US3198917A

US3198917A - Method of assembling the actuating mechanism for air-blast circuit breakers

Info

Publication number: US3198917A
Application number: US266290A
Authority: US
Inventors: Kobayashi Tetsuo; Nakano Zenichi
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1962-04-26
Filing date: 1963-03-19
Publication date: 1965-08-03
Anticipated expiration: 1982-08-03

Description

Aug. 3, 1965 TETSUO KOBAYASHI ETAL 3,198,917

METHOD OF ASSEMBLING THE ACTUATING MECHANISM FOR AIR-BLAST CIRCUIT BREAKERS Filed March 19, 1965 UN/En RS TeTsuo Koboy cniohi a o BY ml), m-mRnEy United States Patent 3,198,917 METHOD 6F ASSEMELHNG THE ACTUATING MECHANISM FGR AIR-BLAST CIRCUIT BREAKERS Tetsuo Kohayashi and Zenichi Nakano, Hitachi-sin,

Japan, assignors to Hitachi, Ltd, Tokyo, Japan, a corporation of Japan Filed Mar. 19, 1%3, Ser. No. 266,290 Qiaims priority, appiication Japan, Apr. 26, 1962, 37/ 16,006 1 tllaiin. (@l. Nth-143) The present invention relates to the assembling of the actuating mechanism for air-blast circuit breakers of the type including an air reservoir, at least one porcelain bushing upstanding from said air reservoir for supporting an interrupter unit, an operating unit and an opening-andclosing control valve operable to supply and exhaust air to and from the operating unit and also serving as a vent tube, an insulating rod vertically extending through said porcelain bushing for operating said control valve, a piston-cylinder assembly arranged on the ground side in said air reservoir at one end thereof, and a link mechanism arranged in said air reservoir and interconnecting the piston of said piston-cylinder assembly and the bottom of said insulating rod for mechanically actuating said control valve upon energization of said piston-cylinder assembly, said actuating mechanism including said link mechanism and associated parts such as hearing brackets therefor.

The present invention has for its object to provide a method of assembling such actuating mechanism in the air reservoir without any need of forming access holes in the wall of the reservoir for the assembling purpose thereby minimizing the use of packing elements on the air reservoir and hence the possibility of air leakage therefrom while providing a simple and neat appearance to the air reservoir.

In brief, this objective is attained, according to the present invention, by first inserting the link mechanism together with the drive piston into the interior of the air reservoir through the cylinder barrel formed at one end thereof and then assembling the mechanism with the hearing bracket conveniently through the vent aperture formed in the reservoir wall for the purpose of charging air from the air reservoir to the interrupter unit.

Other objects, features and advantages of this invention will be apparent from the following description when taken in conjunction with the accompanying drawing, which diagrammatically illustrates one practical example of the invention and in which:

FIG. 1 is a longitudinal vertical cross section of an air-blast circuit breaker actuating mechanism as assembled by the method of the invention; and

FIGS. 2 and 3 are views similar to FIG. 1 illustrating different stages of the method of assembling the actuating mechanism.

In the drawing, like reference characters designate like parts throughout the several figures. Referring first to FIG. 1, which illustrates a single-phase air-blast circuit breaker having two interrupter units, the reference nu- Lmerals 2 and 22 designate respective vent apertures formed in the wall of the air reservoir 1 for supplying air therefrom to the two respective interrupter units of the air-blast circuit breaker. Reference numeral 3 designates a cylinder formed at one end of the air reservoir for receiving a drive piston 11.

Bearing brackets

4 and 24 are inserted into the air reservoir through the respective vent apertures 2 and 22 and include

seating plates

5 and 25, respectively, which seat on the vent apertures in sealing engagement therewith. Connected to the vent apertures 2 and 22 are

porcelain bushings

6 and 26 which support the respective interrupter units in insulating relation "ice thereto and also serve as vent pipes. Insulating

rods

7 and 27 extend vertically through the

respective porcelain bushings

6 and 26 for the purpose of actuating the interrupter units. Bell crank levers 8 and 28 are pivotally secured as at 9 to the

respective bearing brackets

4 and 24 with one arm of each of the levers connected with the bottom of the associated

insulating rod

7 or 27. An actuating link 10 is connected at one end with the drive piston 11 and at the other end with the other arm of the bell crank lever 8. Another actuating link 20 is connected at one end to the link 10 and at the other end to the other arm of the bell crank lever 28. A compression spring 12 is arranged in the cylinder 3 between the drive piston and the cylinder cover, as illustrated. Provided outside of the air reservoir is a solenoid valve 13 for controlling the actuating mechanism and having an exhaust port 14. Air conduits 15 and 16 are arranged to connect the solenoid valve with the cylinder and the air reservoir, respectively.

In FIG. 1, the actuating mechanism is shown with its parts in position to open the interrupter unit. Namely, the solenoid valve 13 is deenergized to communicate the cylinder with the exhaust port 14 by way of the air conduit 15. Accordingly, the drive piston 11 is in its left end position under the air pressure in the air reservoir,

which acts upon the piston in the direction indicated by the arrows, and the

insulating rods

7, 27 are in bottom position under the pull of the actuating

links

10, 20 acting through the respective bell crank levers 8, 28.

