US2074755A - Lightning arrester - Google Patents

Description

March 23, 1937. B, E, O'HAGAN 2,074,755

LIGHTNING ARRESTER Filed March 2, 1935 lNvEN-roR ernard'. OHgan.

E" @um HLS ATTORNEY UNITED STATES PATENT OFFICE LIGHTNING ARRESTER Bernard E. OHagan,

The Union Switch Swissvale, Pa., assigner to & Signal Company, Swissvale, Pa., a. corporation of Pennsylvania Application March 2, 1935, Serial No. 9,074

9 Claims.

My invention relates to lightning arresters. More specifically, my invention relates to improvements in a lightning arrester of the type described in Patent No. 1,022,717, issued April 9 1912 to Alexander Jay Wurts.

One object of my invention is to provide an arrester of the type described above which will insure greater protection against the possibility of short circuiting. Another object is to provide an arrester which may be manufactured more economically. A still further object of my invention is to provide an arrester which may be readily and economically serviced and maintained in the field.

I will describe a few forms of lightning arresters embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Figs. 1 and 2 are plan and side elevation views, respectively, showing one form of lightning arrester unit embodying my invention. Fig. 2a is a view illustrating a part of the arrester shown in Figs. 1 and 2 and also embodying my invention. Figs. 3, 4, and 5 are views illustrating modified portions of the arrester unit shown in Figs. 1 and 2 and each also embodying my invention. Fig. 6 is an enlarged fragmentary isometric view illustrating a portion of the arrester shown in Fig. 5 and also embodying my invention.

Similar reference characters designate similar parts throughout the several views.

Referring first to Figs. l, 2, and 2a, the reference character A designates one of a plurality of uniform electrodes, preferably brass, which is of relatively large cross-sectional area and which has an enlarged head 2 at one end and a point at the other end. These electrodes are arranged in pairs with a spark gap between their points and may be supported in parallel metal plates B in any suitable manner, as, for example, by punching aligned holes in the plates, and inserting the electrodes in the holes. As here shown, the plates B are spaced a predetermined distance and are held in parallel :alignment by the shoulders 3 of an insulating member C (see Fig. 2a) which is inserted in aligned slots provided in the plates B. The enlarged heads 2 of the electrodes A may be held in electrical contact with the plates B, and the plates B may be held against the shoulders 3 of the insulating member C in any suitable manner, such, for example, as by spring clips E. The spring clips E, when compressed, hold the parts of the assembled unit securely in proper engagement and alignment with each other. The

clips E may be held under compression, as here shown, by cotter keys F inserted in holes 4 provided in the outer ends of insulating member C. As here shown, the points of each pair of electrodes are enclosed in a tube G of insulating material, preferably a glass tube, having a hole, the diameter of which is such as to provide a loose fit over the electrodes A. By such a tube I provide a means for insulating each pair of electrodes from the adjacent pairs, thus permitting the pairs of electrodes to be placed much closer together than would be permissible without such insulation. Another feature of the tube is the protection of the spark gap from dust, dirt and insects, etc., which might permit the electrodes to become electrically connected. A further feature of this tube is the indication of the condition of the electrodes; that is, when the electrodes have become fused the fact is indicated by the discoloration of the tube. Still another feature of the tube is the relatively large inner surface of the tube adjacent the spark gap which is free from Contact with the electrodes, so that increased protection against short circuits is provided in the event of coating of the inner surface of the tube by vaporization of the points of the electrodes as a result of lightning discharges.

Since the tubes are provided for protection only and are not required for maintaining the alignment or spacing of the spark gap, such tubes need not necessarily have a uniform length and diameter. The cost, therefore, of the tubes Will be considerably less than would obtain if the tubes were required to be of uniform dimensions.

If the electrodes should become fused or the electrodes or tubes otherwise damaged by lightning discharges, it is apparent that by Withdrawing the cotter keys F, such damaged parts may be very readily replaced in the field Without removing the arrester from service except during the time repairs are being made. Ordinarily the electrodes and tubes will be the only parts which will require replacement, therefore, the lightning arrester embodying my invention will be economical to maintaim The reference character H designates one form of terminal block upon which the lightning arrester unitembodying my invention may be mounted.'

