CA1097757A - Tank-type terminal-bushing construction having grounded collar-support an integral part of bushing structure - Google Patents
Tank-type terminal-bushing construction having grounded collar-support an integral part of bushing structureInfo
- Publication number
- CA1097757A CA1097757A CA287,165A CA287165A CA1097757A CA 1097757 A CA1097757 A CA 1097757A CA 287165 A CA287165 A CA 287165A CA 1097757 A CA1097757 A CA 1097757A
- Authority
- CA
- Canada
- Prior art keywords
- terminal
- bushing
- support
- tank
- casing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Insulators (AREA)
- Gas-Insulated Switchgears (AREA)
- Cable Accessories (AREA)
- Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An improved tank-type terminal-bushing con-struction is provided, having the usual grounded support-ing sleeve an integral part of the bushing structure itself, and fabricated therewith, instead of being a separate fabricated part of the cooperating circuit-breaker tank structure. In addition, such support-sleeve, constituting a part of the terminal-bushing entity itself, is fabricated from a non-magnetic material, such as alumi-num for example. As an ancillary aspect of the instant invention, is the fabrication of the annular grounding flange, secured to the cooperating circuit-breaker tank, being fabricated from a non-magnetic material, such as stainless steel, for example.
An improved tank-type terminal-bushing con-struction is provided, having the usual grounded support-ing sleeve an integral part of the bushing structure itself, and fabricated therewith, instead of being a separate fabricated part of the cooperating circuit-breaker tank structure. In addition, such support-sleeve, constituting a part of the terminal-bushing entity itself, is fabricated from a non-magnetic material, such as alumi-num for example. As an ancillary aspect of the instant invention, is the fabrication of the annular grounding flange, secured to the cooperating circuit-breaker tank, being fabricated from a non-magnetic material, such as stainless steel, for example.
Description
46,989 SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an improved tank-type terminal-bushing structure, which incorporates a grounded, non-magnetic support-sleeve as an integral component thereof~ during the fabrication of the terminal-bushing, itself as a separate entity.
In addition, to minimize eddy-current heating losses, associated with the transmission of line current-flow through the circuit-breaker assembly, when operating, the flange structure, surrounding the circuit~breaker tank opening, the latter accommodating the mounting support of the aforesaid terminal-bushing, is fabricated of a non-magnetic material, such as stainless steel, for example.
In the construction of the improved apparatus, the non-magnetic flange structure may be first welded to the circuit-breaker tank openings. At a subsequent point in time, the terminal-bushing structure itself is placed or inserted within the aforesaid tank openings, so that the non-magnetic support-sleeve of the terminal-bushing (constituting a part of the entity thereof) is fixedly secured, as by mounting bolts, for example, to the aligned bolt openings provided in the periphery of the non-magnetic flange structure, which, as mentioned, is welded to the circuit-breaker tank openings.
BRIEF DESCRIPTION OF T~E DRAWINGS
Fig. 1 is a vertical sectional view taken through a circuit-b.eaker tank structure, illustrating enclosed puffer-type compressed-gas interrupting units, these being illustrated in the closed-circuit position, and the terminal-bushing structures embodying features
In accordance with the present invention, there is provided an improved tank-type terminal-bushing structure, which incorporates a grounded, non-magnetic support-sleeve as an integral component thereof~ during the fabrication of the terminal-bushing, itself as a separate entity.
In addition, to minimize eddy-current heating losses, associated with the transmission of line current-flow through the circuit-breaker assembly, when operating, the flange structure, surrounding the circuit~breaker tank opening, the latter accommodating the mounting support of the aforesaid terminal-bushing, is fabricated of a non-magnetic material, such as stainless steel, for example.
In the construction of the improved apparatus, the non-magnetic flange structure may be first welded to the circuit-breaker tank openings. At a subsequent point in time, the terminal-bushing structure itself is placed or inserted within the aforesaid tank openings, so that the non-magnetic support-sleeve of the terminal-bushing (constituting a part of the entity thereof) is fixedly secured, as by mounting bolts, for example, to the aligned bolt openings provided in the periphery of the non-magnetic flange structure, which, as mentioned, is welded to the circuit-breaker tank openings.
