US3780354A

US3780354A - Vacuum type circuit breaker comprising series-connected vacuum interrupters, individual ones of which are readily removable and replaceable

Info

Publication number: US3780354A
Application number: US00232568A
Authority: US
Inventors: W Sharp
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1972-03-07
Filing date: 1972-03-07
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18
Also published as: ES410488A1

Abstract

A vacuum-type circuit breaker comprises a plurality of vacuum circuit interrupters stacked one above the other and electrically connected in series. For mounting the interrupters, a pair of horizontally-spaced, vertically-extending channels of insulating material are provided. Extending horizontally between the webs of the channels are a plurality of interrupter-supporting plates, to which the interrupters are respectively secured. Each of these plates is detachably connected to the webs and, when detached, is removable laterally of the channels from the space between the webs to permit the plate together with its associated interrupter to be removed from the circuit breaker.

Description

United States Patent [191 Sharp REMOVABLE AND REPLACEABLE William '1. Sharp, Philadelphia, Pa.

General Electric Company, Philadelphia, Pa.

Filed: Mar. 7, 1972 Appl. No.3 232,568

Inventor:

[73] Assignee:

US. Cl. 317/103, 317/112, 200/144 B Int. Cl. H02b 1/04 Field of Search 200/144 B, 145;

References Cited UNITED STATES PATENTS 3,397,293 8/1968 Darrow 200/144 B X 3,594,525 7/1971. Miller 200/144 B FOREIGN PATENTS OR APPLICATIONS 1,080,198 8/1967 Great Britain 200/144 B [451 Dec. 18,1973

Primary Examiner-Robert K. Schaefer Assistant E.raminer--Gerald P. Tolin Attorney-J. Wesley Haubner et al [57] ABSTRACT A vacuum-type circuit breaker comprises a plurality of vacuum circuit interrupters stacked one above the other and electrically connected in series. For mounting the interrupters, a pair of horizontally-spaced, vertically-extending channels of insulating material are provided. Extending horizontally between the webs of the channels are a plurality of interrupter-supporting plates, to which the interrupters are respectively secured. Each of these plates is detachably connected to the webs and, when detached, is removable laterally of the channels from the space between the webs to permit the plate together with its associated interrupter to be removed from the circuit breaker.

4 Claims, 4 Drawing Figures VACUUM TYPE CIRCUIT BREAKER COMPRISING SERIES-CONNECTED VACUUM INTERRUPTERS, INDIVIDUAL ONES OF WHICH ARE READILY REMOVABLE AND REPLACEABLE BACKGROUND This invention relates to a high voltage vacuum-type circuit breaker and, more particularly, to a circuit breaker of this type which comprises a plurality of vacuum interrupting units stacked one above the other and electrically connected in series. Of interest with respect to this type of circuit breaker are the following: US. Pat. No. 3,594,525-Miller et al; US. Pat. No. 3,300,609-Flurscheim et al; and U.S. Pat. No. 2,915,6l l-Luehring et al; and British Patents No. 1,080,198-Licentia; and 981,604-Waterton.

Most prior circuit breakers of this type have relied upon a tubular enclosure for supporting and housing the vacuum interrupting units. Typically, this enclosure is of porcelain. A tubular enclosure is usually quite expensive, especially if it is ofporcelain, and has the additional disadvantage of preventing ready access to the interrupters and their immediately-associated linkages for inspection and adjustment. Moreover, it has not been possible in most prior circuit breakers of this general type to replace the individual interrupting units, if necessary, without disturbing the remaining interrupting units. Still another disadvantage of some prior designs is that they have required tensioning members running longitudinally of the enclosure to effect precompression of the enclosure to enable it to withstand operating loads and also loads which might be encountered in shipping.

SUMMARY An object of the present invention is to provide a vacuum-type circuit breaker of the stacked interrupter type which is so constructed that individual interrupters and their immediately associated linkages are readily accessible for inspection and adjustment and can be easily replaced, if necessary, without disturbing the remaining interrupters and their associated linkages and supporting structure.

