US2839635A - Lightning arresters - Google Patents

Description

June 17, 1958 HASSELHORN 2,839,635

LIGHTNING ARRESTERS Filed Nov. 1, 1956 INVENTOR.

United States Patent 0 LIGHTNING ARRESTERS Walter C. Hasseihorn, Evanston, 11]., assignor, by mesne assignments, to Cook Electric Company, Chicago, Il!., a corporation of Delaware Application November 1, 1956, Serial No. 619,903

8 Claims. (Cl. 200-118) This invention relates to a lightning arrester, and more particularly to a button-type of lightning arrester, although the invention is not necessarily limited thereto.

Lightning arresters normally employ a pair of electrodes spaced apart to provide a discharge gap. They function primarily to permit the passage of high voltage electrical discharges such as may occur by a disturbance of a power line accidentally coming into contact with a telephone line or by abnormal lightning discharges. A lightning arrester may in fact be likened to a spark plug functioning to discharge an electric are between electrodes a great many times. Dependable service is essential. However, in a lightning arrester, the destructive effects of an abnormal discharge across the electrodes shortens the life and requires service or maintenance to assure continued service. This has unduly increased maintenance costs, and it is particularly true for locations at great distances from central oiiices, which, generally, may be called far-flung locations requiring continuous service but always subject to the occurrence of an abnormal discharge across the line and the destruction of the electrodes by a heavy discharge. A heavy discharge of any duration will particularly tend to disintegrate the electrodes and vary the gap between the same. In certain cases, bimetallic arms have been used to carry at least one of the electrodes, but the arrangement proposed has invariably resulted in the flexing action of the arm distorting the arm by not allowing the same to return each time to its original position. The discharge gap would then be altered and the functioning of the arrester also changed, which would require replacement of the arrester.

An object of the invention is to provide an improved lightning arrester which is practically free of maintenance and capable of use for a long period of time.

A further object of the invention is to provide a lightning arrester having electrodes spaced apart to form a normal discharge gap, the electrodes being so arranged that an arc of moderate duration will cause the electrodes to engage each other and establish a direct continuous path to ground. As long as the disturbance continues, the electrodes will remain closed. They will, however, quickly open and return to normal position when the disturbance ceases without causing alteration of the discharge gap.

To this end a lightning arrester embodying the invention preferably is provided with a uniquely mounted bimetallic disk, carrying at least one of the electrodes, which disk is arranged to warp in a direction to engage the other electrode by the heat of a sustained arc and to immediately return to its normal position without distortion or disturbance of the discharge gap.

. A still further object of the invention is specifically to provide a novel form of mounting for the bimetallic disk adapted to control the warping, by the manner in which it is gripped at its periphery, so that it will not become distorted and will return each time to its normal state and thereby maintain the discharge gap intact.

A still further object of the invention is to accomplish the foregoing novel results in a simple, facile and economical manner and by a relatively inexpensive structure.

A still further object of the invention is to provide a lightning arrester, accomplishing the aforesaid novel results, of rugged construction and capable of long life without requiring continuous maintenance.

The lightning arrester is designed and constructed so that it may be easily mounted in a service or other circuit.

Other objects and advantages of the invention will be apparent from the following detailed description when taken in connection with the accompanying drawing which forms a part hereof.

In the drawing:

Figure l is a side elevational view of a lightning arrester embodying the invention;

Fig. 2 is an end view of the same taken along line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view of the unit taken along line 33 of Fig. 1;

Fig. 4 is a side elevational view of a lightning arrester of slightly modified construction embodying the invention;

Fig. 5 is an end elevational view taken along line 55 of Fig. 4; and

Fig. 6 is a vertical sectional view of the same unit taken along line 66 of Fig. 4.

One form of lightning arrester embodying the invention is illustrated in Fig. 1. It comprises housing 2 in the form of a metal sleeve having threads at 3 for use in mounting the housing 2 in grounded relation in an installation.

'This housing 2 may have an annular flange 4 providing a shoulder 5 to seat the unit when threaded in position. A head 6 has a cross slot 7 to receive a sharp-edged tool to permit the rotation of housing 2 when being threaded into, or unthreaded from, its mounting in a given installation.

A conductor member 8 is provided with an electrode 9 at its forward end and s seated in a molded ceramic insulation sleeve 10 that keeps conductor member 8 spaced from housing 2 and ready for contact or engagement with a line circuit or any type of electric circuit adapted to be protected by the arrester. The forward face 11 of electrode 9 is spaced a predetermined distance from face 12 of a second electrode 14. This spacing pro vides discharge gap 15. This second electrode 14 is adapted to be welded or otherwise suitably fixed to a bimetallic disk 16 normally held in surface contact with face 17 of head 6. It is held in this backed-up relation against face 17 by the outer peripheral edge 18 at tapered face 19 of sleeve or spacer 10.

