US1866804A - Means for utilizing wood poles to aid insulators - Google Patents

Description

K. A. HAWLEY 1,866,804

MEANS FOR UTILIZING WOOD POLES T0 AID INSULATORS July 12, 1932.

Filed May 21, 1929 2 Sheets-Sheet l gnoc'ntoz FIG. 2

Ag? W K. A. HAWLEY July 12, 1932.

MEANS FOR UTILIZING WOOD POLES TO AID INSULATORS Filed May 21, 1929 2 Sheets-Sheet 2 Ken A. Hawlay FIG. 5

Patented July 12, 1932 UNITED STATES PATENT OFFICE KENT A. HAWLEY, OF BALTIMORE, MARYLAND, ASSIGNOR T'O LOCKE INSULATOR COR- PORATION, OF BALTIMORE, MARYLAND, A CORPORATION OF MARYLAND i MEANS FOR UTILIZING WOOD POLES TO AID INSULATORS Application filed May 21, 1929.

The invention relates to high tension transsupporting structures including poles and cross arms of one sort or another.

' c As the resistance of wood with the passage of electric current is high, it is contemplated to'take advantage thereof to aid insulators in their work and prevent damage to the poles as the result of lightning. As a matter of fact, the resistance ofwood is high enough that the enormous sudden rush of lightning current practically converts the pole into an insulator in series with the porcelain insulators employed for supporting the conductors. In installations of this general character it is customary to provide an overhead static wire. The intensity of the lightning is reduced by this wire. To be effective, this static wire must be connected to earth by a ground wire at each pole. Ordinarily, these ground wires substantially short'circuit the pole so that its value as insulation is practically lost. In other words, the benefit derived from the employment of the static wire in reducing lightning intensity is, for all practical purposes, counteracted by the short circuiting of the poles. It'is also known that where there is any very great amount of dirt or deposit on the insulators, such as along the seashore or in manufacturing sections where the air is ladenwith fumes, smoke, etc, the resultant coating on the insulator surface permits an appreciable current leakage. It has been discovered that it requires only a remarkably small amount of leakage of this kind to set the cross arms and even the poles on fire. If the insulators on any pole are uniformly dirty, the leakage will be equal on all and the resultant current flow will be zero, but in other instances there will be a leakage. This condition can be overcome by connecting the insulator pins or other hardware upon the pole by means of a bond wire which is generally grounded or connected to the earth wire. The omission of a ground connection is harmless in cases where the insulators are uniformly dirty. The bonding of the pins or other hardware Serial No. 364,889.

together short circuits the wooden cross arms and takes away their value as insulation in series with the insulators. There fore, if an insulator arcs over and the bond wire is connected to the earth wire, there will be a short circuit to ground. If, however, there is an arc over more than one insulator, or string thereof, during a lightning impulse there will be a direct conductor to conductor short circuit which is still worse than a short circuit from conductor to earth.

It is with the above facts in view that I have devised the present invention which has for its object the provision of a novel method and means for overcoming the difiiculties enumerated so that full advantage may be taken of the insulating value of the wooden pole and cross arms while at the same time they will be protected against fire in the event of a lightning discharge.

Before describing the invention in detail, it may be well to state a few additional facts. The effect of the static and earth wire in limiting the intensity of the lightning has no relation to the fact that they are supported by the same structure as the conductors,-this arrangement being merely a matter of convenience. The static wire may be insulated fromthe pole and the ground wire may be carried vertically downward away from the pole, with possibly one guide type insulator for this vertical portion. The ground wire should of course be brought in to the pole at an appreciable height above the ground, for instance six to eight feet, to avoid contact bydomestic animals and the like. The feature of insulating the static and ground wires is in itself not new. If this construction be adopted, it is evident that the earth wire will not be ad- I object of the invention to provide a protective system in which I provide arc extinguishing means in multiple with the cross arm, the number of course depending upon details of the installation in question. For instance in an ordinary three phase circuit carried upon a wooden pole there would be three fuses interposed in the bonding wires, one end of each fuse being connected with the base of an insulator support and the others connected to a common central point so that in the event of a flash-over or are at least one of the three fuses, and possibly two or all three, would be blown, thereby stopping the current flow and preventing further interruptions.

