US2677765A - Antenna element - Google Patents

Description

May 4, 1954 .1. w. COLLINS ETAL 2,677,765

ANTENNA ELEMENT Filed March 9, 1950 INVENTORS z/Ezmes WCo/fibs awe germ 4G M 7 Patented May 4, 1954 UNITED STATES PATENT OFFICE ANTENNA ELEMENT Application March 9, 1950, Serial No. 148,622

1 Claim. 1

This invention relates to antenna elements, particularly those elements used in forming antenna structures for receiving short wave transmissions in the television, frequency modulation and ultra-short wave range, and the method of making such antenna elements as an article of manufacture.

An object of the present invention is to provide a novel antenna element which is an improvement over the extruded tubular elements now used in formin most short wave or television receiver antenna structures.

Another object of the invention is to provide a novel, simple and economical method of producing the present improved antenna element.

A further object of the invention is to provide an antenna element which is light in weight, highly resistant to bending stresses, and low in cost, at the same time presentin no curtailment in efficiency as a collector of high frequency oscillations.

Still another object of the present invention is to provide an antenna element which may be formed in a large variety of lengths and sizes and which may be used as masts and cross supports in antenna structures, as Well as receiving elements, and which are particularly adapted to be used with a suitable insulator such as described in our co-pending application for Antenna for the Reception of High Frequency Oscillations, Serial No. 148,621, filed on even date herewith.

A further object of the present invention is to provide an antenna element which when used in plural sets in an antenna structure results in a minimum of vibration and whistling, reducing breakage due to crystallization and metal fatigue.

Still another object of the invention is to provide a tubular antenna element which because of its core will not collect water, thus eliminating the bursting of the antenna element due to the freezing and expansion of collected water and further eliminatin the need for flattening or sealing of the tube end as in the hollow, extruded tubular element to prevent condensation therein.

A further object of the present invention is to provide an antenna element so formed in a variety of ways such as a butting or overlapping split tube, laminations, coiled sprin wire or longitudinal folded ribs, that the element may expand radially due to temperature expansion or ice pressure from capillary water without rupturing the casing, and return to its original shape when such pressure is relieved.

Another object of the present invention is to provide an antenna element that is considerably more resilient than the extruded tubular element usually used, and which may bend under heavy ice or wind loads and return to an original position without rupture of the casing.

A further object of the present invention is to provide an antenna element that is formed with a metal casing and dielectric core, such as wood, plastic or the like, said core being treated to prevent moisture absorption, and which element may permit the core to extend beyond the metal casing if desired to serve as an insulator for clamping the elements in a holding block of non-insulating material.

A final object of the invention is to provide an element which may be cheaply fabricated by rolling in length or diameter or by dies in a power press and in which the core may be anchored or attached in various Ways to the metal casing,

With the above and other objects in View, as will become presently apparent, the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly claimed.

In the drawings, like characters of reference indicate like parts in the several views, and

Figure 1 is an elevation showing one method of fabricating the elements, as by rolling in length or diameter, and filling the outer tubing with a core and tightly joining the tube on the core;

Figure 2 is a sectiona1 perspective of one form of element;

Figure 3 is a view similar to Figure 2 of another form or modification of the element;

Figure 3a is a section taken on the line 33 of Figure 3; and I Figures 4a, 5, 6, 7 and 8 are views similar to Figures 2 and 3 of further forms or modifications of the element.

Referring to the drawings in detail, in Figure 1 is shown one method of fabricating antenna elements of the present invention, in which a flat ribbon or strip iii of dural or other conducting metal highly sensitive to energization for sound and picture receiving of different wave lengths from different directions, is placed or fed from a strip, roll or reel onto a table i I and from thence, forward between coasting interfitting forming rolls l2 and is placed one above the other and rotatable about their axes It and it held in suitable bearing supports. Roll I2 is shown provided with one or more reduced portions iii into which the flanged periphery or annular conforming and overlappin edge portions ll of roll I2 extends to partially bend the marginal longitudinal edge portions of narrow sheet or strip it up in offset curved fashion by a jog therein at and between the rolls l2 and I3, as shown at it. The strip Ill may be fed simultaneously with a rectilinear core [9 thereon centrally of its Width, so as to be 5 partially bent up against the core. Core i9 is of uniform cross-section throughout its length and suitable electrical insulating material, such as wood, plastic, or even metal or" solid, tubular or laminated form, or plastic Wood to fill the completed outer tube of the element.

