US1168595A - Lightning-arrester. - Google Patents

Description

J. BOWIE, 1R. LIGHTNING ARRESTER.

APPL ICATION FILED FEB. 26, 1910.

Patented Jan. 18, 1916.

2 SHEETS-SHEET I w mgmmgy INVENTOR WITNESSES."

THE COLUMBIA P'LANDGRAPH co., WASHiNGTON, u. c

A. J. BOWIE, JR.

LIGHTNING ARRESTEB. APPLICAUON FILED FEB.26,1910.

Patented Jan. 18, 1916.

2 SHEETS-SHEET 2.

IIVVEIVTOR WITNESSES:

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LIGHTNING-ARRESTER.

Specification of Lettersratent. Patented J an. 18, 19 16.

Am n filed ma 26, smf i ss l 110. 546,180.

Be it known that I',,AUGUsTiis Bowie,

J r., a citizen of the United States, residing at San Francisco, county' of San Francisco,

State of California, have invented, certain new and useful Improvements in Lightning Arresters; and I do hereby declare the fol lowing tobe a run, clear, and exact descrip tion of theinventiomsuch as will enable others skilled inthe art to which it apper-.

tains to make and use the same. I

fromself induction.

' off'th'is' type, should possessthe following i This invention relates. to improvements in lightningarrestersl Y The"ob ect of, the invention is to provide a lightning arrester capable ofwithstanding safely severe h discharges; of discharging without affecting materially the line voltage; also being a free for? all practical purposes The arrester isof the horn type, may

be used with either an. electrolytic, orother resistance element. x The settingof the horns determines the break-down point, and, the

resistance elements; limit, and control the ensuing flow of current; An efiicient arrester qualifications. The discharge path should have very low. self-induction. Y Theactioncaused by the horns should make the resulting arc ascend promptly to the point of "rupture. jThe resistance element through which the current must pass should so limit a the flow of current as not toaifect materially the line voltage. The arrester must have a .free path to. ground to carryofi? severedischarges. :The horn gapshould be the maXimum possible for a given: voltage, and the horns should be so constructed. that they do not burn. The hornssho'uld -be stifl', light, and 'rigid, and also readily adjustable. In all these, particulars myjarrester makes; a

material improvement over, others now in use, as w ll be shown. r 1 V The accompanying drawings lndlcateln detail the principles of the arrester:. I Figure 1 is aplan viewof atwotpol arrester. Fig. 2is an end elevation in section, of the same. Fig. 3 is a diagrammatic arrangement of asingle pOIearresterwith a different resistance connection. T Fig. 4,

and Fig, .5, show diagrammatic arrangements ,of arresters with multiplex connection. Fig. 6 shows an enlarged elevation of a horn; Fig. 7 .showsa crosssection of the sa me,",atS. Fig.8shows aplan ot a re's stance element. "Fig. 9 shows a cross sectional elevationoff the same. Fig. 10 shows an enlarged end elevation of an insulator, with crank for adjusting gap spacing. Fig. 11 shows a siderelevation of detail of tapering horn inade of'two sizes of pipe.

Referring to the drawings Figs. 1 and 2, A A A are insulators carrying the metal caps B B B C C are horns fixed in position in the caps, and E E D D are smaller horns readily adjustable to give the desired gap. From a practical standpoint, the adjustable horns D D ,with larger horns acting as an extension have important advantages over any method of adjusting the main horns, which on account of their length must be rigidly supported. It will be observed that the main horns used in my lightningarrester areof the linear type, Wherein the electrodynamic action of the current, and the heat of the arc combine to F F are resistances connecting the horns C and E to ground, P. Thehorns C D and E are'connected together electrically. G G are horn gaps, and Gr is an air gap. between two plates of metal, H and H H is connected to horn E and H is connected to ground.

F is preferably made a high resistance, and F? a lower resistance. The gaps are usually so set that G requires a smaller voltage-than G but a higher voltage than G 'to break it down.

The action is as follows: The great ma jority of disturbances on electriclines are not severe, and these will pass oil? by breaking down. the gap G and going to earth The line curas not to affect appreciably the voltage.

The heat of the. arc,'and the electromagnetic effect of the horns will cause the arc to rise up the horns rapidly until it is so attenuated thatit can no longer hold, and the circuit will be broken; Should the disturbancegbe more severe and be unable to pass off ,over the. resistance F then the-gap G will in turn break down, and will put the resistanceF in multiple with F and both resistances will handle the current. On

account of the lower resistance this may cause a slight momentary effect on the volt age. However, on account of the limiting effect of the resistance, the current is quickly withdrawn from the gap G and then as 1n the first case, it is limited by the resistance two resistances are unable to carry off, thedischarge will break down the gap G and will go direct to earth without resistance. This free discharge is of the utmost importance for an arrester which is to furnish complete protection. The resistances attached to the gaps will quickly withdraw the current, step by step, as just explained, and the circuit will be broken. At the same time the combined length of all the gaps in series is available to break the circuit in case there is any tendency for the arc to hold.