Another object is to provide supporting structure which is light in weight, has great strength in the direction that ope rating forces are applied, is highly resistant to damage from loads encountered during shipping, and does not require tension members for precompression.

In carrying out the invention in one form, we provide an insulating support and a pair of elongated channels of electrical insulating material mounted atop the insulating support and extending generally vertical. Each channel comprises a web and flanges at opposite ends of the web. The webs of the two channels are disposed in spaced-apart relationship, and the flanges project therefrom outwardly away from the space between the webs. A plurality of interrupter-supporting plates extend generally horizontally across the space between the webs, and fastening means detachably secures the plates to the webs at locations spaced apart along the length of the webs. A plurality of vacuum-type circuit interrupters are provided, and they are respectively mounted on the interrupter-supporting plates, with the housing of each interrupter secured to its associated plate in the space between said webs. For operating the interrupters, a longitudinally-movable operating rod extending generally parallel to the longitudinal axis of the channels is provided in a location laterally spaced from the interrupter-supporting plates. A linkage associated with each interrupter couples the movable contact rod thereof to the longitudinally-movable operating rod. Each of the plates when detached from the webs is removable laterally of the channels from the space between the webs to permit the plate together with the associated interrupter to be removed from the circuit breaker.

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. I is a side elevational view of a circuit breaker embodying one form of the invention.

FIG. 2 is an end view of the circuit breaker shown in FIG. 1.

FIG. 3 is an enlarged sectional view of a portion of the circuit breaker of FIG. 2.

FIG. 4 is a sectional view along the line 44 of FIG.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown a vacuumtype circuit breaker comprising a supporting metal framework 12 and a vertically-extending porcelain insulating post 14 mounted upon the metal framework. Secured in a conventional manner to the top of the insulating post 14 is a metal end cap 16 that includes a pair of spaced-apart vertically-extending lugs 18.

Atop the end cap 16, I mount plurality of vacuumtype circuit interrupters 20 stacked one above the other and electrically connected in series. For supporting these interrupters on the end cap 16, I provide supporting structure comprising a plurality of verticallyextending channels 22, each of a high strength electrical insulating material such as glass-fiber-reinforced polyester resin.

Referring to FIG. 4, each channel is of a U-shaped cross section and comprises a web 25 and a pair of flanges 26 at opposite edges of the web. The longitudinal axis 27 of each channel extends generally vertically. The channels are mounted in spaced-apart relationship with the flanges 26 of each channel projecting from their web outwardly away from the space between the channels. At the bottom of the supporting structure, each of the channels 22 bears against one of the lugs 18 on the end cap 16 and is clamped thereto by bolts 21 extending through the web and the lugs, as is shown in FIG. 2.

At vertically-spaced locations along the length of the channels, I provide interrupter-supporting plates 30, preferably of metal, which are detachably clamped to the channels. Each of the supporting plates 30 comprises a flat body 31 extending between the webs and fastening projections, or flanges, 32 at the edges of the flat body which are bolted to the webs. Each of the bolts 34 which clamps a supporting plate 30 to a web 25 extends through the web and the projection 32 and is removable for reasons which will soon appear.

Mounted atop each supporting plate 30 is a vacuumtype circuit interrupter of a conventional design. As such, each interrupter (FIG. 3) comprises a highly evacuated tubular envelope 40 and a pair of separable contacts 42 and 43 located within the envelope. The envelope 40 comprises a tubular casing 46 of a suitable insulating material such as glass and

metal end caps

44 and 45 at opposite ends of the casing joined to the easing by suitable glass-to-metal seals. Contact 42 is a stationary contact supported on a conductive rod 47 which extends in sealed relationship through upper end cap 44; and the other contact is a movable contact supported on a reciprocally-movable contact rod 48 extending freely through the lower end cap 45. A flexible metallic bellows 50 joined in sealed relationship at its opposite ends to rod 48 and end cap 45 provides a seal about rod 48 and permits it to be reciprocated without impairing the vacuum inside envelope 40. It will be noted that contact rod 48 is longitudinally movable in a direction parallel to the longitudinally movable in a direction parallel to the longitudinal axis 27 of the channels 22.

