US3793494A

US3793494A - Draw out type vacuum circuit breaker assembly with hinged barrier

Info

Publication number: US3793494A
Application number: US00306669A
Authority: US
Inventors: C Cleaveland
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1972-11-15
Filing date: 1972-11-15
Publication date: 1974-02-19
Anticipated expiration: 1991-02-19
Also published as: CA960266A

Abstract

A circuit breaker for metal clad switchgear is provided using vacuum-interrupter elements rather than the usually provided air type circuit interrupter. A rigid mounting for one end of the vacuum-type interrupter elements is provided, together with a connector plate structure for the other end of the vacuum interrupter which permits resilient movement of the interrupter end cap in one direction only. A hinged barrier is provided to facilitate access to the vacuum interrupters without removing the barrier. A porcelain push rod is connected directly between the movable operating rod, coming from the vacuum interrupter, and the breaker operating mechanism, thus providing a porcelain-toground insulation path and electrically isolating the operating mechanism from the vacuum interrupter.

Description

United States Patent 1 Cleaveland Feb. 19,1974

[75] Inventor: Charles M. Cleaveland, Irwin, Pa.

[7 3] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: Nov. 15, 1972 [21] Appl. No.: 306,669

[52] US. Cl. 200/50 AA, 200/144 B [51] Int. Cl. I-I0lh 9/22 [58] Field of Search ..200/50 AA, 144 R, 144 B,

200/147 R, 166 B, 153 SC; 339/230 R 3,321,599 5/1967 Lee 200/147 R Primary Examiner-J. R. Scott Attorney, Agent, or Firm-H. G. Massung [57 ABSTRACT A circuit breaker for metal clad switchgear is provided using vacuum-interrupter elements rather than the usually provided air type circuit interrupter. A rigid mounting for one end of the vacuum-type interrupter elements is provided, together with a connector plate structure for the other end of the vacuum interrupter which permits resilient movement of the interrupter endcap in one direction only. A hin g ed barrier is pro-v vided to facilitate access to the vacuum interrupters without removing the barrier. A porcelain push rod is connected directly between the movable operating rod, coming from the vacuum interrupter, and the breaker operating mechanism, thus providing a porcelain-to-ground insulation path and electrically isolating the operating mechanism from the vacuum interrupter.

12 Claims, 9 Drawing Figures PAIENI FEB} 91914 SHEET 1 OF 5 PATENTE FEB 1 91914 SHEET 5 OF 5 lal llllu FIG;6

DRAW OUT TYPE VACUUM CIRCUIT BREAKER ASSEMBLY WITH HINGED BARRIER BACKGROUND OF THE INVENTION This invention relates to circuit breakers and more particularly to large-type draw out circuit breakers for metal-clad switchgear which utilizes vacuum interrupters as an electric circuit interrupting element.

As well known by those skilled in the art, metal-clad switchgear has achieved extensive use within the industry. Customarily, magnetic air-break arc-chute structures have been employed, such as set forth in US. Pat. No. 3,307,004, issued Feb. 28, 1967, to Samuel A. Bottonari, and assigned to the assignee of the instant application. Such magnetic air-break circuit interrupters are rolled on a movable truck into a cubicle or cell of the metal-clad switchgear enclosure. Metal clad switchgear is built for either indoor or outdoor use, and the surrounding grounded enclosure provides protection to operating personnel.

.Vacuum-type circuit interrupters have developed, and are at the present time, of considerable reliability. It is desirable, therefore, to utilize the new-type vacuum interrupter units in the metal-clad switchgear industry to take advantage of their small size and efficient operation. Prior art circuit breakers such as disclosed in US. Pat. No. 3,603,753, issued Sept. 7, I971 to Russell E. Frink and assigned to the same assignee as the instant application, utilizes vacuum interrupter elements for metal-clad switchgear draw-out circuit breakers. In the breaker disclosed in US. Pat. No. 3,603,753, a metallic portion of the operating linkage, required to operate the vacuum interrupters, is at line potential.

SUMMARY OF THE INVENTION According to a preferred embodiment of the present invention, there is provided a draw-out type circuit breaker unit incorporating vacuum-type interrupter elements so that a three-phase interrupter may be moved into or out of a metal-clad switchgear cubicle or housing. The vacuum interrupter units are rigidly mounted to the draw-out breaker assembly. According to the invention, a porcelain push rod is connected at one end directly to the movable contact rod of the vacuum interrupter unit and at the other end to the circuit breaker operating linkage. Thus, the operating linkage is electrically insulated from the vacuum interrupter. This linkage is composed of lever arms that give the correct amount of contact travel and have a spring and overtravel provision that applies contact pressure when the interrupter is closed, even though the contacts have worn down due to arcing. Electrical contact is made between the movable interrupter rod and a stationary lower end connector by multiple spring-loaded rollers. Bylocating the porcelain push rod in the linkage train after the travel of the operating mechanism has been reduced and by attaching the porcelain push rod diof the metallic parts of the operating linkage can be kept at ground potential, where there is more space.