BRIEF DESCRIPTION OF T~E DRAWINGS
Fig. 1 is a vertical sectional view taken through a circuit-b.eaker tank structure, illustrating enclosed puffer-type compressed-gas interrupting units, these being illustrated in the closed-circuit position, and the terminal-bushing structures embodying features
-2- ~i~
- ~09~757 of the instant invention;
Fig. 2 is a top, plan view of the tank structure per se, illustrating the tank openings, and the surround-ing non-magnetic mounting flange structure;
Fig. 3 is a fragmentary, vertical-sectional view taken substantially along the line III-III of Fig. 2, indicating the non-magnetic supporting grounded-flange structure associated with the tank openings; and, Fig. 4 illustrates a quarter-sectional view taken through the improved terminal-bushing structure of the present invention, as separately fabricated.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and more particularly to Figs. 1-3 thereof, it will be observed that there is provided a tank-type circuit-interrupting structure 1 of the type set forth in Canadian patent application filed April 20, 1977, Serial No. 276,5a5, by Willie B. Freeman et al, entitled "Tank-Type Compressed-Gas Circuit-Inter-rupter of the Puffer-Type Having Improved Assembly Features", and assigned to the assignee of the instant patent application.
As shown generally in Fig. 1, a tank structure
- ~09~757 of the instant invention;
Fig. 2 is a top, plan view of the tank structure per se, illustrating the tank openings, and the surround-ing non-magnetic mounting flange structure;
Fig. 3 is a fragmentary, vertical-sectional view taken substantially along the line III-III of Fig. 2, indicating the non-magnetic supporting grounded-flange structure associated with the tank openings; and, Fig. 4 illustrates a quarter-sectional view taken through the improved terminal-bushing structure of the present invention, as separately fabricated.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and more particularly to Figs. 1-3 thereof, it will be observed that there is provided a tank-type circuit-interrupting structure 1 of the type set forth in Canadian patent application filed April 20, 1977, Serial No. 276,5a5, by Willie B. Freeman et al, entitled "Tank-Type Compressed-Gas Circuit-Inter-rupter of the Puffer-Type Having Improved Assembly Features", and assigned to the assignee of the instant patent application.
As shown generally in Fig. 1, a tank structure
3 is provided, having a pair of electrically, serially-arranged puffer-type interrupting units S, 6 enclosed therewithin, being illustrated in the closed-circuit position. The tank structure 3 has a pair of upper tank openings ~, 9 to accommodate a pair of downwardly-extending inserted terminal-bushings 11, 12, shown more clearly in Fig. 4 of thç drawings.
~7~7 Surrounding each of the tank openings a, 9, as more clearly illustrated in Figs. 2 and 3, is a support-ing mounting flange structure 14, preferably fabricated of a non-magnetic material, such as stainless steel, for example. The stainless-steel support-ring 14 may be, in one form of the invention, welded, for example, to the inner periphery of the tank opening 8, 9, as indicated in Fig. 3.
With reference being directed to Fig. 4 of the drawings, it will be noted that the terminal-bushing structure 11 per se, fabricated as a separate entity, has, as an integral component part thereof, a grounded, cylindrical, support-member, designated by the reference numeral 16, which is formed of a non-magnetic material, such as aluminum, for example. The lower end of the aluminum support-collar, or sleeve, has, preferably, a flange-ring la welded thereto, also preferably fabricated of aluminum, which has, additionally, a plurality of circumferentially-disposed mounting-bolt holes 19 pro-vided therein. These accommodate spaced mounting bolts20, which extend through mounting holes 24 provided in the support rings 14, more clearly illustrated in Fig. 2.
The stainless-steel, non-magnetic support-flange rings 14 may be welded to the inner periphery of the holes &, 9 of the tank structure 3, as illustrated in Fig. 2. When this is done, as a subsequent assembly step, the terminal-bushings 11, 12 themselves, including 46,989 the grounded, aluminum support~sleeves 16, may be placed, or inserted into position, and fixedly secured by the aforesaid mounting bolts 20 to the non-magnetic support flange-rings 14 of the tank structure 3.