Fig. 3 shows diagrammatically a resist ance arrangement where the resistances F and F are in series, the outer end of F being grounded, and the connection between F and F being attached to the horn E The graduation of the resistances F and F wherein the former is made large, and the latter relatively small, is of much importance in the practical operation of the arrester. Thus F will take care of by far the greater part of the disturbances without appreciably affecting the voltage of the system, while F will handle the severe discharges without serious effect on the line. Thus only the discharges of the utmost severity will go to earth without resistance in series, and resistance would be very detrimental to insert in their path.

The arrangement of horns shown in Figs. 1, and 2 is of importance in the economical construction of the arrester, as it allows the horns which are in electrical contact to be mounted on the same insulator caps B To accomplish this practically, and to make the greatest possible arcing distances, the planes of the horn gaps G and G are made divergent. Also the upper end of horn E is made adjacent to horn C with which it is in electrical contact below. This results in a considerable saving in the cost of construction, and has many electrical advantages.

Lightning arresters in addition to protecting each line from excessive voltages to ground, are also called upon to protect against excessive voltage between the different wires of the same circuit. For this purpose it is desirable to afford an easier path between lines than would be available were both lines to discharge through the full resistance and air gaps. To accomplish this, I employ a multiplex connection, joining together electrically corresponding points as J inthe resistance elements. Also an additional gap to ground may be provided in series with all legs of the arrester. This arrangement in effect is shown in Figs. 4,

.and 5, which indicate two diagrammatic arrangements of arresters for three phase circuits with multiplex connection. The notation is the same as in the previous figures.

M and M are wires uniting the different phases resistances.

F is a resistance common to the resistances of all the phases, and G is a common gap to ground. As the air gap determines the point of discharge of the arrester, this arrangement allows'for any relative adjustment of discharge points between lines, and also between lines, and ground. It is generally preferable to use a single gap Gr between the multiplex connection and ground, but if desired a plurality of gaps may be used in place of the gap G It is generally advisable in horn arresters, particularly where the voltage is not very high, and the gap in consequence is small. to make the gap as large as possible, in order to prevent small variations in the length of the gap, due tomechanical or other reasons, from altering materially the point of discharge. The break down voltage between terminals depends on the shape of the terminal. Needle points will break down most readily, and hence for a given voltage require a maximum separation. Large cylinders on the other hand require to be placed much closer together to break down, and on this account are undesirable. However needle points are undesirable since they will burn off, and hence will alter the gap. In this respect cylindrical surfaces are very desirable, as they will not burn readily. In my arrester I combine as far as is practical the advantages of bothv types of gap.

The facing fronts of the two sides of the gap in my arrester have a cross section of a partly circular shape, the circular part being small in section. The metal behind this is made smaller than the diameter of the front of the horn, and is then increased in section farther back to provide ample stiffness. This is shown in Figs. 6, and 7 which are enlarged details of the small horns. The lower part of horn, Q, is made of non magnetic material, and the upper part, B, of iron or steel. Thus the path of the current at the point of break down is as non inductive as possible. After the gap has broken down, it is desi able to rupture the circuit as soon as possible. For this reason the upper parts of the horns are made of magnetic material.

The are is urged upward not only by its own heat, but also by magnetic effect of the current causing it. This effect is greatly intensified in a cylindrical horn of iron or steel, particularly when it is hollow, causimportant-where dealingfwith: horns sup! ported from= insulators since the length" forl high voltagemustLbeconsiderable,entailing ing the current to concentrate nearsthe sur-' face. The hollow cylindrical horn is' of great value not only forthe reasonsmentioned, but also because 1t resists burning by the current, and the wind and weight stresses for such a section area minimum for a given weight of metal. "Thisls most 7 any expensive supporting structure unless-the increases.

