US1600341A - High-tension switch mechanism - Google Patents

Description

2 Sheets-Sheet 1 c. G. KQPPlTz man TENSION SWITGHMECHANISM Filed oct. 18. 192.0

Sept. 21 1926.

HIGH'TENSION SWITCH MECHANISM Filed Oct, 18, 1920 2 Sheets-Sheet 2 Patented Sept. 21, 1926.

UNITED STATES CARL G. KOPPITZ, OF GREENSBURG, PENNSYLVANIA, ASSIGNOR TO RAILWAY AND PATENT OFFICE.

INDUSTRIAL ENGINEERING COMPANY, OF GREEN SBURG, PENNSYLVANIA, A COB- rFORMATION OF PENNSYLVANIA.

HIGH-TENSION SWITCH MECHANISM.

Application med October 18, 1920. Serial No. 417,540.

The tendencies in the art of the electrical transmission of power over conslderable distances has taken a very decided turn towards the use of extremely high voltages. Heretofore the systems of electric power transymission have been limited to rather restricted areas seldom covering any one State but usually only a comparatively small part of any one State. The transmission of power over these areas has been accomplished by the use of voltages never in excess of -one hundred and fifty or one hundred and sixty thousand volts but usually ranging between sixty-six and one hundred and thirtythousand volts. The present tendency is towards the installation of what is called a superpower line having as its objective the tylng together electrically of a large number of the present transmission systems into one network coverin A primary i ea is to equalize the demand from any one system and thereby reduce a large part of the usual standby-equipment, increase the reliability of service and to increase the load factors, thereby materially reducin the operating expenses.

It wil be essential on a system such as outlined to do a considerable part of the switching on the high tension side but the industry finds itself in the osition that no suitable switch for two hun red and twenty thousand volts has been developed. The oil switch is capable of development for such voltage but will necessarily be very expensive. If a suitable airA break switch were available this switching could be done with very much more reasonable investment.

A study of the various forms of orcelains that are on the market leads rea ily to the conclusion that none are suitable as switch insulators for the voltages contemplated. Their-frst difficulty hes in their mechanical weakness when built up to a height suitable for these extreme voltages.

In analyzing the fundamentals of the present standards that are designed it will be noted that these insulators are so constructed as to subject the porcelain to its safe ultipossibly six or eight States.-

mate breakdown capacity thereby requiring the very highest grade of material likewise designed with such dimensions that therefore the strength can not be materially increased owing to the relative shrinkage of the porcelain and metal parts.

Itis one object of the invention to provide an insulator construction which avoids the necessity of using. thev highest grade of materials and which at the same time secures( a higher degree of mechanical strength at`Y lower cost. f

Another object is to secure a construction that would more readily permit such insulators being used in the construction of switching apparatus .by providing a hollow interior protected from the weather through which the switch may be operated without possibility of interference from .the weather, particularly sleet.

In general the insulators at present used are so designed as to put the porcelain under compression which accounts for the fact that the insulation is worked at such high unit stresses. In the present design' it is proposed to work the insulation under tension and make the insulator of such form as to limit the tension to safe values. It is proposed to make this insulator in the customary well known form of stoneware pipe with bell and socket connections cemented `ltogether without the use of hardware thereby eliminating the weak features of the present customary designs of the relative expansions of a metal and porcelain. Further it will be seen that this material is electrically stressed in a longitudinal direction thereby imposing a minimum unit stress on the material, permitting a Working stress of say seven hundred and fifty to one thousand volts per inch of insulating material whereas in the ordinary design of porcelain insulator this stress may run anywhere from twenty to forty thousand volts per inch. For this reason a much lower grade of ceramic material may be used than that heretofore demanded for insulator constructions.

For a full understanding of the invention reference is had to the accompanying drawings in which Fig. 1 is a vertical sectional view of a device constituting the invention:

Fig. 2 is an elevation of a switch construction embodying the invention; and

Fig. 3 is a plan view of the construction shown in Fi 2.

The principal part of the invention is a hollow column of ceramic material of the orm commonly used for sewer ipes. The column is composed of a plura `ty of sections 1 provided with the bells 1 as is customary in sewer pipe construction. The sections, which have an inside diameter of approximately 24, are cemented together to make a solid structure about'ifteen feet high.

