US1481081A - Insulator - Google Patents

Description

Patented Jan. 15, 1924.

UNITED. STATES PATENT OFFICE,

ARTHUR 0. aus'rm, OF BARBERTON, OHIO, nssrenon, BY mnsnn ASSIGNMENTSQTO THE OHIO BRASS; COMPANY, OF MANSFIELD, OHIO, A CORPORATION or NEW JERSEY.

msuLa'ron.

Application filed'Aprfl 10,

To all whom it may comm/m:- f p Be it known that I, An'rrjun U. Aus'rln, a citizen of the United States, residing at Barberton, in the county of Summit and 6 State of Ohio, haveinvented' certain newand useful Improvements in Insulators, of which the following is a specification.

This invention relates to 'insulating"devices and especially to insulating devices designed for'use with high potentials, andhas for its object the provision of insulatorswhich shall provide improved mechanical strength for the amount 0f material em- I ployed without sacrificing electrical 'efliciency' andwhich shall be of improved cOnstruc-' tiona'nd operation. p y y The invention is exemplifiedin the combi-; nation and-arrangement of parts shown in the accompanying drawing-and described; in the following specification; and'it is'mo're particularly pointed out 'in'the appended claims; I ;1 2 l In 'the drawing; the figurerepresents an insulator embodying oneforui of the'=p1'esent invention shown partlylinelevation and partly in section.- In'. the embodiment shown the dielectric or insulating material is intthe former a hollow tubel which is representedias" being ofnnifor m diameter throughout. The tube; I may; however, be of various shapes to'givel strength and convenience in maniufacture. Various insulating, materials t nny be em ployed, one material in co'm mon ;u'se being; 3b porcelain and other vitreous materialsgf'such, as glass, are sometimes employed; M00111. nected with the tube, adjacent the OPPOSitQ ends th'ereo fiare hollow metallic members? 2 and 3 which. are provided with eyesl'or; other fastening devices 4 and 5, respectively by means of which the insulator is "secured to the parts to be insulated. The inembel; 2

y is intended to be connected with'the ground ed sup ort while the inemberB iscOnnected with t e charged conductor. The members 2, and 3are secured to thetube rat points spaced from the ends. ofthe tube, as shown atthe' leftfin the'drawing. iThejoint between thecap 3 and the tube 1 maybe e ffected' in an of the usual anda'p'proved ways for ma iing suchf connections; 1t? being common practice to employ a? grade I of'Portland or .other cementior this urpose, as's'hown at 6 in'the' drawing. e

'tliecenter of t e tube'w ichftends to dry 191 Serial 1%. 289,091.

surfaces Of the tube 1 and the cap 3, which are engagedby the cement, are preferablvj roughened to insure firm connection with the cement. Under certain conditions of operation the: tubular insulator is very desirable for the 6 reason that a tubular section gives a highly efficient distribution of the material tore-j sist bending strains set up by vibration of the insulator'and connected parts and for other reasons; It has been found, however 65 that where tubular insulators are employed there isa tendency'to' discharge through the center 'of the tube and especially is'thisH true if moisture collects within thet'ube.

It is very' desirable to avoid sucha central flash-Over or discharge, for" the reasonjthat adischar e through the tube almost invariably results inian explosion of the, tubular member the least. disastrous eflect of whic'h is the destruction 'of the insulator. I An Ou tQ- 7 side dischargejhoweveriis usual] l-ficcom- Panid bi l t le f I Q s I a co necting caps are secured directly to the ends of 'a" tube. insulator an discharge or flash-- over is very apt to ta e'place through the center of the jtubef for the reason that; t e'j path through the center is as'sho' l; Q1? Shorter a the uts de P th and i r if ii that atmosphericlcondition's within the tube; arelikely' to'befsuch as to Ofl'er lessfresistance 86 tofa ilischarge than the atmosphere utside the tube; A baflie or webiof insulatingnm j trial maybeeittended' across the tube for the purpose of decreasing the liability of dis:- charge throughthe center, but under certain conditions this barrier malyf defeat its own purpose, If, for instance,moisture accumw. lates "within the tube, then practicallythe entire drop of' potential betweenthe ends of the tube occurs in thejshort' space occupied by the baflle web,' for the} reason that this y'vebap rokimat'ely an"infin iteiresi stj ance com'p'ar'e with the resistanceof' the remaining portion of the interior of the 'tube', and as a' result the entire pressure is c'o'n-' centiflated' upon the web "and the web is; siie'rced and; an intern'al discharge results? iipli' across web also: interferes with the; flow ofcha rgin or'lealra e current through an" j 'ni oisture which accumulates within the tu e." A 'web of this kind also interferes with the circulation of atmosphere within the tube and tends to set up atmospheric conditions favorable to flash-Wei.