With reference to Fig. 4 of the drawings, regarding the fabrication and construction of the terminal-bushing 11 itself, as a separate entity, it will be observed that the non-magnetic, support-sleeves, or "support nozzle" 16 constitutes a component part of the terminal-bushing structure 11, itself having an upper support-ring 17 interposed between the outer upper porcelain casing structure 26 and the inner lower frustum-like insulating support-casing 27. The outer upper casing 26 is preferably formed of porcelain, and is of generally cylindrical shape, whereas the inner lower frustum-like support-sleeve 27 is, preferably, of epoxy resin; and, consequently~ has very little dimensional variations. As a result, it may be utili%ed with a relatively-ti~ht fit within the interior of the non-magnetic support-sleeve, or t'support nozzle" 16 itself.
Extending longitudinally through each terminal-bushing structures 11, 12, is of course, the terminal-lead 29, which carries the line current. Tne terminal-bushing 11 or 12 may be, for example, of the gas-ty~e, having â gas-communication hoie 31 in the side of the terminal-lead 29, so as to cornmunicate or feed sulfur-hexafluoride (SF6) gas 32 from the interior of the tank structure 3 and into the surrounding annular space 33 between the terminal-lead 29 and the outc-r casir!g~
structure 26 itself.
46~989 109~7S7 A plurality of circumferentially-disposed com-pression springs 35 may be utilized, and, as well known by those skilled in the art, tend to impose tension upon the internally-disposed terminal-lead 29 and corresponding compression upon the outer porcelain casing 26. At the upper end of the terminal-bushing 11 is a metallic dis-phragm 36, which is welded to both the ring structure 37 and also to a collar 38, which is threaded to the terminal-lead 29 itself.
The compression springs 35 exert compressive force between an annular spring-seat 41 and an upper-disposed spring-seat ring 42, the latter being in abut-ment with a collar 43, secured to the upper end of the terminal-lead 29 itself. Preferably, suitable resilient gaskets 45 are employed to prevent gas lea~age, and to somewhat cushion the imposition of force upon the upper end of the outer procelain casing 26.
At the lower end of the terminal-bushing structure 11, 12 is a lower terminal-ring cap 47 which is threaded to the lower end of the terminal-lead 29 itself.
From the aforesaid description, it ~ill be observed that there is thus provided a very compact, gas-type, terminal-bushing 11, 12, particularly adaptable for the higher-rating circuit-breaker structures, such as those having a rating of 242 ~V, for example. The terminal-bushing 11, 12 is held tcgether as an entity, or assembly, with recessed compression springs ~5, using porcelain external insulation 26 and an epoxy resin 0 internal insulation 27, ~or example. As an integral 46,989 ~ 9 ~
part of the terminal-bushing 11 is the non-magnetic support-ing ground-sleeve 16, which acts as a pressure-vessel support nozzle for bolting to an associated gas-type, circuit-breaker tank 3. There are five features, which allow the longitudinal size of the improved terminal-bushing structure 11, 12 of the present invention to be reduced:
1. The metallic diaphragm 36;
2. The use of the compression springs 35;
3. Utilizing a straight porcelain casing 26, using a non-magnetic "support nozzle" 16 as an integral part of the bushing structure 11 itself, and additionally, employing an epoxy-resin, fabricated, internal frustum-casing structure 27.
The improved terminal-bushing construction 11, 12 of the presenk invention is somewhat conventional, in that it is of the spring-loaded construction, using the electrical terminal-lead 29 itself, in tension, to clamp the assembly together in compression. The rnetallic dia-phra~m 36 is of unique construction, and simplifies theterminal-bushing construction in that it does not weld, or braze to the bushing lead 29 during the assembly pro-cedures. ~he several compression springs 35 are support-ed in a unique ~ashion to allow the largest-diameter springs 35 possible to fit within the s ace provided between the terminal-lead 29 and the porcelain casing 2~. This also simplifies assembly procedures, since this spring assembly 35 is "preloaded", and installed within the terminal-busning 11, using several bolts, rather than an external jack, or load source and fixture 46,989 ~0~757 to load the bushing.
The procelain weather casing 26 is a small, pre-ferably constant-diameter cylinder, with external weather sheds 49. This type construction is more compact and less expensive than the tapered porcelain designs.
The support nozzle 16 is used, instead of a simple flan~e, to mount the terminal bushing 11, 12 to the circuit-breaker tank structure 3. This simplifies the circuit-breaker structure and construction by making these "nozzles" 16 an integral part of the terminal-bushing structure itself, rather than being a part of the circuit-breaker tank structure 3, as is done in conven-tional designs.
