US3315026A - Insulator covered with a protective envelope - Google Patents

Description

INSULATOR COVERED WITH A PROTECTIVE ENVELOPE 2 Sheets-Sheet l 31' 1 ed Nov. 25, 1964 April 1967 w.' c. GREGORY 3,315,026

INSULATOR COVERED WITH A PROTECTIVE ENVELOPE Filed Nov. 25, 1964- 2 Sheets-Sheet 2 Jam; 0%,,

space with an elastomer contract.

United States Patent INSULATOR COVERED WITH A PROTECTIVE ENVELOPE This application is a continuation-in-part of my prior copending application Ser. No. 70,685 filed Nov. 21, 1960, and now abandoned.

A path to Ground is made when out-door insulators that are covered with soluble dust are wetted by natural precipitation. Short circuits may be very expensive.

The object of this invention is to provide means for maintaining the resistance of insulators the same as when new or BETTER.

Another Object sulator that shall cheap to make.

Another object of this invetnion is to break the film of water that runs towards an insulator during a storm.

Another object of this invention is to provide protection for insulators by enclosing the insulator in a self-cleaning envelope.

Still another object of this invention is to change electrolytes formed on dirt covered insulators in wet weather to non-electrolytes.

These and other objects of this invention will be apparent from the following specification when taken with the accompanying drawings, in which: I

FIGURE 1 shows a cap stud insulator. The cap is separated from the stud by filling the space with a nonconducting material.

FIGURE 2 shows of this invention is to provide an inbe light in Weight, simple, durable and sectional views, at different parts, 2A, 2B, 2C and 2D of the insulator for FIGURE 1.

FIGURE 3 shows a cap-stud insulator. The cap and stud are separated mechanically and electrically by filling the space with a rigid non-conducting resin.

FIGURE 4 shows a one-time casting. In this embodiment the conducting members are separated mechanically and electrically by filling the space with a suitable rigid non-conducting resin.

FIGURE 5 shows a self-cleaning two-link-stud insulator. The links in this insulator are separated by filling the or a plastic elastomer.

FIGURE 6 shows an'auto-cleaning poly-link-stud insulator. The links in this insulator are separated mechanically and electrically with an elastomer. FIGURE 7 shows 'a self-cleaning accordion type envelope. The ever changing air pressure within the envelope causes the surface of the envelope to expand and This movement of the outer surface does not permit the accumulation of dust.

FIGURE 8A shows an auto-cleaning envelope that consists of a plurality of sealed tubes cast into the form of an envelope.

FIGURE 8B shows a self-cleaning envelope, the walls of said envelope having various thicknesses.

FIGURES 9A and 9B are sectional views through 8A and 8B.

FIGURE 10 shows an auto-cleaning envelope that consists of a large number of balloons incorporated with an elastormer to form an envelope.

FIGURE 11 shows an auto-cleaning envelope that consists of a cylindrical elastomer tube sealed at both ends and to a supporting wire.

FIGURE 12 shows the end view looking toward the left of FIGURE ll.

3,315,026 Patented Apr. 18, 1967 FIGURES 1, 2, 3, and 4 illustrate a cap-stud tension type rigid insulator. The metal members of the insulator are separated mechanically and electrically with a nonconducting, non-metallic rigid member. The outer surfaces of these insulators are designed so that a continuous film of an electrolyte (water and a soluble dust) can not form between the metal studs, thereby maintaining the original resistance.

FIGURES 5 and 6 show a self-cleaning link-stud tension type insulator. In these embodiments the links are kept separated mechanically and electrically by a non-conducting elastomer or a combination of plastics and elestomers. The outer surface of these insulators are so designed that a continuous film of an electrolyte (soluble dust dissolved in rain water) metal studs, thereby maintaining the original resistance.

FIGURES 7 through 12 show the mechanical Ways of preventing the accumulation of dust on insulating members. Electrolytes are formed on insulators when soluble dusts are dissolved by various form of natural precipitation. When dust is absent electrolysis can not form. With water only, no shorting occurs.

FIGURES 7 thru 12 show mechanical methods of eliminating the accumulation of dust on insulating memers.

FIGURES 1, 2, 3 dead-end service.

FIGURES 6, 8A, 8B, 9A and 9B are designed for vertical or line supporting service.

FIGURES 7, 10, 11 and 12 could horizontal and/ or vertical service.

