US3089927A

US3089927A - Isolating switch arrangement

Info

Publication number: US3089927A
Application number: US6039A
Authority: US
Inventors: Foti Arem
Original assignee: ITE Circuit Breaker Co
Current assignee: ITE Circuit Breaker Co
Priority date: 1960-02-01
Filing date: 1960-02-01
Publication date: 1963-05-14
Anticipated expiration: 1980-05-14

Description

May 14, 1963 A. Fo'n 3,089,927

ISOLATING SWITCH ARRANGEMENT May 14, 1963 A'. FoTl 3,089,927

IsoLATING SWITCH ARRANGEMENT Filed Feb. 1, 1960 3 Sheets-Sheet 2 IN1/EN TOR. fsf/PEM F07/ May 14, 1963 A. FoTl 3,089,927

ISOLATING SWITCH ARRANGEMENT Filed Feb. 1, 1960 3 SheetsSheet 3 INVENTOR.

United States Patent Oiiice 3,56%,927 Patented May 14, 1963 3,089,927 ISLATING SWITCH ARRANGEWNT Arena Foti, Greensburg, Pa., assigner to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Feb. 1, 1966, Ser. No. 6,039 4 Claims. (Cl. 20d-48) The instant invention relates to high voltage protective equipment in general and more particularly to a novel arrangement for isolating circuit lbreakers from a high voltage transmission line.

Heretofore it has been standard practice in applying outdoor high voltage electrical equipment to utilize groupoperated disconnecting switches, one on the source side of the circuit breaker and the other on the load side. 'I'he prior art has also resorted to hook stick operated disconnect switches depend-ing upon the voltage range in question.

Between the two aforesaid commonly used circuit breaker disconnecting switch arrangements the hook stick disconnecting switch scheme is of lower cost since, in a manner of speaking, it entails no switch operating mechanism and utilizes less complicated switch components. Nevertheless, in both of the prior disconnecting switch arrangements previously noted the isolating switches are physically removed from the circuit breakers, being connected thereto by a bus conductor. Thus, the isolating switches require at least two contact supporting insulators for each bridging member of the switch.

The initial cost and physical space required tor insulators of high voltage equipment is relatively high. In addition, maintenance of the insulators in a clean condition entails considerable expense. Thus, mean-s for reducing the number of insulators required is highly desirable.

The instant invention comprises van isolating switch arrangement which requires a minimum number of insulatous. This is accomplished by utilizing a circuit breaker bushing las a common insula-tor ior the circuit breaker and isolating switch.

One embodiment of the instant invention comprises a contact which is secured to the circuit breaker bushing, an apparatus insulator supporting Ianother contact spaced at the required distance trom the breaker bushing contact, and la hook stick operated thrust type disconnecting blade to bridge these contacts. In another embodiment of this invention the bridging member between the two contacts is comprised of a iiexible cable yone end Iof which is secured to the circuit breaker bushing and the other end of which is provided with a contact plug that contains a pull-ring into which the stick-hook can be in-serted for making or breaking the circuit connection.

Still other embodiments of this invention comprise a bridging member which is pivoted at one end thereof to either the bushing or insulator mounted contact.

Accordingly, a prima-ry object of the instant invention is to prov-ide a novel high voltage isolating switch arrangement.

Still another object is to provide an isolating switch arrangement wherein a circuit breaker bushing is utilized as a common insulator for both the circuit breaker and disconnecting switch.

Still `another object is to provide `an isolating switch `arrangement including :a thrust type disconnecting blade supported by a circuit breaker bushing land positioned externally thereof for all positions `of the disconnect blade.

These as well `as other objects of the instant invention shall become readily apparent after reading the following description of the laccompanying drawings in which:

FIGURE 1 is a schematic side elevation of an embodiment of this invention utilizing a thrust type blade.

FIGURE 2 is a cross-section of the structure illustrated in FIGURE 1 'taken through line 2-2 looking in the direction of arrows 2-2.

FIGURE 3 is a fragmentary view ofthe isolating switch illustrated in FIGURES 1 and 2.

FIGURE 4 is an enlarged view illustrating in detail the upper contact of FIGURE 3 'and the contact latch construction.

FIGURE 5 is :a view similar -to FIGURE 2 illustrating another embodiment of this invention utilizing `a flexible conductor as the isolating switch bridging member.

