US2777096A - Lightning arrester - Google Patents

Description

s. M. WEISBERG 2,777,096

LIGHTNING ARRESTER Filed July 24. 1953 Jinnw A? H mm ATTORNEY United States Patent LIGHTNING ARRES'I'ER Sidney Mortimer Weisberg, Maplewood, N. 1., assignor to Allied Electric Products, Inc., 'Irvington, N. J., a corporation of New Jersey Application July 24, 1953, Serial No. 370,128

Claims. (Cl. 317-69) The invention herein disclosed relates to lightning arresters for television sets.

Objects of the invention are to provide a capable, ellicient lightning arrester, adaptable to the different kinds of leadin wires, either the flat tape or the widely spaced open-twin wiring used with television sets, which will make good contact and good grounding connection for both kinds of wiring and which will be small in size, light weight and low cost construction and adapted for mounting to suit different installations; for instance, to be supported on the leadin wires, to be fastened on to a wall or to be mounted on a ground pipe or the like.

A feature of the invention resides in the provision of a pair of flat-surfaced spark gap members each of which is symmetrically positioned with respect to the longitudinal axis of an elongated grounding member. Each spark gap member has an end portion which is positioned in proximity to and spaced from the grounding member, thereby providing a spark gap to the grounding member. The fiat surfaces of the spark gap member are coplanar with respect to a plane normal to the longitudinal axis of the grounding member. An annular leakage member in the form of a high-resistance carbon washer surrounds the grounding member and has a circular flat surface of which symmetrically disposed portions are in simultaneous electrically conductive engagement with the coplanar surfaces of both grounding members. Fastening means such as a nut and washer are threaded on the grounding member and connect the carbon washer to the grounding member while holding the carbon washer pressed into engagement with the two spark gap members. The single carbon washer thus serves as two resistors, the arrester being provided with terminals which are arranged to con nect both conductors of a balanced two-wire transmission line symmetrically to ground through different portions of the carbon washer for draining off electrostatic potentials, each portion being individually shunted by a spark gap for grounding high voltage surges or the like on the transmission line.

The terminals embody special features which permit a wire disposed in either of two parallel grooves to be mechanically and electrically engaged by an H-shaped terminal plate. Advantageously, an arcuate row of insulation piercing contact points may be arranged on one of the legs of the H-shaped terminal plate for piercing the insulation of an insulated wire and establishing positive electrical contact with a stranded wire enclosed within the insulation.

Special objects of the invention are to provide firm, positive combined electrical and mechanical connection with the leadin wires without tearing, cutting or otherwise injuring either the wires or, if insulated, the insulation protecting the wires.

Other desirable objects attained by the invention and the novel features through which the purposes of the invention are accomplished are set forth and will appear in the course of the following specification.

The drawing accompanying and forming part of the Patented Jan. 8, 1957 specification illustrates a present commercial embodiment of the invention but the specific structure may be modified and changed as regards the immediate illustration, all within the true intent and broad scope of the invention, as hereinafter defined and claimed.

Fig. l in the drawing is a plan view of one of the arresters shown connected with tape or ribbon form of wiring, the tape and the ground connection being indicated broken away.

Fig. 2 is a cross-sectional view taken along line 2-2 of Fig. 1.

Fig. 3 is a broken sectional view on substantially the plane of line 3-3 of Fig. 1.

Fig. 4 is an enlarged broken sectional detail of one of the pointed contact plates.

Fig. 5 is a plan view similar to Fig. 1, on smaller scale, showing the invention connected with open twin wiring such as used with U. H. F. or V. H. F.

Fig. 6 is a broken sectional detail on substantially the plane of line 66 of Fig. 5, on a larger scale.

Fig. 7 is a broken cross-sectional view showing the arrester mounted on and connected with a ground pipe.

In the embodiment illustrated, the base 10, of insulating material, may be small enough and light enough to be supported on the wires and it is shown as having a wide V-groove 11 across the bottom of the same, enabling it to be centered and secured as shown in Fig. 7, over a grounding pipe 12.

The top of the base is shown as having a flat, shallow channel 13 extending across the face of the same, wide and deep enough to contain a balanced two-conductor transmission line such as the television leadin ribbon 14 as indicated in Figs. 1, 2, 3 and 7.