FIGURES 1, 2, 3 and 4 could be classified as rigid insulators. The insulator consists of the metal members (or conductors) and the non-metallic members (insulating materials). The metal members may be of the ferrous family or the non-ferrous family of metals, such as copper, aluminum, magnesium and the like. The insulating materials may vary from commercially pure non-conducting organic materials to commercially pure non-conducting inorganic materials. The organic materials may be of a thermoplastic or thermo-setting plastic series and may vary from commercially pure plastic to a plastic heavily loaded with non-conducting fillers. A short list of the rigid plastics that could be used would be the co-polymers of a-crylonitrile or styrene series, cellulose acetate, diallyl phthalates, halogenated hydrocarbons, melamine-formaldehyde, the methacrylates, phenol-formaldehyde, the epoxy family and a host of others. The inorganic non-conducting materials could be the inorganic non-conducting cements that when set are non-conductors and non-absorbers of Water. The properties most and 5 are designed for horizontal or be used in either sulators. a non-metal non-conducting member. The metal member may be of the ferrous family or the non-ferrous family of metals such as copper, aluminum, magnesium and the like. The non-conducting member of the insulator family is either an elastomer or a mixture of an elastomer and a plastic. The elastomers may be loaded with non-conducting fillers. A partial list of the vulcanizable elastomers that could be used includes natural rubber, thiokols, neoprene, styrene family or rubbers, silicone rubbers, acrylate rubbers, Hypalon, chlorinated and/or fluorinated rubbers and the like.

FIGURES 7 through 12 illustrate a flexible envelope that covers an insulator. These envelopes may be of the vulcanizable elastomers family or the flexible plastics which are mostly of the thermoplastic type but do not vulcanize, such as polyvinyl chloride, polyvinyl butyral, polyethylene and the chlorinated and fluorinated hydrocarbons, e.g., the Teflon family.

FIGURE 1 illustrates a tension type cap-stud insulator. The stud 1 is welded 2 to the anchor plate 3 after the anchor plate has been placed within the shell 4 of the cap. The end 5 of the cap is then welded 6 to the said shell. Water-film breakers 7 are shown on the exposed hardware. The hardware or metal conducting parts are separated mechanically and electrically by covering the anchor plate 3 within the cap assembly 4 and 5 with a mechanically strong resin and one that has great insulating properties, such as a suitable epoxy resin, a thermoplastic and/ or thermosetting resin.

The plastic portion of this insulator may be extended thereby enclosing a portion of the insulator with the resin as at 8. When natural precipitation accumulates on dust covered insulators, at least part of the dust dissolves to form an electrolyte. This electrolyte, if not broken, will form a path for the current to run over or are across the insulator. This path can be broken with properly designed water-film breakers 9.

FIGURE 2 shows the cross-section of the FIGURE 1, at sections 2A, 2B, 2C and 2D.

FIGURE 3 is an embodiment of a cap-stud insulator. In this embodiment the stud 10 is screwed into the anchor plate 11, after it has been inserted within the shell 12. The metal portion of the insulator is completed after welding 13 to the end of the cap 14 and the shell 12. The metal parts of the insulator are held apart mechanically and electrically by enclosing the parts with a tailored resin for a particular job 01' area. Efficient water- film breakers 15, 16 and 17 are shown in FIGURE 4. The hardware in this embodiment is a one-time casting. After the molding sand is removed from the casting, and the casting cleaned, the hardware 18 and 19 can be embedded with a suitable resin 20. The resin may be cast to form a plurality of water-film breakers 21. It is also desirable to have water-film breakers on the hardware 22.

FIGURE 5 shows a two-chain-link-stud insulator. In this embodiment studs 23 are welded onto the links 24. The links are held apart mechanically and electrically by enclosing with a suitable resin and/ or elastomer 25. The finished insulator should have a plurality of water-film breakers.

FIGURE 6 shows an insulator of the chain-link type having a plurality of links. In this embodiment the links 27 are held apart mechanically and electrically with an elastomer 28. The finished outer surface of the insulator should have a plurality of water-film breakers 29.

FIGURES 5 and 6 are self-cleaning insulators. As the supporting wires sway in the wind, the elastomers stretch and contract in such a manner that particles of dirt are dislodged and made to fall off. Since the rain has no material to dissolve to form an electrolyte, the rain runs off as water without doing any damage.