The disclosed vacuum circuit breaker assembly also embodies an upper connector between the vacuum interrupter and the upper pole unit conductor, which allows the upper end cap and the stationary interrupter rod, to flex in one direction only, and acts as a stiffener to prevent movement in the opposite direction. This upper connector is rigidly attached to the stationary contact rod of the vacuum interrupter and extends laterally to the outer diameter of the envelope of the vacuum interrupter. In the event that the contacts are welded in the closed position, the connector acts as a stiffener of the end cap and transfers the weld breaking force to the interrupter envelope and the force is then transmitted through the envelope to the rigid interrupter mounting at the opposite end. Thus, the stationary contact and its associated interrupter. end cap are prevented from flexing towards the movable contact during the weld breaking operation. That is, the stationary contact rod and the stationary contact end cap can flex in an upward direction only, during circuit closing. This upward movement during circuit closing results in less bounce and a decrease in the force transmitted to the upper breaker stud. If additional stiffness and weld breaking ability is required, a beam, which extends to the outer diameter of the vacuum interrupter housing, can be attached under the upper connector. The stationary contact and the stationary contact end cap cannot move in a downward direction during a weld breaking operation and this stiffness results in the generation of very high forces for breaking welds during circuit interruption. It has been found that vacuum interrupter contact materials may have superior interrupting properties but have the problem of producing very strong welds as the contacts close on high current. It is part of this invention to provide a novel connection to the upper interrupter rod that stiffens the end cap as a weld is broken, but still is resilient as the contacts impact on closing. Thus, without adding more energy to the operating mechanism, and without causing high forces on closing, the force necessary to break welds of this superior contact material is obtained.

The improved vacuum circuit breaker assembly disclosed in this application has a novel pivoting barrier, unlike the barriers used on prior art vacuum circuit breakers. This barrier unlike the barriers utilized on prior art vacuum circuit interrupters is intended to be attached to the circuit breaker assembly at all times,

even during shipping of the circuit breaker. The barrier is installed at the factory and can be tilted back for accessibility to breaker parts during maintenance and inspection. The circuit breaker assembly may be lifted with the barrier assembly in place. To obtain access to the vacuum interrupters or other breaker parts, the barrier is pivoted on a hinge point. The pivoting barrier has several advantages such as convenience in obtaining access to the interrupters without disassembling or removing the barrier and the safety feature of the barrier being non-removable for access to the vacuum cir-' cuit breaker. There has been a history of fatal accidents where people have removed barriers from the breaker for inspection and have forgotten to reinstall them and have energized the breaker without the barrier in place.

oted to expose the vacuum interrupters and other energized parts. To obtain access to the vacuum interrupters and other potentially live parts, the vacuum circuit breaker assembly must be deenergized and removed from its switchgear cell.

BRIEF DESCRIPTION OF THE DRAWINGS Further advantages will be readily apparent upon reading the following specification taken in conjunction with the drawings, in which:

FIG. 1 is a perspective view of a vacuum-type circuit breaker assembly, with the barrier tilted back for breaker inspection, embodying the features of the present invention;

FIG. 2 is a view similar to FIG. 1 with the barrier shield pivoted to the normal operating position;

FIG. 3 is aside view of the circuit breaker assembly shown in FIG. 1 with the barrier in an intermediate tilted position;

FIG. 4 is a side view partially in elevation and partially in section of a portion of the circuit breaker shown in FIG. 3;

FIG. 5 is a side view of a portion of the vacuum circuit breaker assembly shown in FIG. 4;

FIG. 6 is a side view of a portion of the vacuum circuit breaker assembly as shown in FIG. 5 but with an additional stiffening member in place;

FIG. 7 is a top view of the portion of the vacuum circuit breaker assembly shown in FIG. 6;

FIG. 8 is a side view of a portion of the vacuum circuit breaker assembly immediately after closing of the vacuum breaker contacts showing upward flexing of the stationary end cap; and

FIG. 9 is a front view of that portion of the vacuum circuit breaker shown in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and more particularly to FIG. 1, the reference numeral 10 generally designates a horizontal draw-out, three-phase, metal-clad type circuit breaker. As shown, the three-phase breaker assembly comprises three vacuum-type circuit interrupter elements 12 positioned generally vertically between pairs of horizontally extending

conductor terminal members

18 and 20. The

conductor members

18 and 20 are supported by an insulating pole support 22. The pole supports 22 may be formed of porcelain or other suitable electrically insulating materials.