The manner in which the lightning arrester embodying my invention functions to protect apparatus from lightning discharges is well known and, therefore, no explanation of the principles involved in its functioning is being made herein.

Referring next to Fig. 3, the reference charactor AI designates a modified form of electrode which may be applied to the lightning arrester illustrated in Figs. 1 and 2. The electrode AI has a portion near its pointed end of relatively small cross-sectional area and a portion near its head of relatively large cross-sectional area. It is apparent that an electrode of this form provides for a greater surface inside the tube G adjacent the spark gap which is free from possible contact with the electrode, so that short-circuiting of a, pair of electrodes is less liable to occur as a result of coating of the inside surface of the tube by vaporized metal.

Referring now to Fig. 4, the reference character A2 designates another form of electrode which may be applied to the lightning arrester unit shown in Figs. 1 and 2. The electrode A2, as here shown, is of relatively small diameter and may be an ordinary brass toilet pin with the clip E2.

end opposite the point bent at right angles to the axis of the pin. In order to hold the electrode A2 in proper alignment, a metal sleeve J is provided which has substantially Athe same outside diameter as the aligned holes in the plates B, and which extends through the holes into the tube G, so that the collar of the sleeve is in engagement with the outer face of the plate B. The electrode A2 is inserted in a hole provided in the sleeve' J of substantially the same diameter as the electrode. in contact with the sleeve J and the sleeve is held in contact withfthe plate B by the spring An electrode of the form shown in Fig. 4 provides for a relatively large increase in the distance from the electrodes to the inside surface of the tubepadjacent the spark gap, and, therefore, further removes the possibility of short-circuiting due to vaporization of the electrode. Moreover, since the electrodes A2 may be common toilet pins, the cost of such electrodes may be materially less than the electrodes A or Ai.

Referring now to Figs. 5 and 6, the reference character Ci designates an insulating member similar in all respects to the previously described insulating member C, except in its method of application to the lightning arrester unit. As here shown, the member Ci is a cylindrically shaped key. The key Ci is provided at each end with shoulders 5 and with rectangular shaped heads 6, the heads 6 being spaced from the shoulders 5 by a portion of reduced diameter 1. When the rectangular shaped heads 6 are inserted into similarly shaped aligned slots 8 and 9 in the plates BI and spring clips El, respectively, the shoulders 5 will maintain. the predetermined spacing between the plates BI, and the heads 6, when turned at right angles to the slots 8 and 9 after the clips are compressed, will hold the parts of the assembled lightning arrester unit securely in their proper positions. The member Cl, together with plans BI and spring clips El may be applied as just described to the assembled lightning arrester unit shown in Figs. 1 and 2.

From the foregoing description of lightning arresters embodying my invention, it is apparent that I have provided new and improved forms of lightning arresters which minimize the danger of short-circuiting due to possible vaporization of the electrodes, which may be manufactured economically and which may be readily and economically repaired in the field.

The electrode is held -Although I have herein shown and described only a few forms of lightning arrester units embodying my invention, I do not Wish to limit myself to these specific forms, as various modifications may be made therein without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A lightning arrester comprising two/parallel plates provided with a plurality of aligned holes and with aligned slots, an insulating member extending through said slots and provided with shoulders which cooperate with the confronting faces of said plates to maintain a predetermined spacing between said plates, a plurality of electrodes one disposed in each of said holes and each provided at its outer end with a head and terminating at its inner end in a point, the parts being so proportioned that when the heads of two aligned electrodes are engaging the outer faces of the associated plates the points of the electrodes will have a predetermined spacing between them, a plurality of tubes of insulating material one disposed on each aligned pair of electrodes between said plates and enclosing the points of said electrodes, and two clips one secured to each end of said insulating member and each cooperating with the associated electrodes to hold their heads in engagement with the associated plate.

