US1730169A - High-potential insulator structure - Google Patents

Description

1 Oct. 1, 1929. H. B. SMITH HIGH POTENTIAL INSULATOR STRUCTURE Filed Dec. 11, 1922 iooooi 100005 INVENT'OR Ham/d B Smith ATTORNEY Patented Oct. 1, 1929 UNITED STATES PATENT erries HAROLD B. SMITH, OF WORCESTER, MASSACHUSETTS, ASSIGNO R TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA HIGH-POTENTIAL INSULATOR STRUCTURE Application filed Eecemher 11, 1822. Serial No. 606,016.

My invention relates to insulator structures and particularly to high-potential in sulator structures of the suspension type.

One object of my invention is to provide a suspension insulator structure in which a weather-protective hood having a drip portion disposed outside the are-over zone of highest potential gradient in the dielectric field of the insulator shall, in a certain sense, constitute an element that is mechanically separate from, and independent of, the insulator proper and that may be assembled and shipped as a portion of a supporting tower, as a part of the insulator or as a separate unit.

Another object of my invention is to provide an insulator structure in which the parts shall be so constructed and related as to greatly facilitate the handling, shipping and assembling thereof.

A further object of my invention is to pro: vide a suspension-insulator structure that shall be simple and durable in construction, economical to manufacture and effective in its operation.

In my copending applications, Serial No. 548,818, filed April 1, 1922, and Serial No. 559,743, filed May 10, 1922, both entitled Insulators and assigned to the l/Vestinghouse Electric & Manufacturing Company, are set forth features which are embodied as elements in the combination of my present invention.

In the first of the above-mentioned applications is disclosed the feature of so widely distributing and directing the dielectric stresses between the ends of an insulator as to form what may be termed a hollow field. In other words, there is formed a dielectric field of reduced intensity at its center through which the insulator extends. This construction, as fully set forth in the application, renders the surface of the insulator free of damaging stresses and causes arc-over to occur at a position safely removed from the insulating surface or surfaces.

In the second of the above-mentioned applications is disclosed the feature of so protecting the insulator of the first application as to materially improve the wet arc-over characteristics thereof. This is accomplished by providing a weather-protective hood of such construction and relation to the insulator as to provide a drip portion outside the arc-over zone in the dielectric field of the insulator. i

In the device ofthe second-mentioned application, the weather protective hood is so constructed and related to the insulator as to constitute a component portion thereof. This construction adds weight and bull: to the insulator and, as a result, may, in certain instances, present difficulties in handling and shipping which it is desirable to avoid.

In practicing my present invention, I provide a hood structure of the above-mentioned type that may conveniently constitute a permanently assembled portion of the supporting tower or structure and that is otherwise better adapted for convenient manipulation as a separate unit. In other words, the hood may be the subject of consideration of the tower builder or of another class of operators whose duty it is to mount the hoodsonly. Thus, the work of the operators whose duty it is to mount the insulators will be facilitated to a high degree and an insulator structure obtained which is more economical and effective in every way.

Figure 1 of the accompanying drawings is a View, partially in elevation and partially in section, of a portion of a high-potential, suspension-insulator structure embodying one form of my invention, as viewed in the direction of the transmission line;

Fig. 2 is a View, similar to Fig. 1, of a modified form of my invention, and

Fig. 3 is a View, similar to Figs. 1 and 2, of a further modified form of my invention.

The structure of my invention comprises three main portions in combination, that is, a main supporting structure 1, a weather-protective device 2 and an insulator 8.

The main supporting structure 1 may be in the form of any usual structural-steel, highpotential transmission tower or bracket having an armor member 4 to which the other parts are immediately attached.

As illustrated in Fig. 1, the weather-protective device comprises a portion 5, preferably of inverted substantially bowl shape, but

which may be of frusto-conical or other configuration, aportion 6 permanently secured to the arm at, as by rivets 7, and a portion 8 from which the insulator 3 is flexibly suspended, as by a pin 9 or other suitable means.

The insulator 3 comprises an elongated central supporting or tension member 10, terminal members 11 and 12 and upper and lower electrostatic-flux distributing members 14: and 15. The terminal member 11 is secured to the portion 8, by the pin 9, and the terminal member 12 is adapted to support a high-tension conductor 16. The construction, operation and characteristics of the insulator 3 and the effect thereon of the weather-protective device 2 are all fully set forth in the abovementioned co-pending applications, to which reference may be had for a more full and cor plete understanding of the electrical characteristics of the combination, as herein described. It is believed to suffice herein to point out that the specific combination, in which the device 2 does not constitute the top member of the insulator 3 proper, has not, to the best of my knowledge, been suggested prior to the invention of the device set forth in the above-mentioned application Serial No. 559,743. By not constituting the top member of the insulator proper is meant that the device 2 does not correspond to the upper portion or unit of an ordinary insulator which is shaped like a rain shed. There are many types of the latter form of insulator but in all of them, to the best of my knowledge, water drops form at the lower edges of the shed in the dielectric field of the insulator.

As shown in Fig. 1, the device 2 is adapted for assembly and shipping with a portion of the tower 1. This renders the insulator 3 of less weight and bulk and, consequently, greatly facilitates the mounting of the insulators,

ter the towers have been erected.

In the form of my invention illustrated in Fig. 2, in which similar reference Characters designate similar parts, the portion 6 of the above-described form is modified to permit flexibility therein. This is accomplished by dividing the portion 6 into two parts 13 and 19, the former of which is connected to the arm 4 by the rivets 7, and the latter of which is mounted on the portion 5. The parts 18 and 19 may preferably be formed as eye-and-clevis members for the reception of a pin 20. In this form of structure, the portions 8 and 11 may also preferably be formed for the reception of a screw-threaded mem ber 21, or otherwise, to have the portions 5 and 1d rigidly related.

