Gas-insulated switchgear equipment includes a plurality of vertical-type circuit breakers electrically connected in series, and outside led-out devices connected to connected portions of a series connection of the circuit breakers and at least one main bus bar connected to two of the plurality of circuit breakers located at both ends of the series connection. In the equipment, the circuit breakers are a vertical type circuit breaker and are arranged on a substantial straight line and led-out portions for leading out terminals formed in the circuit breakers in a direction perpendicular to a direction of the arrangement of the circuit breakers, and connecting bus bars interconnecting the circuit breakers in series and the outside led-out devices are disposed on one side of the circuit breakers and the at least one main bus bar is disposed on the other side of the circuit breakers. Therefore, the fixing area can be reduced and the connection between the at least one main bus bar and the circuit breakers and between the circuit breakers and the outside led-out devices can be easily established.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to gas-insulated switchgear equipment and, 
more particularly, to gas-insulated switchgear equipment constituted by 
connecting a plurality of vertical-type circuit breakers. 
2. Description of the Prior Art 
An example of conventional gas-insulated switchgear equipment of this type, 
such as the one shown in FIG. 10 on page 147 of BROWN BOVERI REV. vol. 4, 
No. 73 is known. 
The gas-insulated switchgear equipment is called a one-and-a-half circuit 
breaker system and in the system, a pair of gas-insulated bus bars are 
disposed in parallel and three horizontal-type circuit breakers are 
horizontally disposed on a straight line bridging the pair of bus bars. 
The circuit breakers are connected in series by connecting bus bars 
disposed between the circuit breakers. 
Since this type of gas-insulated switchgear equipment uses connecting bus 
bars which are disposed between the circuit breakers, a large fixing space 
for the equipment is needed in a straight line direction of the 
disposition of the circuit breakers. 
Although the described example of a gas-insulated switchgear equipment is 
constructed by using horizontal-type circuit breakers, it is also possible 
to constitute the same gas-insulated switchgear equipment by using 
vertical-type circuit breakers. However, this method not only has the 
above-described problem but also needs to devise a disposition of the bus 
bars as well as connections between the circuit breakers and between the 
circuit breakers and the bus bars. 
In view of these problems, gas-insulated switchgear equipment such as 
one-and-a-half circuit breaker systems and ring bus system using a 
plurality of vertical-type circuit breakers have been proposed in Japanese 
Patent Unexamined Publication Nos. 57-193911, 57-211915 (U.S. counterpart: 
U.S. Pat. No. 4,503,481), and 59-6706. In this equipment, a pair of main 
bus bars are disposed parallel to a fixing base and a plurality of 
vertical-type breakers are disposed at one side of the bus bars generally 
in parallel to the bus bars. Cable heads provided as outside led-out means 
are disposed at the other side of the main bus bar which is the most 
remote from the breakers. Gas-insulated connecting bus bars electrically 
connected between the juxtaposed circuit breakers, between the circuit 
breakers and the main bus bars and between the circuit breakers and the 
cable heads. 
In the gas-insulated switchgear equipment, each of the vertical-type 
circuit breakers has led-out portions extending from its breaking section 
on the one side facing the main bus bars. Therefore, there is no element 
on the other side of each of the circuit breakers. This is advantageous in 
terms of inspection and maintenance of the circuit breakers. However, the 
equipment has disadvantages whereby the connecting structure using the 
connecting bus bars becomes complex and the fixing area to fix the 
equipment becomes when taking connecting operations into consideration. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide gas-insulated 
switchgear equipment capable of disposing the circuit breakers closer to 
each other and reducing the fixing area thereof. 
It is another object of the present invention to provide gas-insulated 
switchgear equipment in which electrical connections between the circuit 
breakers and between the breakers and the main bus bars are easily 
established. 
