US470721A - Lightning-arrester - Google Patents

Description

(No Model!) 2 Sheets-Sheet 1.

B; THOMSON. LIGHTNING ARRESTER.

No. 470,721. Patented Mar. '15, 1892.

m vmron WITNESSES:

' L'Ziiuv Thornsarv ATTORNEY.

.(No Model.) I 2 Sheets--Sheet 2.

E. THOMSON. LIGHTNING ARRBSTER.

No. 470,721. Patented Mar. 15, 1892'.

my Elzhu A TTORNEY.

UNITED STATES PATENT OFFICE.

ELIIIU THOMSON, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON- HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

LlGHTNlNG-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 470,721, dated March 15, 1892. Application filed December 26,1889. Serial No. 335,063. (No model.)

To all whom it may concern:

Be it known that I, ELIHU THOMSON, a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Lightning-Arresters and Static-Discharge Protectors, of which the following is a specification.

My invention relates to electrical apparatus to in which an electro-inagnet is employed for disrupting or removing an electric are formed between two points or electrodes included in an electric circuit; and it consists more particularly in the relative disposition or the ar- I 5 rangeinents of the electrodes and the arc-rupturing magnet or magnetic field.

My invention is applicable to lightningarresters, static-discharge protectors, electric fuses, or any other electric apparatus wherein two conducting bodies or electrodes are liable to have an are formed between them which it is desired to suppress or remove immediately.

I have in the present specification described my invention as carried out in connection with a lightning-arrester or static-discharge protector, the electrodes of which, being-placed in close proximity, are liable to have an are formed between them and maintained by the current of the dynamomachineorothersource of the circuit to which they are applied after the passage of a lightning or static discharge from one to the other of such electrodes. As before stated, however, my invention is ap- 3 5 plicable likewise to any other device wherein an electro or any other magnet is applied to disrupt or put out an electric are between two electrodes.

The object of mypresentinvention is to increase the power of disruption of the magnetic field and thereby to enable the apparatus to work more etficiently under conditions where a powerful arc would be apt to follow the lightning or static discharge or to ensue upon other changes in the conditions of the circuit or the apparatus-as, for instance, by the rupture of a fuse in a safetyfuse device-in which case an arc would follow and be maintained across the electrodes or conducting-blocks in which the ends of the fuse are held.

My invention consists, first, in the combination, with electrodes connected toan electric circuit supplied or connected with a source of electric energy suflicient to main- 5 5 tain an electric are once formed across the space between said electrodes, of an arc-rupturing magnet or magnets having said electrodes disposed in a portion of the magnetic field or space containing lines of magnetism passing from one pole to another of the magnet in such manner that the line joining said electrodes shall be parallel to the lines of the magnetic field which operates to rupture the are.

My invention consists, further, in giving such a polarity to said magnetic field that the tendency shall be to displace the arc in an upward direction. The effect of so disposing the electrodes is that any are forming between them will be displaced in the magnetic field in a direction to elongate its path very greatly while still remaining in. the field, thereby impelling the discharge or are to take up a movement in the field, whereby it shall inclose such field in a widening are or circle.

My invention consists, further, in the combination, with the arcing-electrodes and their disruptingmagnets, of one or more are diverting or interrupting plates or vanes in the path of the widening are, as will be hereinafter more fully described.

My invention consists, also, of other details of construction and disposition of parts to be hereinafter more particularly described, and then specified in the claims.

In the case of the application of my invention to a lightning-arrester the relative disposition of the electrodes and the arc-rupturing magnet maybe described as one in which the electrodes are presented or directed toward one another, so that the lightning or static discharge will take place in the general direction of the lines of force of the arc-rupturing magnetic field or in a line coincident o with or parallel to the line joining the poles J of the magnet in case the action of both poles of the magnet is resorted to for the purpose of disrupting or putting out the are.

