US1896189A - Apparatus for protecting power-line insulators - Google Patents

Description

Feb. 7, 1933. HIP. SLEEMAN AfiPARATUS-FOR PROTECTING POWER LINE INSULATORS Filed April 50. 1927 1 2 Sheets-Sht' 1 INVENTOR." HflROLD F. SLEEMHN BY W ATTORN EYS 1933- H. P. SLEEMAN 1,896,189

APPARATUS FOR PROTECTING POWER LINE INSULATORS Filed April 30, 1927 2 Sheets-Sheet 2 cg N INVENTOR: HHR'OLD F. 54 EEMI-V/V ATTORNEYS.

Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE HAROLD P. SLEEMAN, OF EAST LIVERPOOL, OHIO, ASSIGNOR TO THE R. THOMAS & SONS COMPANY, OF EAST LIVERPOOL, OHIO, A CORPORATION OF OHIO APPARATUS FOR PROTECTING POWER-LINE INSULATOBS Application filed April 30,

My invention relates to method and apparatus for protecting power line insulators, and particularly multi-unit insulators.

My invention contemplates the protection of the insulator against unequal voltage stresses on the several units by better voltage distribution over the insulator, the means employed for this purpose being such that it does not interfere with live line lnsulator testing appliances.

My invention contemplates the protection of the insulator by providing both a voltage distributor and also an arc-over path, in parallel with the insulator, to protect the latter against injury by flash-over. In such a combination, my invention contemplates the location of the distributor between the lineend of the arc-over path and the power line, so that on arc-over the arc plays not upon the voltage distributor but upon the arc terminal.

Again my invention contemplates, in this combination, a voltage distributor of such construction that should an arc form thereon, it is automatically led to the arc-over terminal.

My invention also contemplates, in this combination, the location of-the voltage distributor closer to the insulator than the terminal at the line-end of the arc-over path, so that on arc-over the are forms at a point more remote from the insulator than the voltage distributor.

From the standpoint of apparatus my in vention contemplates a combined arc terminal and voltage distributor, the latter preferably in the orm of arcuate lateral extensions of the terminal and extending lineward from the terminal, and inward toward the insulator. A pair of such combined arc terminals and voltage distributors, when installed at the line-end of a multi-unit insulator, is so located that the arc-over terminals overlie the line conductor, while the arcuate terminal extensions which constitute the voltage distributors, substantially surround the lower portion of 'the insulator but are sospaced at their adjacent ends as to permit the introduction of live line testing appliances to the insulator.

1927. Serial 1T0. 187,908.

Other features of my invention will be understood from the following description, or from the accompanying drawings, in which Fig. 1 is a broken side elevation of a multiunit suspension insulator to which are applied protecting devices which embody my invention in one form;

Fig. 2 is a plan view thereof;

Fig. 3 is an enlarged plan view of a combined arcing terminal and voltage distributor;

Fig. 4 is a side elevation thereof;

Fig. 5 is a front elevation thereof;

Fig. 6 is a section on the line 6-6, Fig. 3;

gig. 7 is a section on the line 77, Fig. 3; an

Fig. 8 is a section on the line 8-8, Fig. 3.

It has been recognized (see Marvin 1,245,940) that in multi-unit insulators the voltage stresses upon the several units of the insulator are unequal, and that the voltage stress upon the units at the line end of the insulator materially exceeds that impressed upon the units at the opposite or ground end of the insulator. As a result of this condition, failure of the insulator by puncture occurs most frequently in the units adjacent the line. The introduction of metal discs of various dimensions between the several units of the insulator to vary their capacities, effects a voltage distribution which renders more uniform the stresses on the several units. But this manner of accomplishing the desired end is objectionable since it increases the likelihood of flash-over on the insulator surfaces (by reason of the reduction of the leakage path), and moreover tends to cause an arc to cascade from arcing horns into the insulator, thus increasing the prob-ability of damage thereto from the heat of the are.

My invention accomplishes the desired voltage distribution over the insulator string by providing a source of line voltage substantially surrounding the line end of the insulator at a point spaced radially therefrom, the current from this source reaching the units remote from the line, and preventing the concentration of voltage stress upon the unit or units at the line-end of the insulator. This voltage distributor is of such construction that while substantially surrounding the lower portion of the insulator, it permlts safe access to the insulator for the application thereto of live line insulator testing appliances, such as are now commonly used for field test. Preferably my invention is embodied in a voltage distributor which has combined therewith an arcing terminal, and the latter is preferably so located with respect to the voltage distributor that arc-over is invited not to the distributor but to the arcing terminal. Preferably, furthormore, this terminal is of such construction that the arc is caused automatically to move awa from the insulator. Danger that the are, a er formation, will strike into the insulator, is thus minimized.

Referring to the accompanying drawings, I have indlcated in Fig. 1 a multi-unit suspension insulator of the link or Hewlett type, comprising a string of insulator units 15, of which the lowest unit is connected by adapter 16 and hanger 17 to the power line P, while the top unit of the string is connected by adapter 18 and hook 19 to a grounded tower or other supporting structure (not shown). Associated wlth the hanger 17 and secured thereto by bolt 20, is a bar 21, the opposite ends 22 and 23 of which are angled upward and are pierced at suitable points to receive the bolts 24 by which the combined arcing terminals and voltage distributors of my invention are attached thereto.

