US2027733A - Vertical mast wave antenna - Google Patents

Description

Jan. 14, 1936. R L, JENNER 2,027,733

VERTICAL MAST WAVE ANTENNA Filed Aug. 7, 1935 Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE VERTICAL MAST WAVE ANTENNA York Application August 7, 1933, Serial No. 683,933

12 Claims.

This invention relates to wave antennae and more particularly to vertical conductors adapted to radiate radio signals.

An object of this invention is the provision of a rigid vertical fabricated structure (often re ferred to as a mast or tower), adapted to alone function substantially as a vertical electrical conductor and having at least two principal supports to give it stability in two directions in the same vertical plane, and secondary supporting means providing stability in directions lateral to said plane.

Another object of the invention is the provision of a wave antenna of the character referred to above that shall be so insulated from ground that the electrostatic capacity to ground may be reduced to a low value. A further object of the invention is the provision of a vertical antenna of the type referred to above which shall be so supported as to reduce the electrical energy losses to ground to a minimum.

Other objects of the invention will in part be apparent and will, in part, be obvious from the following description taken in conjunction with the accompanying drawing, in which:

Figure l is a more or less diagrammatic view in side elevation of a wave antenna embodying one form of the invention;

Fig. 2 is a view in side elevation of the antenna taken at right angles to the view shown in Figure 1;

Fig. 3 is an enlarged view of the base of one of the principal supports of the antenna and an insulator on which it is mounted;

Fig. 4 is an enlarged View of the base of one of the principal supports and a modified form of insulator mounting;

Fig. 5 is an enlarged view partly in section of a coupling embodied in the secondary supports for the antenna;

Fig. 6 is a fragmentary sectional view of the mast antenna taken on line VTL-VI of Fig. 2, showing a modified form of coupling for attaching the secondary supports thereto; and

Figs. '7 and 8 are views in section taken on lines VII-VII and VIII-NIH, respectively, of the mast showing the shape of the mast in horizontal section at any point above the waist thereof, and the shape of the mast legs in horizontal section at any point below said waist.

Throughout the drawing and specification, like reference characters indicate like parts.

In Figs. 1 and 2, a vertical mast, wave antenna l is illustrated having two principal or primary directions in a vertical plane passing through the vertical axis of the mast, and two secondary supports 4 and 5 disposed in a plane lateral to the plane of the principal supports which provide stability in directions lateral to the plane containing the main or principal supports. It is preferred to place the secondary supports on opposite sides of the plane containing the principal supports and at right angles thereto. As illustrated, the plane containing the secondary supports passes through the vertical axis of the mast.

The base of each principal support comprises a mounting insulator 6 carried by foundation '1' which is suitably anchored in the ground. In order to avoid loading of insulator 6 in tension, in case the mast sways or tilts, the articulation either between the insulators and the foundations, or between the insulators and the base of the mast is made such as to provide freedom of movement either between the base of the mast and the insulators, or between the insulators and the foundations. Thus, the insulators may be relieved of direct tension loads and the attendant tensile stresses.

The secondary supports are anchored in suitable foundations 8 and applied to the mast at one elevation located at a suitable distance from the base of the mast. For convenience, the elevation at which the secondary supports are attached to the mast may be designated as the waist thereof.

The mast, as illustrated, embodies two sections from the standpoint of shape in transverse section; an upper section 9 extending from the waist to the top of the mast, and a lower portion or section I0 extending from the waist downwardly to the mounting insulators.

The upper section of the mast tapers from the waist substantially to a point at its top, whereas the lower portion is formed as two legs H and [2 that diverge downwardly (see Fig. 2) from the waist. These legs also taper downwardly from the waist; that is, the sides of each leg converge to substantially a point at the base thereof.

structurally, the upper portion or section of the mast includes risers l3, l4, l5, and N5, of structural steel or other suitable material, which form the corners of a polygon at any elevation a from the waist to the top thereof (see Fig. '7). These risers are connected by structural members or braces H which tie the risers into the structure and give it the necessary rigidity and stiffness to resist the transverse loads which may be imposed thereon from any angle by wind pressure.

The risers may comprise a series of lengths of angle bars of steel or other metal having the required stren th and rigidity, joined at their ends in such manner as to provide positive and adequate electrical contact therebetween. The struts or braces are joined to the risers and to each other in such fashion as to provide good and adequate electrical contact between them.

structurally, each leg of the lower portion or section ll of the mast includes risers l8, I9, 20, and 2! of structural steel or other suitable material tied together with struts or braces 22 of structural steel or other suitable material in such fashion as to give stiffness and rigidity thereto.

Risers l8 and 2H of log N may be connected to risers i3 and M of upper mast sections in such manner as to effectually form continuous risers extending from the base to the top of the mast. In like fashion, risers l9 and 2| of leg ll may be connected to the risers l5 and 16 of the upper section.