It is to be particularly noted that the epoxy-resin lower frustum support 27 has much closer tolerances on the diameter, than would porcelain, which therefore allows a better "fit-up~' within the inside of the surro~nding lower support nozzle 16, and thus this makes a very practical design.
In general, the disclosed improved terminal-bushing 11, 12 provides a substantially lighter and smaller structure, thus reducing size and stresses imposed upon the cooperating circuit-breaker tank 3.
This allows an overall-product improvement, and, addition-ally, and very importantly, permits a unit also to be assembled without the need of assembly welding or brazing, or the use of special fixtures and loading devices.
Although there has been illustrated and described a specific structure, it .s to be clearly under-0 stood that the same was merely for the purpose of 46,989 ~0C~7757 lllustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope Or the present invention.
~7~7 Surrounding each of the tank openings a, 9, as more clearly illustrated in Figs. 2 and 3, is a support-ing mounting flange structure 14, preferably fabricated of a non-magnetic material, such as stainless steel, for example. The stainless-steel support-ring 14 may be, in one form of the invention, welded, for example, to the inner periphery of the tank opening 8, 9, as indicated in Fig. 3.
With reference being directed to Fig. 4 of the drawings, it will be noted that the terminal-bushing structure 11 per se, fabricated as a separate entity, has, as an integral component part thereof, a grounded, cylindrical, support-member, designated by the reference numeral 16, which is formed of a non-magnetic material, such as aluminum, for example. The lower end of the aluminum support-collar, or sleeve, has, preferably, a flange-ring la welded thereto, also preferably fabricated of aluminum, which has, additionally, a plurality of circumferentially-disposed mounting-bolt holes 19 pro-vided therein. These accommodate spaced mounting bolts20, which extend through mounting holes 24 provided in the support rings 14, more clearly illustrated in Fig. 2.
The stainless-steel, non-magnetic support-flange rings 14 may be welded to the inner periphery of the holes &, 9 of the tank structure 3, as illustrated in Fig. 2. When this is done, as a subsequent assembly step, the terminal-bushings 11, 12 themselves, including 46,989 the grounded, aluminum support~sleeves 16, may be placed, or inserted into position, and fixedly secured by the aforesaid mounting bolts 20 to the non-magnetic support flange-rings 14 of the tank structure 3.
With reference to Fig. 4 of the drawings, regarding the fabrication and construction of the terminal-bushing 11 itself, as a separate entity, it will be observed that the non-magnetic, support-sleeves, or "support nozzle" 16 constitutes a component part of the terminal-bushing structure 11, itself having an upper support-ring 17 interposed between the outer upper porcelain casing structure 26 and the inner lower frustum-like insulating support-casing 27. The outer upper casing 26 is preferably formed of porcelain, and is of generally cylindrical shape, whereas the inner lower frustum-like support-sleeve 27 is, preferably, of epoxy resin; and, consequently~ has very little dimensional variations. As a result, it may be utili%ed with a relatively-ti~ht fit within the interior of the non-magnetic support-sleeve, or t'support nozzle" 16 itself.
Extending longitudinally through each terminal-bushing structures 11, 12, is of course, the terminal-lead 29, which carries the line current. Tne terminal-bushing 11 or 12 may be, for example, of the gas-ty~e, having â gas-communication hoie 31 in the side of the terminal-lead 29, so as to cornmunicate or feed sulfur-hexafluoride (SF6) gas 32 from the interior of the tank structure 3 and into the surrounding annular space 33 between the terminal-lead 29 and the outc-r casir!g~
structure 26 itself.
46~989 109~7S7 A plurality of circumferentially-disposed com-pression springs 35 may be utilized, and, as well known by those skilled in the art, tend to impose tension upon the internally-disposed terminal-lead 29 and corresponding compression upon the outer porcelain casing 26. At the upper end of the terminal-bushing 11 is a metallic dis-phragm 36, which is welded to both the ring structure 37 and also to a collar 38, which is threaded to the terminal-lead 29 itself.
