US1490105A - Lightning arrester - Google Patents

Description

J. T. GREENE LIGHTNING ARRESTER April 15 1924.

Filed April 9, 1919 2 Sheets-Sheet 2 QAM @5% Patented Apr. 15,

UNITED STATES PATENT OFFICE.'

JOHN T. G OF TOLEDO, OMO, ABSIGNOB `NATIONAL mmc SPE'- CIALTY COMPANY, Ol' TOLEO, OHIO, A. CORPORATION OF OHIO.

` Home amm applicano inea- Apru s, 191s. sex-mig. naar.

To all whom it may concern:

Be it known that I, JOHN T. GREENE, a citizen of the United States, residing at Toledo, in the county of Lucas and State of 6 Ohio, have invented certain new and useful Improvements in Lightning Arresters, of whlch the following is a s iication.

My'invention relates to evices, commonly called lightning arresters, for lprotecting electrical a aratus from the estructive effects of lgh potential charges due to lightni crosses with high power wires, and the 'ke.

More particularly my invention relates to a vacuum lightning arrester of the cartridge type, that is, a device comprising an evacuated tube preferably of glass with the leading- 'in line and ground wlres for the electrodes extendin into the tube. Heretofore in devices of t is type particularly those em loying a fragile tube, the two line wires ave been run in through one end of the tube and connected to their respective electrodes and the ground wire has been run in through the other end of the tube and connected to its electrode.

The princi al object of my invention is to provide a liglitnin arrester of the vacuum type employlng a ragile tube, for example, of glass in which any tendency for the ine Wires to short circuit will be reduced to a minimum and to this end my inventionA aimsito provide an arrester of this type in which the three Wires, namely, the two line and ground wires enter the evacuated tube at three different points, each being a substantial distance from the others, and in its preferred form one line wire is run in through one end' of the tube and connected toits electrode and the other line wire is run in throu h the other end of the tube and connecte to its electrode, the ground wire being run in through the side of the tube and connected to its electrode.

lli The glass tube in an arrester of the cartridge type is ordinarily supported at opposite ends in spring cllss or the like. Apparently the great heat evelopedby a discharge between the electrodes tends to i0 soften the glass at the middle of the tube tov a certain extent. The stresses develged on the rarefied gas when a discharge es place alsoap to have a destructive eect upon the adjacent part of the tube. For these 'and possibly other reasons the glass tube in a device of this ty has a tendency yto sag or break in the rmddle. A'further object of my invention is to provide means which will rigidify and stren henthe tube ferred embodiments, in the accompanying drawings, wherein- Fig. 1 is a rester embodymg the principles of my invention.

Fig. 2 is a side elevational view.

whic the line wires are attached.

Fig. 4 is a longitudinal sectional view taken along the line 4-4 of Fig. 1.

Fig. 5 is a longitudinal sectional view taken along the line 5-5 of Fi 2; and

Fig. 6 is a transverse sectiona view taken alon the line 6-6 of Fig. 2.

Li e characters of reference desi ate like parts in the several figures of the rawings.

The base joriblock 10 is made of porcelain or other suitable material and is provided with a binding post 11 for the ground wire 12 and with binding posts 13 and 14 for the respective line wires 15 and 16. Y

The evacuated tube 17 is preferably made vof glass and is provided at opposite ends with the inturned stems 18 and 19. Secured to the stem 18, preferably by a body of asbestos cement 20, is a porcelain base member 21 formed with a pair of lugs 22. A line Wire electrode 23 is secured to the base member 21, preferably by a body of asbestos cement, on t e outer side of one of the lugs 22. A leading-in wire 24 extends from a metal ca 25, surrounding the end of the tube, an is embedded in and electrically connected to the electrode 23. This end of the tube is supported in a. spring clip 26 lan view of a lightning ar- Fi 3 is an elevational view of the end tosecured to theblock 10 by a screw 27 which is electrically connected to binding post 13 by a wire 28.