Referring to FIG. 3, for securing each vacuum interrupter to its supporting plate 30, each vacuum interrupter is provided with mounting studs 54 affixed to its lower end cap 45. These studs extend through openings in the supporting plate 30 and are provided with nuts 55 which are tightened to clamp the lower end cap 45 to the supporting plate 30. It is to be noted that supporting plate 30 has a central opening through which movable contact rod 48 freely extends.

For electrically connecting the interrupters in series, I provide a plurality of flexible conductive braids 58. These braids connect the movable contact rod 48 of each interrupter to the stationary contact rod 47 of the interrupter immediately therebelow. In the case of the bottom interrupter, another flexible braid 59 connects movable contact rod 48 of this interrupter to a lower terminal 60 of the circuit breaker.

For operating the vacuum interrupters substantially simultaneously, I provide an elongated operating rod 64 (FIG. 1) of electrical insulating material that extends generally parallel to the longitudinal axis 27 of channels 22 in a position laterally-spaced from interrupter-supporting plates 30. This operating rod 64 is mechanically connected to each of the interrupters by linkages 65 respectively associated with the individual interrupters.

Each linkage 65 comprises a pivotally-mounted operating lever 68 pivotally connected at one end to the operating rod 64 and at its opposite end to movable contact rod 48 of the associated interrupter. Intermediate its ends, operating lever 68 is pivotally supported on a pivot 69 carried by spaced-apart arms 70 fixed to supporting plate 30 and projecting downwardly therefrom. The pivotal connection to the operating rod comprises a suitable pivot pin 73 which can be removed by a maintenance man to uncouple the operating lever 68 from rod 64, as will soon be explained.

The pivotal connection of operating lever 68 to contact rod 48 comprises a conventional contact-wipe mechanism 75, which includes a downwardly projecting rod 76, and a pivot pin 77 connecting lever 68 to rod 76. The wipe mechanism 75 serves in a conventional manner to maintain pressure on the contacts of the interrupter when they are engaged and to permit some overtravel at the end of a closing operation to assure that all the contacts are properly engaged. Reference may be had to FIG. of U.S. Pat. No. 3,025,375- Frank for a more detailed showing of such a wipe mechanism.

When operating rod 64 is driven in a downward direction from its open position of FIG. 1, it acts to simultaneously pivot all the operating lever 68 in a counterclockwise direction as viewed in FIG. 1. This drives all the movable contact rods 48 upwardly to effect substantially simultaneous closing of all of the interrupters. After such closing, opening of the interrupters is effected by allowing operating rod 64 to be driven in an upward direction from its closed position. This pivots lever 68 in a clockwise direction, enabling the contact rods 48 to be driven downwardly through a downward opening stroke.

For transmitting operating force to operating rod 64, I provide a lower operating rod 80 that is pivotally connected at its upper end to an extension of the lowermost operating lower 68. At its lower end, lower operating rod 80 is pivotally connected to one arm of a bell crank 82. Bell crank 82 is pivotally mounted on a stationary pivot 83. When bell crank 82 is pivoted counterclockwise about pivot 83, it drives lower operating rod 80 downwardly to effect counterclockwise motion of the lowermost operating lever 68 and resultant downward motion of operating lever 64. The lower operating rod 80 is of a suitable insulating material and is located in laterally spaced relationship with respect to insulating post 14.

The supporting channels 22 are able to easily withstand any mechanical forces applied thereto as a result of circuit-breaker operation. These forces will typically load the channels in tension. The channels are especially strong in tension and are able to withstand such tensile forces with little deflection.

