said control elements and said force-equalizing member; l. said force-equalizing member being connected to said three linkage means through three universal joints respectively located at the corners of a substantially equilateral reference triangle; and m. said operating rod being connected to said force-equalizing member at a central point on said triangle substantially equidistant from said corners.

13. A high voltage circuit breaker comprising: a. a plurality of spaced-apart enclosures at a high voltage with respect to ground; b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures and permitting minor shifting of one enclosure relative to another; c. a plurality of circuit interrupting means respectively located within said plurality of enclosures; d. a plurality of control valves respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means; e. a force-equalizing coupling common to said control valves and located in a position between said control valves; f. a plurality of linkage means respectively mechanically connecting Said control valves to said force-equalizing coupling; g. an operating rod pivotally connected at one end to said force-equalizing coupling; h. said force-equalizing coupling being so constructed that the position of its parts can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control valves; i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod; j. said motive means while inactive permitting minor longitudinal movement of said operating rod in response to a slight change in the position of the parts of said force-equalizing coupling; k. said linkage means and said force-equalizing coupling being substantially free of lost motion that would allow said motive means to operate without imparting motion to at least one of said control valves; and l. said force-equalizing coupling comprising a substantially rigid force-equalizing member connected to said linkage means at spaced points and pivotally connected to said operating rod at a point between said spaced points and maintaining a fixed spacing between said spaced points.

14. The circuit breaker of claim 13 in which said force-equalizing coupling acts to distribute a force applied to said other end of said operating rod substantially equally between said control valves despite slight changes in the position of the parts of said force-equalizing coupling.

15. The circuit breaker of claim 14 in combination with: a. valve-operating means located at each enclosure for providing a force for operating the associated control valve against a restraining force applied to said other end of said operating rod; and b. said force-equalizing coupling acting to distribute said restraining force substantially equally between said control valves, thereby to promote synchronized motion of said control valves.

16. A high voltage circuit breaker comprising: a. a plurality of spaced-apart enclosures at a high voltage with respect to ground; b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure relative to another; c. a plurality of circuit interrupting means respectively located within said plurality of enclosures; d. a plurality of control valves respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means, e. a force-equalizing member common to said control valves located in a position between said control valves; f. a plurality of linkage means respectively mechanically connecting said control valves to said force-equalizing member; g. an operating rod mechanically connected at one end to said force-equalizing member; h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without imparting motion through said linkage means to any of said control valves; i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member; j. said operating rod being connected to said force-equalizing member at a central point spaced substantially equidistant from the points at which plurality of said linkage means are respectively connected to said force-equalizing member; k. each of said enclosures containing high pressure fluid acting on the associated control valves therein with substantially equal force and urging said control valves toward predetermined positions of circuit breaker control; l. said motive means providing a restraining foRce applied to said other end of said operating rod which normally restrains said control valves against movement toward said predetermined positions of circuit breaker control; m. means for reducing said restraining force to permit said fluid pressure forces on said control valves to predominate and drive said control valves toward said predetermined positions; and n. said force-equalizing member acting to distribute said restraining force at any given instant substantially equally between said control valves during their motion toward said predetermined positions of circuit breaker control.

17. A high voltage circuit breaker comprising: a. a plurality of spaced-apart enclosures at a high voltage with respect to ground; b. means comprising a plurality of spaced-apart insulating structures respectively supporting said enclosures in a manner which permits minor shifting of one enclosure relative to another; c. a plurality of circuit interrupting means respectively located within said plurality of enclosures; d. a plurality of control valves respectively located adjacent said plurality of circuit interrupting means for initiating operation of the associated interrupting means; e. a force-equalizing member common to said control valves located in a position between said control valves; f. a plurality of linkage means respectively mechanically connecting said control valves to said force-equalizing member; g. an operating rod mechanically connected at one end to said force-equalizing member; h. means for so mounting said force-equalizing member that its position can change slightly in response to minor shifting of one of said enclosures relative to another without control valves; i. means for actuating said operating rod comprising motive means for applying an operating force to the other end of said operating rod, said motive means permitting minor longitudinal movement of said operating rod in response to a slight change in the position of said force-equalizing member; j. said operating rod being connected to said force-equalizing member at a central point spaced substantially equidistant from the points at which plurality of said linkage means are respectively connected to said force-equalizing member; k. said control valves having predetermined seats against which they respectively bear when said circuit breaker is closed; l. said motive means biasing said operating rod in a direction to hold said control valves against their respective predetermined seats; and m. while said circuit breaker is closed, any movement of said force-equalizing member in response to shifting of one enclosure which moves said operating rod against the bias of said motive means applying a reaction force to the control valve of another enclosure that acts in a direction to hold said control valve against its predetermined seat.