In the accompanying drawings, which illustrate the application of my invention to a lightningarrester, Figure 1 shows a side ele- IOO which the poles N S are mounted or of which they form extensions. The coils CO may be included in an electric circuit, in which c'i1rrent flows constantly or in which current is made to flow temporarily only when the occasion arises for disrupting the are. The poles N S are made of opposite polarity by the manner of winding the coils or of causing the current tocirculate through them. In the case of a lightning arrester, where the coils O C are included in the path of the discharge, care must be taken to so wind or connect :the coils to the circuit that the current circulating through such coils and across the discharge points or electrodes D, constituted between the poles, shall set up poles of opposite name at N S. The dischargepoints D are mounted on the poles, as shown, and are preferably electrically connected to or carried by them, though this course is not essential to my invention, the prime object being to locate them withinthe field, and preferably in the middle thereof, in such manner I that the points or discharge-surfaces shall be presented to one another on a line joining the magnet poles or parallelto the magnetic lines of 'force joining such poles. To attain the best construction and action the poles N S are separated by a small space, so that the electrodes D, existing as little buttons of metal, such as copper or other material secured to the poles N S,"may come within a very short distance of each other.

In prior patented devices in which an arcrupturing magnet is employed the arcing electrodes have been disposed in the arc-disrupting field in such way that the line joining the conducting-faces which are presented to one another, and from one to the other ofwhich the electric circuit is normally formed,

is a line transverse to the lines of magnetic force or to the line joining the poles of the arc-disrupting magnet. In my present in-.' vention, however, the line is one such that in the case of a lightning-arrester the discharge shall occur in the line of the magnetic field between which the discharge points or electrodes are placed, instead of transversely to such field, the effect being that the arc following a discharge willbe contorted or twisted out of its straight path to a rotary path or position which will make it include the magnetic field or encircle the same. This distortion of the arc, to make it include a path of considerable length or extent, is facilitated by the addition of devices, which will be hereinafter described, but which are not essential to the operation of the invention.

In the case of a lightning-arrester such as shown herein it is well to have one of the coils, as O, in a circuit or energized from the line, so as to keep up a certain magnetization between the poles N S. I have shown a coil 0 connected into a line passing between 0 d, the coil 0 having its inner terminal connected to the core or magnetic bar on which it is wound and which, therefore, is in connection with the right-hand discharge point or electrode at D. The line 0 d may be any lighting or power line or other electric line which it is desired to protect or a branch from the same. The faces of the poles N S presented under these circumstances will, when the coil C is traversed by current, be very strongly magnetized, and to enhance this the lower ends of the magnetized bars on which the polar extremities are supported are brought near together with an interposed insulation below, as at I, the arrangement shown being virtually a horseshoe-magnet whose bent portion is separated and insulated. The discharge point or electrode D at the left, Fig. 1, and carried by the pole N, is connected to earth at E throughthe coil 0' or to another point, as will be presently described, for carrying off the static discharge. The electrical connection may be formed by connecting one end of the coil 0 to the iron' bar. on which the pole N is mounted, while the other or outer end of such coil is connected to the earth-plate E.'

It is advisable in some cases to have a small discharge-space, as at 0t, between the outer wire of the coil 0' and the core on which it is wound, though this is not necessary in all cases. This discharge-space simply allows a quick or static discharge to leave the discharge point carried by N without going through the, coil 0', which might oppose its passage. A similar arrangement might be provided for the coil 0, it being a sort of disruptive shunt; but these form no features of my present invention.

While the devices as thus organized would be very effectual in disrupting or putting out any are which might form across the elec trodes of the lightning-arrester, I sometimes prefer to prevent the formation of a dischargecircuit or an are at any other point, excepting at the electrodes D, by adding a facing of insulation to each of the poles N S, as indicated at M. This facing may be of mica or slate transverse to the line of the are which will be formed when the electrodes are arranged as described. These vanes, plates, or arc-diverting barriers are shown more clearly in Fig. 2 as radiating outward from the center at which the electrodes D are located in the middle of the insulating facings or disks M, covering the poles. I' also prefer to provide the electrodes D, though it is not essential to do so, each with a projection or extension 6 or e, extending laterally from the electrode outward toward the edge or confines of the magnetic field formed between the poles. These extensions are made of metal, and when the winding of the coils O O and the arrangement of magnetism of the poles is such as to force the arc upwardly are carried downwardly, as indicated in Figs. 2 to 6, inclusive. The faces of these extensions or projections lie a little back of the discharge surface or point of the electrodes D, so that the latter are nearer together than the extensions from them. The extensions 6 e from the discharge-points do not project radially outward on coincident radial lines, but as shown in Fig. 2, while the extension 6 proceeds radially downward to the right. The projection e proceeds in a divergent path, as shown by the dotted lines, or to the left. \Vhile, therefore, the discharge points or electrodes are directly opposite to one another, the projections or extensions therefrom are inclined away or project in divergentradial paths. The utility of this will be seen presently.

