US3152279A

US3152279A - Quench gap structure

Info

Publication number: US3152279A
Application number: US240701A
Authority: US
Inventors: Donald O Misare
Original assignee: Joslyn Manufacturing and Supply Co
Current assignee: Joslyn Manufacturing and Supply Co
Priority date: 1962-11-28
Filing date: 1962-11-28
Publication date: 1964-10-06
Anticipated expiration: 1981-10-06

Description

Oct. 6, 1964 D. o. MlsARE QUENCH GAP STRUCTURE 2 Sheets-Sheet 1 eee:

Filed NOV. 28, 1962 INVENTOR Dam/AL@ /W/SAZE BY t ArroeA/E Ys.

Oct. 6, 1964 n. o. MlsARE QUENCH GAP STRUCTURE 2 Sheets-Sheet 2 Filed Nov. 28, 1962 z y f. w .J 'MN m m a0 f 0 m m m ,55 w/wf 7W@ m ZJ i K/ .Il a, l R.. Nr /H//H////////////H/// :J I g .Mb/,m u 6 I, C 1 /f/ 4./ 0 6 United States Patent O 3,152,279 QUENCH GAP STRUCTURE Donald 0. Misare, Riverside, Ill., assigner to .Ioslyn Mfg. and Supply Co., Chicago, Iii., a corporation of Iliinois Filed Nov. 28, 1962, Ser. No. 240,701 11 Claims. (Cl. 313-231) The present invention relates to a new and improved quench gap structure, and more particularly to a spark discharge structure for insertion into an insulating housing of a lightning arrester or the like.

Heretofore, it has generally been believed that initiation of a spark discharge gap close to the inner wall of a lightning arrester housing would cause the spark discharge to deteriorate the housing insulation. However, it has been found, according to the present invention, that when the spark discharge gap is appropriately confined with the spark discharge occurring close to the housing of the lightning arrester the initial pressure build-up due to the spark discharge will tend to blow or force the spark discharge inwardly away from the wall of the housing.

Moreover, lightning arresters are in a highly competitive market and it is desirable that lightning arresters be readily and cheaply built to provide an economical but efficient lightning arrester which may be sold at a cornpetitively low price.

Accordingly, it is an object of the present invention to provide a new and improved quench gap structure for use in a lightning arrester or the like.

A further object of the present invention is to provide a new and improved lightning arrester.

Yet another object of the present invention is to provide a quench gap structure for a lightning arrester which may be readily and easily manufactured to provide an economical and yet efhcient gap structure which may be competitively sold at low cost.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this speciiication.

In accordance with these and other objects, there is provided an improved quench gap structure for use in a lightning arrester or the like. Although the quench gap structure may be used in any suitable lightning arrester, specifically, the present quench gap structure may be inserted into the lightning arrester disclosed in the copending application of Edward H. Yonkers, Serial No. 157,293, filed November 16, 1961. In accordance with the invention, the spark gap structure includes a gap assembly formed of a plurality of metal plates including a pair of end plates and a selected number of intermediate plates. The intermediate plates are formed with a pair of electrodes opposite each other from the center of the plate and on opposite sides of the plate at a distance closer to the edge of the plate than to the center of the plate. Each electrode contains a surface extending inwardly toward the center of the plate. Adjacent plates are positioned with confronting electrodes forming a spark discharge gap therebetween. The plates are separated by horseshoeshaped insulating spacers, each positioned between adjacent plates to separate and space the plates. The spark gaps and the plates form a current path through the gap assembly extending from one plate to an adjacent plate approximately perpendicular to the plate through the spark gap and then through the central area of the plate to the next gap to describe a zig-zag path through the gap assembly. The spacers are positioned between the plates with the open part of the spacers positioned adjacent the respective spark gap. The gap assembly is held together by spring means. In a first embodiment the electrodes are formed by diametrically opposed dimples embossed near the edge of the plates so that the spark gap is closely spaced from the wall of the lightning arrester housing.

In another embodiment the electrodes comprise identical electrodes opposite each other from the center of the plate and formed from a projection of the edge of the plate having a first portion extending away from the plane of the plate terminating in a spark discharging area and including a spark running area extending inwardly from the spark discharging area toward the center of the plate terminating in an end portion spaced from the plate. Confronting electrodes form spark discharge gaps.

Advantageously, it will be appreciated that any selected number of plates may be combined into a single lightning arrester to provide a desired kva. rating to the lightning arrester. Moreover, any reasonable kva. rating may be built from the identical components of the quench gap structure merely by assembling more or less of the components into the desired quench gap structure. It is therefore necessary to manufacture and stock but a single size and shape of component. Moreover, since the quench gap structure is readily formed with the plates being made of stamped metal, the quench gap structure provides a very inexpensive assembly which may be competitively priced.