stresses are reduced to a minimums; For these reasons the horns (l and C arealso of iron, and are made tapering in sect on,

the upper end being small, and the lowerend being larger.v -In practice I nake these horns of iron pipe, and obtain the taper by using difierent sizes, fitting into one another, theupper edge ofthe outerpipebeing beveled, in order to presentno sharp edge for the arc to hang on. This is shown in Fig. ll which shows a side elevation of the horn, where pipe 9 is driven into pipe '10. As the arc ascends the horns, its resistance important electrical advantages. The size end, is materially less'in value than when it is near the lower end, owing to the high res stance of the long are. The tubular sec-' tioxrhas the very. important advantagev that I the radiating surface of the horn is greatly- 1ncreased,.as the ensuing heat of the arc may be carried awayflfrom within as well as G Correspondingly the gaps G from without, thus greatly increasing the safety, and reliabil ty. of operationif The tubular horn 1s also of particular value, as

r. it presentsnoedge on which the arc may hang, and cause burning of. the horn. If

' desired an increased numberofhorn orother gaps in series may be used. Allgaps f the 'arrester may be adjusted when the arrester is alive by mounting the insulator pins holding;

the insulators A on a rock shaft.

This will give simultaneous adjustment of all gaps simultaneously adjusted.

Fig. 10 shows, an enlarged endjelevation of the insulators A and their support, illustrating the manner of adjustment justmen- '7 somecasesI cover the surface of the liquid tionec The insulators A are mounted oninsulator pins 1, which ,in turn are rigidly mounted. on a rock shaft .11 which issup ported on bearings 4L,mou11ted on the sup-- portingstructure 3. A nut 7, is rigidly mounted on thesupporting structure, and I carries a screw 5, provided. with a hand wheel 6,, and tWo ,stops, 8, 8,. which-engage The tapered tubular horn has veying the current into and may be aluminum which arc,-and results in promptly extinguishing the-arc.

tTheresistance element 'is shown in Figs. 8 and 9." It consists of several jars filled with a liquid resistance, the ars setting vertically over one another, the lower part of each jar serving as a cover for the jar below. The jars are fastened together by bolts K which prevent their overturning. They are. supported only from the bottom, but if-desired may "be braced at the top by connections from the caps of the insulators electrically connected to the'top jar. 'Thejars are preferably made of porcelain or earthen ware, and this method of support isof important practical' advantage in avoiding any costly method suchasproviding in' sul'ato rsffor supporting the column, and at the same time-it allows a cheap grade of material to be used for the jars,'the potential gradientalong the outside of the same being verysmall. The division of the resistanceelement into'comparatively small unit-s has other practical advantages in that each unit is readilyhandled, and resistances of anyvaluemay b'ereadily assembled from a small number of standard resistances. Each jar L has two electrodes 0 and N for con- The lower electrode 0 consists of a fiat plate, butthe upper electrode N is made with its lower sides inclined to the horizontal. This construction is used to'prevent the collection-o-fbubbles due to electrolysis-which out of the liquid.

would form on the plate electrode if horizontal and would affect the resistance. T

is a metallic connection between the lower.

electrode of one jar and'the upper electrode of the jar-below. It is firmly cemented "in the upper jaw; The electrodes are made of I find has practicallyno effect on theconductivity of the liquids I employ; 'l o guard against evaporation in with oil and also I make connection between the top of eaclr jar and the atmosphere through thevalve V. A second valve W may I aporation. The valve V is a pressure relief valve which W111 openbefore the P re in thejar rises to a dangerous point. The valve W is the reverse type of valve to take care of the condition of a partial vacuum in the jar such as might arise after the ,was overheated. Ii desired one valve of suitable design may be used to perform the two functions and to provide safety against both pressure and vacuum.

I have described my invention in what I consider its best form, but the invention may have other applications and may be embodied in various structures. The invention should not therefore be limited to the application or the structure shown.

Reference is made to my co-pending application Serial No. 297,433 filed January 23rd, 1906, in which I have broadly claimed certain elements which are further elaborated and employed in the invention covered by these specifications.

lVhat I claim is z 1. In a horn type lightning arrester, a plurality of air gaps in series, primary horns substantially vertical at the gap limits, secondary horns mounted in electrical connection with said primary horns, the horns mounted on insulated supports.

2. In a horn type lightning arrester, a plurality of air gaps in series, primary horns substantially vertical at the gap limits, secondary horns mounted in electrical connection with said primary horns, the horns mounted on insulated supports, the primary horns on one side of the gaps diverging from the primary horn mounted on the opposite side of the gap.

3. In a horn type lightning arrester, a plurality of air'gaps in series, primary horns substantially vertical at the gap limits, secondary horns mounted in electrical connec-.

tion with said primary horns, the horns mounted on insulated supports, a conductor between one or more of the pairs of said horns in which is interposed a resistance.

4. A plurality of horntype, single pole, lightning arresters, with resistances between corresponding horns and a common electrical connection, in combination with an air gap connected between said connection and ground.

