US829055A - Lightning-arrester. - Google Patents

Description

No. 829,055. PATENTED AUG. 21. 190e. J. E. BRBLSFORD a; J. w. LUTZ.

` LIGHTNING ARRESTER.

MPMan-10N FILED Hman. 1905.

.UNITED STATES ijnlrnNT OFFICE.

JOHN E. BRELSFORI) AND JOHN W. LUTZ, OF DAYTON, OHIO.

LIGHTNING- Specification of Letters Patent.

ARRESTER.

Patented Aug. 21, 1906.

i Application filed January 30,1905. Serial No. 243,319.

To a/ZZ whom it may concern.-

Beit known that we, JOHN E. BRELSFORD and JOHN W. LUTZ, citizens of the United charge of the normal States,'residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Lightning-Arresters; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to those devices, commonly known as lightning-arresters, used for grounding or discharging excessive potential charges from electrical lines for protection of instruments of fine and delicate mechanism, as in telegraphic, telephonic, and electric-lighting circuits, and especially for guarding the line from the effects of lightning or atmospheric electricity or other induced charges of high potential.

Important objects attained by the invention are, first, sensitiveness or nicety of action in such devices, enabling the setting of the electrodes to allow uninterrupted passage of current of a certain potential or the regular current having a desired voltage for performing the necessary work or for operating apparatus on the line and to ground or discharge any dangerous overload or surplus current or charge of higher potential, thus insuring erfect protection for delicate instruments y uninterrupted flow of the 'regular current and arrest or cut out of any charge of excessive potential; second, simplicity of construction and the provision of a device which can be readily applied by a single workman at any point on the line-wire Without cutting the wire for protection of electrical apparatus; third, safety and protection against injury or re from sparks or flashes caused by the arc of currents of high tension, as where a lightning-bolt or other induced current strikes the wire; fourth, avoidance of any permanent ground or discurrent by short-circuiting from rain, sleet, dust, or scale by thorough protection of the mechanism of the device rom these elements.

A preferred embodiment of the invention is illustrated in the accompanying drawings, which form a part of this specification and with'reference to which the invention will be fully described, and then articularl pointed out and defined in the ollowing c aims.

In said drawings, Figure 1 is a side elevation of the device shown in electrical connection with the line-wire and ground-wire, and Fig. 2 is a central vertical section of the saine. Fig. 3 is a top view of the cap.

The mechanism of the device comprises three distinct parts-wiz., the cap A, the ground-rod B, and the insulation C, connecting them. These parts assembled form a rigid unitary structure. The cap and groundrod may be of any suitable metal or other appropriate conductive material, preferably brass or steel. The insulation may be made of vulcanized rubber, porcelain,A lava, or other firm and enduring non-conductive niaterial.

The cap A has a depending stud or projection a, preferably circular, with a squaredoff end or flat terminal surface. This constitutes the line-electrode of the arrester, the cap bein indirect Contact with the line-wire. Preferably the cap has also a depending peripheral flange, as at a, which embraces the upper beveled or reduced end of the insulating-shell C.

The ground-rod B is a hollow tube Whose upper end b constitutes the other electrode and is serrated or furnished with points or projections, preferably V-shapcd points, having their extremities equidistant from and in close proximity to, but not in contact with, the flat end of the stud or electrode a.

The insulation C is a tubular shell inclos- `ing and connecting the stud a` of the cap and the upper part of the ground-rod. It may be secured to these parts by transverse pins, as at c and c', or otherwise rigidi 1 fastened thereto. Preferably a substantial length c f the rod is contained in this shell or coveringsay about an inch and a half or two inches cr more. The outer diameter of the shell is desirably the same as that of the cap, but its upper end is formed to fit in the concavity in the under side of the cai, whpse flange a" embraces the top perip eral edge of the shell, forming an air-tight and water-tight joint, which is the only exposed joint in the device.