The closing operation of the interrupter units is as follows. The solenoid valve 13 is energized to close the exhaust port 14 while allowing flow of air from the air reservoir 1 through air conduit 16, solenoid valve 13 and air conduit 15 into the cylinder 3 so that the piston 11 is moved to the right by the air pressure acting in the same direction as the compression spring 12. The piston 11 thus acts through actuating

links

10, 20 and associated bell crank levers 8, 28 to force the respective insulating rods upwardly to close the interrupter units mounted on top of the

porcelain bushings

6 and 26, respectively.

With this arrangement, since, as illustrated in FIG. 1, the

insulating rods

7, 27 operable for opening and closing the respective interrupter units extend vertically through the porcelain bushings 6 and are connected at the bottom with the drive piston 11 through the intermediary of the link mechanism arranged in the air reservoir, the air-blast circuit breaker has an extraordinarily simple and neat appearance and is free from the danger that the actuating mechanism be damaged by external forces as with the case of conventional air-blast circuit breakers having their actuating mechanism arranged outside of the air reservoir.

However, the arrangement of such actuating mechanism accommodated in the air reservoir 1 has been extremely dllTlClllt to assemble its components therein thus requiring the provision of access holes in the reservoir wall for the assembling purpose and hence of coverings therefor with packing means to sealingly close the access holes.

According to the present invention, there is provided a method of assembling the actuating mechanism in the air reservoir in a simple manner and without forming any access holes for the purpose.

The assembling method of the present invention will now be described in detail with reference to FIGS. 2 and 3, which illustrate the different stages of the assembling procedure. At the first, bell crank lever 8, actuating link It) and drive piston 11 are interconnected and inserted into the air reservoir 1 through the cylinder 3 at one end thereof and the bell crank lever 8 is pulled out of the reservoir from outside through one of the vent apertures 2. The bearing bracket 4 and insulating rod 7 are pivotally connected to the lever 8 at its opposite ends exteriorly 3 of the reservoir and then inserted together with the lever 8 into the reservoir 1 through the vent aperture 2. The seating plate 5 of the bearing bracket 4 is fixed to the vent aperture 2 and porcelain bushing 6 is secured to the plate 5 to extend vertically therefrom.

In assembling the actuating mechanism for a singlephase air-blast circuit breaker having two interrupter units as illustrated herein, the other bell crank lever 28 previously inserted into the air reservoir together with the actuating link 20 is pulled out of the reservoir (FIG. 3) through the vent aperture 22, after the lever 8 and associated parts have been assembled, and then is assembled with the bearing bracket 24 and insulating rod 27. The assembly is inserted into the air reservoir and the seating plate 25 of bearing bracket 24 is fixed to the vent aperture. Finally porcelain bushing 25 is secured to the plate 25 to extend Vertically therefrom.

It will be understood that the actuating mechanism for three interrupter units supported by respective porcelain bushings upstanding from a single air reservoir may also be assembled progressively in quite the same manner as described above.

It will be apparent from the foregoing that according to the present invention the actuating mechanism of the type described can be assembled with ease by making use of the vent apertures, formed in the air reservoir and communicating with the respective interrupter units, and the actuating cylinder formed at one end of the air res ervoir. Thus, there is no need of forming access holes in the Wall of the air reservoir for the assembling purpose and the use of packing elements on the air reservoir and hence the possibility of air leakage therefrom are minimized.

Having fully described our invention, it is to be understood that we do not wish to be limited to the details set 4 forth, but our invention is of the full scope of the appended claim.

What is claimed is:

In an air-blast circuit breaker of the type including an air reservoir, at least one porcelain bushing upstanding from said air reservoir for supporting an interrupter unit and also serving as a vent tube, an insulating rod vertically extending through said porcelain bushing for actuating said interrupter unit, a piston-cylinder assembly arranged at one end of said air reservoir, and a link mechanism arranged in said air reservoir and including an actuating link connected at one end with the piston of said piston-cylinder assembly and a bell crank lever connected at one end with the other end of said actuating link and at the other end with the bottom of said insulating, rod, a method of assembling the actuating mechanism including said link mechanism and a bearing bracket therefor having a seating plate comprising inserting said actuating link and said bell crank lever into the air reservoir through the cylinder of said piston-cylinder assembly, pulling said bell crank lever out of the vent aperture formed in the wall of said air reservoir and to which said porcelain bushing is to be secured, assembling the hearing bracket to said bell crank lever exterlorly of said air reservoir, inserting the parts thus assembled into the interior of said air reservoir through said vent aperture, fixing the seating plate of the bearing bracket to said vent aperture, and securing said porcelain bushing to the top of said seating plate to extend vertically therefrom, said steps being repeated progressively as many times as correspond to the number of said porcelain bushings.

No references cited.

BERNARD A. GILHEANY, Primary Examiner.