In the form of my invention shown in Fi 3, the electrostatic stress distributing members 14c and 15 are both of toroidal form similar to the member 15 in Figs. 1 and 2. The pin 20 is disposed at right angles to the similar pin of Fig. 2 and the pin 9 is at right angles to the pin 20. This construction provides a substantially universal flexible connection by which the device as a whole may move in the direction of the conductor 16 and the insulator may move laterally to the conductor. C o-operating stop portions 22 and 23 on the portions 8 and 11, respectively, limit the amount of lateral movement of the insulator to prevent engagement of the parts 14 and 5 and to thus, prevent too great a distortion of the field adjacent to these parts.

In all of the figures, the construction is such as to confine substantially all of the main electrostatic field between the members 1 1 and 15 and to ensure that arc-over shall never occur between the members 15 and 5, even under wet conditions when a relatively heavy flood of water may be dripping from the lower edges of the member 5.

Also, in all of the forms, the device 2 is adapted to constitute a permanent portion of the device 1 and, in the forms shown in Figs. 2- and 3, the device 2 may be a separate unit for connection to the insulator or to the tower previous to the final installation.

By my present invention, the devices of the above-mentioned co-pending applications are further developed and rendered more flexible and better adapted to operating conditions.

lVhile I have shown and described particu-. lar forms of my invention, changes may be effected thereinwithout departing from the spirit and scope thereof, as set forth in the.

appended claims.

I claim as my invention:

1. In a high-potential insulator suspension device, the combination with a weather-protective hood structure and means for securing the latter to, and supporting the same independently of the insulator on, a main supporting structure, said hood structure having insulator-attaching means disposed adjacent to its inner upper portion, of an insulator comprising an insulating member, means adjacent to the upper end thereof for detachably securing the same to said attaching means, and terminal means including an annular upper terminal portion disposed around the longitudinal axis of the insulating member in definite predetermined relation to the hood for confining ultimate arc-over to a Zone under, and away from, the hood.

2. In a high-potential insulator suspension device, the combination with a weather-protective hood structure and means for securing the latter to, and supporting the same independently of the insulator on, a main supporting structure, said hood structure having insulator-attaching means disposed adjacent to its inner upper portion, of an insulator comprising an insulating member, means adjacent to the upper end thereof for detachably securing the same to said attaching means, and terminal means including annular upper and lower terminal portions disposed in definite predetermined relation to the hood around the inner upper portion, of an insulator comprising an insulating member, means adjacent to the upper end thereof for detachably securing the same to said attaching means, and terminal means including substantially toroidal conducting surfaces in definite predeter mined relation to the hoodaround the longitudinal axis of the insulating member adjacent to the ends thereof providing a weakened electrostatic field through which the insulating member extends and a field zone of maximum strength outside said weakened field and inside the lateral limits of the hood, the relation of parts preventing arc-over to the hood.

4. In a high-potential-insulator-suspension device, the combination with a weather-protective hood having an annular water-drip outer edge below the center thereof and means for securing the hood to, and supporting the same independently of the insulator on, a main supporting structure, said hood having insulator-attaching means disposed adjacent to its inner upper portion, of an insulator comprising an elongated insulating structure, means adjacent to the upper end thereof for detachably securing the same to said attaching means, and terminal means including substantially toroidal widely radially rounded conducting surfaces in definite predetermined relation to the hood around the longitudinal axis of the insulating structure adjacent to the ends thereof providing a weakened electrostatic field through which the insulating structure extends and a field zone of maximum strength outside said weakened field and inside the lateral limits of said waterdrip edge, the relation of parts preventing arc-over to the hood.

5. In ahigh-potential-insulator-suspension device, the combination with a weather-protective hood having an annular water-drip outer edge below the center thereof and means for securing the hood to, and supporting the same independently of the insulator on, a main supporting structure, said hood having insulator-attaching means disposed adjacent to its inner upper portion, of an insulator comprising an elongated insulating structure, means adjacent to the upper end thereof for detachably securing the same to said attaching means, and terminal means, the upper of which is disposed within the hood above said water-drip edge in definite predetermined relation to the hood, including substantially toroidal widely radially rounded conducting surfaces around the longitudinal axis of the insulating structure adjacent to the ends thereof providing a weakened electrostatic field through which the insulating structure extends and a field zone of maximum strength outside said weakened field and inside the lateral limits of said water-drip edge, the

relation of parts preventing arc-over to the hood.

6. In a high-potential-insulatorsuspension device, the combination with a weather-protective hood having an annular water-drip outer edge below the center thereof and means for securing the hood to, and supporting the same independently of the insulator on, a main supporting structure, said hood having insulator-attaching means disposed adjacent to its inner upper portion, of an insulator comprising an elongated insulating structure, means adjacent to the upper end thereof for detachably securing the same to said attaching means, and terminal'means, theupper of which is disposed within the hood above said water-drip edge in definite predetermined relation to the hood, including substantially toroidal widely radially rounded conducting surfaces around the longitudinal axis of the insulating structure adjacent to the ends thereof providing a weakened electrostatic field through which the insulating structure extends and a field zone of maximum strength outside said weakened field and inside the lateral limits of said water-drip edge, the relation of parts preventing arc-over to the hood, said detachable securing means permitting relative movement between the insulator and the hood and means for definitely limiting said relative movement.

In testimony whereof, I have hereunto subscribed'my name this fourth day of December, 1922.

HAROLD B. SMITH.

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