As stated, the cap A is designed for direct contact with the line-wire, which is designated bythe s mbol For this purpose said cap has pre erably a groove across its top to receive said wire, which is seated therein and secured by a tie-wire 1,/,insertcd through a transverse hole in the cap and having its ICU ends wound or twisted around the line-wire. This makes a simple and convenient means of installing the device in the line, a safe and secure fastening, and a perfect contact with the line-wire upon which the current is turned. Obviously a single workman can easily and quickly apply the device at any desired point on the line-wire merely by inserting a tie through the.cap and then fastening it in close contact to the wire in the manner explained without expense, difficulties, and ob- }ections incident to cutting, splicing,.or soldering the line-wire. The oint in the line Where the device is insta led depends, of course, upon the position of the instrument or instruments to be guarded, the device being connected in advance of such a paratus to prevent the passage of any over oad or current of excessive potential. The ground-rod B is adapted for electrical connection with the ground-wire z, which may be connected thereto by any secure and convenientlymanipulated means. For example, a binding-screw Amay be employed or the groundwire ma be inserted through a hole in the rod and ave its end wound around the same. A iirther mode suggested is to solder the ground-wire in a groove cut inthe rod. This may be done in the shop Where the device is manufactured.

In operation the regular current fiowsuninterruptedly over the line-wire and through the ca A, while any current of excessive potentia (according to the initial adjustment or setting of the electrodes, as hereinafter explained) leaks or arcs across the gap be-` tween a and b and discharges to the ground in the usual manner. The cap A is preferably considerably` larger than the line-wire`say six or more times as large-having thus a larger relative capacity.

The construction and relationof the electrodes results in very eective and accurate operation,and this 1s deemed an important feature of our invention, for the lower end of the electrode a has a fiat, smooth, or plain surface evenly charged, while the upper end of the eoacting electrode l1 has its points or projections in close proximity to such surface. This causes a rapid and easy discharge or arci'ng between the electrodes, and it allows set-` ting or initial adjustment of the electrodes to a very fine degree, since the points of b can be arranged so closely to the surface ofa as to nearly contact. The same effect is gained as would be obtained b actual projections on both electrodes in tllie same intimate electrical relation, if that only conceivable in theory, but impossible in practice-that is, the actual points on b produce electrical points on a, the latter colnciding with the former or occupying the same spaces or fields. Moreover, 1t is to be noted that the electrical density is greatest at the lower periphery of the electrode a, it bewere possible7 for it is ing well known that electrical distribution is nearly uniform for a plain disk surface except at its periphery, where the density is a maximum. In our device, wherein the groundrod is preferably of substantially the same diameter as the stud a, the points of the electrode b conse uently project into the region of greatest ensity. Furthermore, by virtue of the hollow electrode b there are two surfaces exposed to electrical action, the inside and outside surfaces of the ground-rod, thus doubling the surface of the usual dcvices` The hollow ground-rod also renders the device safest against accidental 'fires resulting from overcharged wires, for in the event of the jumping of the current and production of an arc the spark will die out by the time it reaches the lower end of the groundrod. The total length of the ground-rod should be adequate for this protection, preferably two or three inches or more, Whereas the stud a on the cap may be 'very short. The arc within the insulating-tube causes the air to expand and tends thereby to expel the arc downward through the tube.

The electrodes can be arranged to meet any and all requirementsthat is, to act for i higher or lower excess voltage, as the nature of the case may demand. For protection of delicate mechanism the electrodes are prefer ably set in such close relation as to almost contact.

The insulating outer shell or covering C performs four separate and distinct functions: first, rigid connection between the parts, holding the electrodes a andA b in constant relation; certain desired current to pass at all times over the line-wire, but never an overload; third, protective covering and insurance against grounding the line wire by rain, snow, sleet, ice, dust, or scale by virtue of the housing of the electrodes and` the fluidtight joint at a', and, fourth, confinement of the arcing within the shell as well as within the hollow ground-rod, so. that when a lightning-bolt orother charge of high tension is induced in the line-wire the flash or sparks will die out before reaching the lower end of the ground-rod, thus making a safe device to place in `or on buildings and secure-against causing fire. We thus provi e an effective device of extreme simplicity havin the minimum number of parts attainable, fulfilling the several objects rimarily stated, and adapted to be installed lby a simple means of` direct fastening tothe linewire. As before stated, this means for direct fastening is one of the important features of the invention.` We do not -limit ourselves, however,to the preciseconstruction or Vmeans therefor explained, for'we contemplate obtaining such direct attachment of the cap in other ways, y as by'soldering it to the line-wire or by using a split cap or a two-partmap and-fastening YOC second, insulation allowing a by means of a set screw or screws or by sol- 1 dering. i It will be understood that the device is susceptible of modifications in details and that 5 certain of its separate 'features exclusive of the entire combination, as well as such combination independent of the specific features, are all embraced within `the scope of our invention as defined in the following claims. It will also be understood that the groundwire, while presumably connected with the earth, may be in some cases successfully connected with some other reservoir or conductor having capacity for absorbing the electricity or current discharged from themain line,

and hence the words ground, groundline, and "ground-rod" in the claims will be construed with this significance in view.

