Патент USA US2118396код для вставки
May 24, 1938. N. E.. DAVIS ET AI. 2,118,396 CONSTRUCTION OF AERIAL SYSTEMS FOR USE ON SHORT WAVES Filed Jan. l0, 1935 2 Sheets-Sheet l INVENTOR. NORMAN E. DAVIS FREDERICK J. AINSLEY ATTORNEY. May 24, 1938. N. E. DAVIS Er AL 2,118,396 CONSTRUCTION OF AERIAL SYSTEMS FOR USE ON SHORT WAVES Filed Jan. 10, 1955 2 Sheets-Sheet 2 „_____.._._.___..__/.________ ___-___ INVENTOR. NORMAN E. DAws FREDERlcK J.A|NsLEY BY 7 r/@É - _-_ /w‘w-(VL/ ATTORNEY, Patented May 24, 1938 2,118,396 UNITED STATES PATENT «OFFICE 2,118,396 CONSTRUCTION OF AERIAL SYSTEMS FOR USE ON SHORT WAVES Norman Eustace Davis, Chelmsford, and Fred erick James Ainsley, Chislehurst, England, as signors to Radio Corporation of America, a corporation of Delaware Application January 10, 1935, Serial No. 1,190 In Great Britain January 20, 1934 4 Claims. (Cl. Z50-_33) This invention relates to constructions of aerial lengths of the aerial are, of course, in series with systems for use on short waves or so-called ultra one another, the series connection being made by short waves. More specifically, the invention re short transverse portions of conductor which are lates to constructions for extending aerial systems at right angles to the three lines of extension. 5 wherein the aerial is extended not in a single Figs. 3, 4 and 5 of the above mentioned United 5 straight line, but in effect, in a plurality of more States Patent No. 1,957,949 illustrate aerials of a or less parallel straight lines, portions of the type similar to that of Fig. 2, and the present in aerial system lying in said plurality of lines being vention is also applicable to these aerials. joined in series by transverse connections be The object of the present invention is to pro 10 tween them. vide a simple, rigid, easily erected and relatively It is very important that such aerials, more es portable construction for an aerial of the kind pecially when they are for use on wave lengths of only a few meters or less, should be of rigid construction in order that variations in the dis 15 tances between different parts of the aerial and between the aerial and adjacent objects-with consequent variations in aerial properties and characteristics-shall be reduced as far as pos sible. It is also often required that the aerial construction shall be self-supporting, i. e., shall not require supporting guys. As will be seen later, which is extended in a plurality of parallel or ap proximately parallel lines. According to this invention, a construction for an aerial of the kind referred to comprises a plu rality of approximately parallel adjacent masts (for example in the form of rods or tubes) each mast lying in one of the plurality cf lines of ex tension of the aerial, and portions only of each mast being utilized as the aerial proper, said por tions being connected together as required by transverse connectors extending between the the present invention enables these requirements to be readily satisfied. masts. Aerials which may be regarded as extended in a plurality of lines in the sense in which this phrase is used herein, are described in United Where anv aerial construction, according to this invention, is required to be of any very great height, it will generally be necessary to provide States Patent No. 1,957,949, dated May 8, 1934, cross braces and diagonal struts or tension mem which patent describes directive aerials of the type set forth in British Patents Nos. 242,342 and bers between the masts, these braces and struts or tension members being additional to any brac 285,106 and wherein the intermediate, folded por ing effect provided by the inter-connections be tions of the wire or conductor are so arranged tween the masts. According to an important sub-ordinate fea ture of this invention, the cross braces are 1o cated at, and diagonal struts or tension members are arranged between, points in the masts where the alternating voltage on the aerial portions that they radiate effectively in the same direc tion as the straight portions. For example, Fig. 2 of United States Patent No. 1,957,949, illustrates 35 an aerial system in which a straight half-wave length A is followed by a reversed or folded half Wave length B and then by a straight half-wave length C, a reversed half wave length D, a further straight half wave length E in the same straight 40 line as portion A, a further reversed half wave length F, a straight half wave length G in line with length C, and so on, the phase relation of the currents in successive half wave lengths being such that the reversed sections B, D, F add to the 45 ell’ective field strength due to the straight wire sections A, C, E. Thus, from the point of view of this application, an aerial as illustrated in Fig. 2 of United States Patent No. 1,957,949 may be re _ garded as an aerial system which is extended in 50 three parallel lines, one line including the straight lengths A and E, another line including the straight lengths C and G, and the third line in cluding those parts of the remaining lengths whose directions are opposite to the directions of the straight lengths A, C, E and G. All the 15 30. proper is zero. In preferred embodiments of the invention, three masts arranged at the corners of an equi lateral triangle are employed and cross bracing is 40 provided by means of bracing tubes or plates having a triangular arrangement of holes through which the masts pass, the masts being built up of sections insulated fi‘om one another where re quired. The invention is illustrated in the accompany ing drawings in which: Fig. 1 shows one form of construction in ac cordance with the invention; Fig. 2 is a diagrammatic view showing in full 50 lines the portions which constitute the aerial proper; and Figs. 3-6, inclusive, show details oi construc tion. Referring to the drawings, an aerial system 65 2 2,118,396 comprises three vertical or approximately ver~ straight tubes il', each of which is split at both tical masts l, 2, 3, arranged close together and ends as shown at 20. On each mast (e. g. mast 2) is an externally screw-threaded sleeve 24 held in place by pins 22 and 23, and over this sleeve is iitted an insulator i 9 formed like a tube with two at the corners of an imaginary equilateral tri angle. Each mast stands upon a foot insulator 4, 5 or 6 mounted on a suitable carrier or bed plate 'l and the masts are braced together at suit able intervals in the