FIGURE 6 is a fragmentary View illustrating a modication of the instant invention utilizing -a pivot switch blade which is operated downwardly for opening of the switch.

FIGURE 7 i-s van end View illustrating the contact receiving jaw rassembly of FIGURES 6 and 8.

FIGURE 8 is a fragmentary view illustrating still another embodiment fof this invention wherein a pivot switch blade is operated upwardly to effect opening of the switch.

Now referring t-o the figures and more particularly to FIGURES 1-4, high voltage transmission structure 1t) includes spaced supporting towers 1l, 12. Three energizing bus conductos 213-15 are supported in spaced parallel relationship between towers 11 'and 12 in a well known manner. Apparatus insul-

ators

17, 18 extend downwardly from platform 19` which extends between towers 11, 12. A iinst stationary contact assembly 21 of each of the isolating switches 20 is secured to one of the

insulators

17, 18 at the lower ends thereof. Conductors 22 electrically connect the stationary contact assemblies 21 at the lower ends [of insulators 18 to energizing buses 13-15.

Each isolating switch 20 further includes -a second stationary contact assembly 23 secured to the free end of circuit breaker bushing 24 and a thrust type blade 25 which bridges the gap between

contact assemblies

21, 23 when isolating switch 20 is closed. Circuit breaker 26 is of the -oil filled type described in detail in the F. H. Cole U.S. Patent 2,156,663, assigned to the General Electric Co., yand includes Ia tank like casing 27 with bushings 24 extending upwardly therefrom.

Bracket 29 extending from a side of casing 27 provides a platform for supporting grounding contact 2'8 which is positioned to receive the lower ends of switch blade 25 when isolating switch 20v is in the open position. Switch blade 25 comprises a vertically positioned hollow elongated member having ra bullet shaped nose 31 fat the upper end thereof. Also at the upper end of blade 25, below nose 31, is hook-ring 32 which is secured to blade 25 as by fastener 33. Latch member '34 is pivotally secured at 35 to hook-ring 32 and is biased in a clockwise direction about pivot 35 by torsion spring 36 which has one end thereof bearing against bracket extension 37 of hook-ring 32 and the other end thereof bearing against latch member 34. The upper end of lat-ch member 34 is provided with latch tip 38 which is adapted to be captured by cooperating ledge 39 of stationary contact assembly 21 and thereby prevent downward movement of blade 25.

Ledge 39 is lan inward extension of the flared portion 40 lat the lower end of the housing 4l of stationary contact assembly 21. The upper end of housing il is generally cylindrical. Disposed within this cylindrical p0rtion of housing 4l are a plurality 0f Contact lingers 42 whose upper ends are fixed by being clamped between housing 41 and the upper conducting lmember 43. Garter spring 43, disposed at the lower ends of contacts 42, biases contacts 42 inwardly into engagement with tip 31 of switch blade 25.

Latch 38 is released by `extending a hook tool into hook-ring 32 and exerting a downward thrust. This causes latch member 34 to pivot in a counterclockwise direction about pivot 35 so that latch tip 38 clears ledge 39. As blade 2:3 moves upward cam surface 38a of latch member 34 is engaged by latch ledge 39 and in this manner member 34 is cammed in a counter/clockwise direction until latch tip 38 moves above surface 39.

Lower stationary contact assembly 23 comprises a generally cylindrical housing 46. Housing extension 47 is clamped to terminal stud connector ed which is an integral part of the upper free end of circuit breaker bushing 24. VFastening means (not shown) xedly secures stationary contact assembly 23 to bushing 2f. at terminal 48. A plurality of spring contacts 49 are circularly arranged within housing 46 and secured thereto, by rivets 50, at the lower ends thereof. Garter spring 51 biases the upper ends of contacts 49 into engagement with the outer surface of switch blade 25.

When isolating switch 20 is operated from the closed position of FIGURE 3 to the open position switch blade Z5 moves axially through the central opening 52 of lower Contact housing 46. When hook-ring 32 reaches the position indicated by the dotted lines of FIGURE 3 isolating switch 20 is opened. At this time the lower end of switch blade 25 is in engagement with the contact fingers 55 of grounding contact 2S. Garter spring S6 biases the upper ends of contacts 55 into engagement with the outer surface of switch blade 25.