@f the various materials I have tried, such as common sewer pipe, rebrick in stoneware crooks and chemical stoneware, I find the latter as best suited for the poses of the invention. There is, of course, considerable latitude in the selection of the material for making the tiles. I contemplate the use of any material from which the tiles can be cheaply made and which aords a sutiicient electrlcal resistance.

f The column is in practice supported upon a concrete base 3 and anchored thereto by any suitable means as by means of rods 4 and a collar 5 bearing upon the bell flange of the lowermost of the tile sections. The

- joint between the collar 5 and the column l rality is preferably sealed by a layer of cement.

At its upper end the column carries switch blades v6. In the particular instance shown the blades 6 constitute a so called vertical break switch. `The blades 6 are pivotally supportedupon a frame 7 by means of pins 8 jonrnaled inl bearings 9. Each of the pins 8 carries a pinion 10 which engages a beveled gear 11y keyed upon a shaft `12. 'l

The shaft 12 in turn carries a beveled gear which is in mesh with a beveled ear 13 mounted upon the end of a stub s aft 14 disposedv axially of the column. The stub shaft 14 is secured to the up er end of a.

:smaller column 15 which exten s downwardly through the column and carries at itsl lower en another stub shaft 16.

The column 15 is also composed of a plu-l of tile sections cemented together and carries at its upper and lower ends metallic caps 17 and 18 respectively to which the stub shafts 14 and 16 are secured.

The concrete base 3 has a depression de- Y ning a chamber for receiving the lower end r16, a gear 20 on the of the column, a metallic frame 19 for supportlng the column and centering the shaft the gear 20. city have shown only so much of the mechatric motor 21 for drivin Fonthe sakeof simpfi and described purshaft 16 and an elec-v nism as is necessaryvfor operating the switch blades. In practice, however, I contemplate the use of auxiliary mechanism such as overload relays and connecting elements for automatically operating the switch when an overload or a short circuit occurs on the line. Such mechanism may be conveniently housed within the column and eiectively protected together with the other mechanism enclosed therein.

As shown in Figs. 2 and 3, va switch for breaking a high tension line may include a central column 22 carrying the switch blades 25 and columns 23 and 24 carrying stationary contacts 26 and 27 respectively and horns 28 and 29.

These insulators can be cheaply made of such a size as to permit the safe operation of very ,long switch blades thereby securing a very large break or ap in the opening of the switch. In the esign proposed the lengths of the blades are of the order of fourteen feet each, which upon opening simultaneously cause a break between the tips of the horns of approximately fifty-one feet between the tips of the arcing horns.

rIhe usual form of vinsulator is equipped with petticoats' 2 in order to insure that a portion of the surface between the metal parts is maintained in a dr condition but it is obvious that if the vo tage stress per unit length is suiiiciently low that it will not be necessary to have any portion of the surface of the insulating column kept The total length of the column as proposed for two hundred and twenty thousandrvolts is approximately fifteen feet which reduces the voltage stress per inch to about eight hundred volts which appear to be safe against surface over-flash. is found not to be safe it will be possible to e uip the -column with some form of shiel or petticoats to insure a portion of its surface remaining A three-phase transmission line would If, however, this require three switch units such as shownin Figs. 2 and 3 and a separate motor would be used for operating each switch unit, the different motors to be electrically interconnected oroperation in unison.

In the claims the term column is intended tofdene a structure of considerable height approachin fifteen feet in height and rising from t e ground, in contradistinction to insulators of relatively small size supported on Walls, masts or poles.

claimz., A a

1. High tension switch mechanism includ- -ing a hollow column of ceramic material,- a

movable switch element supportedV at the top of the column and means extendin axially through the column for operating t e switch element.

2. High Vtension switch mechanism including a hollow Acolumn of ceramic material,

a movable switch elementl supported at the switch element supported at the top of the to of the column and means ncludin n. column and means for o rating the 'switch 10 co umn of ceramic material extending axlalelement including a. colmn composed of l throu h the said column for operating hollow tile sections and extending axially tlie switc element. through the said column.

3. High tension switch mechanism includ- In testimony whereof, I ailix my signaing a. hollow column composed of a plurality ture. of hollow tile sections in superposition, a CARL G. KOPPITZ.

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