The strip and core are then fed forward from rolls l2 and :3 between similarly mounted and journaled additional mating rolls 2e and iii oi similar formation peripherally except that they may be differently proportioned in size and diameter and overlap to turn the edges of the strip I6 up further in coiled form, as indicated at 22, so that the longitudinal, marginal edges of the strip ill are brought toward each other in closer relation on and about the core Eli but still in slightly separate relation to each other. After this, the strip and core are run between similarly mounted coacting circumferentially or peripherally concaved rolls 23 and 24, which turn the strip edges further to extend entirely around the core with their edges meetin and in contact to form a tubular shell about the core. The "clgee may be left in abutment as formed or joined in any suitable way, as by welding, soldering, or otherwise, along the joint formed by the ing edges of the formed tube it which is of un form cross-section throughout its length so t the core 59 and the tube 25 will snugly interns each other throughout the length thereof.

As shown in Figures 1 and 2, the tube along the marginal abutting edges of the joint or seam 25 may be indented as at 2%? in one or more rows of indentations to push the into e as at 28, and effectively anchor the tube to the core against separation, shifting movement or displacement relative thereto. This may be accomplished in any suitable way, as by coacting concaved rolls 29 and similarly journaled the other rolls and provided with intermeshing circumferential peripheral teats, pins or projections on one or both rolls iorci? the tube metal at such points into forming depressions in the core with tight contact between the core and shell or tube. The tube and core may be of suitable cross sectional shape, and the tube wall of any thickness, and enveloping the core may be deposited by electrolysis or plati if desired. The core may be natural wood, formed of plastic wood or any suitable pla or even metal, the latter being preferably, but not necessarily, a non-conductor of electric Cllrrent, and may be solid, tube or laminated to give desired thickness and tensile strength, and of any diameter suitable for the purpose.

In Figures 3 and 3a, the parts are similarly designated, but instead of anchoring the tube on the core as in Figures 1 and Z, the rolls and 36 may be formed peripherally to produce elon gated intermeshing lineal indentations 33 which may or may not enter depressions 3?. or be depressed into the core iii.

In Figure 4 the indentations are the same as employed in connection. with i and 2, but, in addition and instead of the edges of the strip shell or tube casing being brou ht into ab t ting relation and joined or otheri ise iistenel together or on the core, the edge margins are brought into overlapping relation, as indicated at 3.3, and similarly fastened, if desired, as previously explained.

In Figure 5, the construction method and product article of manufacture is the same as in Figures 1 and 2, except that the rolls are formed to produce a tube 34. of rectangular and oblong cross-section with the sides bent at right angles relatively to snugly receive or lit the core 35 of similar cross-section. Flanges 3S along the marginal edges are brought together to form the seam 31 and anchored by similar indentations and depressions 21 and 28 as previously described, in the tubular shell and core, respectively.

In Figure 6, the tube 38 has the seam 39, and is fitted, formed or filled with core 40. However, in this instance, the tube is shown formed with longitudinal reinforcing ribs 4| which better allow for expansion of diameter and return to original shape. This tube may be anchored on the core by indentations i2 entering depressions 43 formed thereby in the core which has external ribs l-t longitudinally to enter the concavities of the ribs 4| on the inside.