Conductors

18 and 20 have plug on type conductors 14, attached to their ends, opposite the vacuum interrupters. When the circuit breaker 10 is positioned in a switchgear cell (not shown), connectors 14 make electricalcontact with mating studs (not shown).

The three insulating pole supports 22 are bolted at 24 to a lower metal frame support 26. The lower metal frame support 26 is mounted upon wheels 28 and is adapted for insertion into and withdrawal from a metal clad switchgear structure. As can best be seen by FIG. 3, a stored energy operating mechanism 30 may be provided within the lower framework 26 of the circuit breaker assembly 10. Reference may be had to US. Pat. No. 3,183,332 issued May 22, 1965 to Russell P rink et al. for a typical stored energy operating mechanism 30 which may be used. The stored energy operating mechanism 30 is contained within frame 26. The

operating mechanism 30 comprises a closing spring 32 in which energy is stored by compressing the spring 32, for closing the circuit breaker 10. By following the teaching of the present invention, the size of closing spring 32 required, as compared with prior art US. Pat. No. 3,603,753, can be dramatically reduced. Once the stored energy of spring 32 is released, cam 34 is rotated and. vacuum interrupter 12 is closed. As the cam 34 moves from the open to the closed position, the antibounce spring assemblies 36 are raised. As the antibounce spring assemblies 36 move to the closed position, they move operating lever assemblies 38 and the porcelain operating rods 40 thus closing the vacuum interrupters 12. Near the end of operating rods 40 stroke, the

contacts

50 and 52 in the interrupter 12 touch and the springs 36 are compressed. As these springs 36 are compressed the correct contact pressure is generated in the interrupter and this force prevents the contacts from bouncing.

Referring now to FIG. 4, there is shown a portion of the circuit breaker 10. The vacuum interrupter 12 is shown partially in section, illustrating its internal construction. The vacuum type circuit interrupter 12 comprises a highly evacuated envelope 42 formed of glass or suitable ceramic material and a pair of

metallic end caps

44 and 46 closing off the ends of the insulating envelope 42. Suitable seals 48 are provided between the end caps 44 and 46 and the insulating envelope 42 to render the envelope 42 vacuum tight. The vacuum in the envelope 42 under normal operating conditions, is lower than 10' Torr to assure the mean free path of electrons will be longer than the potential breakdown distance within the tubular envelope 42, and thus high dielectric strength is obtained.

Disposed within the insulating envelope 42 are a pair of electrodes or

contacts

50 and 52. The upper contact 50 is stationary and is secured to a conducting rod 56 by a suitable means, such as welding or brazing. The conducting rod 56 is secured at its upper end to the stationary end cap 44 by suitable means, such as welding or brazing. The lower contact 52 is movable and is joined to a conducting rod 58. The electrically conducting rod 58 is suitably mounted for movement along the longitudinal axis of the tubular insulating envelope 42.. The movable rod 58 projects through an opening 60 in the bellows end cap 46. As shown in FIG. 4, flexible metal bellows 62 is secured in sealing relationship at its respective opposite ends to movable rod 58 and the opening 60 in the bellows end cap 46. The flexible metal bellows 62 provides a seal about the rod 58 to allow for movement of the rod 58 without impairing the vacuum inside the insulating envelope 42.

The porcelain operating rod 40 links the conducting rod 58 to the operating mechanism 30. The operating mechanism 30 is provided for driving the movable contact 52 upward into engagement with the stationary contact 50 so as to close the interrupter 12. The operating means 30 is also capable of returning the contact 52 to its open position as indicated by the phantom lines 64 in FIG. 4 so as to open the interrupter 12. Once

contacts

50 and 52 are separated, there is an arcing gap formed therebetween. When

contacts

50 and 52 of vacuum interrupter 12 are opened at the beginning of a circuit interruption, a metallic arc initiates between the separated

contacts

50 and 52 and serves as the vehicle for current conduction until the arc is extinguished. In an alternating current circuit the arc is usually extinguished near the first current zero of the alternating current wave. The are that is established across the arcing gap between the

contacts

50 and 52 when they are opened and also when they are closed vaporizes and melts some of the contact material. The vapors and particles are dispersed from the arcing gap toward the inside of envelope 42. The internal surfaces of the insulating envelope 42 are protected from the condensation of the are generated metallic vapors and particles thereby by means of a tubular metallic shield66. The tubular metallic shield 66 is supported on the insulating envelope 42 and is preferably electrically isolated from both

end caps

44 and 46. This shield 66 acts to intercept and condense are generated metallic vapors before they can reach the insulating envelope 42. To reduce the chances of metallic vapors or particles bypassing the main shield,66, end shields 68 and 70 are provided. To prevent the bellows 62 from being bombarded by the are generated metallic vapors or particles, a portion of end shield 70 surrounds the bellows 62.