2.A A lightning arrester comprising two parallel plates each having a plurality of relatively large aligned holes, a plurality of uniform electrodes one disposed in each of said holes and each havingv a relatively small cross-sectional area, a metal sleeve disposed in each aligned hole and each having an outside diameter substantially the same size as the aligned holes and an inside diameter substantially the same size as the cross-sectional area of the electrodes, means for spacing said two parallel plates a predetermined distance and means for maintaining said electrodes and the associated sleeves in contact with each other and in contact with the associated plates.

3. A lightning arrester comprising two parallel plates provided with a plurality of aligned holes and with aligned slots, a plurality of electrodes one disposed in each of said holes and each provided at its outer end with a head, two spring clips one engaging the heads of the electrodes in each plate and each having a slot which aligns with the slot in the associated plate, and an insulating key extending through all of said slots and provided with shoulders which cooperate with said plates to maintain a predetermined spacing between them, and with a head at each end which cooperates with the associated clip to hold the clip in engagement with the heads of the electrodes, the heads of said key being so shaped that they will pass freely through said slots when said key is rotated to one position relative to the slots but not when the key is rotated to another position relative to the slots.

4. A lightning arrester comprising two parallel plates having a predetermined spacing therebetween and each provided with a hole which is in alignment with the hole in the other plate, a pair of electrodes each having a head, one electrode being disposed in the hole in each plate to provide a spark gap between the confronting ends of said electrodes, and removable spring means for holding the head of each electrode in engagement with the associated plate.

5./ A lightning arrester comprising two parallel plates having a predetermined spacing therebetween and each provided with a hole which is in alignment with the hole in the other plate, a pair oi' electrodes each having a head, one electrode being disposed in the hole in each plate to pro- 5 vide a spark gap between the confronting ends of said electrodes, an insulating tube enclosing said confronting ends for protecting said spark gap, and removable spring means for holding the head of each electrode in engagement with the l associated plate.

6. A lightning arrester comprising two parallel plates having a predetermined spacing therebetween and each provided with a hole which is in alignment with the hole in the other plate, a pair l of electrodes each having a head, one electrode being disposed in the hole in each plate to provide a spark gap between the confronting ends of said electrodes, an insulating tube enclosing said confronting ends, the parts being so proportioned 20 that a relatively large portion of the inner surface of said tube is free from contact with said electrodes, and removable spring means for holding the head of each electrode in engagement with the associated plate.

25 7. A lightning arrester comprising two parallel plates having a predetermined spacing therebetween and each provided with a hole which is in alignment with the hole in the other plate, a pair of electrodes each having a head and each having 30 the portion nearest the head of relatively large cross-sectional area and the portion farthest from the head of relatively small cross-sectional area, one electrode being disposed in the hole in each plate to provide a spark gap between the 35 confronting ends of said electrodes, and removable spring means for holding the head of each electrode in engagement with the associated plate.

8. A lightning arrester comprising two parallel plates having a predetermined spacing therebetween and each provided with a relatively large hole which is in alignment with the hole in the other plate, a pair of electrodes each having a head and each having a relatively small crosssectional area, one electrode being disposed in the hole in each plate to provide a spark gap between the confronting ends of said electrodes, a metal sleeve disposed in each aligned hole and each having an outside diameter substantially the same as the aligned holes and an inside diameter substantially the same size as the cross-sectional area of the electrodes, and removable spring means for maintaining the head of each electrode and the associated sleeve in engagement with each other and in contact with the associated plate.

9. A lightning arrester comprising two parallel plates each provided with a hole which is in alignment with the hole in the other plate, an insulating member extending through said plates and provided with shoulders which cooperate with the confronting faces of said plates to maintain a predetermined spacing therebetween, a pair of electrodes each having a head, one electrode be'- ing disposed in the hole in each plate to provide a spark gap between the confronting ends of said electrodes, removable spring means for holding the head of each electrode in contact with the outer face of the associated plate, and means cooperating with the outer ends of said insulating

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