Antenna support structure

July 24, 1962

3,045,952

L. E. UNDERWOOD

ANTENNA SUPPORT STRUCTURE

Filed March 23, 1959

Sheets-Sheet 1

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FIG. 1

INVENTOR:

LAWRENCE E. UNDERWOOD

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ATTORNEYS

July 24, 1962

L. E. UNDERWOOD

ANTENNA SUPPORT STRUCTURE

3,045,952

Filed March 23, 1959

Sheets-Sheet 2

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LAWRENCE E. UNDERWOOD

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ATTORNEYS

United States Patent Office

3,045,952

Patented July 24, 1962

3,045,952

ANTENNA SUPPORT STRUCTURE Lawrence E. Underwood, 24296 Hesperian Blvd., Hayward, Calif.

Filed Mar. 23, 1959, Ser. No. 801,168

Claim. (Cl. 244—33)

The present invention relates to means for supporting antennas, and is particularly directed to lighter-than-air antenna support structure.

In very high frequency communications such as television, frequency modulation (FM) radio, radio link, and the like, the short wave length electromagnetic waves propagate substantially by line-of-sight. Hence any obstruction, for example a hill or tall building, positioned in a straight line path between the transmitting antenna and a receiving antenna intercepts the high frequency waves and distorts, and in some instances completely blocks reception of the signal. The foregoing is particularly true in television reception where the receiver may be in a hollow or other critical location defiladed from the transmitting antenna site.

In order to improve reception of very high frequency communications waves where obstructions are involved it is hence necessary that the antenna be placed in an unobstructed line of sight position high above the ground surface. To accomplish the foregoing various material rigid mast structures have been heretofore employed to support the antenna in elevated position. Such structures are seriously limited by various structural and economical considerations to relatively low heights; for example, of the order of thirty feet. In many instances the feasible height is not sufficient to provide optimum reception of the very high frequency waves. Moreover, such mast support structures are tedious and time consuming to erect.

The present invention overcomes the limitations and difficulties of conventional material mast antenna support structures by providing a lighter-than-air support structure which is capable of supporting an antenna at heights heretofore unrealizable, e.g., heights of 50 to 100 feet and even hundreds of feet.

It is accordingly an object of the present invention to provide antenna support structure which is capable of supporting antennas at extreme heights above the ground surface.

Another object of the invention is to materially improve the reception of line-of-sight communication signals in fringe reception areas.

Yet another object is the provision of lighter than air antenna support structure which is relatively simple and economical in its construction.

A further object of this invention is to provide antenna support structure which may be erected and lowered quickly and easily.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawing and description may be adopted within the scope of the invention as set forth in the claim.

FIGURE 1 is an elevational view of the lighter-than-air antenna support structure of the present invention in erected position.

FIGURE 2 is a plan view of this structure as viewed from plane 2—2 of FIGURE 1.

FIGURE 3 is a cross sectional view of a preferred embodiment of the balloon of the support structure.

Considering now the lighter-than-air antenna support structure of the present invention and referring to the drawing, the support structure is seen to generally comprise a lighter-than-air vehicle, preferably a balloon 11 filled with lighter-than-air material adapted for support5 ing connection to an antenna 12, and guyed in fixed position above the ground surface by a plurality of guy lines 13. The lighter-than-air material may be a gas such as, for example, helium.

The envelope 14 of the balloon 11 is best multi-ply 10 to the ends of durability and replaceability. More specifically, envelope 14, as illustrated in FIGURE 3, preferably comprises an inflatable plastic inner bladder 16 having a valve 17 at its lower extremes to facilitate filling with the lighter than air material. Inner bladder 16 is dis15 posed within a nylon bag 18 having a zipper opening 19 to permit insertion of the bladder. The intermediate bag 18 is in turn contained within an outer covering bag 21 made preferably from heavy canvas or the like. Outer bag 21 is similarly provided with a zipper opening 22 to 20 facilitate insertion of intermediate bag 18 and bladder 16 contained therein. The zipper openings 19 and 22 additionally facilitate ready access to valve 17 for the purpose of periodically replenishing lighter-than-air material to the bladder 16.

