US3003022A

US3003022A - Finned insulator

Info

Publication number: US3003022A
Application number: US789356A
Authority: US
Inventors: Meier Jean Henri
Original assignee: Compagnie General dElectro Ceramique SA
Current assignee: Compagnie General dElectro Ceramique SA
Priority date: 1958-03-07
Filing date: 1959-01-27
Publication date: 1961-10-03
Anticipated expiration: 1978-10-03

Description

Oct. 3, 1961 J. H; MEIER mmm: INSULATOR Filed Jan. 27, 1959 v 03,022 a FINNED INSULATO Jean Henri Meier, 'hi-bes, France, ssignor to Compagie Generale d'EIeetro-Ce'amlqe, Paris, Seine,

France, a company of France y Filed Jan. 27, 1959, Se-. No. e V Clalms priority, application France Mar. 1, 1958 3 Cllms. (CI. 174-211) The invention concerns improvements relating to self-` cleaning high-tension insulators, that is to say, insulators which are automatically self-cleaned by rain water, having` one or more vertical cylinder.

In the French patent application, February z, 1957, for "Finned Insulator, the applicants have proposed to improve the behaw'our of such insulators under impulse voltages by providing the edge of the fin or rib with a flange projecting on both faces.

The present invention has for its object the improvement of the resistance of these insulators to tracking in a contaminated atmosphere.

To this end, according to the invention, one prow'desp on thei one face of the helical fin or on the one and the other face of this fin, a protuberance situated between the cylinder of the insulator 'and the free edgesof the fin.

There may be more than one protuberance on the fins or ribs'disposed helically along a p shown that the insulator with z g stacked fins of the normal type withstood 10 cycles whilstthe'insulator with the helical fin improved as described with respect to FIG. 1 withstood cycles before tracking.

FIG. 2 shows a simplified embodiment in which ai single, protuberance 6 is provided on the upper face of the fin between the post 3 of the insulator and the free edge of the fin. v

a This intermediate protuberance may also be provided onthe lower face of the fin as at 7 in FIG. 1 or, again, such a protuberance may be provided on each face ot the fin or theone ,or the other face or `both may bear same face of the fin. It is advantageous for one of the protuberances to be at the edge of the fin, and the preferred combination is that in which the edge of the fin bears a protuberance on each face with at least one intermediate protuberance, because one then improves at the same time the behaviour under Shock voltages of the behaviour in contaminated atmospheres.

The following description in conjunction with the accompanying drawings, given by way of non-limitative i example, shows the different, features of the invention and the way in which they are realised, all arrangernents, as is clear from the text as wellas the figures, lying within the scope of the present invention.

FIG. 1 is a view in elevation, partially sectioned, of one preferred embodiment of an insulator according to the invention.

FIG. 2 is a partial sectional view embodiment.

In the embodiment according to FIG. 1, the insulator according to the invention is constituted basically by an of a simplified insulating body 1 sealed at its extremities' into two metali lic caps 2; the insulating body is constituted by a cylindrical post 3 hearing a fin in the form 'of a helical rib 4. The fin 4 is provided at its extremitywith a flange 5 projecting from the one and the other face of the fin as described in the patent application referred to above` Moreover, the fin is provided with swellings or

protuberances

6 and 7 on the oneand the other face.

Tests carried out on insulators of the support" type so constituted and of general dimensions: 756 mm., diameter 180 mm. for insulator with helical fins, diameter 210 mm. for an insulator with fins of the usual type, subjected to oycles of contamination comprising, under normal service voltage, an exposure 'to a dusty atmosphere for two hours followed by an exposure to a saline mist for four hours under stn'ctly defined conditions, have several protuberances, this lattedisposition being equally applicable in the case where there is a terminal protuberance on the edge of the fin as at 5 in For reason of simplification the examples shown bear only one helical fin. It is however clear that the invention is equally applicable when the number of helical fins is greaterthan one. Moreover, the invention is applicable whether the post of the insulator is solid or hollow, whether it transmits forces either in compression or tension or only serves as a protective envelope for electrical conductors without mechanical action, and whether the head of the fin is inclined to the longitudinal axis of the insulator or is perpendicular to its axs as is shown in FIGS. 1 and 2.

lt is preferable as shown in FIG. 1 that the section of the fin in an axial view should be such that the line delimiting the space between the two faces of adjacent turns, a-b-c-d, a'-b'-c'-d' possesses an axis of symmetry 0-0'. In efiect, it is then possible to manufacture the insulator by turning.

e It is sufiicient to turn a fresh cylinder of ceramic paste (that is to say, an unfired blank of a ceramic material the rib intermediate said insulator body and the peripheral edge of the rib and extending coaxially with said peripheral edge of the rib.

2. A self-washing insulator comprising an elongated body of dielectric material having a helical rib integral thereon extending :along the length of said body, the rib having an upper and a lower face and on at least one face' thereof a single protuberance extending longtudinally, along the length of the rib intermediate said insulator body and the peripheral edge of the rib, and outermost symmetrical protuberances along the peripheral edge of the, rib, symmetrical with respect to the :rib and forrning a groove between one of said outermost the intermediate protuberance.

3. A self-cleaning insulator comprising an elongated body ,of dielectric material having a helical rib integral protuberances and thereon extending along the length of said body, the rib having an upper and a lower face and oneach of said faces a single protuberance attending longitudinally along i 3,oo3,o22

the length of the rib intermediate said 'nsulator body and References Cited in the file of this patent the peripheral edge'of the rib, the rib having outermos't 'UN STATES PATENTS protuberances along the peripheral edge thereof symmetrical with respect to the rib faces and fou'm'ng grooves on 1394392 Gram Jam 1933 said faces between the outermost protuberances and the 5 ?0155348 Tayq` 1939 intermediate protuberances, and said outermost and nter- FOREIGN P ATENTS mediate protuberances and said grooves being disposed 436397 Great Britain Oct 10, 1935 coaxially, and the intermediate protuberances being disposed symmetficauy on said f lss France P 1958