US2728896A - Lightning arrestor - Google Patents

Description

Dec. 27, 1955 V, ALEKS 2,728,896

LIGHTNING ARRESTOR Filed Jim@ 4, 1954 7 r I l 1 9 14 I9 33 l? @www United States Patent LIGHTNING ARRESTOR Vytant Aleks, Rockford, Ill., assignor to General Cement Mfg. Co., Rockford, Ill., a corporation of Illinois Application June 4, 1954, Serial No. 434,515 3 Claims. (Cl. 339-97) This invention relates to improvements in electrical connectors generally, and is more particularly concerned with a lightning arrestor designed and especially adapted for use in F. M. radio and television receiver installations.

The principal object of my invention is to improve the molded plastic body of the arrestor with a view to the use of insulation penetrating serrated contacts and provide good electrical connections regardless of the kind of line used, a novel feature of the present arrestor permitting either a hollow, oval, or regular transmission line to be placed in a wide, deep groove extending diametrically of the face of the body in chordal relationship at its opposite sides to the circles defined by the two serrated contacts, whereas, if an open ladder-type transmission line is employed, it can be placed in right angle relationship to the aforesaid groove in two parallel, narrower, shallower grooves provided in the same face also in chordal relationship to the circles dened by the aforesaid serrated contacts.

Another object is to provide an arrestor of simple and economical construction affording the necessary high resistance safe leakage paths from both conductors to ground.

The invention is illustrated in the accompanying drawing, in which- Fig. l is a fragmentary View of an antenna installation showing the lightning arrestor of my invention;

Fig. 2 is a face view of the lightning arrestor shown approximately full size with a hollow transmission line applied thereto in the deeper and wider middle groove;

Fig. 3 is a similar view showing the application to the lightning arrestor of an open or ladder-type transmission line using the parallel shallower grooves provided therefor, and

Figs. 4 and 5 are sectional details on the correspondingly numbered lines of Figs. 2 and 3, these sections serving not only to show the form of the grooves but also the improved internal resistance construction.

Similar reference numerals are applied to corresponding parts throughout the views.

Most television and F. M. radio antennas are mounted on steel or aluminum masts. Hence, in addition to using the lightning arrestor, indicated generally by the reference numeral 1l) in Fig. l, for protection of the TV or F. M. set against lightning and static electricity, it is generally recommended that the mast itself be grounded to the same ground rod 11 by connecting a ground wire 12 thereto leading from the mast. The transmission line indicated at 13 extends from the antenna itself, and, as appears in Fig. l, is connected to and extends past the lightning arrestor and into the house for connection with the set which it serves. Each of the conductors 14 and 15 that are molded in the flexible plastic insulation material of line 13 are connected through a resistor inside the arrestor 10 with a terminal 16 extending radially from one side thereof so that a ground wire 17 fastened by means of a screw 18 to the terminal 16 and extending therefrom and connected to the ground rod 11 will serve to protect the set against lightning and static electricity.

The lightning arrestor 10 comprises a hollow, generally cylindrical body 19 of hard molded insulation material. Two bolts 20 and 21 which serve as threaded terminal posts are inserted in parallel holes provided therefore in the body on opposite sides of a diametrically extending substantially half-round groove. The groove is fairly wide and deep but is widened a little at the top on both sides, as indicated at 23, to define ledges on which to locate the longitudinally extending beads or flanges 24 on opposite sides of the hollow transmission line 13 in which beads or flanges the wires 14 and 15 are molded, whereby to facilitate impressing the sharp ends of teeth 25 on the serrated circular contacts 26 into the molded plastic insulation covering of the line 13 well enough to insure good contact with the wires 14 and 15 when these contacts are tightened by the tightening of nuts 27 on the bolts 20 and 21. The bolts 20 and 21 are both connected with the terminal 16 through a central bolt 28 and a carbon resistor washer 29, the bolt 28 having a nut 30 which forces the inner end of the terminal 16 against the carbon resistor washer 29 and that in turn against the spaced ends of two plates 31 which are held in place inside the body 19 by the heads of the bolts Ztl and 21. The inside of the body 19 is filled with a plastic insulation material 32 while the latter is in molten condition, embedding all of the internal parts in the relationship described. The carbon washer provides the necessary high resistance for safe leakage of high voltage to ground 11 from both wires 14 and 15.