A pair of antenna support rings 23, 24 are secured in coaxial spaced relation to outer bag 21 on opposite sides of an equatorial buy fastening ring 26 secured thereto. The rings 23, 24, 26 may be imbedded in the outer bag 21 or otherwise rigidly fixed thereto. Rings 23, 24, 26 30 moreover are best fabricated from tubing of light weight structural material, such as aluminum, so as to be as light weight as possible. The antenna proper 12 may then be rigidly secured to rings 23, 24 as by means of support brackets 27 attached thereto and detachably connectable 35 to, for example, a short vertical post 28 secured at its end to the antenna.

The guy lines 13, of which there may be any desirable number, are secured to ring 26 as by brackets 29 at points of equal angular separation. In the instance of the four 40 guy lines depicted in the drawing, the lines are respectively separated by 90 degrees of arc in their connection to ring 26. Guy lines 13 then extend downwardly from the balloon 11 and are secured to the ground surface at points of corresponding angular separation.

In order that the lighter-than-air antenna support structure of the present invention may be readily and quickly erected and lowered for maintenance or in case of a severe storm, it is preferable that suitable controllable play-out means be employed in the securing of the guy lines to the ⁵⁰ ground surface. More specifically, a pulley 31 is secured to the ground surface as by means of a pier 32 rigidly mounted thereon at each of the guy line anchor points of equal angular separation at the ground surface. The planes of pulley 31 moreover are disposed to intersect at ⁵⁵ common center, i.e., the planes of the pulleys are radially disposed. A pier 33 is secured to the ground surface at the common center. A vertical shaft 34 is journalled to pier 33 as by means of vertically spaced-apart journal bearings 36, 37 secured thereto. A plurality of pulleys 38 60 corresponding to the number of guy lines 13 employed are in turn secured in coaxial juxtaposition to shaft 34 and means are provided to controllably rotate same. Such means may be, for example, a motor coupled in rotational driving relation to shaft 34 or as depicted in the 65 drawing, a manually operable hand crank 39 secured to the end of the shaft. The guy lines 13 respectively engage pulleys 31 and are led therefrom each to a different one of the pulleys 38 for rotatable engagement therewith. The shaft 34 may consequently be rotated to simultane70 ously play-out or pull-in guy lines 13 and hence functions as a winch or windlass. Upon playing out the guy lines 13 to the desired height of the antenna supporting balloon

3,045,952 above the ground surface, the balloon is retained in such position as by means of conventional braking means (not shown) engageable with shaft 34.

In order that the signal received by the antenna 12 may in turn be relayed to the ground surface, a conventional lead-in transmission line 41 is conductively connected thereto and trails downwardly therefrom. The transmission line 41 may be for example played-out simultaneously with the guy lines as from an additional pulley (not shown).

Considering now the operation of the lighter-than-air antenna support structure of the present invention, the inner bladder 16 of balloon 11 is first inflated with lighter than air material and the zippered openings of the intermediate and outer bags 18, 21 are closed. The antenna 12 is secured to support rings 23, 24 by post 28 and brackets 27. With guy lines 13 secured to the balloon 11 and in operable relation to pulleys 31 and 38, the winch shaft 34 is rotated to slowly and simultaneously play out the guy fines 13 as the balloon carries the antenna with transmission line 39 coupled thereto to an elevated position. Upon attaining the desired height above the ground surface, the shaft 34 is locked to prevent further rotation. The initial angular orientation of the antenna 12 may be appropriately varied as by interchanging pairs of guy lines in their relations to pulleys 31. In the case of four guy fines, the orientation may be thus changed in steps of 90 degrees of arc. The balloon 11 and antenna 12 affixed thereto may be withdrawn to the ground surface as desired for purposes of maintenance and the like merely by rotating shaft 34 in the reversed direction.

The present invention hence provides novel support means for the rapid and easy erection of antennas to heights heretofore unrealizable. In various embodiments of the invention, the antenna support structure may be employed for individual home use as well as for large groups of users such as entire towns and cities.