US970556A - Lightning-protector. - Google Patents

Description

A. P. ROSENBERGER.

LIGHTNING PROTECTOR.

APPLIUATION FILED JAN. 2, 1908.

970,556. Patented Sept. 20, 1910.

BEST AVAILABLE COP ANDREW F. ROSENBERGEB, OF CHICAGO, ILLINOIS LIGHTNING-PROTECTOR.

Specification of Letters Patent.

Patented Sept. 20, 1910.

Application filed January 2, 1908, Serial No. 408,895

1'0 all whom it may concern:

Be it known that I, ANDREW F. Rosenl, BERGER, a' citizen of the United States, residling at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Lightning-Proteeters, of which the following :wspecilication.

2 This invention relates to improvements in lightning protectors, and refers more specifieally to improvements in that type of protector wherein the spark gap is provided for between carbon electrodes spaced apart loya dielectric.

A.mong the salient objects of the present invention are to provide a construction in which the spacing apart of the electrodes by the dielectric may be practically accomplished in a more accurate, reliable and less expensive manner than has heretofore been the case; to provide a construction in which theparticles of carbon dust dislodged by the passage oi cm-rent across the gap will he -more certainly prevented from lodgmcnt in the gap; to provide a construction in which the spark gap is provided {or along a liuc ol' practicz lly inapprtariable thickncss but ol' considerable length as distinguished l'rom a spark gap in which lhc clot-trodes are spaced apart over av considerable area ol' approximately uniform distance of spacing, and to provide a construction which may he made rapidly and by the use of labor of only mod- "erate skill and still-secure reliable and accurate results. I 1

i The invention consists in the matters hcreinatter described and particularly delincd in the claims. I

In'the accompanying dran'ing diigiirc l is a plan view of one practical and p'reterred embodiment of the invention; Fig. 2 is an edge elevation ofthe device shown in position set at ninety degrees out of the angular position in which it is ordinarily used (the device as shown in Fig. 1 being in correct position); Fig. 3 a cross sectional view taken on line 3--3 of Fig. 2; Fig. 4t is an exploded View sh the relative arrangeinentot the dischrirgc electrodes.

Referring to the drawing, 1 designates a suitable base which is made of porcelain or other suitable insulating material. Upon the base is mounted a conductor p ate :4, preferably of L-shape, one end tln reot' being arranged to rest flat upon the base, being extended radially outward and connected with a binding stud 3, and the other end being arranged to extend at right angles to the base and constituting a support. against which two pairs of carbon electrodes, as 4, l, and 5, 5, are arranged to rest. 'l'hat to say, the outstanding portion 2 ol the conductor plate 2 is common to both pairs of electrodes The two mcmlwrs of each pair of carbon electrodes are placcd t'acc to l'acc against each other, and each pair is held yicldingly against the supporting plate 2 by means of a corrcsptnnling plate spring, as (3 and 7; these plate springs being provided with base portions t3 and T, respectively,bent to lie llatwise upon the porcelain has and scveially connected at their outer ends with terminal posts 8 and S). The outermost members and 5 of thcpairs of electrodes are longitudinally i'oorcd to rcccirc thc corrcslmndiug spring lingers t3 and Ti so that the springs serve to hold thcsc clcclrodcs against lateral displaccmcul. but. as u ual in plolct'lol's ol this gcuclal typo, tlic pairs-of clcctrodcs may he slipped out cudwisc l'rom hctwccu the swings and opposed supporting plate.

lhrscribing now the essentially novel lcaturcs ot the device, it will be noted that each pair of electrodes is separated by a dielectric sheet, as it), prtl'erably athin sheet of mica. The dielectric, instead of covering the meeting surfaces oi the clectrodcs, is cut away hctwcen its ends and from one edge inwardly, as best indicated in 'l ig. 4, so as'toleave two opposed sur tacos, .11 and 12, bcl'wccli the electrodes 12.

covered and constituting the spark gap bctween the two. 'lhcse opposed surfaces which constitute the spark gap are divergent; orcr the entire area of the gap, and, as best scen in Fig.3, the edge .13 of the dielectric l() is arranged coincident with the angle ol intersection oi said gap surfaces. It "follows that. since the current will leap the gap some place along the line of closest; approach between the two electrodes, where the latter are not covered by the dielectric, therefore the sparkis bound to leap. across or within the divergent gap and is most likely to occur along the eXposed edge '13 of the dielectric.