The arrangement holds bimetallic disk 16 tightly against a flat surface at its outer periphery on one side, which forms a flat surface shoulder for this outer peripheral surface against the fiat surface 17 of head 6. When a heavy discharge occurs across gap 15 and continues for any duration, the heat will warp bimetallic disk 16 to the right to bring face 12- of electrode 14 into contact or engagement with face 11 of electrode 9. This flexing of bimetallic disk 16 will bring the periphery of bimetallic disk 16 into surface engagement with the tapered face 19 of insulation sleeve 10 and serve to restrain the bimetallic disk 16 during said flexing in order to prevent any permanent distortion. It may be mentioned that the area of the face of bimetallic disk 16 carrying electrode 14 thereon and designated as 22 in Fig. 3 may be considered as the inner peripheral shoulder of disk 16 capable of surface engagement with insulated spacer or sleeve 10 at thetapered face 19. The movement of bimetallic disk 16 is relatively small. This movement is only enough to bring the face 12 of electrode 14 against face 11 of electrode 9 The periphery of the bimetallic disk 16 will then be supported in surface engagement with tapered face 1? to restrict further warping.

Another form of embodiment of the lightning arrester'. is shown in Figs. 4-6, inclusive. In this form, a grounded housing has a closed end 26 provided with a reduced neck 27 and a tapered head 28 adapted to hold the arrester unit in mounted position aninstallation having, say, aslot to receive the reduced neck 27 and the tapered head 28 instead of a threaded opening to receive threads 3 of the previous embodiment. It will be understood that the housing may be varied in construction according to the type of mounting embodied in the'installation. intended to receive the arrester unit. A molded ceramic or insulation sleeve 2% of cup shape is inserted Within housing 25 with a conductor member 30 extending through a central opening 31, the. conductor member preferably being formed with an integral head 32 serving as a backup plate for bimetallic disk 33 carrying an electrode 34, say, in welded relation. A corresponding back-up plate 35 supports a second bimetallic disk 36 carrying a second electrode 37 in welded relation. Back-up plate 35 is held by a coil spring 38 and also by a snap ring 3?". Bimetallic disks 33 and 36 are held spaced apart by a dielectric or molded ceramic separator 44) having opposite tapered faces 41 and 42. The outer peripheral corners 43 of separator 4%) are adapted normally to engage the peripheral shoulders of bimetallic disks 33 and 36 to hold the same in position against back-up plates 32 and 35 whereby to keep electrodes 34 and 36 spaced apart to maintain discharge gap 45. In the case of the embodiment illustrated in Fig. 1, the parts are held in assembled relation to maintain discharge gap 15 by a lip or depressed portion' 46 struck in the end. of sleeve 2 as shown in Figs. 1, 2 and 3, while in the form illustrated in Figs. 4 to 6,

inclusive, a similar struck-up bead or lip 47 may be used to hold the cup-shaped sleeve 29 pressed against coil spring 38, the discharge gap being maintained by the insulation ceramic separator 49.

In the form of arrester shown in Figs. 4 to 6, inclusive, both electrodes 33 and 36 are movable toward each other by bimetallic disks carrying these electrodes. Each of these disks is limited in its Warping movement, and its peripheral surface facing the discharge gap 45 engages the tapered surface provided by the opposite tapered faces 41 and 42 of the insulation separator 49. These tapered faces 41 and 42 form back-up shoulders adjacent the peripheries of both disks so as to restrict the warping action of the disks and prevent them from taking permanent sets when flexing. Likewise, the electrodes 34 and 37 cover enough area of the disks 33 and 36 to restrict the warping and limit them to a relatively small movement. The parts are easily assembled.

With the electrodes of either embodiment made of metal alloy similar to, if not the same as, that used in spark plug electrodes, arcing of short durations will not pit or otherwise destroy the gap surfaces. Arcing of moderate duration will generate enough heat to flex the bimetallic electrode carrying disks and cause the electrodes immediately to engage each other to effect a direct continuous path to ground. No destructive effects will occur and the line will remain grounded under this protected arrangement until the disturbance is removed.

Without further elaboration, the foregoing will so fully explain the character of my invention that others may, by applying current knowledge, readily adapt the same for use under varying conditions of service, without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured tome by the following claims.