In view of the fact that the ordinary guy wires short circuit wooden poles, as the usual interposed strain insulators are of practically no help, it is a further object of the invention to complete the insulating arrangement by employing guy strain insulators of a different type and greater length instead of the variety commonly known as goose egg.

lVhile the invention comprises broadly the bonding of the metallic supports for the insulators and the interposition of fuses in the bonding wires, I have in the accompanyng drawings illustrated various detailed arrangements whereby the desired protective effect can be accomplished, it being, however, understood in advance that I do not intend to be limited to the exact arrangements.

In the drawings:

Figure 1 is an elevation of a wooden pole and cross arms equipped with insulators of the pin type showing the preferred arrangement of bonding wires and fuses,

Figure 2 is a side elevation thereof,

Figure 3 is an elevation showing substantially the same structure with certain of the fuses omitted.

Figure 4 is an elevation showing a modification,

Figure 5 is a similar view showing another modification,

Figure 6 is a plan view of what is shown in Figure 5,

Figure 7 is an elevation of another type of support with the invention applied to strings of depending insulators.

Figure 8 is a view similar to Figure 7 with certain fuses omitted,

Figure 9 is a view of another common type of installation showing the invention applied in conjunction with suspension insulators, and

Figure 10 is a similar view of another variation.

Referring more particularly to the drawings and especially Figures 1 and 2, the numeral 1 designates a wooden pole carrying a plurality of wooden cross arms 2 on which are mounted metallic pins 3 carrying insulators 1 with which are connected the conductors'5. Mounted on the top of the pole is a bracket 6 carrying an insulator 7 which supports the static wire 8. The numeral 9 designates the guy wires which are secured to the pole in any ordinary or preferred manner and within which are interposed, in accordance with my invention, elongated insulators 10 which may be of the wood stick type and which are employed instead of the usual goose egg type as having a far greater puncture distance and leakage distance. The numeral 11 designates a ground wire which is connected with the static wire 8 and which extends down and is preferably held away from the pole by an insulator 11 and which may be secured to a bracket 12 mounted on the pole at a point sufliciently far above the surface of the ground to avoid contact by domestic animals and the like. The bracket itself is grounded either within or outside of the pole as indicated diagrammatically at 12. I also provide wires 13 connected with the ground wire 11 and with the insulator pins 3 for bonding all together. In these figures I have illustrated fuses 14 interposed in all of the bonding wires 13 and also fuses 15 in the wire between the points of connection of the bond wires, as well as a fuse 15 interposed between the wire 11 and bracket 6. While there is given no detailed disclosure of the fuses, they may be and preferably are of the expulsion type, for instance as manufactured and sold by the General Electric Company, such fuses generally containing parts which will be forcibly ejected or expelled upon the passage of a current sufficiently strong to melt away and reduce whatever retaining means is provided for the expulsion means.

It is conceivable that the fuses 15 and connection to the ground wire may be omitted, as in Figure 3, in which event there is a common conductor 16 provided for connecting the bond wires 13, the fuses 14 being provided as before.

In Figure 4 I have illustrated a somewhat different type of installation in which the wooden pole 17 carries a single cross arm 18 on which are mounted metal pins carrying insulators 20 for the conductors. There is also bracket 21 at the top of the pole carrying an insulator 22 for the static wire 22" to which is connected a ground wire 22". The pins are all shown as connected by a bond wire 23. Fuses 25 are interposed in the bond wire 23 between its points of connection with the pins and a fuse 25 is connected between the bond wire 23 and the ground wire 22'.

In Figures 5 and 6 I have illustrated a slight modification in which the pins at the ends of the cross arm 18 are connected by a bond wire 26 which is connected by a wire 27 with a wire 28 connected with the intermediate pin and with the static wire 22*. Interposed in the bond wire 26 are fuses 29 located between the outer pins and the point of connection of the bond wire 26 with the wire 27 There are also provided fuses 30 and 30 interposed in the wire 28 at opposite sides of the connection of the wire 27 therewith.

In Figure 7 I have shown yet another common type of installation in which the pole carries cross arms 31 in V form, strings of suspension insulators 32 depending from the ends of the arms and the point of connection thereof. Whatever hardware is provided for supporting these strings is connected by bond wires 33 with a common wire 34 which also connects with a ground wire 35 leading from the static wire to ground. Fuses 36 are interposed in the bond wires 33 and fuses 37 and 37 are interposed in the wire 34 between the points of its connection with the wires 33 and in advance of its connection with the ground Wire 35, respectively. In Figure 8 the ground wire and one fuse are omitted.

