US1689781A - Bpst available cop - Google Patents

Description

Oct. 30, 1928.

E. H. JACOBS LIGHTNING ARRESTER Filed Feb. 4, 1921 2 SheetsSheet Oct. 30, 1928. 1,689,781

E. H. JACOBS LIGHTNING ARRESTER Filed Feb. 4, 1921 2 Sheets-Sheet 2 Patented Oct. 30, 1928.

UNITED S S PATENT OFFICE.

ERNEST JACOBS, OF CHICAGO, ILLINOIS, ASSIGNOR TO ELECTRICAL ENGINEERS EQUIPMENT COMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION OF ILLINOIS.

LIGHTNING ARR'EsTER.

A lication filed Eeb riiary 4, 1921. Serial No. 442,341.

This invention relates to protective devices forelectrical circuits, and more particularly to thosc'jdevices known a's lightning arresters of the Fair break or horn gap'type. 1, In electrical distribution syster n s it 1 necessary to ,previde. some meansior protecting the ,,li nes ',.andl connected apparatus a st pe a al d u es e. n rally termed lig-htning, As lightning, is they most .frequent oauselof .these disturbances, .su'ch vdevices are-'usually-known as lightning arresteiis. e purposeis'to dischargethe-excessive; potential to ground the'least possible del a with as little disturbance and damage to the apparatusend lines. Horn .gap arrestersot-the type tot-which my invention relates consists generally of a pair of proximate electrodes,. one' connectedto the line and the other connected to ground through a ithigh resistance. The resistance unit. should befof ,a,cap:'a, 'city:"large enough to :relieve thecdisturbancefonthe'line, but at the same timeitshould havefsutlicient resistance to. exclude i the .fiow, of v anyj appreciable amount ofdy namiccurre nt which tends to follow the dischargetoearth. .4

The difiiculty ihereinbefore encountered in the employment of a resistance'between the grounded electrodes and ground is the inability to maintain the capacityof theresistance approximately constant -and secure satisfactory operation thereof. Because of the well known surface flow oriskin effect of conductors, thereis a tendencyior the excessive potential to flow to ground by way of the surface of theresistance. If the po tential or. inertia of the. discharge varies, the efiiciency :or effectiveness of tlie'resistancevaries. Qther causes, such as rain and sleet tend todeerease the resistance, besides atmospheric. electricity manifests apredomr nantinfiuence upon varying thecapacity 7 It is one oftheimportant features'of the invention to provide means whereby the ,re-

5 sistance isrmaintained substantially constant in capacity. To this end an insulating chamber surrounds the resistance within which fluid or semi-fluid is kept for the purpose of sealing the resistance from the atmosphere. Since the tendencyof the discharge is to flow along the outer surfaces of V the resistance, and since the insulating mass is in contact. therewith, there is a tendency for. the insulating material to; carry a part tentialidiscli arges. I

thergdesi rablel{characteristic that it is's elfheallngjbentuseof thefiuid or semi fluid of the discharge. The insulating mass is preferably a compound of bituminous character, whichis only slightly conductive, but which in reality, forms a conductor of large capacity "and high resistance for high po- "This mass has the furcharacter of the same! I v The present invention as represented in the "einbodimenthereinafter described in detail is desighed'to meet the demand for a simple and inexpensive, .yet compact and durable lightning arrester capable ofquick and facile assembly and/installation. The

embodiment described is particularly well suited for use in installations involving comparatively. low voltageswhere it is desired to provide ample protection for the line, but

Where the use of the more elaborate devices of this character would entail an'initial outlay'or expense which wouldbe prohibitive.

The invention provides an insulated electrode connected toline and mounted on a snitable base, the electrodes carrying an, arc ing horn on which a discharge'balljiis' adjustably mounted. A second grounded electrode carrying a similarYdischarg e ball is also mounted on said base, and includes an arcing member and grounded conductor of relatively large area and high resistance of the character above described. This insures a large capacity with sufficient resistance to prevent continuous arcing of the dynamo potential after asurge has passed through the arrester.

The ,discharge balls or spheres are mounted on parallel axes, namely the horns,

and they are rotatable to present fresh dishe to lot I line i of Figure 3.