5. A plurality of horn-type, single-pole, lightning arresters, with resistances between corresponding horns and a common electrical connection, in combination with an air gap and resistance connected between said connection and ground.

6. A lightning arrester consisting of three or more air gaps, a primary horn, and a secondary horn mounted on each side of one or more of the air gaps, conducting members between two or more of said gaps, a path of electrical conductivity between each of said conductors and the ground and resistance interposed in said path.

7. In a horn-type lightning arrester, a horn, the lower part of which is of non-magnetic material and the upper part of mag netic material.

8. In a horn type lightning arrester, a pair of diverging horns, one of said horns comprising a main horn in combination with a small adjustable horn having a base and an arcing edge, connection between said base and said arcing edge, said connection being substantially vertical near said arcing edge.

9. In a horn type lightning arrester a pair of diverging horns, one of said horns comprising a main horn in combination with a small adjustable horn the upper end of which is so located as to form substantially a continuance of the main. horn, said adjustable horn having a base and an arcing edge, connection between said base and said arcing edge, said connection being substantially vertical near said arcing edge.

10. A lightning arrester consisting of three or more air gaps, a primary horn, and a secondary horn mounted on each side of one or more of the air gaps, conducting members between two or more of said gaps, a path of electrical conductivity between each of said conductors and the ground and resistance interposed in said path, said electrical paths joining before they reach the ground and a resistance interposed in their common circuit to the. ground.

11. A lightning arrester consisting of three or more air gaps, a primary horn, and a secondary horn mounted on each side of one or more of the air gaps, conducting members between two or more of said gaps, a path of electrical conductivity between each of said conductors and the ground and resistance interposed in said path, said electrical paths joining before they reach the ground and said resistance being adjustable.

12. In a horn type lightning arrester, a primary horn in combination with a secondary horn of greater length and of magnetic material.

13. In a horn type lightning arrester, a primary horn in electrical connection with a secondary horn of magnetic material.

14. In an electric arc-breaking device, a tubular tapering horn of magnetic material and annular cross section having its interior open to the atmosphere.

15. In an electric arcbreakingdevice, a

tubular tapering horn of magnetic material and annular cross section having its interior open to the atmosphere, mounted upon an insulated base, and adapted to convey a formed are in an upward direction.

16. In an electric are-breaking device, a tubular tapering horn of magnetic material and annular cross section having its interior open to the atmosphere, mounted upon an insulated base, and adapted to convey a formed are in an upward direction, in combination with a primary horn of smaller proportions on which the are is first formed.

17. In anelectric arc-breaking device, a tubular tapering horn of magnetic material and annular cross section having its interior open to the atmosphere, mounted upon an insulated base, and adapted to convey a formed are in an upward direction, in combination with a primary horn of smaller proportions on which the arc is first formed, said primary horn of non-magnetic material.

18. In an electric arc-breaking device, a tubular tapering horn of magnetic material and annular crosssection having its interior open to the atmosphere, mounted upon an insulated base, and adapted to convey a formed are in an upward direction, in combination with a primary horn of smaller proportions on which the arc is first formed,

said primary horn of non-magnetic mate rial, and said primary horn being formed with a. curved edge of smaller cross section than the body of said primary'horn, substantially as described.

19. In an electric arc-breaking device, a tubular tapering horn of magnetic material mounted upon an insulated base and adapted to convey a formed are in an upward direction.

20. In an electric arc-breaking device, a tubular tapering horn of magnetic material mounted upon an insulated base and adapted to convey a formed arc in an upward direction, in combination with a primary horn of smaller proportions on which thearc is first formed. 7

21. In an electric arc-breaking device, a

tubular tapering horn of magnetic material mounted upon an insulated base and adapted to convey a formed arc in an upward direction, in combination with a primary horn of smaller proportions on which the arc is first formed, said primary horn of non-magnetic material.

22. In an electric arc-breaking device, a tubular tapering horn of magnetic material mounted upon an insulated base and adapted to convey a formed arc in an upward direction, in combination with a primary horn of smaller proportions on which the arc is first formed, said primary horn of non-magnetic material, and said primary horn being formed with a curved edge of smaller cross section than the body of said primary horn, substantially as described.

23. In an electric arc-breaking device, a tubular tapering horn of magnetic material.

24. In an electric arc breaking device contacts at the limit of a gap or gaps, horns adjacent to two or more of said contacts formed with curved edges on which the arc first forms, said curved edges of smaller cross section than the body section of the horn and projecting from the body section substantially as described.

In testimany whereof, I atfix my signature in the presence of two witnesses.

AUGUSTUS JESSE BOWIE, J R.

Witnesses:

M. H. WHITE, H. W. CRozmR.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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