Each combined arcing terminal and voltage distributor comprises a shank 25 channeled to fit the bar end 22 or 23 and apert-ured to accommodate securing bolts 24. At its free end the shank 25 is enlarged to form a spoon-shaped arcing terminal having a spheroidal surface 26 which merges into a contracted tip 27. This terminal is described and claimed in the copending application of H. B. Vincent Serial No. 184,987, patented A ril 12th, 1932, Patent No. 1,854,083 an insofar as it is claimed therein I make no claim to it here. This terminal has the characteristics of a sphere or high speed gap at the area 26, and of a needle point gap at the tip 27. U n arc-over, between one of these termina s and a cooperating terminal at the ground end of the insulator, the arc strikes the area 26 and automatically travels outward to the tip 27. The are thus moves away from the insulatorimmediately after its formation, and the danger that the arc will strike into the insulator is minimized. The spheroidal area 26 of the terminal is also thus protected against injury incident to the play of an arc thereon. Inasmuch as the ratin of the gap is governed by the s acing o the line and ground terminals at t eir adjacent spheroidal areas 26, the protection of the latter against injury is of great advantage in stabilizing the rating of the gap so that the latter may be set accurately for a given arc-over value, which is maintained in spite of repeated arcovers. I

Associated with the arcin terminal and extending from opposite si es thereof are arcuate wings 28 and 29 which form the voltage distributor element of the appliance. These wings join the terminal at a point removed from the crest of the spheroidal area 26 and preferably extend lineward therefrom, so that they do not invite the arc to strike the distributor wings. The upward inclination of the wings automatically causes the arc, should one form on the distributor, to rise to the arcing terminal. The wings are also spaced radially from the insulator a less distance tlTan the arcin terminal. They are located substantial y at the level of the lowermost unit 15 of the insulator string, but their osition will vary with the line voltage and the character of the units which compose the insulator. The lo-i cation indicated in the drawings therefore is merely illustrative of a single appro riate location for the type of insulator use and at a given line voltage.

In cross section the wings 28 and 29 are preferably arched on a rather long radius with their convex faces toward the gap. Corona formation on the distributor is thus minimized. A stifienin rib 30 may be pro-v vided on the concave ace of each wing to add to its rigidit It will be no that between the ends of a pair of voltage distributors located as indicated in Fig. 2, a space 31 is afi'orded through which a live-line testing appliance 31 through which the tester passes is lo-' cated at a point remote from the line and in a plane substantially normal to the latter.

I have shown the voltage distributor applied only to the line end of the insulator, while at the ground end of the latter an arcing horn 32 is provided which, while having the characteristics of the terminal of the fitting at the line-end of the insulator, lacks the voltage distributor wings. If for any reason desired, however, the distributor fit- {ing may be used at both ends of the insuator.

It will be understood further that the invention is not restricted in its utility to multiunit insulators of the link or Hewlett type illustrated 1 and 2, but is equally applicable to insulators of the cap and pin t pe, or to multi-unit post insulators. I .use t e expression multi-unit insulator therefore in a sense broad 'eno'ugh'to include any type of insulator in which; the '.problem of V0 tage distribution is one of 1II1POIt8J1CC.

It will be understood furthermore that Whether or not the voltagedistributor has associated therewith an arcing terminal'of the type indicated, it possesses features of novelty and advantage which are not dependent upon the combined use therewith of an arcing terminal of the type shown. Certain of the claims which point out my invention are not restricted to this combined structure.

The details of contour and arrangement of parts are subject to wide variation, while still embodying the thoughts which underlie what I claim as my invention.

I claim- 1. A fitting for a multi-unit power-line insulator comprising arcuate conductors adapt-. ed to be connected to the line and extend around the line-end of the insulator to form a voltage distributor, said conductors having associated arc-gap terminals whereby arcing over the surface of the insulator units is prevented.

2. A fitting for a multi-unit power-line insulator comprising arcuate conductors adapted to be connected to the line and extend around the line-end of the insulator, said conductors having associated arc-gap terminals spaced radially more remote from the insulator than the voltage distributor.

3. A combined arc-gap terminal and voltage distributor for multi-unit power-line insulators, comprising a high speed gap terminal and a voltage distributor at one side thereof, said distributor comprising arcuate extensions from said terminal.

4. A combined arc-gap terminal and voltage distributor for multi-unit power-line insulators, comprisin a high speed gap terminal and associate arcuate voltage distributor extensions on opposite sides thereof, said extensions having convex surfaces faced toward the gap.

5. A combined arc-gap terminal and voltage distributor for multi-unit power-line insulators, comprising a spoon-shaped gap terminal and voltage distributor wings extending from opposite sides of the terminal.

6. A combined arc-gap terminal and voltage distributor for multi-unit power-line insulators, comprising a spoon-shaped gap terminal and voltage distributor wings extending from opposite sides of the base of the terminal.

7. A combined arc-gap terminal and voltage distributor for a multi-unit power-line in- 1 tributor adjustably connected to said support,

for va ing the position of the 'di'stn utor in the irection of the axis of the insulator.

8. In combination, a multi-unit power-line.

whereof I have signedm) CERTIFICATE OF CORRECTION.

Pmm No. 1,896,189. February 7, 193a.

HAROLD P. SLEEMAN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 33, claim 2, after "insulator" and before the comma, insert the words "to form a voltage distributor"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the caae in the Patent Office.

Signed and sealed this 9th day of May, A. D. 1933.

M. J. Moore (Seal) Acting Cormnissioner of Patents.

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