height of the aerial structure. The three masts are sectionalized and the sec tions insulated from one another in a manner to v be described later. As above stated, those por tions of the masts which are to constitute the aerial proper are connected in Series with one another. The aerial proper comprises a ñrst, vertical portion A included in the mast I and 15 extending upwards from the bottom thereof; a second, horizontal portion B connecting the top of the portion A to the top of a portion C of mast 2 which is spaced some distance from the bottom thereof; a third, vertical portion C in 20 cluded in mast 2; a fourth, horizontal portion D connecting the bottom of the portion C to the bottom of a ñfth, vertical portion E in mast 3; a sixth, horizontal portion F connecting the top of the fifth portion E to the top of a seventh, 25 vertical portion G in mast 2; an eighth, hori Zontal portion H connecting the bottom of the seventh portion G to the bottom of a ninth, vertical portion J in mast l and in the same straight line as portion A; and so on until the 30 required height has been obtained. Insulators are included at 8 and 9 in mast l to insulate the portions A and J from one another; insulators are included at l0, Il, l2 and I3 in mast 2 to insulate the portions C and G from one another 35 and also to insulate these portions from the mast portions respectively below and above them; and insulators are included at l5 and I6 in mast 3 to insulate the portion E at both ends; in short, insulators are interposed in the masts as neces sary properly to insulate the portions thereof which are included in the aerial proper. It will be appreciated that the aerial proper (Fig. 2) is thus so constructed as to consist of a straight half wave length, followed by a reversed or folded hali wave length, followed by a straight half wave will be obvious without further description beyond that 26 and 21 are insulators. As will be ap parent, the split tubular method of gripping tapered insulators is also employed in Fig. 5. Fig. 6 shows the details at points such as X (Fig. 1) 28 being an insulator. What is claimed is: 1. An aerial comprising a plurality of rigid, approximately parallel and adjacent hollow me tallic masts each of which is composed of a plu- C rality of conductive sections insulated from one another, and transverse metallic tubular con nectors extending between the masts and con necting certain of the conductive sections to gether in series, the sections and transverse con- : nectors being so arranged that said connectors together with the mast sections interconnected thereby constitute an aerial proper which is in sulated from the rest of the mast structure, and hollow metallic braces interlacing said masts at points of zero alternating potential and insulated therefrom. 2. An aerial comprising three rigid, approxi mately parallel hollow and metallic masts ar at points of zero alternating potential so far as ranged at the corners of an imaginary equi lateral triangle and each standing on an insu lator, each mast being formed of a plurality of conductive sections insulated from one another. and transverse metallic tubular connectors ex tending between the masts and connecting certain l the aerial proper is concerned, and thus losses due to circulating currents in these braces are sections and transverse connectors being so ar minimized or eliminated. ranged that said connectors together with the mast sections interconnected thereby constitute length, followed by a reversed half wave length, followed b-y a straight half wave length and so on. Insulated triangularly arranged braces l1, I8 are arranged as shown and are, like the insulators, 50 slightly tapered radial arms. The insulator is located by nuts 25 on the sleeve 24. The split ends of the tubes Il’ are threaded and are pushed over the insulator arms, and the arrangement is such that when the nuts 2l are screwed along the tubes Il' towards the mast, the slits 20 are closed down somewhat to allow the tubes to taper down so as to ñt upon and grip the tapered insulator arms. When the bores in the ends of tubes Il’ are being machined, the slits should be opened slightly so that when they are closed by the nuts the tube taper will ñt the insulator taper. Fig. 5 shows partly in section the detail at points, such as the ends of the portions between portions A and J, and it will be thought that these ilgureS The whole construc tion may be additionally strengthened by diag 55 onal struts or tension members which are diagonal with regard to the races of the imaginary tri angular prism sections into which the whole structure may be regarded as divided. Thus there may be a diagonal member between the 60 bottom of mast i and that end of portion B which is in mast 2, another diagonal member be tween the top end of the said ñrst diagonal mem ber and the bottom of portion J, and so on, there being one diagonal strut or tension member in 65 each face of the triangular prism sections wheth er long or short. Guys may, ii’ desired, be at tached to the apices of one or more of the tri angular braces to assist in giving support. It will be appreciated that aerial structures, 70 in accordance with this invention, can readily be made portable and are relatively easy to erect in high situations, such as on the ridges of buildings. Figs. 3 and 4 show the details of construction at triangular brace points, such as the location 75 of the brace Il. The brace includes three of the conductive sections together in series, the an aerial proper which is insulated from the rest l of the mast structure, and hollow metallic braces interlacing said masts at points of zero alternat ing potential and insulated therefrom. 3. An aerial in accordance with claim 2, char acterized in this that said masts are arranged 60 vertically and are supported at their lower ends. 4. An aerial comprising a plurality of rigid, approximately parallel, adjacent hollow metallic masts arranged each in one of the plurality of lines of extension of the aerial, portions only of said masts being utilized as the aerial proper, said portions being connected together in series by transverse metallic connectors extending be tween the masts, insulators between said portions and the immediately adjacent portions in the same straight line, said masts being erected ver tically and supported at the base of the aerial. NORMAN EUSTACE DAVIS. FREDERICK JAMES AINSLE'Y.