The channels 22 are light in weight and low in mass compared to a comparable porcelain supporting structure. This is advantageous in reducing the likelihood of damage from impact forces which might develop during shipping of the circuit breaker. In addition, the channels of glass-fiber-reinforced resin have a much greater strength than porcelain in tension and in bending, and for this reason alone are more able to withstand without damage forces that might be applied thereto as a result of shocks encountered during shipping. Because of this high strength in tension and bending, the channels do not require the precompression rods that are typically needed by porcelain structures to impart strength with respect to tensile and bending loads.

It should be appreciated from the above that it is a simple matter for a maintenance man to inspect and adjust the interrupters and their associated linkages. Since the space between the channels 22 is open, the maintenance man can easily examine the interrupters when he looks between the channels 22 in the direction of arrow 89 in FIG. 1. He can also make any minor adjustments of the wipe mechanism that might be needed by reaching into the space between the channels and appropriately adjusting the wipe mechanism 75.

If, for some reason, he should desire to remove an interrupter 20 or its associated linkage for more extensive adjustments, for repairs or for replacement, he can readily effect such removal in the following manner. First he removes the associated pivot pin 73 to disconnect the linkage 65 in question from operating rod 64. Then he disconnects the braids 58 at opposite ends of the interrupter, after which he removes the bolts 34 which attach the interrupter-supporting plate 30 to the channels. Thereafter he can slide plate 30 laterally to the right, carrying with it the associated interrupter and the associated linkage, but leaving behind the channels 22 and the operating rod 64.

He may then make any repairs or replacements which might be desired on the removed subassembly at a convenient working location, after which he can return the subassembly to its original position and restore the above connections.

It will be apparent from the above that removal of any supporting plate together with the immediately associated interrupter 20 and linkage can be effected without disturbing any of the other interrupters or their linkages or their supporting structure.

In order to improve the voltage distribution between the breaks of the circuit breaker when they are open, it is often desirable to connect capacitors in parallel with the breaks. My circuit breaker readily lends itself to the inclusion of such capacitors, which are shown at 90 in FIG. 4. More specifically, I mount such capacitors 90 on the outer side of the channels in the space between the flanges of the channel. Each capacitor comprises a stack of ceramic disks of the general type shown and claimed in 1.1.8. Pat. No. 3,586,934-Nakata, assigned to the assignee of the present invention. Since these capacitor stacks are nested within the space between the flanges 26, they are advantageously protected by the channels from damage through forces or blows inadvertently applied in this region.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the invention in its broader aspects; and I therefore intend herein to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A vacuum-type circuit breaker comprising a. an insulating support,

b. a pair of elongated channels of electrical insulating material, each comprising a web and flanges at opposite ends of said web,

c. means for mounting said channels atop said support with the longitudinal axis of each channel extending generally vertically, with the webs of said channels disposed in laterally spaced-apart relation, and with the flanges of each channel projecting from their associated web outwardly away from the space between said webs,

d. a plurality of interrupter-supporting plates extending generally horizontally across the space between said webs,

e. fastening means for detachably securing said plates to said webs at locations spaced-apart along the length of said webs,

f. a plurality of vacuum-type circuit interrupters, each comprising an evacuated housing comprising a tubular insulating casing and end caps at opposite ends of said casing, a pair of separable contacts within said housing, and a conductive rod supporting a movable one of said contacts and projecting through one end cap of said housing,

g. means for respectively mounting said vacuum interrupters on said plates in the space between said webs, with said one end cap of each vacuum interrupter housing secured to an associated one of said plates, the tubular casing of each housing having a longitudinal axis extending generally parallel to the longitudinal axes of said channels,

g. means for electrically connecting said vacuum interrupters in series,

h. a longitudinally-movable operating rod extending generally parallel to the longitudinal axes of said channels in a location laterally spaced from said interrupter-supporting plates,

'. and a linkage associated with each interrupter and pivotally supported on said associated interrupters supporting plate for coupling the movable contact rod thereof to said longitudinally movable operating rod,

j. some of said plates, when detached from said webs, being movable laterally of said channels from the space between said webs to permit said detached plates together with the associated interrupter and linkage to be removed as a unit from said circuit breaker.