Itefer-ring new ,tothe struetnralarrangement of ny i iyentio nlprovide ametallic base lO hav-ingia standard -1 1 preferehly integ a a vt a ea it an exte ie lupuher imm t 096 sai ilthbas T standard 11 'earigies an insulator 12, having a head 13, below which is formed a periphergl' QV 4.: The lin e s de i le m d on t rir s i at 12,. d E e tro e]comprismg a rod. ieqeivahlebetive'en the tire jaivs 6, d .11 f ta s a'min ill 3 a d 9 i i p iz ting a d ievsl imd 7; sa d e a g oiiposie yex e asaims 291 M 21 re'speetiyel y, said arms being curved ,to confoii n' tolthe shape Of the neck or groove 14 of theinsulator. ai1d adap,tedto seat in said roov sui ble Belts?? 2.2'ig i t i ing tlnoughthe' iipeeeigds of the arins and 21 e em'a' i hiss- .9? t 7i$lt-3 .T lugs. are each provided with recesses and 24 respectively,and slots 25. (a sjsho\vr i detail Figure {1;} The recesses. are adapted to receivethemed? .26 end .7, P bpl 's .28 and 23, said' bolts; extending through the an; 2, l nd 'l liriq g efiw lija' vs i eble= nut 3 'a i 3,1, bei arr e by the .upperfends of the bolts. A connect he he 32 11 awe n one mas we the bolts, inuthe present instance, on the boltz'ZS under tl1e-nut 3 O thereof, said lug 32 haying eorinecti onivith ,the lineby suitable eonduetor'32fl The standard, ll'is made cross shaped. in crosslsection, vvhieh niakes for strength and yet lightness construction. The base lQ-rnay be constructed of b a s i es red, and, isQP iYi- IW. w h a plu a y (if el a e-d.ep n sl i 0. ..se r n t e sam s ita e amend d support. l .7

The inner end of theelectrode is bent upwardly at 34, and then a, freely rotatable hafll35 is mounted thereon, a eoliar an ehored on .the electrode serving as a bearing for the balL The free endof the elect-rode is bent outwardly as at 3'Z after the ball has been placed in positionand servesto prevent the same from becoming displaced from the electrode. 7 i

' The purpose of permittingfree rotation of the ball is so that a renewable arcing surface is provided which willprolon'g the, life of the device; j

The grounded electrode is supported in a foot piece 38, the same being mounted on the base 10 in a manner which will be described presently. The foot piece 38 is provided With an exterior annular flange 39 and an interior ifiange 40, the inner peripheral surface of the fiange39 and itsjuneture with the foot-piece 38 preferably being beveled "as at fll A sleeve or shell 42 of insulating material, suel as heavy fiber or the like, is seated and eeme'nte'd in the recess provided b th ang 39 aid he l b ing l y less n dia neterthan the flange. The shell Agreein a u p end i ete as Jr iotede $3 and serve 19051 1 1 9 t am said ivate'rfsihed {B'having an external Lande' ieni ling flange 45c, and aninternal sun flange the under surface/thereo The ya r-shed hasheen 'slioiv fas c011 cs sel ti bi hi 4 th m t? adhs eda e-J "A sam is i' .i.., ii@awa 01 th g eri-b e 43, an l PiQYldQd tha threade" openiiigfl, tore- (delve i thrj dei MB 16 r An arcing ball is carried by the 'rod49 "and is rotatable thereon, fonpresenting a fresh surem. The. upper end are; fed 49 may be straight or bentaw'ay from the insula't'ed electrode as shown at 51,t0 the hem v A nd 1torte 'bf relatively high resiste, i i' l ewe d" h duet or seating? the recess formed by theflan e 4Q,said co'i'ldueto r being slightly less i ifj "ziii etq "'th ntli flange: The" r m son forforrning bfthe shell and the con du et or offle ssfdianieter than those of the flanges39 and fiO'fivfll appear later. 'The subs tanee frorn ivhic'h; the co ndri et or 52 is made up not essence o'f ftl1is invention, but the same may be o f a mixture of clay gra ihite ".ei -rhorundurn," or 'any other suitaIjle mat-erial of relatively high resistaiiee stren th; a The conductor carries a"nietallie cap me n b er 53 0n theupper end thereof, said vpartly receivable within the poe lgetfitforliied by the flangef45. The Jeep ii Prefer bly mended i an axial lug 55, uid. a'qe ll l i g .6. see f a legend v ii teriie l d B ihi'fid h socket iieed in th 'hetf bm f 'h a rs d and th me alli ar L 31 T i ng P m ready i and nairitains eo'nta'ct even vvitlr variation? iii the parts vvhieh inakeupthe alss'einhled devieef 7 It can "readily seen'that"theshell A2 forms aleh mbe i w i i o e i e is designated 57, said 'char nb er receiving afiller 58, isof eonduetiv.ity, infact, an insuiat'or for; 'norri al voltages. The foot- 38 is provided plurality of open- 59' 59,i serveifor the purpose of l i itroducing' filler, as will be explained presently; The niobflityof the filler 58 is arranged 'c'oncentriealljiapd vaeeaiiy IOU causes the same to contact closely with the surface of the resistance rod (2. The effective resistance due to skin effect or surface flow is thereby appreciably reduced. The filler 58 is not a pure insulator, and possesses someconductivity, but only to the degree that it serves as'an exceedingly high resistance. Being so disposed, it is in parallel to the resistance rod 52 and begins to act when the flow through the rod is excessive.