In the embodiment of FIGURES 1-4 with buses 13-15 at a potential of 138 kv. lower contact assembly 23 is typically positioned 16 feet above ground and upper contact assembly 21 is typically positioned 22 feet above ground.

In the embodiment of FIGURE 5 the rigid thrust type switch blade 25 is replaced by a flexible cable 60. One end of lexible cable 60 is lixedly secured to the upper end of circuit breaker bushing 2dr. The free end of cable 60 is provided with a hook-ring 32 and latch member 34 as well as bullet shaped member 31 as previously described in connection with FIGURES 1-4. In the embodiment of FIGURE 5 grounding contacts 61 are disposed with the open ends thereof facing downwardly so that an upper thrust is required to insert tip 31 therein. Grounding contacts 61 are of a constiuction substantially that of upper stationary contact assemblies 21.

Now referring `more particularly to FIGURES 6 and 7, isolating switch 70 comprises stationary contact assembly 71 mounted to the free end of circuit breaker bushing 24 by bolt means 72. Switch blade 73 is pivotally mounted at 74 to stationary contact assembly 71. In the closed position of switch 70 the free end of switch blade 73 is in engagement with stationary contact assembly 75, mounted to energizing bus 76 by member 77 which extends to the upper end of apparatus insulator 78.

Stationary contact assembly 75 comprises a plurality of spaced

spring contact fingers

79, 80 which are positioned to engage the oblong vshaped tip 81 of blade 73 at opposite surfaces thereof. Bolts 82 secure contact lingers 79, S to therdownwardly Vextending portion 03 of stationary contact 7S. Latch iingers 84, also secured to member 83, are provided with recesses S within which blade tip 81 is disposed in the closed position of isolating switch 70.

Hook-ring member S6 is pivotally mounted to blade 73 and operatively positioned between the bifurcated portions at the free end of blade tip S1. Hook-ring member v36 is provided with outwardly projecting paddles 37 which engage the downwardly ilared tree ends of latch members S4 when hook-ring 85 is rotated clockwise about `its pivot as a downward thrust is applied to switch blade 73. The spreading of latch members 84 releases blade tip S1 and permits blade 73 to be moved to the dotted line position of FIGURE 6 wherein isolating switch 7 0 is opened.

Means, indicated generally as S8, having one end secured to switch blade 73 and the other end secured to stationary contact assembly 71 is a spring means which comprises a device for exerting ra force to counterbalance the weight of switch blade 25 thereby relieving stationary assembly contacts 7S from an unnecessary mechanical load and also for reducing operating efforts. ln the einbodiment of FIGURES 6 and 7 switch blade 73 is gcnerally horizontal in the closed position of switch and is rotated downwardly in a clockwise direction about pivot 74 to oper-ate switch 70 to the open position indicated by dotted lines.

isolating switch of FIGURE 8 comprises a rigid elongated switch blade 101 pivoted at 102 to stationary contact assembly 103. Bolted means (not shown) secures stationary contact assembly 103 to the top of vertical insulatorrcolumn 104'. Energizing bus 105 is secured at one end thereof to stationary contact assembly 103 and in this manner is supported by insulator column 104.

The free end of switch blade 101, in the closed position of switch 100, is engaged by contact lingers 106 of stationary contact assembly 107. Bolted means (not shown) secures stationary contact assembly 107 to the top of conducting adapter 108 which is secured by nut 109 to terminal stud 110 at the upper end of circuit breaker bushing 111.

Pull-ring 112 is pivotally mounted at 113 to switch blade 101. Latch pry-out member 114 is pivotally mounted at 115 to blade tip 116. Link 117, pivotally secured at 118 to hook-ring l'member 112 and at 119 to latch pryout member 114, provides a connecting linkage whereby rotation of hook-ring member 112 brings about a corresponding rotation of latch pry-out member 114.