The compression springs 35 exert compressive force between an annular spring-seat 41 and an upper-disposed spring-seat ring 42, the latter being in abut-ment with a collar 43, secured to the upper end of the terminal-lead 29 itself. Preferably, suitable resilient gaskets 45 are employed to prevent gas lea~age, and to somewhat cushion the imposition of force upon the upper end of the outer procelain casing 26.
At the lower end of the terminal-bushing structure 11, 12 is a lower terminal-ring cap 47 which is threaded to the lower end of the terminal-lead 29 itself.
From the aforesaid description, it ~ill be observed that there is thus provided a very compact, gas-type, terminal-bushing 11, 12, particularly adaptable for the higher-rating circuit-breaker structures, such as those having a rating of 242 ~V, for example. The terminal-bushing 11, 12 is held tcgether as an entity, or assembly, with recessed compression springs ~5, using porcelain external insulation 26 and an epoxy resin 0 internal insulation 27, ~or example. As an integral 46,989 ~ 9 ~
part of the terminal-bushing 11 is the non-magnetic support-ing ground-sleeve 16, which acts as a pressure-vessel support nozzle for bolting to an associated gas-type, circuit-breaker tank 3. There are five features, which allow the longitudinal size of the improved terminal-bushing structure 11, 12 of the present invention to be reduced:
1. The metallic diaphragm 36;
2. The use of the compression springs 35;
3. Utilizing a straight porcelain casing 26, using a non-magnetic "support nozzle" 16 as an integral part of the bushing structure 11 itself, and additionally, employing an epoxy-resin, fabricated, internal frustum-casing structure 27.
The improved terminal-bushing construction 11, 12 of the presenk invention is somewhat conventional, in that it is of the spring-loaded construction, using the electrical terminal-lead 29 itself, in tension, to clamp the assembly together in compression. The rnetallic dia-phra~m 36 is of unique construction, and simplifies theterminal-bushing construction in that it does not weld, or braze to the bushing lead 29 during the assembly pro-cedures. ~he several compression springs 35 are support-ed in a unique ~ashion to allow the largest-diameter springs 35 possible to fit within the s ace provided between the terminal-lead 29 and the porcelain casing 2~. This also simplifies assembly procedures, since this spring assembly 35 is "preloaded", and installed within the terminal-busning 11, using several bolts, rather than an external jack, or load source and fixture 46,989 ~0~757 to load the bushing.
The procelain weather casing 26 is a small, pre-ferably constant-diameter cylinder, with external weather sheds 49. This type construction is more compact and less expensive than the tapered porcelain designs.
The support nozzle 16 is used, instead of a simple flan~e, to mount the terminal bushing 11, 12 to the circuit-breaker tank structure 3. This simplifies the circuit-breaker structure and construction by making these "nozzles" 16 an integral part of the terminal-bushing structure itself, rather than being a part of the circuit-breaker tank structure 3, as is done in conven-tional designs.
It is to be particularly noted that the epoxy-resin lower frustum support 27 has much closer tolerances on the diameter, than would porcelain, which therefore allows a better "fit-up~' within the inside of the surro~nding lower support nozzle 16, and thus this makes a very practical design.
In general, the disclosed improved terminal-bushing 11, 12 provides a substantially lighter and smaller structure, thus reducing size and stresses imposed upon the cooperating circuit-breaker tank 3.
This allows an overall-product improvement, and, addition-ally, and very importantly, permits a unit also to be assembled without the need of assembly welding or brazing, or the use of special fixtures and loading devices.
Although there has been illustrated and described a specific structure, it .s to be clearly under-0 stood that the same was merely for the purpose of 46,989 ~0C~7757 lllustration, and that changes and modifications may readily be made therein by those skilled in the art, without departing from the spirit and scope Or the present invention.
Claims (7)
1. A terminal-bushing structure adaptable for use in tank-type circuit-breakers, comprising, in com-bination, a longitudinally-extending, internally-disposed, electrical terminal-lead, a pair of surrounding confront-ing insulating casing structures, an interposed flange-ring between the two confronting ends of the said casing-structures, and a non-magnetic support-sleeve fixedly secured to said interposed flange ring and constituting the support-sleeve for the terminal-bushing structures,
2. The combination according to claim 1, wherein the external casing structure is composed of porcelain and has a relatively constant diameter.