In Figure 9 I have illustrated a common form of installation known as the H type in which there are provided two poles 38 carrying a cross arm 39 from which depend strings of insulators 40, two of which are located at the ends of the arm and the re maining one of which is located between the poles. Both poles are represented asprovided with brackets 41 carrying insulators 42 for the static wires 42*. In carrying out the invention in connection with this variety of installation, I provide bond wires 43 connecting whatever suspension elements are provided for the strings of insulators, and ground wires 44 connected with the static wires. Interposed in the bond wires 43 and ground wires 44 are fuses 45 and 45 respectively.

In Figure 10 there is the same type of structure as in Figure 9 except that there is only one static wire with the necessary supporting bracket and insulator therefor. In this form the suspension elements for the outermost strings of insulators, or those at the ends of the arm, are bonded together by a wire 46 which connects with a conductor 47in turn connected with the ground wire 44 leading from the static wire 42 There is also a bond wire 48 connected with the suspension element for the intermediate insulator string and connected with the bond wire 46. Fuses 49 are interposed in the bond wires 46 and 48 and a fuse 49* is provided in the connection 47.

In all forms of the invention, regardless of whether the common wire connecting the bonding wires is grounded or not, it will be apparent that in the event of a sudden surge, such as a lightning flash, causing a flash-over Or arc from conductor to conductor, one, or possibly considerably more than one, of the fuses will blow and will extinguish the arc in addition to throwing a section of the wood. of a pole or cross arm or both into series with the insulators, thereby accomplishing the desired result. Though I have illustrated numerous variations and several different types of installation, it should be understood that the action will be at least substantially the same in every instance. From the foregoing it is believed that the'construction, operation and advantages will be readily apparent to one skilled in the art without further explanation.

While I have shown and described preferred embodiments of the invention, it should be understood that thedisclosure is merely an exemplification of the principles involved as the right isreserved to make all such changes in the details of construction as will widen the field of utility and increase the adaptability of the device provided such changes constitute no departure from the spirit of the invention or claims hereunto appended.

Having thus described the invention, I

claim:

1. In an installation wherein conductors are supported and insulated from a supporting structure formed of wood, the combination of means bonding together the insulator supports, and fuses interposed in said bond-" ing means.

2. In a transmission line installation embodying a wooden structure, metallic elements mounted thereon and conductor insulators carried by said metallic elements, the combination of bonding wires connected with the metallic elements, a connection common to all of said bonding wires, and fuses interposed in said bonding wires.

3. In a transmission line installation embodying a wooden structure, metallic elements mounted thereon and conductor insulators carried by said metallic elements, the combination of bonding wires connected with the metallic elements, a connection common to all of said bonding wires, fuses interposed in said bonding wires, and means for grounding said common connection.

4. In a transmission line installation embodying a wooden structure, metallic elements mounted thereon and conductor insulators carried by said metallic elements, the combination of bonding wires connected with the metallic elements, a connection common to all of said bonding wires, and fuses inter posed in said bonding wires, a static wire, an insulator for supporting the static wire, a bracket for supporting said last named insulator, said bracket being connected with said common connection.

5. In a transmission line installation embodying a wooden structure, metallic elements mounted thereon and conductor insulators carried by said metallic elements, the combination of bonding wires connected with the metallic elements, a connection common to all of said bonding wires, fuses interposed the scope of thein said bonding wires,

lator for supporting the static wire a bracket for supporting said last named insulator, said bracket being connected with said common connection, and fuses interposed in said common connection.

6. In a transmission line installation embodying a wooden structure, metallic elements mounted thereon and conductor insulators carried by said metallic elements, the combination of bonding Wires connected with the metallic elements, a connection common to all of said bonding wires, fuses interposed in said bonding wires, a static wire, an insulator for supporting the static wire, a bracket for supporting said last named insulator, said bracket being connected with said common connection, fuses interposed in said common connection, and means for ground- 0 ing said common connection.

In testimony whereof I affix my signature.

KENT A. HAWLEY.

a static wire, an insu-

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