Risers l8 and 2!] of each leg run to the middle of the waist of the mast at points midwaybetween risers l3, M, and i5, 46, respectively, of the upper section.

With a mast so constructed, it will be apparent by inspection of Figs. 1 and 2 that the shapes in transverse section of the upper section of the mast and of legs ii! and H taken at any horizontal plane, are substantially square or polygonal and that the risers form the corners of each square or polygon. The structural membersof the mast being electrically connected, the mast in effect forms a single vertical conductor adapted to alone function as an antenna.

The form of the mounting insulators 6 illustrated in Figs. 1 and 2, and the means for connecting them to the bases of the mast legs and the foundations are illustrated more clearly in detail in Fig. 3. As shown, each insulator 6 is in the form of an inverted truncated cone of porcelain of suitable ceramic material, or of some suitable insulating material. The small end of each cone is disposed in a metal cap 23 having a curved outer surface 24 that rests or bears on a bearing or pad 25 which is bolted to each foundation 1. The bearing pad has an opening 25 into which 2. lug or dowel 21 formed as a part of cap 23, may extend. This dowel takes any lateral thrust that may be imposed on the mast at the base and allows the lower end of the insulator to move with cap 23 relative to the pad or bearing. Provision for freedom of movement at this point insures that the mounting or base insulators S will not be subjected to direct tension loads, but only to compression loads and stresses.

The upper end of each insulator 6 is nested within a circumferential flange 29 formed as an integral part of a shoe 36 to'which the risers of the associated tower legs are secured in any suitable manner.

In Fig. 4, a modified form of mounting or base insulator is shown. This form embodies a truncated cone 3! having its small end uppermost. The large end of. the insulator is disposed or nested within a circumferential flange 32, forming a part of the pad or plate 33 which is bolted to the foundation. The upper end of the cone is provided with a bearing cap 34 having a dowel or sheer pin 35 extending upwardly through the bottom of a shoe 38 to which the risers of the associated tower leg are secured. Thus, the

bases of the tower legs have freedom 01' movement relative to the caps 34 in case the mast should sway or tilt, and because of this, the base insulators will not be subjected to direct tension loads and the attendant tensile stresses. 5

The secondary supports sand 5 are similar in construction so that a description of one of these, as illustrated in Figure 5, will serve also as a description for both. Each secondary support comprises a guy rod 3? connected by a coupling 10 38 to the midpoint of a side of the mast at the waist thereof. As is apparent from Fig. 1, one guy is disposed on each side of the vertical plane containing the principal supports, the points of attachment being at the crotch of mast legs ll 15 and H2. The lower end of each guy rod is anchored in a foundation 8 and the upper end thereof is connected to its associated coupling 38.

Coupling 38 includes a stirrup 39 having a circular seat 46 in which the base of a truncated 2o hollow cone 4! of insulating material may be disposed. The upper end of the stirrup is provided with an extension 42 to which one end of a tension member 43 may be secured, the other end being secured to the mast. The upper end 25 of guy rod 3'! extends through cone 4! and a bearing cap it mounted on the small end thereof, and is threaded to accommodate a nut 45.

When a mast such as illustrated, has been erected and mounted in a vertical position on 30 insulators 6, and nuts 45 of the couplings have been tightened -until the guy rods are taut, insulators t! are placed in compression and the guy rods 31, stirrups 39, and the tension members 43 in tension. 35

A mast antenna supported as above described, is insulated from ground at the base of the mast legs by insulators 6, and from the ground through the guys by insulators 4|. Therefore, there are four parallel capacitive impedance paths to 40 ground; but by utilizing insulators of the type shown, the impedance through each path may be made so high that the electrical energy losses as such, in the insulators and the structure are relatively negligible. 5

Instead of connecting the secondary supports to the mast as in Figs. 1 and 2, these supports may be coupled to the mast at a point wholly within the structure, preferably at a point in or at such points as to act along the vertical 5o axis of the mast. The form of coupling employed may be of the double cone type illustrated in my copending application, Serial No. 542,518, filed June 6, 1931, and assigned to Lapp Insulator Company, Inc., or a single cone coupling may 55 be used.

This type of coupling comprises two hollow truncated cones 4'? and 48 of porcelain or other suitable material, having their large ends disposed in contiguous relation in a flanged thrust 60 plate 49 which is attached to structural members 553 secured to the risers of the mast. The cones are tied together and placed under initial compression by means of a through bolt 5|, bearing caps 52 and a nut 53 which, when drawn uptight, puts the bolt in tension and the insulators in compression. If desired, cone 48 may be omitted and only cone A? used, or a coupling such as shown in Fig. 5 may be employed.

The mast antenna illustrated is adapted to alone function as a single vertical radiator; embodies two principal supports that provide stability in a plane containing the supports, and two auxiliary supports which provide stability in 7 a direction lateral to the plane containing the principal supports.