Gas-insulated switchgear equipment according to the invention comprises a 
plurality of circuit breakers electrically connected in series, outside 
led-out means connected to each of connecting portions of the circuit 
breakers, and at least one main bus bar connected to two of the plurality 
of circuit breakers disposed at ends of the electrical connection, in 
which the plurality of circuit breakers are of a vertical type and 
arranged on a straight line and have led-out portions of terminals thereof 
in directions perpendicular to the direction of the arrangement of the 
breakers and connecting bus bars for connecting the circuit breakers in 
series and the outside led-out device are disposed on one side of the 
circuit breakers while the main bus bar is disposed on the other side of 
the circuit breakers. 
With the arrangement, the equipment of the invention can dispose the 
circuit breakers closer to each other in comparison with the prior art 
equipment in which the connecting bus bars are disposed between the 
circuit breakers, thereby reducing the fixing area. Further, since the 
connecting bus bar and the outside led-out device are arranged at one side 
of the arrangement of the circuit breakes and the main bus bars are 
disposed at the other side, it is possible to simplify the electrical 
connections among the elements.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Embodiments of the present invention will be described hereinafter with 
reference to the accompanying drawings. A circuit shown in FIG. 4 is 
called a one-and-a-half circuit breaker system to which gas-insulated 
switchgear equipment according to the present invention is applied. Three 
circuit breakers CB.sub.1, CB.sub.2 and CB.sub.3, having at their opposite 
sides disconnecting switches DS.sub.11 and DS.sub.12, DS.sub.21 and 
DS.sub.22, DS.sub.31 and DS.sub.32, are placed on a fixing base and 
electrically connected in series. Outside led-out means 5A and 5B such as 
cable heads are led out from points between the disconnecting switches. 
The three circuit breakers CB.sub.1, CB.sub.2, and CB.sub.3 connected in 
series are connected between main bus bars 1 and 7. 
Gas-insulated switchgear equipment based on the circuit arrangement is 
shown in FIG. 1. The circuit breakers CB.sub.1, CB.sub.2, and CB.sub.3 are 
of a vertical type and include a breaking unit adapted for three or one 
phase disposed in a grounding tank which is filled with insulating gas. 
The circuit breakers CB.sub.1, CB.sub.2, and CB.sub.3 are disposed on a 
straight line. Led-out portions 11, 13, 14, and 15 of terminals and 
connecting bus bars 3, 4, which are used to electrically interconnect the 
circuit breakers as indicated by broken lines in FIG. 1, are provided at 
one side of the circuit breakers CB.sub.1, CB.sub.2, and CB.sub.3. In more 
detail, as shown in FIGS. 1 to 3, the circuit breaker CB.sub.1 has a 
led-out portion 11 provided at an upper portion thereof that leads out an 
upper terminal of the breaking unit to the one side, and the adjacent 
circuit breaker CB.sub.2 has a led-out portion 13 provided at an upper 
portion thereof and another led-out portion 14 provided at a lower portion 
thereof which lead upper and lower terminals of the breaking unit to the 
one side, respectively. A connecting bus bar 4 to interconnect the led-out 
portions 11, 13 is also disposed at the one side. The circuit breaker 
CB.sub.3 has, as shown in FIGS. 1 to 3, a led-out portion 15 at a lower 
portion thereof which leads a lower terminal of the breaking unit to the 
one side. A connecting bus bar 3 to interconnect the led-out portions 14, 
15 is also disposed at the one side. A lower terminal of the breaking unit 
of the circuit breaker CB.sub.1 is led by a led-out portion 12 provided at 
a lower portion of the circuit breaker to the other side of the circuit 
breaker and is connected to a main bus bar 1 extending in a direction of 
the arrangement of the circuit breakers. Similarly, as can be understood 
from FIGS. 1 to 3, an upper terminal of the breaking unit of the circuit 
breaker CB.sub.3 is led by a led-out portion 16 extending from the other 
side of the circuit breaker and is connected to a main bus bar 7 which 
extends above and generally in parallel with the main bus bar 1. In the 
embodiment, as shown in FIG. 1, a disconnecting switch DS.sub.11 for the 
circuit breaker CB.sub.1 is provided within the main bus bar 1 and a 
disconnecting switch DS.sub.12 is provided within the connecting bus bar 
4. A disconnecting switch DS.sub.21 for the circuit breaker CB.sub.2 is 
provided within the connecting bus bar 4, and a disconnecting switch 
DS.sub.22 is provided within the connecting bus bar 3. A disconnecting 
switch DS.sub.31 for the circuit breaker CB.sub.3 is provided within the 
connecting bus bar 3 and the disconnecting switch DS.sub.32 is provided 
within the main bus bar 7 extending at a higher level. 