7e claim as our invention and desire to secure by Letters Patent of the United Statesl 1. An arrester having, in combination, op-

osing electrodes, one of which is tubular and las terminal points, while the other has a smooth terminal surface in close proximity to but-not in Contact with said points.

2. An arrester having, in combination, an electrode Yfor `electrical connection with the line conductor having a flat terminal surface, and an opposed electrode for electrical connection with the ground, the latter electrode comprising a hollow rod or tube having its terminalfurlushed with points in proximity to but out of contact with said flat surface.

3. An arrester having, in combination, an electrode for electrical connection with the line conductor having a ilat terminal surface, and an opposed electrode for electrical connection with the ground, the latter electrode comprising a hollow rod or tube having its terminal furnished with points in proximity to but out of contact with said fiat surface, and an insulating-shell inclosing said electrodes. i

4. An arrester having, in combination, circuit terminals or electrodes and an insulating-stell inelosing the same and rigidly holding them in proper spaced relation, the lineelectrode having a grooved cap and adapted for attachment to and in direct contact with the line conductor.

5. An arrester having, in combination, alined circuit terminals or electrodes and a Ptubular insulating-shell inclosing portionsof Sfvthe same and rigidly holding them in proper spaced relation, one electrode having a series of points closely adjacent to but not in contact with the other electrode.

6. An'v arrester having, in` combination, an electrode for connectionwith the line conductor having a terminal surface where the electrical charge is of maximum density, and an olpposed hollow electrode for connection with t e ground having its terminal endfurnished with points projecting into the region ofgreathaving est density, but out of Contact with said 'lirst electrode. i

7. An arrester having, in combination, circuit terminals or electrodes arranged end to end or in alinement to form a gap, the groundelectrode being of tubular form.

8. An arrester having, in combination, circuit terminals or electrodes arranged to form a gap, the ground-electrode being of tubular form, and an insulating-shell inclosing and connecting said electrodes.

9. An arrester having, in combination, an

spaced to form a spark-gap, and an insulating-shell inclosing the electrodes, the lineelectrode having a flat terminal surface and the ground-electrode having a serrated terminal edge in proximity to such surface.`

11. An arrester having, in combination, a cap having means for direct contact with the line-wire and having a depending stud and a depending peri heral flan e, a round-electrode alined wit said stu an having its terminal arranfcd with relation thereto to form a gap, an( a tubular insulating shell inelosing said stud and ground electrode and having itsup er end fitted in the under side of the cap an embraced by the fiange thereof, forming a fluid-tight joint.

12. An arrester having, in combination, a cap having means for direct contact with the line-Wire and having a depending stud and a depending peripheral flange, said stud constituting a circuit-terminal, a ground-rod its terminal arranged with reference to sai stud to form a gap, and a tubular insulating-shell inclosing and connecting said stud and ground-rod and havin its upper end fitted in the under side of sai cap,`f'orm ing a fluid-tight joint.

13. An arrester comprising a rigid unitaryr structure having a ga and having a cap Wit a groove to receive t e line-wire and with a transverse hole to allow a tie-wireto be inserted `therethrough for fastening the cap to the line-wire.

14. An arrester, comprising a tubular insulation-shell, a metallic cap at one end thereof having a transverse groove adapted to receive the line-wire and a transverse hole ada ted to receive the tie-wire for securing sai ca to the line-wire, said cap having an electro e secured in said tubular shell, and an ISO oliliposed ground-electrode secured in said with a series of points in close proximity to s ell and spaced with relation to the former but not in contact with the line-electrode.

to produce a gap. l In testimony whereof We aHLi our signa- 15. An arrester comprising a tubular intures in presence of two Witnesses. 5 sulation-shell, a metallic cap at one end there- JOHN E BRELSFORD of having a stud secured in the said shell and constituting a line-electrode, said electrode JOHN W' LUTZ' having a flat terminal surface, and a ground- Witnesses: electrode secured in said shell consisting of. a ELMER L. GERBER,

m metallic tube having its terminal' furnished l URBAN C, THIEs.

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