2. The vacuum-type circuit breaker of claim 1 in which:

a. the linkage associated with each interrupter comprises an operating lever, a pivot on which said operating lever is pivotally mounted intermediate the length of said lever, means for supporting said pivot on the associated interrupter-supporting plate, and means for pivotally connecting the respective ends of said lever to said operating rod and the contact rod of the associated interrupter, and

b. said lever is disconnectable from said operating rod to allow said linkage to be removed from said circuit breaker with said associated interruptersupporting plate but independently of said operating rod.

3. The vacuum-type circuit breaker of claim 1 in which:

a. each of said supporting plates has lateral projections at its opposite edges that are respectively positioned adjacent said webs,

b. each of said lateral projections is clamped to the web thereadjacent by said fastening means,

c. and each of said fastening means comprises a part extending through the associated web in the region of a lateral projection.

4. A vacuum-type circuit breaker as defined in claim 1 and further comprising:

a. ceramic capacitors for distributing voltage between said interrupters,

b. and means for mounting said ceramic capacitors on one of said channels adjacent the outer side of said web in the region between said flanges.

Claims

1. A vacuum-type circuit breaker comprising a. an insulating support, b. a pair of elongated channels of electrical insulating material, each comprising a web and flanges at opposite ends of said web, c. means for mounting said channels atop said support with the longitudinal axis of each channel extending generally vertically, with the webs of said channels disposed in laterally spaced-apart relation, and with the flanges of each channel projecting from their associated web outwardly away from the space between said webs, d. a plurality of interrupter-supporting plates extending generally horizontally across the space between said webs, e. fastening means for detachably securing said plates to said webs at locations spaced-apart along the length of said webs, f. a plurality of vacuum-type circuit interrupters, each comprising an evacuated housing comprising a tubular insulating casing and end caps at opposite ends of said casing, a pair of separable contacts within said housing, and a conductive rod supporting a movable one of said contacts and projecting through one end cap of said housing, g. means for respectively mounting said vacuum interrupters on said plates in the space between said webs, with said one end cap of each vacuum interrupter housing secured to an associated one of said plates, the tubular casing of each housing having a longitudinal axis extending generally parallel to the longitudinal axes of said channels, g''. means for electrically connecting said vacuum interrupters in series, h. a longitudinally-movable operating rod extending generally parallel to the longitudinal axes of said channels in a location laterally spaced from said interrupter-supporting plates, i. and a linkage associated with each interrupter and pivotally supported on said associated interrupter''s supporting plate for coupling the movable contact rod thereof to said longitudinally movable operating rod, j. some of said plates, when detached from said webs, being movable laterally of said channels from the space between said webs to permit said detached plates together with the associated interrupter and linkage to be removed as a unit from said circuit breaker.

2. The vacuum-type circuit breaker of claim 1 in which: a. the linkage associated with each interrupter comprises an operating lever, a pivot on which said operating lever is pivotally mounted intermediate the length of said lever, means for supporting said pivot on the associated interrupter-supporting plate, and means for pivotally connecting the respective ends of said lever to said operating rod and the contact rod of the associated interrupter, and b. said lever is disconnectable from said operating rod to allow said linkage to be removed from said circuit breaker with said associated interrupter-supporting plate but independently of said operating rod.

3. The vacuum-type circuit breaker of claim 1 in which: a. each of said supporting plates has lateral projections at its opposite edges that are respectively positioned adjacent said webs, b. each of said lateral projections is clamped to the web thereadjacent by said fastening means, c. and each of said fastening means comprises a part extending through the associated web in the region of a lateral projection.

4. A vacuum-type circuit breaker as defined in claim 1 and further comprising: a. ceramic capacitors for distributing voltage between said interrupters, b. and Means for mounting said ceramic capacitors on one of said channels adjacent the outer side of said web in the region between said flanges.