3. The combination according to claim 2, wherein an internally-disposed epoxy-resin insulating support-casing is provided internally of the said non-magnetic support-sleeve and extends thereinto.
4. An improved circuit-breaker gas-type tank structure including, in combination, a grounded metallic tank having an insulating gas disposed therewithin, said tank having a pair of terminal-bushing openings provided at one end thereof, a non-magnetic flange-ring surround-ing each tank opening, a terminal-bushing structure inserted within each tank opening, said terminal-bushing structure including individually a longitudinally-extending terminal-lead and a pair of surrounding con-fronting insulating casing structures, a non-magnetic 46,989 metallic support ring interposed between the confronting ends of the two insulating casing structures, a non-magnetic support-sleeve affixed to said interposed non-magnetic support ring and constituting a cylindrical mounting support for the terminal-bushing and constituting a mounting structure for the terminal bushing.
5. The combination according to claim 4, wherein the grounded supporting sleeve is fabricated from aluminum.
6. The combination according to claim 4, wherein one of the casing structures for the terminal-bushing is of porcelain and the other internally-disposed second casing structure, situated internally of the non-magnetic support sleeve, is of epoxy resin material.
7. The combination according to claim 4, wherein a plurality of circumferentially-disposed com-pression springs are situated within the casing structure at the outer end of the terminal-bushing, and impose tensile stress upon the terminal-lead and corresponding compressive stress upon the outer-disposed casing structures.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US73416176A | 1976-10-20 | 1976-10-20 | |
| US734,161 | 1976-10-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1097757A true CA1097757A (en) | 1981-03-17 |
Family
ID=24950565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA287,165A Expired CA1097757A (en) | 1976-10-20 | 1977-09-21 | Tank-type terminal-bushing construction having grounded collar-support an integral part of bushing structure |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS5351494A (en) |
| CA (1) | CA1097757A (en) |
| NO (1) | NO773208L (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS425411Y1 (en) * | 1965-11-17 | 1967-03-17 |
-
1977
- 1977-09-19 NO NO773208A patent/NO773208L/en unknown
- 1977-09-21 CA CA287,165A patent/CA1097757A/en not_active Expired
- 1977-10-18 JP JP12414977A patent/JPS5351494A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| NO773208L (en) | 1978-04-21 |
| JPS5351494A (en) | 1978-05-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4090028A (en) | Metal arcing ring for high voltage gas-insulated bus | |
| US4618749A (en) | Solid insulator-type vacuum switch gear | |
| US4670625A (en) | Electrical insulating bushing with a weather-resistant sheath | |
| US3380009A (en) | High voltage current transformer | |
| US4511873A (en) | Current transformer insulated by pressurized gas | |
| US4161621A (en) | Spacer mount for a gas insulated transmission line | |
| CA1184960A (en) | Dead tank housing for high voltage circuit breaker employing puffer interrupters | |
| EP2057644B1 (en) | High voltage bushing | |
| CA2109852A1 (en) | Duct, particularly for high voltages with special electrode holder | |
| KR970004305B1 (en) | Circuit breaker | |
| CA1097757A (en) | Tank-type terminal-bushing construction having grounded collar-support an integral part of bushing structure | |
| US4458101A (en) | Gas-insulated epoxy bushing having an internal throat shield and an embedded ground shield | |
| US3325583A (en) | Insulator for pressure gas-insulated fully enclosed switchgear apparatus | |
| US4185161A (en) | Modular guyline insulator | |
| JPH0951609A (en) | Gas-blast circuit-breaker | |
| US3242251A (en) | Bushing device for introducing current conductor into compressed gas switch chambers | |
| RU2254632C2 (en) | Surge arrester module for high-voltage installation | |
| US3236982A (en) | Electric switchgear including insulator member capable of withstanding tension | |
| US4754363A (en) | Metal-encapsulated gas-insulated high-voltage installation with an overvoltage arrester | |
| US3178504A (en) | Pressure-cap assembly for terminal bushings | |
| US3040203A (en) | Expulsion lightning arrester | |
| US4320372A (en) | Current transformer for a high-tension installation | |
| JPH0721983B2 (en) | Circuit switchgear | |
| US3160701A (en) | Electrical apparatus | |
| JPH0370332B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |