US701032A - Lightning-arrester for overhead wires. - Google Patents

Description

No. 701,032. Pafented May 27, I902.

a GOLA. LIGHTNING ARRESTER FUR OVERHEAD WIRES.

(Application filed Dec. 10, 1901.)

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UNITED STATES PATENT OFFICE.

GIOVANNI GOLA, OF GENOA, ITALY.

LlGHTNlNG-ARRESTER FOR OVERHEAD WIRES.

SPECIFICATION forming part of Letters Patent No. 701,032, dated May 27, 1902.

Application filed December 10, 1901. 'Serial No. 85,367. (No model.)

To all whom, it may concern:

Be it known that I, GIOVANNI GOLA, electrical engineer, a subject of the King of Italy, residing at 21 Via Cafiaro, Genoa, Italy, have invented certain new and useful Improvements in Lightuing-Arresters for Overhead Wires; and I 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.

My invention relates to lightning-arresters for overhead Wires; and it consists in a device by means of which the electric discharge by which an electric conductor may happen to be struck is prevented from reaching the parts thereof that are to be protected by laying open to said discharge another way connected with the ground or earth.

The apparatus is based on the following principles: first, the tendency of static electricity and high-frequency alternating currents to avoid the central portion of conductors and accumulate for the greater part on the superficial portions,(skin effect;) second, the tendency of the electric lines of force acted upon bya magnetic field perpendicular thereto to be displaced in a direction perpendicular to their own as well as to the direction of the magnetic lines of force;' third, the difliculty met with by atmospheric discharges on their path from conductors of large surface to such ones of small surface and small crosssection, especially when the direction is to be abruptly changed.

In the accompanying drawings, Figure 1 is an elevation, partly in section; and Fig. 2 is partly a plan from above and partly a section on line w y, Fig. 1, showing by way of example how my invention may be carried into effect.

The apparatus chiefly consists in a hollow body A, the outer surface and the cross-section of which are by far larger than the crosssection and outer surface of a corresponding length of the conductor to be discharged. The body A, preferably having the form of a solid of revolution, with its minor axis vertically directed, is made of magnetic material coated with a layer of material which is not magnetic.

The hollow body A consists, according to the drawings, of two sections B B, bolted to gether by means of bolts 0. A zinc frame D, extending outwardly and forming a projecting rib all along the middle plane a) 'g of the body A, just where its section is the greatest, is placed between B and B and faces with its outer ends the earth-conductors G. Two small blocks H of suitable material, as coppered coal, making good contact with A, are fastened thereto along its middle plane just where its radius of curvature is the smallest.

The part of the earth-conductors Gfacing the blocks H preferably consists in a bundle of pointed copper rods having a large surface as well as a large cross-section in comparison with that of the conductor to be protected. The overhead wire is externally connected at E with the upper section B. The inward face of the lower section B is connected with a T-shaped piece F, which pro jects downwardly outside the body A. An outer-point L of the piece F is connected with the wire L M, leading to the part of the circuit into which the machinery and apparatus to be protected are inserted. The wire L M is wound in the form of a coilaround the core N of an electromagnet with proper expansions 0, giving rise to a vertical magnetic field all around the body A. It ensues therefrom that the bodyA is inserted in series into the overhead wire from which atmospheric electricity is to be discharged and is surrounded bya magnetic field directed along its minor axis. Under these circumstances atmospheric electricity finds its direct path toward the machinery to be protected obstructed by the apparatus hereinbefore de scribed, owing to the impedance of the magnetic and magnetized materials it would have to flow through along said direct path, as well as owing to the circumstance that in order to follow said direct path it would be compelled abruptly to change the direction of its displacement, quickly passing from a conductor of very large outer surface to one whose surface is comparatively very small and possessing inductive resistance on account of the aforesaid vertical magnetic field generated by the series coil L M. Owing to the effect of said field directed perpendicularly to the electric lines of force on the outer surface of the hollow body and owing to the latter be- ICC) the same length of the line to be protected ing thus shaped as to have its radii of curvature gradually decreasing up to a minimum along the lateral rib and the points thereof facing the earth-conductors current as well as static atmospheric electricity finds an easy path to the ground through the zinc rib D and the rods G" facing it, which path is not obstructed either by inductive resistance or impedance depending upon magnetic effects.

What I claim as my invention is 1. A lightning-arrester for overhead lines to be inserted in series into the line to be discharged and consisting in a body having an outer surface far much larger than that of and a protecting-rib along the plane of its greatest section, and coacting earthconductors.

2. A lightning-arrester for overhead lines to be inserted in series into the line to be discharged, consisting in a hollow body having a very large outer surface and a protectingrib along the plane of its greatest section, which latter is connected with the part of the overhead wire subjected to atmospheric discharges while its inward surface is connected with the part of the conductor which the apparatus is intended to protect, and earth-conductors arranged to cooperate with said rib. 3. A lightning-arrester for overhead lines to be inserted in series into the line to be discharged consisting in a hollow body of magnetic material, having a very large outer surface which latter is connected with the part of the overhead wire subjected to atmospheric discharges, while its inward surface is 0011- I nected with the part of the conductor, which 1 the apparatus is intended to protect, a protecting-rib disposed along the plane of greatest section, and earth-conductors arranged to cooperate with said rib.

4s. A lightning-arrester for overhead lines to be inserted in series into the line to be discharged having the form of a hollow body whose radii of curvature very much differ between each other, those points where such radii are the smallest facing the earth-conductor, and a zinc frame around the longer radii of said body.

5. A lightning-arrester foroverhead lines to be inserted in series into the line to be discharged, having the form of a hollow body, whose inward surface is connected with the part of the circuit to be protected by means of a conductor having a small cross-section and whose direction abruptly changes, combined with a zinc frame on said body, and earth-conductors cooperatively arranged with relation to said frame.

6. A lightning-arrester for overhead lines to be inserted in series into the line to be discharged, surrounded by a magnetic held intended to act on the lines of force of the electricity to be discharged so as to turn them aside from the part of the circuit to be protected, and earth-conductors disposed at the terminals of the larger section of said arrester.

In witness whereof lhave hereunto set my hand in presence of two witnesses.

GIOVANNI GOLA.

\Vitnesses:

CEHO NAZARIO GRILLE, ANouLo liojmonvo.

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