While various modifications and changes may be made in the embodiments of the invention as illustrated herein, without departing either from the spirit or the scope of the invention, it is to be understood that only such limitations shall be placed on the invention as are imposed by the prior art and the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. A wave antenna comprising a rigid vertical mast provided with two principal supports at the base which carry the entire weight of and give stability to the mast in two directions in a vertical plane containing said supports, and secondary supporting means applied to said mast at one other elevation only, adapted to give stability to the mast in two directions at right angles to the plane containing the principal supports, said mast being electrically insulated from ground and adapted to alone function as an antenna.

2. A wave antenna comprising a rigid vertical mast provided with two principal supports at the base on which the full weight of the mast is carried, and secondary supporting means applied at one other elevation only, said means being disposed in a vertical plane at right angles to the plane containing the principal supports, whereby said mast is supported as a cantilever individually and jointly by said principal supports and secondary supporting means, said mast being electrically insulated from ground, whereby said mast alone functions as an antenna.

3. A wave antenna comprising a rigid vertical mast provided with two principal supports at the base, and secondary supporting means connected to the mast at a single point within the same located between the ends of the mast, said means being disposed on opposite sides of the principal supports and acting to support the mast as a cantilever and resist bending forces applied thereto in any lateral direction, said mast being insulated from ground and adapted to alone function as an antenna. 1

4. A wave antenna comprising a rigid vertical mast adapted to function as a single vertical electrical conductor, said mast being provided with two principal supports at the base which carry the entire weight of and give stability to the mast in two directions in a vertical plane containing said supports, and secondary supporting means applied to the mast at a single elevation located between the ends thereof providing stability for the mast in directions lateral to the plane containing said principal supports, said secondary supporting means being guy wires in tension.

5. A wave antenna comprising a rigid vertical mast adapted to function as a single vertical electrical conductor, said mast being provided with two principal supports at the base which carry the entire weight of and give stability to the mast in two directions in a vertical plane containing said supports, and secondary supporting means applied to the mast at a single elevation located between the ends thereof providing stability for the mast in directions lateral to the plane containing said principal supports, said secondary supports being guy wires in tension and insulators in compression.

6. A wave antenna comprising a rigid vertical mast adapted to function as a single vertical electrical conductor, said mast being provided with two principal supports at the base giving stability to the mast in two directions in a vertical plane containing said supports, and secondary supporting means coupled to the mast at a single point located wholly within the same, said single point coupling being disposed between the ends of the mast, said secondary supporting means being guy wires in tension.

7. A wave antenna comprising a rigid vertical mast adapted to function as a single vertical electrical conductor, said mast being provided with two principal supports: at the base giving stability to the mast in two directions in a vertical plane containing said supports, and secondary supporting means coupled to the mast at a single point located wholly within the same, said single point coupling being disposed between the ends of the mast, said secondary supporting means including guy wires in tension and at least one insulator so interposed between the mast and ground that the insulator is in series circuit with each of the guys between the mast and ground.

8. A wave antenna comprising a relatively slender vertical mast formed of structural members bonded together so as to constitute a continuous conductor adapted to alone function as an antenna, the lower portion of the mast being shaped to provide two diverging legs adapted to be mounted on supports of insulating material and to carry the full weight of the mast and give stability to the mast in a plane containing said supports, and means applied to the mast on opposite sides thereof adapted to give stability thereto in directions lateral to said plane.

9. A wave antenna. of the vertical self-supporting type comprising a relatively slender mast made up of structural members bonded together to constitute effectually a continuous conductor adapted to alone function as an antenna, said -1 mast having a girth located at a substantial dis-- tance from the base thereof, the portion of the mast above said girth being polyhedral in form with the sides thereof converging substantially to a point at its top, and the portion of the mast below said girth being shaped to form two legs that diverge towards the base and having their longitudinal axes disposed in a plane containing the vertical axis of the mast, said legs giving stability to the mast in said plane, and guys connected to said mast adapted to give stability thereto in directions lateral to said plane.

10. A wave antenna comprising a rigid vertical mast adapted to function as a single vertical electrical conductor, said mast being provided with termediate of and connected with the legs at two opposite sides of the tower, said insulators having their axes lying in the same planes as said tower sides, and a plurality of hold-down insulators anchored to the ground intermediate of and connected with the tower legs at the other opposite sides of the tower, said hold-down insulators being spaced above the ground and having their axes lying in the same plane as the second named opposite sides of the tower.

12. Supporting means for a radio tower of the self -ra.diating type having legs terminating above the ground, a pair of compression insulators anchored to the ground beneath and intermediate the opposite sides of the tower, downwardly converging members secured to the lower ends of the legs at opposite sides of the tower and secured to the top of said insulators whereby the tower will have in effect a V-shaped lower portion resting gravitationally upon said insulators, and a plurality of hold-down insulators located beneath the other opposite sides of the tower and anchored to the ground and connected with the tower legs.

' RALPH L. JENNER.

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