Two

rigid conducting plates

76 and 78 extend from the end of conductor 20. Conducting

plates

76 and 78 have openings through which the movable conducting rods 58 can pass. A plurality of multiplicity of conducting spacers 80 are'provided between

plates

76 and 78. Spring loaded conducting rollers 82 are disposed between the movable conducting rod 58 and the conducting rod spacers 80, to provide a conducting path therebetween. Thus, a continuous current path is established from the movable conducting rod 58 through the spring loaded rollers 82, through the spacers 80, through the conducting

plates

76 and 78, into conductor 20.

A porcelain tie rod 80 may be provided between the frame 26 for operating mechanism30 and the plate 78 to increase the rigidity of the

structure comprising members

76, 78 and 80. As discussed previously, a porcelain operating rod 40 is provided to directly connect the movable conducting rod 58 to the operating mechanism 30. By coupling the porcelain rod 40 directly to the operating rod 58, several advantages over prior art vacuum breakers as described in US. Pat. No. 3,603,753 are achieved. By placing the porcelain operating rod 40 in the linkage train after the travel of the operating mechanism 30 has been reduced a relatively massive moving body, the porcelain operating rod 40, is moved closer to the center of rotation. Thus, energy required to accelerate the porcelain operating rod 40 has been reduced by approximately a factor of 4, since the distance to the center of rotation was cut in half. By making this change, the size of the closing spring 32 necessary to operate the breaker is reduced, and wear and tear on the operating mechanism 30, during operation, is reduced. By connecting the porcelain operating rod 40 directly to the movable operating rod 58, the entire operating lever assembly 38 is kept at ground potential. By keeping all of the operating assembly 38 at ground potential, electrical clearance from the operating mechanism 30 to energized parts is improved.

Another advantage of connecting the porcelain operating rod 40 directly to the movable conducting rod 58 is that the force supplied to the operating rod is very nearly linear. That is, the operating force applied is generally parallel to the longitudinal axis of the vacuum interrupter 12. By applying a linear force with a very small transverse component to the conducting rod 58, stress on the vacuum interrupter guide bearings and the bellows 62 is reduced. An operating linkage with operating rod is placed or disposed to operate linearly and parallel to the axis of the interrupter and connected directly to the moving conducting rod 58, where there is little or no rotational inertia and very little stroke allows the insulating operating rod 40 to be made of relatively heavy porcelain. If the operating rod 40 were in the linkage train closer to the end of the operating lever assembly 38 as shown in prior art US. Pat. No. 3,603,753, it would have high rotational inertia and be moving at a much higher velocity and require higher levels of energy than an operating rod 40 placed as shown in the instant application. By placing operation rod 40 shown in the instant application, the size of spring 32 can be reduced over the prior art sizeand electrically superior porcelain rather than lighter weight plastic can be used for the material of the rod 40. These higher velocities and higher energy levels required in prior art breakers might necessitate the use of an insulating material other than porcelain for the operating rod 40. Other advantages of near linear motion of the operating rod 40 are that it allows the use of a simple control mechanism for transferring current from the movable conducting rod 58 to conductor 20 and that it simplifies guiding and reduces friction in the guides of the movable conducting rod 58. With the operating linkages 38 at high potential and close to the interrupter as in prior art the side forces on the movable rod 58 are greater.

Electrical connection is made to the top stationary rod 56 of the vacuum interrupter 12 by means of two clamping

plates

86 and 88. As can be seen in FIGS. 5, 6 and 8

Clamping plates

86 and 88, of the general type described and claimed in copending application Ser. No. 172,075 filed Aug. 16, 1971 by Norman Davies, are secured to the stationary rod 56 by means of a clamping bolt 90 and they are secured to the left hand portion 13 of upper terminal member 18 by bolts 92. A s'can best be seen in FIG. 7 and FIG. 9,

plates

86 and 88 have a slot 87. As bolt 90 is tightened, slot 87 tends to collapse and

connector plates

86 and 88 come into high pressure engagement with stationary rod 56. 8

Vacuum interrupter 12 has butt-type contacts and 52 which are closed at high speed. In order to reduce contact bounce and to reduce the impact forces on the upper conductor member 18 and on the porcelain pole unit 22 flexibility or resilience must be provided in the

interrupter clamping plates

86 and 88. As can best be seen in FIG. 8 which shows the vacuum interrupter l2 shortly after contact engagement, the clamping

plates

86 and 88 act as leaf springs to provide this resilience.