Also provided in the top of the base are the more widely spaced parallel grooves 15, located at opposite sides of the central groove, and spaced wide enough apart to receive the conductors 16, Figs. 5 and 6, of the open twin leadin wires.

A single set or pair of H-shaped centrally apertured terminal or binding plates is used, holding either the ribbon or the open twin form of conductors.

These H-shaped clamping or binding plates are designated 17 and they are shown in Fig. 1 with the transverse bar of each H seated in a transversely extending groove 18 in the top of the base, at opposite sides of the central longitudinal groove 13, and as having longitudinally extending lugs or fingers 19 formed by one leg of each H at their inner edges, entered in the center groove 13 and similar longitudinally extended fingers or lugs 20 at their outer edges, formed by the other leg of each H entered in the outer longitudinal grooves 15.

Additionally, these H-shaped terminal plates are shown as having downwardly struck, separately pointed, integrally formed insulation piercing contact points 21 along their inner edges, approximately in line with the stranded conductors 22 of the ribbon.

It will be noted in Fig. 1 that the points 21 in each plate are arranged in an arcuate line having a curvature sufiicient to take inthe Width of a stranded conductor, thus to insure that one or more points will make contact with the strands of the conductor.

Fig. 4 shows how the points 21 are forged out of the metal of the plate in hollow, rounded, separately pointed cones which will pierce the insulation 23 of the ribbon and force their way between the strands of the conductor, displacing the material in each case, rather than cutting or tearing the same.

These are very important advantages assuring firm, positive contact without cutting or injuring the fine wire strands and without opening up or destroying the insulation.

The contact plates are adjustably secured on the base in the illustration by screws 24 extended through the back of the base, Fig. 2, and secured by nuts 25 at the front of the base, these screws continued through openings provided in the plates and carrying the binding nuts 26 which can be turned down to clamp the plates firmly engaged with the conductors.

A pair of spark gap plate members 27 are disposed in a recess within the insulating body 10. The spark gap plate members 27 are symmetrically arranged with respect to the longitudinal axis of an elongated grounded member illustratively shown as a grounding screw 28 and comprise flat surfaces which are coplanar with respect to a plane normal to the longitudinal axis of grounding screw 28.

Each spark gap member 27 comprises an end portion which is disposed in proximity to and spaced from the grounding screw 23 to define a spark gap from each spark gap member 27 to the common grounding screw 28.

An annular leakage member exemplified by a washer 29 formed of high-resistance material such as carbon surrounds the grounding screw 28. The carbon washer 29 has a fiat circular surface which is arranged with symmetrically disposed portions thereof in simultaneous electrically conductive engagement with both of the two coplanar surfaces of the spark gap member 27.

Fastening means are provided such as an electrically conductive nut 30 threaded on the shank of grounding screw 28 which engages a metal Washer 31. The metal washer 31 in turn presses against the high-resistance annular carbon washer 29. The nut 30 and metal washer 31 engage a surface portion of carbon washer 29 remote from its opposite flat circular surface which symmetrically engages the coplanar surfaces of spark gap plate members 27. This provides symmetrical leakage connections to grounding screw 28 through different portions of the carbon washer 29 for each of the spark gap plates 27, each leakage connection being individually shunted by one of the spark gaps.

The spark gap plate members 27 are secured to the insulating body by the headed inner ends of terminal screws 24 and are thus connected to both conductors of a two-wire transmission line through the H-shaped terminal plates 17.

In Figs. 1, 2 and 3 the ground connection is shown as provided by a grounding strip 32 engaged on screw 28 beneath the nut 30, this strip carrying a binding screw 33 for a ground wire 34.

The grounding strip 32 is shown as extended from the screw 28 through the side of the base by way of a slot 35 and it will be noted in Figs. 2 and 7 that aligned apertures or slots 35 are provided in both sides of the base so that a grounding strip or strips may be brought out at either or both sides and so that, when required, a grounding clamp strip 36 may be looped through the base and about a ground pipe 12, or other such support, and have its ends secured together by a screw 37, or the like. This grounding clamp, as shown in Fig. 7 in engaged over the screw 28 at the center and held between nut 30 and metal washer 31 so as to form a complete grounding connection.