In assembly of the shell, water-shed and foot piece, the conductor 52 is seated in the recess formed by the -fiange 40, and cement such as Babbitt metal indicated at 60 is poured around the space between the conductori52 and thefiange 40. The shell 42 is now placed in position, and cement indicated at 61 is poured around the space provided between said shell and said flange 39. When this has set, the foot piece and shell and conductor are inverted, and the spring, cap 53 and shell are all seated in the recess in the water-shed 43; cement, such as babbitt in molten form, is now -poured around the space between the shell 42 and the flan e 44 and )ermitted to set this cement being indicated at 62. After-"the cement has set, the tiller 58 is introduced hot into the shell 42 through the openings 59. The filler is of a cementitious and somewhat plastic nature, and does not set firmly, and therefore, when the foot piece and shell and as sociated parts are returned to normal position, and the device assembled, it is necessary that some means he provided to prevent the escape of the filler 58, as it would do more or less rapidly under different conditions of temperature. I have therefore arranged a disk 63 of sheet metal, paper fiber, or other material, between an annular shoulder 64 formed on the under face of the foot piece 38, and a ring 65 conforming to the shoulder 64 formed on the base 10, said shoulder and ring gripping the disk when the foot piece is clamped on to the base by means of the bolts (36-456. The heads 67 67 of the bolts are arranged within the base 10, the base 10 being made of a semi-hollow construction for lightness. The bolts extend through the disk.

From the foregoing, it will be apparent that I have provided an improved protective device of the character referred to, which, while simple in construction and inexpensive -to manufacture, is highly effective to safeguard an electrical distribution system against damage due to electricalsurges set up, either by lightning or other causes. The setting of the discharge gap may be very readily regulated by the adjustable electrode 15. Due to the general arrangement and construction of the various parts, the device is rugged and durable. Those parts which might become affected by water,

and a singlegap provided, but it will be readily apparent that a plurality of gaps might be obtained by mounting an additional one or more electrodes on the base 10, where such arrangement is desired. "While I have shown the insulated electrode as the adjustable one, it willbe obvious that the other electrode may bemade adjustableby modifying the arrangement of the structure without departing from'the spirit, of the invention..

The entiresupporting column for "the electrode 49'comprises a' conductor of highf' resistance. This column includes three paths, namely, the rod 52, the compound 57, and the sleeve 42, all of progressively greater degrees of resistance respectively.

The device may be shipped for use assembled, or with'the electrodes and the balls demounted, and, in fact, in some instances it is possible to ship the device completely disassembled, and assemble the same in the field. I have stated that the above described device is designed for low voltage systems, but it is apparent to those skilled in the art that such a limitation is not inherent. It may also be desirable. in some instances, to have the standard 11 detachable from the base 10, and therefore I do not limit the in vention to the exact mounting of the standard as shown.

I contemplate changes in the device which are warranted by the scope of the claims.

I claim:

1. An electrode for lightning arresters comprising, in combination with a base, a foot piece removably secured to said base, a shell of insulating material carried on said base, a water shed on the other end of said shell, means for sealing said shell in said foot piece and shed, a solid resistance element in said shell, a filler surrounding said solid resistance element, means for introducting this filler into the shell after the same has been secured to said foot piece and water-shed, and a plate interposed between said foot piece and base for preventing said filler from working out of the shell, and an arcing terminal carried by the water-shed.

2. In a lightning arrester, a sleeve of in sulating material, a metallic closure for one end of said sleeve, said closure having an opening for filling of the sleeve, a cap for the other end of the sleeve, said cap having a petticoat, said cap and closure being secured to the ends of the sleeve, a high resistance conductor connecting the cap and closure and lying within the sleeve, a filling of bituminous compound in the sleeve surrounding the high resistance conductor, means seu ed y h clq u e,fopclosing id filli g Ope ning, and lip elecfirqdc mounted directly 9n the top of thl gil p, x v

3. In an clectrodc, l1hg cqmbinvation of a base, a shell of insulating material, a resistance clement insaid shllQal fill er disposed in the shell and surrounding said yesistance element, a fqot picqmjoiuified upon thc shell 4. In combifiation a sheu'bf H; JACOBS}:

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