As shown in FIGS. 1 and 2, outside led-out devices 5A and 5B are connected 
to side portions of the connecting bus bars 3 and 4. Each of the outside 
led-out devices 5A and 5B that extends downward comprises a casing, a 
connecting conductor disposed in the casing, and an insulated terminal 
while establishing gas-insulation. That is, the outside led-out device 5A 
is connected to a side portion of the connecting bus bar 4 interconnecting 
the circuit breakers CB.sub.1 and CB.sub.2 and the outside led-out device 
5B is connected to a side portion of the connecting bus bar 3 
interconnecting the circuit breakers CB.sub.2 and CB.sub.3, and these 
devices are disposed such that they extend downward from their connecting 
portions. 
Accordingly, the outside led-out device 5A is connected between the 
disconnecting switches DS.sub.12 and DS.sub.21 in the connecting bus bar 
4. Similarly, the outside led-out device 5B is connected between the 
disconnecting switches DS.sub.22 and DS.sub.31 in the connecting bus bar 
3. 
The circuit arrangement shown in FIG. 4 will now be described. It should be 
noted here that the led-out portions 11, 13, 14, 15 and the connecting bus 
bars 3, 4 used to establish electrical connection between the circuit 
breakers CB.sub.1, CB.sub.2, CB.sub.3 are not placed on portions of the 
circuit breakers facing each other. With the construction, it is possible 
to reduce a distance between, for example, the circuit breakes CB.sub.1, 
CB.sub.2 to an extent of an axial length of the connecting bus bar 4 
inclusive the disconnecting switches DS.sub.12, DS.sub.21. 
In this embodiment, as three circuit breakers CB.sub.1, CB.sub.2, CB.sub.3 
are arranged on the straight line and are electrically connected in 
series, two connecting bus bars 3, 4 are required. However, as the led-out 
portions 11, 13 respectively provided at the upper portion of the circuit 
breakers CB.sub.1, CB.sub.2 are interconnected by the connecting bus bar 3 
and the led-out portions 14, 15 respectively provided at the lower portion 
of the circuit breakers CB.sub.2, CB.sub.3 are interconnected by the 
connecting bus bar 4, it is possible to vertically dispose the both 
connecting bus bars 3, 4 substantially parallel with each other with a 
linear structure, so that the structure thereof can be made simple. In 
this construction, the positions of connections between the circuit 
breakers and the outside led-out devices 5A and 5B and the heights of the 
devices are different from each other, and the connecting position of the 
outside led-out device 5B connected to the connecting bus bar 3 coincides 
with a level of the led-out portion 15 leading out the lower terminal of 
the circuit breaker CB.sub.3, as shown in FIGS. 2, 3, 5. In a case where 
the outside led-out device 5B is a cable head, the height does not become 
a disadvantage by structuring the cable head as illustrated in FIG. 6. 
That is, internal conductors 9, which are provided within the connecting 
bus bar 3 are led through a connecting portion l7a formed in a portion of 
cable head casing 17 and are turned upward along a side of cable heads 6 
and are connected to upper terminals of the cable heads 6. Since 
conductors 8 turned upward face insulators of the cable heads 6, they can 
be disposed within the cable head casing 17 without increasing the 
diameter of the casing 17 while a suitable degree of insulation from the, 
cable head casing 17 is maintained. Therefore, when cable heads are used, 
it is possible for the outside led-out devices 5A, 5B to have identical 
appearances except for the positions of the portions connected to the 
connecting bus bars 3, 4. 