In Figure '7, the tubing 45 is formed of a coil wound on or filled with core 48, may be fabricated by the conventional method of telescoping or by coiling wire or strap stock around the core compression therewith. In this form, the coils may form indentations or projections at the inside of the tube encircling the core and entering depressions or circuinscribing annular or helical spiral grooves in the core periphery formed by pressing the helical coils of the tube, or by filling the tube with a plastic non-conductor, as heretofore described. It is also to be understood that in all the forms hereinbefore set forth, the tube may be filled completely with core to interiit at the indentations and depressions formed by the indentations at the inside of the tube entering the core at its pe riphery.

In Figure 8, a second coil or shell it? with or without core 46, the same as in Figure 7, coiled or fitted over the coil forming a laminated covering or tube with plural layers, as may also be done with the other forms of the invention not formed of coils, but layers of sheet metal plied one on the other. Also, this form may be used with or without solid core 28, the inner coil serving as a hollow core.

The tube may be tempered as desired, and the core, especially of wood, can be coated or waxed to prevent moisture absorption, or the core may be treated in any suitable or known way for this purpose. Also, an adhesive may be used to fasten the tube to the core, especially where the tube is too thin to firmly grasp and conform to the core tightly and stay tightly thereon.

In Figure do, the tube 2'6 and core it are the same as in Figures 1, 2, 3 and 4, except that the joint may be a reinforcing and stiffening rib it, as in Figure 6, running longitudinally, and formed by a rolled lap or look joint 49 at the marginal edges of the metallic sheet or strip sealed at the inside at to hide and cover any raw or exposed edges of the strip.

In all forms, the element is of light weight, strong and rugged, an excellent conductor, except the core which may be a non-conductor, and which may be extended from the tube and utilized as an insulator. The laminated or covered core construction results in superior strength over a simple tube, and may be used in proper sizes or diameters and wall thicknesses, as a mast or cross support for antenna as in our co-pending application filed on even date herewith, or in stacking one antenna on another supported by cross support bars on the mast to which they are secured. Moreover, the core prevents the tube from crystallizing and breaking due to vibration and metal fatigue in wind, and since it is impossible for the tube to collect water on the inside to freeze and crack the element, as a result of condensation, as is the case with tubing alone, no flattening of the tube ends or use of plugs therein is necessary to seal the ends of the tube or give additional strength. The tubes can be fabricated as described by rolling or turning in connection with Figure 1, or by rolling in length or diameter by rolls or discs, or progressive dies, in a power press, and with the tube or casing completely or partially surrounding the core. The element may also be formed of a spring or group of laminated springs, one within and in contact with the other, and so wound as to be rigid enough to hold its own weight and more. The advantage is that a heavy ice load which would break or destroy a hollow tube, would cause such spring elements to sag instead of breaking or permanently bending, and when the ice melts, the element would return to its original straight and true rectilinear form.

While there is herein shown and described the preferred embodiment of the invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

What is claimed as new is:

As a new article of manufacture, an antenna {5 element for receiving short wave transmissions in the television, frequency modulation and ultra-short wave range, comprising an elongated electrical conducting tubular shell of uniform cross-section throughout its length and a dielectric core therein and snugly and tightly interfitting within the tube throughout their lengths, said shell being anchored at closely spaced points throughout its length to the core and being provided with longitudinal reinforcing and stiffening formations, said reinforcing and stiffening formations being ribs located on the core and channels within the shell snugly interfitting thereon and thereby completely filling the shell.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 469,663 Greenfield Feb. 23, 1892 1,305,104 Hewitt May 2'7, 1919 1,495,537 Stafford May 27, 1924 1,684,009 Brown Sept. 11, 1928 1,917,205 Horle July 4, 1933 1,981,090 Christman Nov. 20, 1934 2,160,258 Berliner May 30, 1939 2,412,249 Brown Dec. 10, 1946 2,440,597 Atwood Apr. 27, 1948 2,542,884 Trebules et al. Feb. 20, 1951 FOREIGN PATENTS Number Country Date 2,242 Great Britain May 18, 1911 of 1911 502,460 Great Britain Mar. 17, 1939

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