FIGURE 7 shows how insulators may be kept clean and not lose their resistance by enclosing them in an auto-cleaning envelope. In this embodiment the envelope 30 is made to enclose the insulator 31 and then sealed at both ends 32. The wall of the envelope has corrugations 33 and is preferably black so as to adsorb the maximum amount of heat energy. The energy from the sun heats the air within the envelope and expands the surface of the envelope. At night the air is cooler, thereby contracting the envelope. This swelling and contracting breaks loose any dust particles. The envelope should be made of a plastic, that is wetted with water with difficulty, e.g., a fluorinated hydrocarbon, e.g., Teflon.

FIGURE 8A is an envelope made up of a plurality of cylindrical sealed tubes 34 made into an envelope 35. This envelope is made to enclose the insulator 36. The outer surface of this envelope is coated alternately with insulator of a heat absorbing material 37, e.g., black paint, and a heat repellant material 38 e.g., white paint. The difference in the heat energy absorbed will make the cylinders distort the envelope unevenly, thus causing foreign materials such as dust particles to fall off. The areas of black and white should be approximately the same size and the design should be evenly and equally spaced.

FIGURE 9A shows the cross-section through 9A-9A.

FIGURE 8B shows an envelope 39 made up of the same plastic elastomer material but having different areas thicker than the adjoining areas. The areas of thick walls and thin walls should be approximately the same size and the design should be evenly and equally spaced. The thickness should be such as to flex readily with a slight change of internal pressure. The envelope 39 is shown enclosing the insulator 40. A water-film breaker 41 is shown between the corrugations.

FIGURE 9B is a cross-section of FIGURE SE at 9B-9B.

FIGURE 10 is an envelope made by having a plurality of small balloons 42 cemented together with an elastomer to form a structure 43 capable of contracting and expanding with the change of atmospheric temperature and pressure.

To increase these changes to a maximum, alternate areas on the surface of the envelope are coated with an energy absorbing surface 44 and an energy repelling surface 45. The drawing shows an insulator 46 encased in the envelope. A foam, the cavities of which are non-conducting, could be substituted for the balloon structure.

FIGURE 11 shows an insulator 47 encased in a flexible envelope 48. In this embodiment, the ends are sealed together and to the supporting wires. The fins that are formed by the sealing process act as vanes in the wind. The envelope should be made of an elastomer or a plastic elastomer.

FIGURE 12 is an end view of FIGURE 11, looking toward your left.

The resistance of insulators and insulating envelopes can be increased by covering the outer surface with a grease-like material. This grease-like material may act in two ways, namely (A) mechanically, (B) and/or chemically. (A) The grease-like material used mechanically may be a hydrocarbon,--C--C--C--, and/ or a silicone, Si-SiSi-. The viscosity of the material should be about 10 S.A.E. when used in a spray gun to spray insulators supporting energizing wires. The advantage silicone grease has over a hydrocarbon grease is the silicone grease does not deposit a graphite streak on the insulator should a flash-over occur. By spraying the surface of an insulator with a grease-like material, water can not wet the surface but will run off in the spheroidal state. (B) Chemically. This increased resistance is obtained chemically by changing the water soluble dust particles that are dissolved in rain water and that forms an electrolyte into a non-electrolyte. The water-soluble dusts that are found around industrial cities and near bodies of salt water are innumerable. These water soluble dusts accumulate on the insulators. At night or on the first precipitation the soluble dusts dissolve to form electrolytes and at that moment electric energy starts toward ground." However, if this electrolyte is changed immediately to a non-electrolyte this shorting does not occur. For example, insulators near a salt water body, the salt spray, carried by the wind, settles on the insulators and evaporates, leaving finely divided crystals of salt. A heavy dew falls and the crystals dissolve forming an electrolyte. Now if the insulator is coated withsay a silver stearate the electrolyte is changed to a non-electrolyte thus:

Silver stearate-l-sodium chloride =sodium stearate+silver chloride Sodium stearate (a soap) is soluble enough to run off the i sulat r and at the Same time wash the surface clean.

' pellant, flexible material Again, near a potash plant, the dust of potassium salts settles on insulators for miles around. In this case an organic ester could be used, for example:

Methyl stearate-f-potassium hydroxide =potassium stearate-l-methyl alcohol There are thousands of other combinations that could be used. Stearic products are relatively cheap, difiiculty soluble in water but soluble in alcohols. It is advisable to use material that is difficultly soluble in water but soluble in an organic solvent e.g., an alcohol. The salt, ester or other compound when dispersed for spraying should have a consistency so that it can be sprayed from a conventional air spray gun, similar to conventional lubricating oils sold as S.A.E. 10.