Latch pry-out member 114 is provided with outwardly extending paddles 120 which serve to `spread latch members 121 for release of blade tip 116 for movement of switch lblade 101 to its vertical position from its horizontal position, the vertical position being indicated by line A which is approximately 15 clockwise of the directed vertical. The operation of paddles 120 and latch members 121 is substantially as previously described in connection wtih paddles 87 and latch members 84 of FIG- URES 6 and 7. Spring counterbalancing means 126, `secured at one end to switch blade 101 and at the other end to stationary contact assembly 103 is provided to counterbalance the weight of switch blade 101 thereby relieving stationary contact assembly 107 of a substantial portion of mechanical stress and also reducing switch operating eiort.

Isolating switch 100 is operated from its horizontal closed position of FIGURE 8 to the open position by inserting a hook-tool in hook-ring opening 125 and thereafter applying an upward thrust. This causes a clockwise rotation of hook-ring member 112 moving pivot 118 to the right with respect to FIGURE 8. Link 117 is thereby carried to the right bringing with it pivot 119. Movement of pivot 119 to the right brings about a clockwise movement of latch release member 114 so that paddles 120` thereof engage and spread latch members 121 thereby releasing blade tip 116. Thus, upon further upward thrust of the hook-tool switch blade 101 pivots clockwise about pivot 102 to the vertical position indicated by line A in which isolating switch 100 is open.

Thus, I have provided a novel isolating switch arrangement in which a conventional circuit breaker bushing is used as an insulator for the circuit breaker as well as an insulator support for a stationary contact of the isolating switch blade. In this construction a minimum number of expensive insulators are required.

It is to be noted that even though the claims of this case each recite the common bushing support as being part of a circuit breaker, it is to be understood that the equivalents thereof extend to `any type of electrical apparatus normally having a bushing insulator extending therefrom, such as a power transformer.

In the foregoing, I have described my invention only in connection with preferred embodiments thereof. Many variations and modifications of the principles of my invention within the .scope of the description herein are obvious. Accordingly, I prefer to be bound not by the specific disclosure herein but only by the appended claims.

I claim:

g1. yIn combination a high voltage circuit breaker, an energizing bus, and an isolating switch operable between a first and second posi-tion Iwherein said circuit breaker is connected and disconnected respectively from said energizing bus; said circuit breaker including a casing, an insulator bushing secured to said casing and having a free end dispo-sed externally of said casing; said switch comprising a lirst stationary contact secured to said bushing tree end, a second stationary contact electrically connected to said energizing bus and in iixed spaced relation with respect to said rst stationary contact, and a bridging member for completing `a circuit between said stationary contacts when said switch is in said iirst position; said bridging member comprising ra rigid elongated conducting means movable along the longitudinal axis thereof for operation of said switch between said tir-st and said second positions the `axis of said bushing being at an angle to said longitudinal axis of said bridging member; said bridging member having a ring secured thereto for receiving a hook stick; said free end of said insulator bushing extending beyond the periphery of said casing.

2. In combination a high voltage circuit breaker, an energizing bus, and an isolating switch operable between a iirst and second position wherein said circuit breaker is connected and disconnected respectively from said energizing bus; said circuit breaker including a casing, an insulator bushing secured to said casing and having a lfree end disposed externally of said casing; sai-d switch comprising a first stationary contact secured to said bushing free end, a second stationary contact electrically connected to said energizing bus `and in xed spaced relation with respect to said rst stationary contact, and a bridging member `for completing a circuit between said stationary contacts when said switch is in said rst position; said bridging member comprising a rigid elongated conducting means movable along the longitudinal axis thereof for operation of said switch between said -iirst and said second positions the axis of said bushing being at an angle to said longitudinal axis of said bridging member; said bridging member being disposed externally of said bushing for all positions of said switch; said bridging member having a ring secured thereto for receiving a hook stick; said free end of said insulator bushing extending beyond the periphery of said casing.

3. In combination a high voltage circuit breaker, an energizing bus, and an isolating switch operable between a rst and second position wherein said circuit breaker is connected and `disconnected respectively from said energizing bus; said circuit breaker including a casing, an insulator bushing secured to said casing and having a free end disposed externally of said casing; said switch comprising a iirst stationary contact secured to said bushing free end, a second stationary contact electrically connected to said energizing bus, and a bridging member for compiet-ing a circuit between said stationary contacts when said switch is in said first position; said bridging member comprising a rigid elongated conducting means movable along the longitudinal axis thereof for operation of said switch between said first and said second positions, the axis of said bushing being at an angle to said longtiudinal axis of said bridging member; said bridging member being disposed externally of said bushing Lfor all positions of said switch; said second stationary contact being disposed above said first stationary contact; said bridging member having a second end in engagement with said seco-nd stationary contact when said switch is in said irst position; said second end moving toward said rst stationary contact :as said switch is operated from its said iirst position toward its said second position; a latch means tor maintaining said bridging member second end in engagement with said second stationary contact; a pull ring secured to said bridging member near its said second end; said pull ring being engageable by a tool for operation of said switch between said first and said second positions; said free end of said insulator bushing extending beyond the periphery of said casing.