In the present invention the tendency to discharge through the center of. the tube is overcome by connecting the end ca) at a point spaced inwardly from the cut of the tube and by forming the cap so that every point thereof is located at a considerable distance from the opening at the mouth of the tube. The cap mey be shaped so that approximately all the points of the cap will have the same resista n c i between them and the mouth of the tube his menus that the oint of content between the cap and the time is spaced a greater'distance from the end of the tube theriI the points in the cap nearer the end of t e insulator. The reason for this is that any lcuka ge from the point: of contact between the cap and the tube will extend qlong the surface of the ube inst ad of across] an air-gen, A s: charge from poin s QPPO it he. open end of the tube must puss through the sun spafi be ween e p a d t ube, we hen sp'ce; between the cap, end the end. of the hi e at e e peint efed n t be $9 g eet e. mis s edia ehfi t -h w't e we n the cen nd th tube A disrhmrge from, any intermecliat .pqi11t in'thec'eP would probably ak 1; h r p rt y through we aimed partly e long the surface of tube sov that the, zip would gradually diverge tram the surfe ce otthe tube as it extends toward the end of the. insulator. A c ap designed, there e o i n pr ximate i m esiste ee t shwe f a u i i in the cup to the center of the'tube would have u shupe similar to that shown in the drawing. This shape. also is desirable. from mech ni s ndp int e it s Wei suited to h ths ei l t t P a d W1 9 t e r by the tension exerted 'upon the eye. 5. It

will be understood, of course, that other shapes of connecting capfn ey be employed without sacrificing the benefits of resistance due to the spacing of thc'uzallsof the. cap r m e end 0 e ube, r i s nce a cylindrical cap could be used connected to. the tube by wall members at its innr $1.1 1 extending inwardly to the tube at right 2141- gles to ts exis and various other shapes buld he empleyed- It is desirable for mqliy reasons that a free circulation 0t air. through the. center of the insulator may be possible, for otherwise the air within the insulator may be a-ixe ctedby' the electrical stresses so as to produce pgessure within the insulator, or. to ecreas t e 'stwee te'fl shve ir la o of he a r t l g i'the s lator it :i ite e y es t he, etefibi; f he W t-Pd th s ec ases. he 'e de cy 0 ee geend discharge '3 free 011;.- hhe; er en" t-hie flea ii'llteire in; hie -t s eless iie e u. m us ssmwl 7 may be conne'ted with the end cups 2 and 3, these breathers being. constructed to exclude water from the interior of the insulntor but to permit free passage of air. The end, f h br ather tube 7, may b enclose in a mber 8 having peripheral perf tions 9 through which 'water may escepe independently of the position of the insulator and the tube 7 preferably extends :1 short distance into the chamber 8 and is provided at its curl with a circumferential head 10 to collect water of condensution and prevent its entering the insulator through the tube 7.

The flash-over of a high tension insulator depends to, a great extent upon the distribu: tion of electrostatic flux of lines of force and where a. concentration of the electrostatic lines of; force is permitted there is danger; of a power discharge along. the path of these lines, of force. It is therefore desirable, to distribute the electrosstatic fluxas nearly evenly. as possible in order to pre: vent it wnfi ntmtion 0f the lines of force at ne mih For t is reason an elec rostatic re n,- hown at 11 in, the d ew-hug, s. onnect d to. the nd ap 3 and exte ls ou wardly from its point of connection with the n mp an t ard. the oppos te end of the insulutor. The. electrostatic sc een 11 is p e rab y made of Qpen c nstruction. havn arms 12 which carry-e u i rmly curred circularrim 13 a their forwa end the rim 13 surrounding the tube 1 and spaced ad a yhe tu eith this arr n e t h .eletwst tic u is. cause to emm "ate substantial y u i rmly om the sur face of the rim 13 so that there is no conentm ien o flux, at any one n iut, i u consequent tendency to flash-owl from that point- The. Open construction of the creen pe s o was i g by r the hen e thefscreezr is kept clean by its exposure to h Whether l hile the cogcnegto s. 2 and 3. are shown in he drawing, as so id shells, they t ey, f cour e, b of open r k le n on true: tion without losing the. adrentuge of having he parts 0; the connectors spaced from the end 0 ub lar insule qlf member. when an 0 en construction is used, the breuthers wil of course. not he. necessary.