A base member 29 formed with a pair of lugs 30, is secured by a body of asbestos cement'3l to the stem 19 at the other end of the tube. A line wire electrode 32 1s secured to the base member 29, preferably by a body of asbestos cement, on the outer side of one of the lu 30 but on the side o posite that side of t e lug 22 to which the e ectrode 23 isvsecured. A leading-in wire 33 extends from a metal cap 34, surroundin this end of the tube, and is embedded in an electrically connected to the electrode .32. This end of the tube is supported in a sprmg clip 35 secured to the block 10 by a screw 36 which is electrically connected to the binding post 14 by a wire 37.

A ground wire electrode 38 is secured to 4the base member 21, preferably by a body of asbestos cement, between the lugs 22, 22. A leading-in wire 39 extends from a metallic band 40, surrounding the middle of the tube, and is embedded in and electrically connected to the 'electrode 38. When the ends of the tube are pressed down into the spring clips 26 and 35 the band 40 resses firmly against a s ring terminal mem r 41 secured to the bloc 10 by a screw 42 which is electrically connected to the binding post 1]. by a wire 43. vOne end of the band 40 is provided with a transverse slot 44 and the other end is provided with a tongue 45 which is adapted to slip through the slot 44 and be bent over after the band has been pressed closely around the tube. Preferably the band is secured to the tube by a layer of suitable cement 46. Preferably the respective spring clips 26 and 35 are rovided with lugs 26 and 35* to prevent tlie longitudinal displacement of the arrester in this direction in case the arrester is positioned verticall It willI be apparent from Fig. 5 of the drawings and the foregoing description that the electrodes are arrange in an interlocking relationship between the respective lugs provided on the base members 2l and 29. This arrangement in connection with the metallic band around the tube bearing against the spring clip strengthens and rigidilies the entire device against and tendency to sag when the tube is heated, or to break because of vibration or other causes when in service, or because of rough handling in shipment. In manufacturing the device, each base member may be united with its stem, the electrode secured to the base member, and the leading-in wire sealed through the stem. The ground electrode may be secured to either base member and the leading-in wire sealed through the side of the tube and -connected to the metallic band. The structures may then be placed in the interlocked relationship described and the stems sealed to the tube.

It will be apparent from the foregoing description that an tendency of the line wires to short circuit is reduced to a minimum. Although I refer to have the two lines discharge into t e evacuated tube from each end as described, thus maintaining constant equal distribution and balance on both sides of the line to be protected, it will. be understood that both line wires may run into the tube through one end and the ground wire be connected to the band and run into the tube through the side, or, if desired, any other similar arrangement may be employed as, for example, the ground wire may be run into the tube through one end, one of the line Wires through the other end and the other line wire beconnected to band and run into the tube through the si e.

It. will be apparent to those skilled in the art that further modifications might be made without departure from the principle of the invention. Therefore, I do not wish to be understood as limiting the invention to the precise constructions, arrangements and devices, except only so far as certain of the claims are specifically so limited.

claim:

1. A lightning arrester comprising a base, an exhausted tube mounted on said base and having hollow inturned stems at opposite ends, line electrodes supported on said stems in fixed spaced relation to each other, line wires entering the tube through said inturned stems at a substantial distance from each other and connected to said elec-- modes, a ground electrode disposed between said line electrodes and in fixed spaced relation thereto to provide spark gaps, the ground leading in wire entering said tube through one side thereof and at a substantial distance from each of said line wires and being connected to said ground electrode, a metallic band around said tube in close proximity to said spark ga serving to strengthen and reinforce the tilise against internal pressure and to which said ground leading-in wire is connected, and a spring terminal member mounted on said base and bearing against Said band so as to serve both'as an electrical connection between said band and the ground wire and as a support to prevent sagging of the intermediate portion of the tube when the latter is heated by an electrical spark passing across one of said spark gaps.

2. A lightning arrester comprising a base, an evacuated fragile tube, line electrodes electrically connected with line wires and supported in fixed spaced relation to each ot er near the middle point of said tube, a ground electrode supported between the line electrodes and in fixed spaced relation thereto so as to provide spark gaps, a ground leading-in Wire sealed through the side of the tube and connected to the ground elec- 5 trode, a metallic band connected to said ground leading-in wire and extending around the tube in close proximity to said spark gaps to reinforce the tube against internal pressures, and a ground terminal member mounted on said base and bearin 10 against said band to support the same and prevent sagging of the tube when the latter is heated by an electrical spark passing across one of said spark gaps.

JOHN T. GREENE.

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