As can be seen in FIG. 8 and FIG. 9, the stationary end cap 44 bows in an upward direction to allowfor slight upward movement of the stationary contact upon initial contact engagement. This upward flexing of the stationary end cap 44 also reduces the tension force in the envelope 42 and is taken up in the

resilient clamping members

86 and 88. Although upward flexing of the stationary end cap 44 during initial contact engage ment is desirable, to prevent contact bounce and to reduce the resulting force on the pole unit 22, downward flexing of the end cap 44 during circuit interruptionis undesirable, since this increases the weld break problem by decreasing the forces necessary to break welded contacts. As the operating mechanism 30 applies a downward thrust on the movable rod 58, the nonmoving stationary rod 56 must react in the opposite diber 18 since the

upper clamping plates

86 and 88 are' flexible for reasons given hereinbefore. By forming the ends of clamping

plates

86 and 88 which are held by the clamping bolt 90 into a generally C-shaped configuration and by extending the C-shaped portion of clamping

plates

86 and 88 to the outer diameter of the vacuum interrupter l2, downward flexing of stationary end cap 44 during circuit interruption can be reduced or eliminated. If additional stiffness of the stationary rod 56 from movement in the downward direction is desired, a cross beam 94 as illustrated in FIGS.'6 through 9 can be provided. Stiffening of the stationary end cap by the clamping

plates

86 and 88 and/or the cross beam 94 results in the generation of high forces for breaking welds. Thus, the end cap 44 is stiffened in one direc- ,tion, it can flex in an upward direction as desired but downward movement is limited by the clamping

plates

86 and 88 and/or the cross beam 94. The reaction force necessary to hold the stationary contacts against slight downward movement during circuit interuption is transferred through compression of the ceramic envelope 42 of the vacuum interrupter 12 to the lower end cap 46 which is held rigidly to conducting plates 76. The envelope 42 is very strong in compression. Such a construction by providing an upper terminal mounting that is flexible in one direction only can double or triple the weld breaking forces on welded

contacts

50 and 52 in a vacuum interrupter 12 without adding to the energy supplied by the operating mechanism 30. As shown in FIGS. 6 through 9, when it is desired to add a cross beam 94 for additional stiffness, the top portion 96 of stationary rod 56 is threaded and a nut 98 is used to force the clamping

plates

86 and 88 tightly against the stiffening cross beam 94. Note that the stiffening cross beam 94 extends in the phase-to-phase or side-toside direction and not from front to back, this is necessary to allow the

clamping plates

86 and 88 to act as leaf springs and to take up flexing of the end'cap 44 in the upward direction.

An electrically insulating barrier 100 which can be pivoted in a clockwise direction as shown in FIGS, 1 to 3, to expose the vacuum interrupters 12, is also pro-" vided. The barrier 100 is pivotally fastened to the pole support 22 by means of U-shaped brackets 102 and pins l04. The vacuum-type circuit breaker is shipped I from the factory completely assembled with the main barrier assembly 100 in place. The breaker 10 may be lifted and moved with the barrier 100 on the breaker. In order to either tilt the barrier 100 back or to remove the barrier 100 from the breaker it is necessary that the breaker 10 be removed completely from the switchgear cell. This is a safety feature intended for the protection of operating-personnel. To gain access to the vacuum interrupters 12 after the breaker 10 has been removed from the switchgear cell, the barrier 100 is rotated around pivot pins 104 until the upper edge 106 of the barrier 100 comes to rest on the floor behind the breaker 10. The barrier cannot be removed or tilted around pins 104 while the circuit breaker 10 isin the switchgear cell. The switchgear cell is constructed so that when the breaker 10 is positioned therein, the upper edge 106 of barrier 100 is in close proximity to the top of the cell and any appreciable rotation of barrier 100 is prevented. The barrier 100 has several advantages over prior art insulating barriers for use on vacuum circuit breakers 10. One advantage is that the barrier is generally non-removable yet quick and easy access can be had to the vacuum interrupter 12 after the breaker 10 is removed from the switchgear cell. Also the breaker 10 can be crane-lifted and moved with the barrier 100 in place on the breaker 10. Also the barriers can be shipped on the breaker and thereby eliminate crating for separate shipment.