I claim:

1. An insulator comprising a first central terminal element made of electrically conductive material, a second central terminal element made of electrically conductive material, a substantially rigid dielectric material binding a portion of said first and second terminal elements together in a fixed relative position wherein said terminal elements are spaced and insulated from each other by said dielectric material to provide a spaced juncture, an envelope made of electrically nonconductive, water resealingly engaged at opposite ends to said first and second central terminal elements respectively, and spaced from the juncture of said terminals and the dielectric binder material which are completely encapsulated by said envelope, wherein said envelope is formed with adjacent alternatively varying expansion means which cause it to expand and to contract automatically in response to atmospheric temperature variations so as to substantially dislodge dust particles settling thereon.

2. An insulator as defined in claim 1 wherein the outer surface of the envelope thereof is covered by a thin film of an electrically nonconductive grease-like substance selected from the group consisting of substantially water insoluble hydrocarbons and silicones.

3. An insulator as defined in claim 1 wherein said envelope is formed with a plurality of annular corrugations which provide the means which causes said envelope to expand and to contract.

4. An insulator as defined in claim 1 wherein the outer surface of said envelope is provided with a plurality of alternating heat absorbing and heat reflecting areas which provide the means which causes said envelope to expand and to contract.

5. An insulator as defined in claim 1 wherein the envelope is formed with alternating relatively thick and thin areas which provide the means which causes said envelope to expand and to contract.

6. An insulator as defined in claim 1 wherein the envelope is formed with a plurality of internal sealed tubes with electrically nonconductive interiors which provide the means which causes said envelope to expand and to con-tract.

7. An insulator as defined in claim 1 wherein the envelope is formed with a plurality of internal, resiliently bounded, sealed cavities having electrically nonconductive interiors which provide the means which causes said envelope to expand and to contract.

References Cited by the Examiner UNITED STATES PATENTS 467,941 2/1892 Lee 174-184 474,569 5/ 1892 Anderson 174185 476,193 5/1892 Elliott 174185 834,392 10/1906 Mead 174185 1,166,391 12/1915 Stein-berger 174-180 1,717,281 6/1929 Thomson 174-184 X 1,728,531 9/ 1929 Estorff. 1,806,854 5/1931 Hesson 17430 X FOREIGN PATENTS 9,517 1904 Great Britain. 213,005 3/ 1924 Great Britain. 385,699 1/ 1933 Great Britain. 426,212 3/ 1935 Great Britain. 740,93 8 11/ 1955 Great Britain.

LARAMIE E. ASKIN, Primary Examiner.

Claims (1)

1. AN INSULATOR COMPRISING A FIRST CENTRAL TERMINAL ELEMENT MADE OF ELECTRICALLY CONDUCTIVE MATERIAL, A SECOND CENTRAL TERMINAL ELEMENT MADE OF ELECTRICALLY CONDUCTIVE MATERIAL, A SUBSTANTIALLY RIGID DIELECTRIC MATERIAL BINDING A PORTION OF SAID FIRST AND SECOND TERMINAL ELEMENTS TOGETHER IN A FIXED RELATIVE POSITION WHEREIN SAID TERMINAL ELEMENTS ARE SPACED AND INSULATED FROM EACH OTHER BY SAID DIELECTRIC MATERIAL TO PROVIDE A SPACED JUNCTURE, AN ENVELOPE MADE OF ELECTRICALLY NONCONDUCTIVE, WATER REPELLANT, FLEXIBLE MATERIAL SEALINGLY ENGAGED AT OPPOSITE ENDS TO SAID FIRST AND SECOND CENTRAL TERMINAL ELEMENTS RESPECTIVELY, AND SPACED FROM THE JUNCTURE OF SAID TERMINALS AND THE DIELECTRIC BINDER MATERIAL WHICH ARE COMPLETELY ENCAPSULATED BY SAID ENVELOPE, WHEREIN SAID ENVELOPE IS FORMED WITH ADJACENT ALTERNATIVELY VARYING EXPANSION MEANS WHICH CAUSE IT TO EXPAND AND TO CONTRACT AUTOMATICALLY IN RESPONSE TO ATMOSPHERIC TEMPERATURE VARIATIONS SO AS TO SUBSTANTIALLY DISLODGE DUST PARTICLES SETTLING THEREON.

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