In order to make the outside led-out device 5A connected to the connecting 
bus bar 4 and the outside led-out device 5B connected to the connecting 
bus bar 3 have the same height, an arrangement, for example as shown in 
FIG. 7, may be adapted in which an upwardly extending intermediate 
connecting bus bar 3a is connected at its lower end of the lower led-out 
portion 15 of the circuit breaker CB.sub.3 and is connected at its upper 
end to the outside led-out device 5B at the same level as the led-out 
portions of the circuit breakers CB.sub.1, CB.sub.2. With this 
construction, the outside led-out devices 5A, 5B have the same height, so 
that parts for the devices can be commonly used and a side profile of the 
gas-insulated switchgear equipment can be a suitable profile. 
The connecting bus bars 3, 4 and the intermediate connecting bus bar 3a, 
which are used to connect the circuit breakers CB.sub.1, CB.sub.2, 
CB.sub.3 in series so as to construct a plurality of gas-insulated 
switchgear devices of the one-and-a-half circuit breaker type, may be of a 
type having a cylindrical casing in which a connection conductor in a 
gas-insulation manner is disposed similarly with the well known main bus 
bars 1, 7, or of other specifically designed types. 
FIGS. 8 to 10 show gas-insulated switchgear equipment of another embodiment 
according to the present invention. This embodiment is based on a ring bus 
bar type of circuit arrangement shown in FIG. 10, in which the circuit 
breakers CB.sub.1, CB.sub.3 located at both ends of a series connection of 
three circuit breakers are connected to a main bus bar 20. 
This embodiment will be described with reference to FIG. 8 and FIG. 9. In 
this embodiment, components identical to those of the first embodiment are 
indicated by the same reference characters and descriptions for the same 
constructions are omitted. This embodiment will be described with respect 
to points of difference from the first embodiment. 
As can be understood from comparison between the circuit shown in FIG. 4 
and the circuit shown in FIG. 10, the connection between the circuit 
breakers CB.sub.1 and CB.sub.2 and the connection between the circuit 
breakers CB.sub.2 and CB.sub.3 are the same as the circuit shown in FIG. 4 
and only the connection between the circuit breakers CB.sub.1 and CB.sub.3 
is different. That is, as shown in FIGS. 8 and 9, a led-out portion 12 
which leads out a lower terminal of the circuit breaker CB.sub.1 in an 
opposite side to the connecting bus bar 4 side is connected to a portion 
of a main bus bar 20 which extends downward from the main bus bar 20 so 
that it is generally L-shaped, while a led-out portion 16 which leads out 
an upper terminal of the circuit breaker CB.sub.3 in an opposite side to 
the connecting bus bar 3 side is connected to the main bus bar 20 which 
extends at a higher level in a direction of an arrangement of the circuit 
breakers, thus constituting gas-insulated switchgear equipment 
corresponding to the ring bus bar system shown in FIG. 10. The main bus 
bar 20 may be disposed so as to extend at a lower level. In this 
construction also, the circuit breakers CB.sub.1, CB.sub.2 and CB.sub.3 
are arranged on a straight line and the main bus bar 20 is disposed at one 
side of the arrangement of the circuit breakers and is extended in the 
direction of the arrangement, and the connecting bus bars 3, 4 and the 
outside led-out devices 5A, 5B are disposed on the other side as with the 
first embodiment. Therefore, the circuit breakers can be disposed closer 
to each other in the direction of the arrangement, so that total fixing 
space can be reduced. 
As can be understood from the above-described embodiments, the present 
invention can be applied to a gas-insulated switchgear system, in which a 
plurality of gas-insulated switchgear devices are provided, in each of 
which a plurality of circuit breakers are arranged on a straight line. One 
or two main bus bars are provided, extending in the direction of the 
arrangement, and the circuit breakers and the main bus bar or bars are 
interconnected. 
As described above, a plurality of vertical-type circuit breakers are 
closely arranged on a substantially straight line and connecting bus bars 
interconnecting the circuit breakers and outside led-out devices are 
provided on one side of the arrangement of the circuit breakers and one or 
more main bus bars are extended on the other side of the arrangement. 
Therefore, no connecting bus bars exist between opposite portions of the 
circuit breakers as in the case of the conventional system, so that a 
plurality of gas-insulated switchgear equipments can be closely disposed, 
thereby reducing the installation space. Also, electrical connection among 
the elements can be easily established.