I c aim An. insulator comprising u tube, o,[ insuleting inete 'iel haying gm open end, l; pair, of comicctin members. secured to, the. ut-s surfaced Shir ih edi 'e ht h -12 posite. en ds, thereoi and insulated from one. wi her 9 w. 9i e eiebiit his 1 wi eless-d to. engage tube only; at poi sudjecent e end. ens teem R e 2- he. m eite t eemriiees e tu er i s an ori ng est hsllg ietls e h sh hr eh.

nd Beer 9 t e m m r sec re to th we ite 0 s e tu and. web d fine ne mik s o e f ed. meshe be:

ing arranged to engage said tube only at points spaced inwardly from the open end thereof.

3. An insulator comprising a tube havlng the end thereof open, and a pair of connectin members secured to the outside of said tu e and insulated from one another thereby, one of said-members being arranged to engage said tube only at points spaced inwardly from the open end thereof, said connecting member having all points thereof spaced from the end of said tube.

4. An insulator comprising an integral elongated insulating member having an opening therethrough, and a mechanical connector cap disposed entirely externally of said member and secured to said member adjacent one end thereof, said cap having all of the points thereof spaced from the end of said insulating member.

5. An insulator comprising a tubular insulating member having the end thereof open, and a mechanical connector cap secured to said member adjacent said end, said cap being disposed entirely externally of said member and arranged to surround the open end of said member and having the walls thereof spaced away from the end of said member.

6. An insulator comprising a tubular in sulating member having an open end, and an external connector secured externally to said member at a point spaced inwardly from said end, said connector extending from its point of connection with said insulating member outside of said member past said end and having all points thereof spaced from said end.

7. An insulator comprising a unitary tubular insulating member having a free passage extending therethrough, end caps secured to the outside surface of said member and enclosing the ends of said member and having the walls thereof spaced from the ends of said members at all points of said walls.

8. In an electric insulator, an insulating mechanical load carrying member comprising a unitary tube of vitreous material having an opening extending therethrough, and external mechanical load carrying metal end caps secured to said tube externally thereof and adjacent the ends thereof, said caps having the walls thereof spaced from the ends of said tube, said tube being the only mechanical connection between said end caps.

9. An insulator comprising a tubular insulating member, an end cap secured to said member at a point spaced inwardly from the end thereof, the Walls of said cap being shaped to diverge outwardly from said insulating member and to extend toward and surround the end thereof so that all points in the walls of said cap are spaced from the end of said member at distances to effect approximately uniform resistance to flash over between the various points in the walls of said end cap and the open end of said tubular insulating member.

10. An insulator comprising a tube of insulating material having an open end and a pair of connecting members secured to the outer surface of said tube adjacent the opposite ends thereof and insulated from one another, one of said members being arranged to engage said tube only at points adjacent to and spaced from said open end, and a flux distributing screen secured to one of said connecting members and extending outwardly from said tube and toward the opposite end of said member.

11. An insulator comprising a tube having an opening extending entirely therethrough and a pair of connecting members secured to the outside of said tube and insulated from one another, one of said members being arranged to engage said tube only at points spaced inwardly from the open end thereof, and an electrostatic screen secured to said connecting member and extending toward the opposite end of said tube and outwardly therefrom.

12. An insulator comprising a tube having the end thereof open, a pair of connectin members secured to the outside of said tufie and insulated from one another thereby, one of said members being arranged to engage said tube only at points spaced inward y from the open end thereof, said connecting member having all points thereof spaced from the end of said tube, and an electrostatic screen secured to said connecting member and extendin toward the op posite end of said tube an outwardly therefrom, said screen having a curved rim surrounding said tube at the portion of said screen farthest removed from said connecting member.

In testimony whereof I have signed my name to this specification on this 3rd day of April, A. D. 1919.

ARTHUR O. AUSTIN.

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