Advantageously, it has been found in both of the embodiments, according to the present invention, that initial spark discharge in the spark gap causes the spark discharge to move inwardly along the spark running areas of the electrodes and away from the inner walls of the lightning arrester housing. Although the reason for this is not definitely known, it is believed that initial discharge creates a circumjacent pressure which first strikes the wall of the housing and then builds back toward the discharge to blow the discharge inwardly toward the center of the plates. It will be appreciated that movement of the spark discharge inwardly along the spark running area is effective to elongate the spark and to provide for sharp cutoff and quickl cutoff of the discharge.

Moreover, although all embodiments of the present invention have been found to work satisfactorily, the second described embodiment, wherein the current flow is to the edge of the plate and then down toward the spark discharging area and thereafter inwardly through the electrode along the spark running area of the electrode, adds the force of the induced magnetic field to move the spark discharge more positively inwardly along the running area and elongating and breaking the spark discharge.

For a better understanding of the present invention, reference may be had to the accompanying drawings, wherein:

FIG. 1 is a fragmentary cross-sectional view of a lightning arrester employing the improved quench gap structure according to the present invention;

FIG. 2 is a cross-sectional view of the lightning arrester of FIG. 1, taken along line 2 2 thereof, and assuming that FIG. 1 shows the entire arrester;

FIG. 3 is a fragmentary cross-sectional view of a portion of the spark gap structure of FIG. 1, taken along line 3 3 of FIG. 1;

FIG. 4 is a fragmentary cross-sectional view of the improved gap structure of FIG. l, taken along line 4-4 of FIG. 3;

FIG. 5 is an exploded isometric View of the improved gap structure of FIG. 1;

FIG. 6 is a fragmentary cross-sectional view of a lightning arrester using a modified embodiment of a quench gap structure according to the present invention;

FIG. 7 is a cross-sectional view of the lightning aradriaan/a rester of FIG. 6, taken along line '7-7 of FIG. 6, and assuming that FIG. 6 shows the entire arrester;

FIG. 8 is a fragmentary cross-sectional view of a portion of the improved spark gap structure of FIG. 6, taken along line 8 8 of FIG. 6;

FIG. 9 is a fragmentary cross-sectional view of a spark gap structure of FIG. 7, taken along line 9-9 of FIG. 8; and

FIG. l is an exploded isometric view of the improved spark gap structure of FIG. 6.

Referring now to the drawings, and particularly to the embodiment of FlGS. l through thereof, there is illustrated an improved isolating or quenching gap structure Ztl assembled in a lightning arrester 2l. As heretofore described, the lightning arrester 2l may be of any suitable type, for example, of the type disclosed in the aforementioned patent application of Yonkers, and may include a generally cylindrical housing 22 of suitable insulating material such as clay or porcelain which houses not only the gap structure 2i) but additionally a characteristic element 23, here shown as being of the valve type employing a nonlinear resistance or valving material of the type more fully described in the above-mentioned Yonkers application. The gap structure 2) is serially connected electrically between the characteristic element 23 and a terminal member 24 positioned at one end of the housing 22 by suitable end cap structure 25. An upper end of the gap structure 2% is electrically connected to the end cap structure 25 and terminal member 24E- through a compression spring 2S which additionally serves to hold the components of the gap structure together, while the other end of the gap structure 24B rests on an electrically conductive support 29 which additionally serves to separate the gap structure 20 and the characteristic element 23.

In accordance with the present invention the quench gap structure 20 comprises a gap assembly formed of a plurality of metal plates including a pair of end plates 30a and Slb and a plurality of intermediate plates 30C. As best illustrated in FIG. 5, the lower end plate 3tlg is formed of a circle, and the remaining plates are derived from the same size circle with two equal arcs of the circle for two opposed edges 3l and 32 and equal chords of the circle for the remaining

opposed edges

33 and 34.