Fig. 1 shows how, in addition to the possibility of supporting the arrester on the wires, or mounting it on a ground pipe, the device may be mounted on a wall, or the like, by passing screws 38 through mounting lugs 39 extended from diagonally opposite corners of the base.

The lugs 19 and 20 extended from the inner and outer edges of the clamp plates, securely grip and hold the conductors, both in the ribbon and in the open twin forms of wiring, providing adequate strain relief.

The resister washer, in addition to providing a gap for lightning discharge, also serves to dissipate static charges providing further protection for the television set.

What is claimed is:

1. A lightning arrester of the class described, comprising a body of insulating material; an elongated electrically conductive centrally disposed grounding member carried by said body; a pair of electrically conductive flat-surfaced spark gap members carried by said body and symmetrically arranged with respect to the longitudinal axis of said grounding member, said flat surfaces being substantially coplanar with respect to a plane normal to the longitudinal axis of said grounding member, each of said spark gap members comprising an end portion disposed in proximity to and spaced from said grounding member for defining a spark gap thereto; an annular leakage member formed of high-resistance material surrounding said grounding member coaxially therewith, said leakage member having a circular flat surface with symmetrically disposed portions thereof in simultaneous electrically conductive engagement with both of said coplanar surfaces; electrically conductive fastening means carried by said grounding member, said fastening means electrically connecting said grounding member with a portion of said leakage member remote from said flat surface symmetrically with respect to said coplanar surface engaging portions thereof and maintaining said portions of said flat surface in said engagement with said coplanar surfaces; first terminal means carried by said body and electrically connected to said grounding member for connecting said grounding member to ground; and second terminal means carried by said body and electrically connected to both of said spark gap members, said second terminal means being adapted to connect both conductors of a balanced two-wire transmission line symmetrically to ground simultaneously through different portions of said leakage member, each of said different portions being individually shunted by one of said spark gaps.

2. An arrester according to claim 1, in which said grounding member is a screw having a threaded shank portion upon which said annular leakage member is slidably mounted and wherein said fastening means comprises an electrically conductive washer slidably mounted on said shank portion and engaging said leakage member, said fastening means further comprising an electrically conductive nut threaded on said shank portion and pressing said washer into engagement with said leakage member.

3. An arrester according to claim 2, wherein said body has a recessed back adapted to be mounted against a flat supporting surface, said nut and said Washer being mounted in said recess, and in which said body has opposed aligned lateral apertures formed therein communicating with said recess and affording access to said grounding member, said first terminal means comprising an elongated metallic ground strip adapted to extend around and secure said arrester to a ground pipe, said ground strip extending through both of said apertures and through said recess, the portion in said recess extending between said nut and said washer for combined electrical and mechanical connection to said grounding member.

4. In combination with an insulating body having two spaced parallel grooves formed therein and a transverseextending groove interconnecting said parallel grooves, the provision of a threaded binding post disposed in said transverse groove intermediate said parallel grooves and extending in a direction normal to the plane of said parallel grooves; a centrally apertured H- shaped terminal plate mounted on said binding post with said binding post extending freely slidably through said aperture, each of the parallel legs of said H-shaped plate being disposed in one of said parallel grooves and extending inopposite directions beyond said transverse groove, the transverse bar of said H-shaped plate being disposed in said transverse groove; and a nut threaded on said binding post and engageable With said plate for pressing a leg of said H-shaped plate into electrically conductive mechanical gripping engagement with a conductor disposed in either of said parallel grooves.

5. The combination according to claim 4, further comprising an arcuate row of integrally formed hollow, conical insulation piercing contact points extending 1ongitudinally along one of the parallel legs of said H-shaped plate, said row of points being adapted to pierce the insulation of an insulated conductor disposed in one of said parallel grooves and establish positive electrical contact with the conductor portion thereof which is enclosed within said insulation.

References Cited in the file of this patent UNITED STATES PATENTS Brach Apr. 1, 1930 Everett Jan. 22, 1935 Walter June 21, 1938 Wallace Nov. 4, 1947 Johnson May 4, 1948 Reder June 14, 1949 Finkel Oct. 6, 1953 Klostermann Jan. 19, 1954

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