US1069310A - Lightning-arrester. - Google Patents

Description

A. J. WURTS.

LIGHTNING ARRESTER. APPLIOATION FILED AUG. 2, 1905.

Patented Aug. 5, 1913.

O O 15 0 0 0 045 1 12 i /3 7'55 8 WITNESSES: INVENTOR UNITED STATES. PATENT OFFICE.

ALEXANDER JAY WURTS, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

and State of Pennsylvania, have invented a new and useful Improvement in Lightning- Arresters, of which the following is a specification.

My invention relates to li htning arresters for the protecting of electric circuits and it has "for its object to provide an improved device of the character and for the purpose indicated.

Among the various forms of lightningarresters which have been constructed is one.

which comprises a pair of horn-shaped or slender curved terminal pieces, that are so disposed with reference to each other as to provide a narrow air gap between two corresponding ends thereof and so that the remaining portions diverge. The occurrence of a static charge upon a circuit which is protected by means of such a device is the cause of a discharge across the narrow air gap between the terminals, and if an are due to the current in the main circuit follows the discharge, it will travel toward the most widely separated ends ofthe terminal pieces and will rupture itself by reason of the greater length of the gap. In the use of such devices the arcs which are formed between the terminals are frequently of sufiicient duration to permit of surgings of the static charge in the circuit, which cause abnormal strains upon the insulationof the circuit.

In order -to prevent the continuation of such arcs, I provide for the introduction of a resistancein series with the are after the passage of the disru tive dischar e, and to this end I preferab y construct t ose ortions of the terminal pieces between w ich the discharge first occurs of low resistance material, and introduce comparatively high resistance intothe diverging portions.

In one form of my device the diverging extended portions of the terminal pieces comprise a plurality of conducting ieces that are insulated from each other an that are arranged with air is aces between them. In another form the iverging extensions.

1 me be constructed of higher resistance ma;

1' terial than the portions which are separated by the smallest air space. Thus when an aredue to the current in the main circuit fol- Specification of Letters Patent.

LIGHTNING-ARBESTEB.

lows a disruptive static discharge across the air space between the terminals and moves toward the diverging ends of the terminals, 1t encounters greater resistance and ruptures more quickly and surelythan would otherwise be the case.

Figure 1 of the accompanying drawing is a diagrammatic view of a system embodying my invention and Fig. 2 is a similar view of a system embodying a modification thereof.

An electric circuit which it is desired to M protect from the destructive effects ofstatic discharges,-- comprises distributing conductors 1 and 2 that'are supplied with electrical energy from any suitable source,'such as a generator 3, and a protective circuit 4 for the main circuit comprises a lightning .arrester 5, that is connected between conductor 2 and the ground 6. The lightning ,arrester 5.comprises a pair of horn-shaped or slender curved terminal pieces 7 and 8 which are ararnged so that corresponding I Patented Aug. 5, 1913. Application filed August 2, 1905. Serial No. 272,401.

ends 9 and 10 thereof are adjacent to each other with a narrow air space 11 between them, and so that the remaining portions 12 and 13 thereof diverge from each other. The terminal pieces 7and 8 are preferably composed of non-arcing metal or other conducting material that is not readily decomposed upon the occurrence of arcs between the terminals. Extensions 14 and 15 for the terminal pieces 7 and 8 comprise two sets of conducting pieces 16 that are separated from each other by air spaces 17 and that are otherwise suitably insulated from each other. The pieces 16 may also be composed of non-arcing metal or similar material.

If the main circuit becomes charged by lightning-or otherwise a discharge will occur-between the ends 9 and 10 of terminals 7 and 8 and, if an arc is produced, it will travel from the ends 9 and 10 of the terminals 7 and S'toWa-rd the opposite ends and will continue to travel toward the outer ends of the extensions- 14 and'15 until it becomes so attenuated that it breaks. The

cause undue strains upon the insulation.

miv

In Fig. 2 extensions 18 and 19 of the terminals 20 and 21 are composed of any suitable high resistance material such as a mixture of clay and graphite or carbon, and the resistances oi. the extensions may be made uniform, or they may be caused to increase as the distance from the lower resistance portions of the terminals 20 and 21 illcreases, so that, as the arc travels from the narrow portion of the air space to the wider portion, the resistance included in series circuit therewith is rapidly increased. The operation of the lightning arrester of Fig. 2 is the same as that of the form shown in Fig. 1.

An extremely important feature of myinvention is that resistance 'is introduced into the discharge circuit only after the passage of a disruptive discharge through the circuit, and is not connected permanently in series with the lightning arrester air space, as has been done previously, thereby oiiering resistance, to the disruptive dis charge.

Other means than those here specifically shown and described for introducing resistance into the circuit of a disruptive dischargemay be employed, and the construction and arrangement of the circuits and devices here shown may be varied considerably without departing from the spirit of my invention.

I claim as my invention: I

1. A lightning arrester comprising diverging terminal pieces of lowresistance and high resistance extensions for said terminal pieces.

2. A lightning arrester comprising diverging, discharge terminals, the most widely separated portions of which are of higher resistance than the remaining portions.

3. A lightning arrester comprising stationary diverging discharge terminals and high resistance extensions.

4:. The combination with electric circuit conductors, of a lightning arrester which affords circuit connections between the same Copies of this patent may be obtained for after the occurrence land the ground and comprises terminal n pieces separated by an air space and diverg' and stationary means for automatically increasing the resistance of the circuit between the discharge terminals immediately after the occurrence of an initial discharge.

6. A lightning arrester of the horn type in which one at least of the diverging electrodes consists of refractory material of relatively high specific resistance.

'7. A lightning arrester'comprising electrodes of refractory material of high resistance, sa'id electrodes being placed in proximity to one another and diverging from one another to expand an are fo med therebetween.

8. A lightning arrester having electrodes in proximity to each other to form an air gap across which an abnormal current may pass, said electrodes being disposed to produce a progressive movement of said are and having a specific resistance suilicient to produce a. marked increase in the resistance of the path traversed by the arcing current.

9. A lightning arrester having diverging carborundum electrodes separated by an air gap, means for connecting one of said electrodes to the line to be protected, and means for connecting the other electrode to ground.

10. A lightning arrester consisting of a plurality of horn shaped refractory electrodes having a relatively high specific resistance and separated by an air gap across which an abnormal potential may, establish an arc. v i

In testimony whereof, I have hereunto subscribed my name this 28th day of July,

ALEXANDER JAY VVURTS. Witnesses:

OTTO S. SCHAIRER, BIRNEY HINES.

five cents each, by addressing the Commissioner of Patents, Washington, 1). c2-

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