In practice I have found it mostpractical to first glue or otherwise secure the sheet of dielectric to the face of one of the electrodes so that it completely covers the latter and projects somewhat beyond the edges of the electrode all around, and I then grind away the dielectric and underlying surface of the carbon to produce the inclined spark gap surface 11. When the two electrodes are thereafter assembled, the unrecessed or unground end portions of the recessed electrode fit fiatwise against the flat face of the opposed electrode and so determine the angle of divergence between the two opposed surfaces which constitute the spark gap. With the parts thus constructed and assembled it .is obvious that whenever current asses from one electrode to the other it is bound to jump across some part of the divergent gap, and accordingly, if the protector be arranged with the gaps opening downwardly, as it should be in )ractice, the particles of carbon dislodged y the discharge fall out of the gap and leave the ap-insulation unimpaired when the discharge ceases. The construction is r such. that the effective separation of the electrodes in the ap is equal to the thickness of the sheet of dielectric, and this distance of separation is very uniform throughout the whole length of the spark gap along the edge of thedielcctrica This is of "impoi'tance in securing a protector which is certain to transmit the current at an approximately uniform predetermined voltage, and the construction is also important in that it insures an ample area of opposed surfaces to take care of very heavy discharges without impairing the protector.

The electrodes are preferably and usually covered by a casing to protect them against the weather. In the preferred construction shown, a threaded thimble 14. provided with an out-turned or radial flange 14: is suitably secured to the base so as to surround the base portions of the electrodes; this member being separated from the underlying portions of the springs 7 by an insulating washer 8 of mica or the like. A sheet metal tubular cap '15 is fitted to screw upon the thimble 14, as shown clearly in the drawing; this cap being provided with vent apertures in its upper end to 'wrmit gases formed-by discharges to escape.

As will be well understood by those familiar with-this art, the particular device illustrated is adapted to protect two lines by providing a spark gap between each and a common return or ground; the terminals 8 and. 9 being fortwo-line wires and the terminal 3 for the common returnor ground. Willle' I have herein shown a preferred construction of the clectrpdes, yet it is to be understood that the invention may be i'it-herwisc embodied.

I claim as my invention:

1. in a protector, the combination with suitable electrical connections, of a pair of coveredponvergent surfaces and a dielectricof greater insulating resistance than air separating said electrodes at their place of nearest approach.

in a protector, a pair of GIBUMCOUBS having parallel contacting portions and divergent gap surfaces and a sheet of'insulating material interposed between and covering said contacting portions of the electrodes and arranged with its edge coincident with the intersecting angle of the gap.

4. [n a protector, an electrode block one side of which has the form of a plane surface except for a recess extending from one edge inwardly, said recess having an inclined bottom and being of decreasing depth from said edge inwardly and terminating short-of the opposite edge, a sheetof insulating material entirely covering the unrccesscd portion ofsaid plane surface of the electrode and cut out to register with the said recess, and a second electrode block provided with a plane surface arranged in" bearing with said insulating sheet, whereby a divergent air gap is formed between said (lttl rodcs.

5. In a protector, an electrode block, one side of which has the form of a plane sur+ face except for a recess extending from one edge innardly, said recess having an inclincd bottom and being of decreasing depth from said edge inwardly andterminating short of the opposite edge, a sheet of insu lating material adherent to and entirely covering the unreccssed portion of said plane surface of the electrode and cut out to register with the said recess, and a second electrode block provided with a plane surface arranged'in bearing with said insu lating sheet, whereby a divergent air gap is formed between said electrodes.

(3. In aruotector, an electrode block, one side of which has the form of a plane surface except for a recess extending from one edge invardly, said recess having an inned bottom and being of decreasing depth from said edge inwardly and termihating short of the opposite edge, a sheet of insulating material adherent to and entirely covering the unrecessed portion stand plane surface of the electrode and cut out to I register with said recess, a second electrode 7. A spark gap device for lightning resters, comprising a plurality of carbon block provided with a plane surface an i plates spaced apart by an insulating washer ranged in hearing with said insulating 5 sheet, whereby a divergent air gap is formed between said electrodes, a conductor support engaging one side of the pair of elecvtrorles and a spring, bearing yieldingly against the opposite side of said pair.

and having cut away portions to form an are expanding chute.

ANDRElV F. ROEENBERGER. \Vitnesses EMILLE Rose, E. L. BELKNAP.

DISCDILAIMEIBL Lronrnmo'lno'rncron. Patent 70.556r-u1l1'2d7t10 F. Rosenberg/er, Chicago, Ill.

Disclaimer filed February "6 1912. hr the trustee.

dated September 20, 1914').

Charles- J Schmidt. Enters this disclaimer To claims 1; 2, and, 7, which are as follows: v 1. In a protector, the comliiination with suitable electrical connections, of a pair of electrodes provided with opposed spark gap surfaces which converge, and a solid dielectric interposed between the most contiguous portions of said electrodes and arranged to divert passing discharges across the gap between said convergent surfaces.

2. In a. protector, the combination with suitable supports and terminal connections, of a pair of electrodes having opposed uncovered convergent surfaces and a dielectric of greater insulating resistance than air separating said electrodes at their place of nearest approach. I

7. A spark gap device for lightning arresters, comprising a plurality oi carbon plates spaced apart by an insulating Washer and having cut-away portions to form an are expanding chute.

[Ofict'ol Gazette, February 13, 1912.]

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