I claim:

1. A horizontal draw-out type vacuum circuit interrupter for metal clad switchgear comprising:

a plurality of V vacuum-type circuit interrupters mounted in a side-by-side relationship wherein each of said vacuum type circuit interrupters comprises,

an insulating envelope being highly evacuated and having a tubular shape,

a first end cap sealing one end of said insulating envea second end cap sealing the other end of said insulating envelope,

a stationary contact disposed within said insulating envelope,

a movable contact disposed within said insulating en- 7 velope movable between a first position in-engagement with said stationary contact and a second position spaced from said stationary contact to establish an arcing gap therebetween,

a movable conducting rod connected to said movable contact and passing through said first end cap,

a stationary conducting rod connected to said stationary contact and passing through and connected to said secondend cap; V

an upper terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; V

a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member each of said resilient terminal connectors being electrically connected at one end to said stationary conducting rod of said vacuum interrupter and at the respective jopposite'end to said upper uum interrupter and at the respective opposite end 7 able conducting rod to said rigid terminal connec-- tor;

an'operating mechanism for the simultaneous operation of all the vertically disposed vacuum-type circuit interrupters.

2. A horizontal draw-out type circuit interrupter for metal clad switchgear comprising:

a plurality of vacuum-type circuit interrupters mounted in afside-byaside relationship wherein each of said vacuum circuit interrupters comprises,

a stationary contact,

a movable contact movable between a first position in engagement with said stationary contact and a second position spaced from said stationary contact to establish an arcing gap therebetween,

a highly evacuated tubular insulating envelope having said stationary contact and said movable contact disposed therein,

a conducting movable rod connected to said movable contact,

a stationary conducting rod connected to said stationary contact;

an upper terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter;

a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member, each of said resilient terminal connectors being electrically connected at one end to said stationary conducting rod of said vacuum interrupter and at the respective opposite end to said upper terminal member;

a lower terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter;

a rigid terminal connector disposed between each vacuum interrupter and associated lower terminal member, each of said rigid terminal connectors being rigidly connected at one end to said vacuum interrupter and at the respective opposite end to said lower terminal member;

roller contact means for electrically connecting said movable conducting rod to said rigid terminal connector;

an operating mechanism for the simultaneous operation of all the vertically disposed vacuum type circuit interrupters.

3. A vacuum-type draw-out circuit breaker as claimed in claim 2, including: an insulating operating rod mechanically connected between said conducting movable rod and said operating mechanism to electrically insulate all parts of said mechanical operating mechanism from said vacuum interrupter.

4. The combination as claimed in claim 3, wherein said insulating operating rod comprises porcelain, and said insulating operating rod is directly connected to said movable operating rod.

5. Avacuum-type circuit breaker as claimed in claim 2, including: a stationary end cap for said vacuum interrupter, said stationary end cap attached in vacuum tight relationship with said stationary conducting rod and said highly evacuated insulating envelope, stiffening means to provide stiffness for said stationary end cap and allowing said stationary end cap to flex substantially in one direction only. l

6. The combination as claimed in claim 5, wherein said stiffening means comprises: a cross beam extending to the outer perimeter of said highly evacuated insulating envelope, said cross beam positioned in close proximity to said stationary conducting rod and said cross beam lying in a plane generally parallel to the formed portion extendingto the-outer diameter of said highly evacuated insulating envelope and said formed portion associated with each of said vacuum interrupters lying in a common plane defined by the formed portions associated with said plurality of vacuum type circuit interrupters.

8. The combination as claimed in claim 7, wherein: said formed portion is C-shaped; said resilient terminal connector is slotted and has an openingthere-through located on the slot through which said stationary conducting rod passes; including, a clamping bolt, disposed in the C-shaped formed portion of said resilient terminal connector, extending to the outer diameter of said highly evacuated insulating envelope; and said clamping bolt retained in the C-shaped portion so that as said clamping bolt is tightened the slotted portion of said resilient terminal connector is forced into high pressure engagement with said stationary conducting rod.-

9. A horizontal draw-out type vacuum circuit interrupter for metal clad switchgear comprising;

a plurality of vacuum type circuit interrupters mounted in a sideby-side relationship, wherein each of said vacuum type circuit interrupters comprises an evacuated housing, a pair of relatively separable contacts disposed within said evacuated housing, a first vacuum interrupter terminal means electrically connected to one of said pair of contacts and having a first terminal outside of said evacuated housing, and a second vacuum interrupter terminal means electrically connected to the other of said pair of contacts and having a second terminal outside of said evacuated housing;

a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member and being electrically connected at one end to said first vacuum interrupter terminal and at the opposite end to said upper terminal member;

a rigid terminal connector disposed between each vacuum interrupter and associated lower terminal member and being electrically connected at one end to said second vacuuminterrupter terminal means and at the opposite end to said lower terminal member; l I

an operating mechanism for thesimultaneous operating of all the vertically disposed vacuum type circuit interrupters; and including,

a truck for said draw-out type vacuum circuit interrupter, a housing for said operating mechanism mounted'on said truck, insulating support means connected between said housing and said lower terminal member to rigidly support said lower terminal member with respect to said housing.