To provide a plurality of spark gaps 35 in the gap assembly, each of the intermediate plates 363C is provided with a pair of identical electrodes 36 opposite each other from the center of the plate and on opposite sides of the plate located midway relative to edges 3l and 32, respectively, at a distance from the plate center greater than one-half the radius of the circle from which the plate is derived. The electrodes 36 are formed by diametrically opposed dimples embossed near the curved periphery of the curved edges 3l and 32 of the plates. Each electrode is formed with a spark discharging area 36a, at its center and is provided with a spark running surface 36]; extending inwardly therefrom. The end plates 30a and 30h are each provided with one electrode 36 identical to those in the intermediate plates 30C. Adjacent ones of the plates are positioned with an electrode of each plate confronting an electrode of the adjacent plate so that the spark discharge gap 35 is provided between the spark discharge areas 36a of confronting electrodes, and a spark running gap is formed between the spark running surface 36h of confronting electrodes and having an increasing length inwardly toward the center of the plates.

For separating the plates 30a, Mtb, and 30e, there is provided a plurality of horseshoe-shaped ceramic type insulating spacers 4t). Each of the spacers 4t) is of somewhat U-shape, open at one end. The spacers 46 are positioned with the open part adjacent the respective spark gap 35 between the separated plates. Moreover, to provide for adequately locating the plates 30a, 30h, and 30C, and the spacers 40 relative to each other, the

plates are provided with a plurality of aligning bosses il and the spacers iti are provided with corresponding detents i2 to provide for quick and ready alignment of the members. If desired, the spacers 40 may be of ceramic type resistor material. The plates 30a, 30h, and 30C may be provided with holes or other preforations therein preferably not touching the spacers 4t).

As heretofore described, the compression spring 28 is effective to bias together the elements of the gap assembly structure.

It will be understood in operation that the spark gap 35 and plates 36a, 30h, and 30C form a current path extending from one plate to an adjacent plate through the spark gaps 35 approximately perpendicular to the plates, to the spark gap, and then through the central area of the plates to the next gap to describe a Zig-zag path through the gap assembly. Although it would be expected that a spark formed in the spark gap 35 close to the inside surface of the housing 22 would deteriorate the housing 22, unexpectedly it has been found that in actuality a spark formed in the spark gap 35 is blown inwardly toward the center of the plates where it is extended between the spark running surfaces 36h of confronting electrodes 36 and quickly extinguished.

Although a lightning arrester according to the abovedescribed embodiment has been found to operate quite satisfactorily, it has further been found that the induced magnetic force of a owing current can be used to further push the arc inwardly along its expanding gap to more readily extinguish the arc. This is accomplished by the gap structure illustrated in the embodiments of FIG. 6 through lO. As therein illustrated, there is shown an improved gap structure 50 according to another embodiment of the present invention. The gap structure 50 is assembled in a lightning arrester 51 which, as heretofore described, includes a cylindrical housing 52 of suitable insulating material and including a characteristic element 53 of the type heretofore described. The gap structure Sti is serially connected electrically between the characteristic element 53 and a terminal member 54 of the lightning arrester 51, which is secu-red to the housing 52 by an end cap structure 55. A compression spring 58 is effective not only to electrically connect the gap structure 50 with the terminal member 54 and the end cap structure 55, but additionally to compress the elements of the gap structure 50 into assembled relation. The lower end of the gap structure 50 rests on an electrically conducting support 59 which is effective to interconnect the gap structure 50 with the characeristic element 53.

Referring now to the improved gap structure 50 according to the present invention, the gap structure 50 cornJ prises a plurality of metal plates including a pair of end plates 60a and 6019 and a plurality of intermediate plates 60C. As heretofore described, each of the plates 60a, 6tlb, and 60e is derived from a circle with two equal arcs of the circle for two

opposed edges

61 and 62, FIG. l0, and equal chords of the circle for two remaining

edges

63 and 64.

To provide for a spark gap 65 between adjacent ones of the plates 60a, 60h, and 60C, each of the intermediate plates 66C are formed with a pair of electrodes 66, and each of the

end plates

60a and 60b are formed with an identical electrode 66. The electrodes 66 on the intermediate plates are opposite each other from the center of the plate on opposite sides of the plate midway along the

straight edges

63 and 64 formed by the chords of the circle, while the electrode in the respective end plates 60a and 6tlb extends in one direction from the plate midway relative to a

respective edge

63 and 64 formed by a chord of the circle. Each electrode 66 is shaped from a projection extending from the

chord edge

63 or 64 of the plate and is provided with a first portion extending away from the plane of the plates and terminating in a spark discharge area 66a, FIGS. 6 and 10. Moreover, each of the electrodes 66 includes a spark running area 66h extending inwardly from the spark discharging' area toward the center of the respective plate terminating in an end portion spaced from the plate. It will be understood that adjacent plates have confronting elec-trodes 66 establishing the spark gap 65 therebetween which has the spark discharging area 66a and the spark running area 66h of increasing length inwardly toward the center of the plate.