4. In combination a high -voltage circuit breaker, an energizing bus, and an isola-ting switch operable between ia first Iand second position wherein said circuit breaker is connected and disconnected respectively from said energizing bus; said circuit breaker including a casing, an insulator bushing secured to said casing and having a free end disposed externally of said casing; said switch compri-sing a rst stationary contact secured to said bushing free end, a second stationary contact electrically connected to said energizing bus, and a bridging member for completing a circuit between said stationary contacts when said switch is in said lirst position; said bridging member comprising a rigid elongated conducting means movable along the longitudinal axis thereof for operation of said switch between said first and -said second positions the axis of said bushing being at an angle to said longitudinal axis of said bridging member; said bridging member being disposed externally of said bushing for all positions of said switch; said second stationary contact being disposed above said iirst stationary contact; said bridging member having a second end in engagement with said second stationary contact when said switch is in said first position; said second end moving toward said first stationary contact as said switch is operated from its said iirst position toward its said second position; a latch means for maintaining said bridging member second end in engagement with said second stationary contact; a pull ring secured to said bridging member near its said second end; said pull ring being en-gageable by a tool for operation of said switch between said iirst and said second positions; a first means for releasing said latch; said iirst means being engaged by the tool for operation thereof when the tool is inserted in said pull ring and manipulated to operate said switch `from said rst to said second position; said free end of said insulator bushing extending beyond the periphery of said casing.

References Cited in the tile of this patent UNITED STATES PATENTS 1,697,769 Koppitz Ian. 1, 1929 `1,774,377 Huttinger Ang. 26, 1930 1,808,570 Powers June 2, 1931 2,489,426 Linde Nov. 29, 1949 2,668,201 Welsh IFeb. 2, 1954 2,794,870 Thommen et a1 June 4, 1957

Claims

1. IN COMBINATION A HIGH VOLTAGE CIRCUIT BREAKER, AN ENERGIZING BUS, AND AN ISOLATING SWITCH OPERABLE BETWEEN A FIRST AND SECOND POSITION WHEREIN SAID CIRCUIT BREAKER IS CONNECTED AND DISCONNECTED RESPECTIVELY FROM SAID ENERGIZING BUS; SAID CIRCUIT BREAKER INCLUDING A CASING, AN INSULATOR BUSHING SECURED TO SAID CASING AND HAVING A FREE END DISPOSED EXTERNALLY OF SAID CASING; SAID SWITCH COMPRISING A FIRST STATIONARY CONTACT SECURED TO SAID BUSHING FREE END, A SECOND STATIONARY CONTACT ELECTRICALLY CONNECTED TO SAID ENERGIZING BUS AND IN FIXED SPACED RELATION WITH RESPECT TO SAID FIRST STATIONARY CONTACT, AND A BRIDGING MEMBER FOR COMPLETING A CIRCUIT BETWEEN SAID STATIONARY CONTACTS WHEN SAID SWITCH IS IN SAID FIRST POSITION; SAID BRIDGING MEMBER COMPRISING A RIGID ELONGATED CONDUCTING MEANS MOVABLE ALONG THE LONGITUDINAL AXIS THEREOF FOR OPERATION OF SAID SWITCH BETWEEN SAID FIRST AND SAID SECOND POSITIONS THE AXIS OF SAID BUSHING BEING AT AN ANGLE TO SAID LONGITUDINAL AXIS OF SAID BRIDGING MEMBER; SAID BRIDGING MEMBER HAVING A RING SECURED THERETO FOR RECEIVING A HOOK STICK; SAID FREE END OF SAID INSULATOR BUSHING EXTENDING BEYOND THE PERIPHERY OF SAID CASING.