10. The combination as claimed in claim 9, wherein said insulating support means comprises a porcelain rod.

11. A horizontal draw-out type vacuum circuit interrupter for metal clad switchgear comprising;

a plurality of vacuum type circuit interrupters mounted in a side-by-side relationship, wherein each of said vacuum type circuit interrupters comprises an evacuated housing, a pair of relatively separable contacts disposed within said evacuated housing, a first vacuum interrupter terminal means electrically connected to one of said pair of contacts and having a first terminal outside of said 7 evacuated housing, and a second vacuum interrupter terminal means electrically connected to the other of said pair of contacts and having a second terminal outside of said evacuated housing;

a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member and being electrically connected at one end to said first vacuum interrupter terminal means and at the opposite end to said upper terminal member;

a rigid terminal connector disposed between each vacuum interrupter and associated lower terminal member and being electrically connected at one end to said second vacuum interrupter terminal means and at the opposite end to said lower terminal member;

an operating mechanism for the simultaneous operation of all the vertically disposed vacuum type circuit interrupters; and including, an insulating barrier means being manually movable between a raised position and an operating position said insulating barrier means being pivotable around an axis fixed with respect to said vacuum interrupters, a portion of said insulating barrier being disposed between said vacuum interrupters when said insulating barrier means is in the operating position during operation of said circuit breaker to increase the insulating characteristics between different potential parts within said circuit interrupter.

12. The combination as claimed in claim 11, including:

ually pivoted to a raised position.

Claims

1. A horizontal draw-out type vacuum circuit interrupter for metal clad switchgear comprising: a plurality of vacuum-type circuit interrupters mounted in a side-by-side relationship wherein each of said vacuum type circuit interrupters comprises, an insulating envelope being highly evacuated and having a tubular shape, a first end cap sealing one end of said insulating envelope, a second end cap sealing the other end of said insulating envelope, a stationary contact disposed within said insulating envelope, a movable contact disposed within said insulating envelope movable between a first position in engagement with said stationary contact and a second position spaced from said stationary contact to establish an arcing gap therebetween, a movable conducting rod connected to said movable contact and passing through said first end cap, a stationary conducting rod connected to said stationary contact and passing through and connected to said second end cap; an upper terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member, each of said resilient terminal connectors being electrically connected at one end to said stationary conducting rod of said vacuum interrupter and at the respective opposite end to said upper terminal member; a rigid lower terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a rigid terminal connector disposed between each vacuum interrupter and associated lower terminal member, each rigid terminal connector being connected at one end to said first end cap of said vacuum interrupter and at the respective opposite end to said rigid lower terminal member; conducting means electrically connecting said movable conducting rod to said rigid terminal connector; an operating mechanism for the simultaneous operation of all the vertically disposed vacuum-type circuit interrupters.

2. A horizontal draw-out type circuit interrupter for metal clad switchgear comprising: a plurality of vacuum-type circuit interrupters mounted in a side-by-side relationship wherein each of said vacuum circuit interrupters comprises, a stationary contact, a movable contact movable between a first position in engagement with said stationary contact and a second position spaced from said stationary contact to establish an arcing gap therebetween, a highly evacuated tubular insulating envelope having said stationary contact and said movable contact disposed therein, a conducting movable rod connected to said movable contact, a stationary conducting rod connected to said stationary contact; an upper terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member, each of said resilient terminal connectors being electrically connected at one end to said stationary conducting rod of said vacuum interrupter and at the respective opposite end to said upper terminal member; a lower terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a rigid terminal connector disposed between each vacuum interrupter and associated lower terminal member, each of said rigid terminal connectors being rigidly connected at one end to said vacuum interrupter and at the respective opposite end to said lower terminal member; roller contact means for electrically connecting said movable conducting rod to said rigid terminal connector; an operating mechanism for the simultaneous operation of all the vertically disposed vacuum type circuit interrupters.