To provide for separating and spacing the plates 66a* 601;, and 60C relative to each other, there is provided a plurality of horseshoeor C-shaped spacers 'itl formed of a circle of the same exterior radius as the curved portions of the plates 69a, ilb, and 60C, of suitable electrically insulating material. The spacers 70 are each formed with an open end positioned adjacent to, and equally spaced from the respective spark gap 65 between the respective pairs of separated plates. Moreover, in order to adequately align and locate the plates 60a, del), and 69C, and the spacers 7i?, the plates and spacers are provided with a plurality of interitting bosses 71 and de-tents 72.

ln operation, the gap structure 5t) initially is similar to the gap structure 2t) heretofore described. It will be appreciated that the spark gaps 65 and the plates 60a, tlb, and 60C form a current path extending from one plate to an adjacent plate approximately perpendicular to the plate through the spark gap and then through the central area of the plate to the next gap to describe a zig- Zag path through the gap assembly. Moreover, in like manner as heretofore described in connection with the embodiment of FIGS. 1 through 5, immediately upon initiation of the spark discharge in the spark gap 65, spark discharge is blown inwardly from the spark discharge area 66a along the spark running surface 66h thereby to elongate the discharge to aid in terminating the spark discharge.

In the embodiment of FGS. 6 through 10, once the spark discharge has moved a minute distance from the spark discharge area 66a along the spark running area deb, then the current ow through the plates will be outwardly from the discharge through the spark running sun faces 661; and spark discharge surfaces 66a, then inwardly toward the respective plates and across extending along the plate from one electrode 66 to the opposite electrode 66. The magnetic field set up by the current owing in the running surface 6617 outwardly to the periphery of the plate will be effective to establish a magnetic field which tends to drive the discharge inwardly along the running surface 66h to aid the blowing of the discharge inwardly. thereby extending and terminating the discharge.

The quench gap struc-ture according to the present invention may be assembled in any desired ratting merely by selection of the required number of intermediate plates in the assembly. This is readily accomplished without the necessity of stocking additional component parts. Moreover, in view of the travel ofthe spark discharge inwardly away from the inner surface of the lightning arrester housing, a very inexpensive gap structure may be made from simple sheet electrode elements. Additionally, the pressure build-up bouncing from the inner wall of the lightning arrester housing which blows the spark discharge inwardly toward the center of the gap structure is also effective to prevent overheating and deterioration of the housing by the hot discharge.

Although the present invention has been described by reference to various embodiments thereof, it will be apparent that numerous other modifications and embodiments may be devised by those skilled in the art, and it is intended by the appended claims to cover all such modiications and embodiments which fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A quench gap structure for insertion into a ceramic housing of a lightning arrester or the like and comprising a gap assembly for insertion in the housing formed of a plurality of metal plates including a pair of end plates and at least one intermediate plate, at least the intermediate plates deriving from a circle with two equal arcs of the circle for two opposed edges and equal chords of the circle for the remaining two edges, each intermediate plate being formed with a pair of identical electrodes opposite each other from the center of the plate and on opposite sides of the plate located midway relative to an edge at a distance from the plate center greater than onehalf the radius of said circle, at least one surface of each electrode extending inwardly toward the center of said plate to form a spark running area, adjacent ones of said plates being positioned with one electrode of each plate confronting an electrode of the adjacent plate to form a spark discharge gap therebetween, said end plates each being provided With one electrode identical lto each of the above described electrodes and positioned toward a confronting electrode in an adjacent plate, said spark gaps and said plates forming a current path extending from one plate to an adjacent plate approximately perpendic ular to said plate through said spark gap and then through the central area of the plate -to the next gap to describe a zig-zag path through the gap assembly; and a plurality of horseshoe-shaped ceramic type insulating spacers, each positioned between adjacent plates to separate and space said plates, the open part of said spacers being positioned toward the edge adjacent the respective spark gap.

2. A quench gap structure as set forth in claim 1 above wherein the number of said intermediate plates is selectable to provide a desired quench gap voltage capacity.

3. A quench gap structure as set forth in claim 1 above wherein said plates and said spacers are provided with bosses and detents to provide for aligning the same.

4. A quench gap structure as set forth in claim 1 above wherein said spacers are ceramic type resistor spacers.

5. A quench gap structure as set forth in claim 1 above and including spring means biasing said plates and spacers together.

6. A quench gap structure as set forth in claim l above wherein said electrodes are formed by diametrically opposed dimples embossed near the curved periphery of the curved edges of the plates.