I claim:

1. A buttondype lightning arrester comprising two 7 4 V parts, one of which is grounded and the other of which includes an electrode adapted for connection to a line terminal, means for positioning said electrode with respect to said grounded part, a second electrode spaced from said first electrode to form a discharge gap, and means for connecting said second electrode electrically to said grounded part, said means including a bimetallic plate supported at its periphery by a relatively flat surface shoulder on one side and a tapered shoulder on the other side whereby the periphery of said bimetallic plate will engage said tapered shoulder to restrict the Warping of said bimetallic plate when it is flexed by the heat of a discharge at said gap.

2. A button-type lightning arrester comprising two parts, one of which is grounded and the other of which includes an electrode adapted for connection to a line terminal, means for positioning said electrode With respect to said grounded part, a second electrode spaced from said first electrode to form a discharge gap, means for connecting said second electrode electrically to said grounded part, said means including a back-up plate of bimetallic material carrying said second electrode, said back-up plate being carried by said grounded part, said grounded part providing a relatively fiat surface shoulder against which the periphery of said back-up plate abuts on one side, and a tapered shoulder on the opposite side of said back-up plate against which the periphery thereof engages to restrict the Warping thereof when said backup plate is flexed by the heat of a discharge at said gap.

3. A button-type lightning arrester comprising two 7 spaced electrodes forming a discharge gap, a grounded part and a line part for carrying said electrodes, a bimetallic rnounting for one of said electrodes, said bimetallic mounting being carried by said grounded part, each of said parts providing a relatively flat surface shoulder for the peripheral surface of said bimetallic mounting, the shoulder of said line part being tapered so as to receive the peripheral surface of said bimetallic mounting in surface engagement so as to restrict the Warping thereof when said bimetallic mounting is flexed by the heat of a discharge at said gap. I

4. A button-type lightning arrester comprising two spaced electrodes forming a discharge gap, a grounded part and a line part for carrying said electrodes, a bimetallic mounting for one of said electrodes, each of said parts providing a relatively flat surface shoulder for the peripheral surface of said bimetallic mounting, the shoulder on one of said parts being tapered so as to receive the peripheral surface of said bimetallic mounting in surface engagement so as to restrict the warping thereof when said bimetallic mounting is flexed by the heat of a discharge at said gap.

5. A lightning arrester comprising two spaced electrodes forming a discharge gap, a grounded part and a line part for carrying said electrodes, said line part including an insulated portion separating said electrodes, a bimetallic mounting for one of said electrodes, a relatively flat surface shoulder on said grounded part for one side of said bhnetallic mounting, and a relatively flat tapered surface shoulder on said insulated portion for the opposite side of said bimetallic mounting, said tapered shoulder receiving said bimetallic mounting in surface engagement so as to restrict the warping of said bimetallic mounting when the latter is flexed by the heat of a dis- 7 charge at said gap.

$3 against which the peripheral surface of said bimetallic mounting engages to restrict the warping thereof when flexed by the heat of a discharge at said gap.

7. A lightning arrester comprising two spaced electrodes forming a discharge gap, a grounded part and a line part for carrying said electrodes, an insulation portion separating said parts and said electrodes, 21 bimetallic mounting for one of said electrodes, said insulation portion holding said bimetallic mounting in relatively flat surface engagement at its periphery on one side with one of said parts, and a tapered relatively flat surface shoulder on said insulation portion for receiving the opposite side of the periphery of said bimetallic mounting and for restricting the warping thereof when the latter flexes by the heat of a discharge at said gap.

8. A lightning arrester comprising two spaced electrodes forming a discharge gap, a grounded housing part and a line part projecting into said grounded housing part, an insulation portion separating said parts, means carrying said electrodes on said parts, the mounting of at least one of said electrodes being a bimetallic plate, one of said parts providing a relatively flat surface engagement at the periphery and at one side of said bimetallic plate, and a tapered relatively flat shoulder to provide a surface engagement at the periphery and at the opposite side of said bimetallic plate to restrict the warping thereof when it ilexes by the heat of a discharge at said gap.

References Cited in the file of this patent UNlTED STATES PATENTS 1,883,251 Spencer et a1. Oct. 18, 1932 1,907,869 Raney May 9, 1933 1,939,286 Spencer Dec. 12, 1933 2,127,575 Thompson et al Aug. 23, 1938 2,442,945 Andersen June 8, 1948 2,732,461 Huber Jan. 24, 1956 FOREIGN PATENTS 519,545 Great Britain Mar. 29, 1940

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