It should be understood that the plates or vanes V and extensions e e are not essential features of my invention, though they are of value as adjuncts to it, the main principle being to cause the discharge to pass from one electrode to the other in the middle of the field or on a line, as before described, which shall be coincident with or parallel to that joining the polar faces of the arc-disrupting magnet, or, in other words, on a line substantially parallel to the magnetic axis of the arcdisrupting magnet, and thereby be acted on powerfully and take the course whichwill be described in case an are forms.

To show the operation of the device, Fig. 3 exemplifies the position taken by an are immediately after a discharge has occured between the points D upon the poles. The dischage does not remain for an instant at the center point, but separates at once radially outward in all directions and runs down the discharge points or extensions 6 e, which, diverging relatively, lead the heated gas at each side to a distance of separation, while the arc or discharge plays outwardly in the space between the poles or between the insulated faces M, surrounding or facing these poles. The radial wings or vanes between the insulating-faces, when they exist, as in Fig. 5, act as are interrupting or diverting plates or barriers to cut up or further elongate the arcdischarge, which is being driven outward in that the direction of current in them will be such as to produce a field which will cause the discharge or are to be driven upward or into the position or form shown in Figs. 3 and 5, so as to be interrupted or broken up by the rings or vanes. If the discharge were driven downward instead of upward, the space traversed by the are between the ends of the extensions of the eiectrodes obviously would not be so long and the action would be less efficient.

Fig. 4: shows a lateral view of the course which would be taken by the arc in Fi 3, leaving one discharge-point to go to the other. It is turned about in the course there indicated, and if the extensions 6 c are properly located will not continue discharging from the dischargepoints at all, but will follow down the extensions to their extremities.

Modifications in the shape of the parts, not departing from the essential features of the invention, maybe made. Thus in adding the vanes or radial project-ions V between the faces M they may be made to still further separate the heated gases while being driven outward by giving them the form shown at V in Fig. 6, where they are shown enlarged or thickened at their outer ends, so as to contract the openings or increase the distance between the same outside the wings or vanes. The construction thus produced, it will be seen, affords virtually a ring or envelope of insulating material having a number of discharge-openings almost of the character of jets around the central discharge points or electrodes D, so that the heated gases being driven outward are expelled in separate streams and cannot reunite to continue the arc-discharge.

Fig. 7 shows the discharge-points at D, made in one piece with the poles N S and such poles covered all over with a coating of insulating material, which, however, is not herein claimed.

Fig. 8 shows the presentation of the poles N S as blunted cones, their extremities making the discharge-points or being capped with copper buttons for the same purpose, while over each pole is fitted a flanged cap or hollow conical shell with flanges M M, which enable the discharge to play out from between the poles into the free air beyondwithout reaching or settling down upon the magnet-poles themselves.

Fig. 9 shows the separation of the dischargepoints into two sets D D in series, with an intermediate insulating-plate M interposed between-the two sets of discharge-spaces. In this case two arcs are formed and two spaces for disruption are provided in the same field.

fect of having a number of disruptive points.

in series. When a number of dischargespaces in series are thus provided, the effects are intensified to a great degree, owing to the fact that any static disruptive discharge will leap a number of separate spaces of a given width arranged in series more readily than it will pass over a single space whose width is the sum of the small spaces.