7. A quench gap structure as set forth in claim 6 above wherein said spacers are somewhat U-shaped generally conforming to the shape of the intermediate plates.

8. A quench gap structure for insertion into a ceramic housing of a lightning arrester or the like comprising a gap assembly for insertion in the housing formed of a plurality of metal plates including a pair of end plates and at least one intermediate plate, at least the intermediate plates deriving from a circle with two equal arcs of the circle for two opposed edges and equal chords of the circle for the remaining two edges, each intermediate plate being formed with a pair of identical electrodes opposite each other from the center of the plate and on opposite sides of the plate located midway relative to an edge along the edges formed of chords, and shaped from a projection of said edge having a first portion extending away from the plane of said plate terminating in a spark discharging area, and including a Spark running area extending inwardly from the spark discharging area toward the center of the plate terminating in an end portion spaced from the plate to form a spark running area, adjacent ones of said plates being positioned with one electrode of each plate confronting an electrode of the adjacent plate to form a spark discharge gap therebetween, said end plates each being provided with one electrode identical to each of the above-described electrodes and positioned toward a confronting electrode in an adjacent plate, said spark gaps and said plates forming a current path extending from one plate to an adjacent plate along said spark running gap outwardly of said plates through said first portion and then inwardly through said plate and through the central area of said plate to the next electrode structure; and a plurality of horseshoe-shaped ceramic type insulating spacers, each positioned between adjacent plates to separate and space said plates, the open part of said spacers being positioned toward the edge adjacent the respective spark gap.

9. A quench gap structure as set forth in claim S above wherein said spacers are somewhat C-shaped having an outer periphery approximately equal to the radius of said circle.

10. A quench gap structure for insertion into an insulated housing of a lightning arrester or the like and comprising a gap assembly formed of a plurality of metal plates including a pair of end plates and at least one intermediate plate, at least said intermediate plates being formed with a pair of electrodes opposite each other from the center of the plate and on opposite sides of the plate at a distance closer to the edge of the plate than to the center of the plate, each electrode being provided with a surface extending inwardly toward the center ot said plate, adjacent plates being positioned with confronti ing electrodes forming a spark discharge gap therebetween, and a plurality of horseshoe-shaped insulating spacers, each positioned between adjacent plates to separate and space the plates.

1l. A quench gap structure for insertion into a ceramic housing of a lightning arrester or the like and comprising a gap assembly for insertion in the housing formed of a plurality of metal plates including a pair of end plates and at least one intermediate plate; each intermediate plate being formed with a pair of identical electrodes opposite each other from the center of the plate and on opposite sides of the plate at a distance from the plate center greater than one-half the distance to the edge, at least one surface of each electrode extending inwardly toward the center of said plate to form a Spark running area, adjacent ones of said plates being positioned with one electrode of each plate confronting an electrode ot the adjacent plate to form a spark discharge gap therebetween, said end plates each being provided with one electrode identical to each of the above described electrodes and positioned toward a confronting electrode in an adjacent plate, said snarl; gaps and said plates forming a current path extending from one plate to an adjacent plate approximately perpendicular to said plate through said spari; gap and t'nen through the central area of the plate to t .e next gap to describe a zig-zag path through the gap assembly; and a plurality of insulating spacers, each positioned between adjacent plates to separate and space said plates.

References Cited in the file of this patent UNITED STATES PATENTS 2,623,197 Kalb Dec. 23, 1952 3,106,662 Cunningham Oct. 8, 1963 FOREIGN PATENTS 264,187 Great Britain Apr. 2l, 1927

Claims

10. A QUENCH GAP STRUCTURE FOR INSERTION INTO AN INSULATED HOUSING OF A LIGHTNING ARRESTER OR THE LIKE AND COMPRISING A GAP ASSEMBLY FORMED OF A PLURALITY OF METAL PLATES INCLUDING A PAIR OF END PLATES AND AT LEAST ONE INTERMEDIATE PLATE, AT LEAST SAID INTERMEDIATE PLATES BEING FORMED WITH A PAIR OF ELECTRODES OPPOSITE EACH OTHER FROM THE CENTER OF THE PLATE AND ON OPPOSITE SIDES OF THE PLATE AT A DISTANCE CLOSER TO THE EDGE OF THE PLATE THAN TO THE CENTER OF THE PLATE, EACH ELECTRODE BEING PROVIDED WITH A SURFACE EXTENDING INWARDLY TOWARD THE CENTER OF SAID PLATE, ADJACENT PLATES BEING POSITIONED WITH CONFRONTING ELECTRODES FORMING A SPARK DISCHARGE GAP THEREBE-