It is apparent from the drawing and the foregoing description that the opposite sides of the groove 22 ex tend in chordal relationship to the circles defined by the serrated circular contacts 26 in order to enable penetration of the Contact teeth 25 through the plastic insulation of the flange portions 24 of the line 13 for good electrical contact with the wires 14 and 15 provided in these ange portions and that in this way both wires are connected with the ground wire 17 and ground rod 11. The groove 22 will accommodate hollow, oval or regular style transmission lines. Occasionally however, open transmission lines, like that indicated at 13 in Figs. 3 and 5, are used and the present insulator 10 has the narrower, shallower, parallel grooves 33 and 34 provided in the substantially at top face of the body 19 to accommodate the wires 14' and 15 of this style of transmission line. In this style the wires are insulated by bars 35 of insulation material which resemble rungs of a ladder and from which this style of line derives the name ladder type. Here again, the grooves 33 and 34 extend in chordal relationship to the circles defined by the contacts 26 thereby insuring these contacts taking hold of the wires with their teeth 25 well enough when the nuts 27 are tightened to insure good electrical connections.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modications and adaptations.

l claim:

l. In an electrical connector of the character described comprising a body of electrically nonconductive material having a substantially tlat external face, and a pair of electrically conductive terminal posts carried by said body in spaced parallel relationship to one another and substantially at right angles to the plane of said fiat face, each post carrying outside said body an electrically conductive contact of circular form having a rim projecting toward the aforesaid face of said body and adapted to be forced inwardly toward said face so that the rim of the contact makes electrical connection between the wire and the related post, the improvement which consists in the provision in said at face adjacent each of said posts of a plurality of intersecting grooves of different form and dimensions in substantially the same plane for reception of different wires interchangeably, said grooves extending in substantially the saine chordal relationship to the circles d'eiinedv by said rims of said contacts. so that said' contacts are adapted' to make good electrical connection with wires placed in either of said grooves.

2. In an electrical connector of the character described comprising a body of electrically nonconductive material having a substantially ilat external face, and a pair Yof electrically conductive terminal posts carried by said body in spaced parallel relationship to one another and substantially at right angles to the plane of said flat face, each. post' carrying outside said body an electrically conductive contact of circular forni having a rirn projecting toward the aforesaid face of saidV body and adapted to be forced inwardly toward said face so that the rim ofthe contact makes electrical connection between the wire and the related post, the improvement which consists in the provision in saidat face of a single relatively wide groove for reception interchangeably of any one oi' a plurality of styles of single wires containing two conductors, said groove having its opposite sides in substantially the same chordal relationship to the circles defined' by said rims of' said contacts so that said contacts are adapted to make f good electrical connection with both conductors of a two-conductor wire, and the provision in the same face of a pair of parallel relatively narrow grooves in substantially the same plane with the rst groove but spaced farther apart than the opposite sides of said rst groove for reception ofv a pair of correspondingly spaced parallel wires of' a ladder type transmission line, the latter pair of grooves being in transverse relationship to the irst men- 4. tioned groove and in substantially the same chordal relationship to the circles dened by said rims of said contacts so that said conductors are adapted to make good electrical connection with both of said wires.

3. In an electrical connector, a body of electrically nonconductive material having a substantially at external face, and an electrically conductive terminal post carried by said body substantially at right angles to the plane of said at face, said post Carrying an electrically conductive contact of circular form having a rim projecting toward the aforesaid face of said body and adapted to be forced inwardly toward said face so that the rim of the contact makes electrical. connectionI between the wire and the related post, the improvement which consists in the provision in said at face of two grooves of different form and dimensions for reception of diierent wires interchangeably, said grooves being in substantially the same plane and extending in intersecting relation to one another and in chordal relationship to the circle dened by the rim' of said contact so that said contact is adapted to make good electricaly connection with a wire placed in either of said grooves.

References Cited inthe le of this patent UNITED STATES PATENTS 1,189,272 McClintock July 4, 1916 1,925,283 Searles Sept. 5, 1933 1,988,650 Everett Ian. 22, 1935 2,372,653 Beckett Apr. 3, 1945 2,440,748' Johnson May 4, 1948 2,567,783 Richardson Sept. 11, 1951 2,654,857 Finkel Oct. 8, 1953 2,666,908 Klostermann Ian. 19, 1954

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