Fig. 10 shows the interposition between the two sets of discharge-points of a mass of iron G, intended merely to 'act as a conveyer of the magnetic force. This figure illustrates how it would be possible to put a number of discharge-points in series, since the magnetic bar or portion G might even be wound with energizing-coils, which would increase the magnetization, though generally it would be magnetized from-the poles N S to a sufficient extent. In this case the insulating disks or washers face the polar portions and are indicated by the letters M M M M Modifications in the forms and disposition of the discharge-points themselves in relation to each other, not departing from the essence of my invention, may be made.

The action of the extensions 6 e, in connection with theinterrupting-plates,willbeclearly understood from Figs. 3 and 5. The extensions act to cause the arc to be first formed at points somewhat below the level of the electrodes D, where they are nearest together; but owing to the action of the magnetic field the arc following is instantly thrown upward, and thus caused to traverse a long space, in which are interposed the vanes or wings V. Being thus prolonged or extended, it may be broken with comparative ease.

What I claim as my invention is 1. The combination, with an arc-rupturing magnet, of the arcing electrodes connected to a circuit supplied from a source of energy sutficient to maintain a continued are once formed from one to the other and presented to one another on a line parallel to the lines of magnetism or line joining the poles of said magnet.

2. The combination, with the arc-rupturing magnet and the arc electrodes presented toone another on a line joining the magnetpoles, of one or more arc-diverting plates or vanes arranged in the arc of a circle around said electrodes and in planes substantially parallel to the line joining said electrodes.

3. The combination, with the arcing electrodes or abutments, of an arc-disrupting magnet tending to give the arc arotary or twisted path transverse to the lines of magnetic force and surrounding them, and one or more barriers or plates disposed in a manner to oppose the free movement of such rotary arc and cause it to beinterrupted or to assume a more lengthened path, substantially as and for the purpose described.

4. The combination, with the arc-rupturing magnet having poles brought into close proximity and adapted to produce an arc-rupturing magnetic field in which the lines of ,force may pass directly or without diversion from one pole to the other, of arcing electrodes located at or near the center of the magnetic space between the poles of the magnet and presented or directed toward one another on a line joining said poles and substantially parallel to the axis of the magnetic field or lines of force flowing between the poles, as and for the purpose described.

5. The combination, with the arcing electrodes and arc-rupturing magnet, of a surrounding cage or barrier arranged around the electrodes and provided with a number of discharge-openings.

6. The combination, with the arc-rupturing magnet and two ,or more sets of arcing electrodes arranged in series between the magnet-poles, of an intermediate conveyer of magnetism, as and for the purpose described.

7. The combination, with the opposed magnetic poles, of the discharge points or electrodes located between the same and provided with extensions for leading the discharge outward in difierent directions toward the confines of the magnetic field.

8. The combination,with the magnetic poles and the discharge points or electrodes located between the same, of disks or plates of insulating material over the pole-faces and connecting vanes or wings of mica between such plates.

9. In a lightning-arrester, two or more sets of discharge points or electrodes arranged in and in line with one another substantially parallel to the lines of magnetic force or the magnetic axis of such field.

10. The combination, in a lightning arrester, of two or more sets of electrodes arranged in series, means for diverting or forcing the arc laterally outward, and are diverting or interrupting plates contiguous to the spaces between the several sets of electrodes and placed in the path of the are following any discharge. 7

11. The combination, in a lightning arrester, of two or more sets of discharge points or electrodes placed in series, in combination with an arc-rupturing magnet, between whose poles the said two or more sets are arranged in a line parallel with the line joining said poles.

placed in an arc-rupturingfield,of extensions projecting toward the confines of the field, but on divergent lines.

14. The combination, in a lightningarrester, of arc-rupturing magnet ormagnets having their poles brought close together, and discharge-electrodes electrically connected to the poles and directed toward one another in the magnetic field or space in which the lines of magnetic force pass from one pole to the other, as described, and so that the discharge from one to the other will take place in a line coincident with or parallel to the line joining the pole-faces.

15. The combination, substantially as described, of discharge points or electrodes D,

connected to an electric circuit supplied With ELIHU THOMSON.

Witnesses:

JOHN W. GIBBONEY, ALBERT L. ROHRER.

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