5. A vacuum-type circuit breaker as claimed in claim 2, including: a stationary end cap for said vacuum interrupter, said stationary end cap attached in vacuum tight relationship with said stationary conducting rod and said highly evacuated insulating envelope, stiffening means to provide stiffness for said stationary end cap and allowing said stationary end cap to flex substantially in one direction only.

6. The combination as claimed in claim 5, wherein said stiffening means comprises: a cross beam extending to the outer perimeter of said highly evacuated insulating envelope, said cross beam positioned in close proximity to said stationary conducting rod and said cross beam lying in a plane generally parallel to the plane defined by the longitudinal axis of said plurality of vacuum type circuit interrupters.

7. The combination as claimed in claim 5, wherein said stiffening means comprises: a formed portion on the end of said resilient terminal connector, said formed portion extending to the outer diameter of said highly evacuated insulating envelope and said formed portion Associated with each of said vacuum interrupters lying in a common plane defined by the formed portions associated with said plurality of vacuum type circuit interrupters.

8. The combination as claimed in claim 7, wherein: said formed portion is C-shaped; said resilient terminal connector is slotted and has an opening there-through located on the slot through which said stationary conducting rod passes; including, a clamping bolt, disposed in the C-shaped formed portion of said resilient terminal connector, extending to the outer diameter of said highly evacuated insulating envelope; and said clamping bolt retained in the C-shaped portion so that as said clamping bolt is tightened the slotted portion of said resilient terminal connector is forced into high pressure engagement with said stationary conducting rod.

9. A horizontal draw-out type vacuum circuit interrupter for metal clad switchgear comprising; a plurality of vacuum type circuit interrupters mounted in a side-by-side relationship, wherein each of said vacuum type circuit interrupters comprises an evacuated housing, a pair of relatively separable contacts disposed within said evacuated housing, a first vacuum interrupter terminal means electrically connected to one of said pair of contacts and having a first terminal outside of said evacuated housing, and a second vacuum interrupter terminal means electrically connected to the other of said pair of contacts and having a second terminal outside of said evacuated housing; an upper terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member and being electrically connected at one end to said first vacuum interrupter terminal and at the opposite end to said upper terminal member; a lower terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a rigid terminal connector disposed between each vacuum interrupter and associated lower terminal member and being electrically connected at one end to said second vacuum interrupter terminal means and at the opposite end to said lower terminal member; an operating mechanism for the simultaneous operating of all the vertically disposed vacuum type circuit interrupters; and including, a truck for said draw-out type vacuum circuit interrupter, a housing for said operating mechanism mounted on said truck, insulating support means connected between said housing and said lower terminal member to rigidly support said lower terminal member with respect to said housing.

11. A horizontal draw-out type vacuum circuit interrupter for metal clad switchgear comprising; a plurality of vacuum type circuit interrupters mounted in a side-by-side relationship, wherein each of said vacuum type circuit interrupters comprises an evacuated housing, a pair of relatively separable contacts disposed within said evacuated housing, a first vacuum interrupter terminal means electrically connected to one of said pair of contacts and having a first terminal outside of said evacuated housing, and a second vacuum interrupter terminal means electrically connected to the other of said pair of contacts and having a second terminal outside of said evacuated housing; an upper terminal member associated with each vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a resilient terminal connector disposed between each vacuum interrupter and associated upper terminal member and being electrically connected at one end to said first vacuum interrupter terminal means and at the opposite end to said upper terminal member; a lower terminal member associated with eAch vacuum interrupter and horizontally disposed with respect to the longitudinal axis of said vacuum interrupter; a rigid terminal connector disposed between each vacuum interrupter and associated lower terminal member and being electrically connected at one end to said second vacuum interrupter terminal means and at the opposite end to said lower terminal member; an operating mechanism for the simultaneous operation of all the vertically disposed vacuum type circuit interrupters; and including, an insulating barrier means being manually movable between a raised position and an operating position said insulating barrier means being pivotable around an axis fixed with respect to said vacuum interrupters, a portion of said insulating barrier being disposed between said vacuum interrupters when said insulating barrier means is in the operating position during operation of said circuit breaker to increase the insulating characteristics between different potential parts within said circuit interrupter.

12. The combination as claimed in claim 11, including: a truck for said draw-out type vacuum circuit interrupter; said insulating barrier means being pivotally mounted to said truck; a switchgear cell into which said truck is inserted for operation of said draw-out type vacuum circuit interrupter; stopping means rigidly connected to said insulating barrier means and being disposed in close proximity to said switchgear cell when said truck is inserted in said switchgear cell to substantially prevent said insulating barrier means from being manually pivoted to a raised position.