US3393480A - Antenna supporting tower and method of constructing same - Google Patents

Description

July 23, 1968 J. K. GROSECLOSE ET Al.

7 ANTENNA SUPPORTING TOWER AND METHOD OF CONSTRUCTING SAME Filed June 25, 1965 4 Sheets-Sheet 1 INVENTORS. J. K. GROSECLOSE BY 0.6. PELKEY v MAHONEY.

MILLER & RAMBO BY M J M,

ATTORNE Y5 July 23, 1968 J, GROSECLOSE ET AL 3,393,480

ANTENNA SUPPORTING TOWER AND METHOD OF CONSTRUCTING SAME Filed June 25, 1965 Sheets-Sheet 2 INVENTORSv J. K. GROSECLOSE BY 0.6. PELKEY B ms n m R E 0 M/m M M m W M July 23, 1968 J, GROSECLOSE ET AL 3,393,480

ANTENNA SUPPORTING TOWER AND METHOD OF CONSTRUCTING SAME Filed June 25, 1965 I 4 Sheets-Sheet 5 N junuqn [I] EECIIIII': I:II:

INVENTORS. J. K. GROSECLOSE 0.6. PELKEY BY MAHONEY. MILLER & RAMBO ATTORNEYS y 1968 J. K. GROSECLOSE' ET AL 3,393,480

ANTENNA SUPPORTING TOWER AND METHOD OF CONSTRUCTING SAME Filed June 25, 1965 4 Sheets-Sheet 4 0 ME 8 5 M o A. s QY W. WEE& N N SK R R ma %m Q GPU. A K.G. M w J.O. z m 4 wHw m d H H 4 4 5 5 Z 1 United States Patent ANTENNA SUPPORTING TOWER AND METHOD OF CONSTRUCTING SAME John K. Groseclose, Columbus, and Orville G. Pelkey, Worthington, Ohio, assignors to Dresser Industries, Inc.,

Columbus, Ohio, a corporation of Delaware Filed June 25, 1965, Ser. No. 467,003 11 Claims. (Cl. 52-40) ABSTRACT OF THE DISCLOSURE A tower structure for the support of television and/or radio antennas. The tower structure is of an industrial type suitable for outdoor installation and comprises a central main tower structure from which is cantilever supported at least one antenna supporting truss.

This invention relates to an antenna supporting tower and method of constructing same. It relates, more specifically, to towers of a type which include a central main support tower with one or more antenna support structures extending radially outwardly therefrom at the upper end thereof or other selected level.

Various tower structures have been provided in the prior art for supporting a plurality of antennas. The prior art tower structures employ a single main supporting tower, either guyed or free-standing, having a relatively complicated and heavy support platform arrangement, usually full platforms with knee-braces, at its upper end for supporting upstanding antennas at laterally spaced positions. Due to the nature of the support platform arrangement, it not only is expensive to fabricate but complicated and expensive methods and equipment are required to erect the platform structure or structures at the very high elevations to which these towers now commonly reach.

According to the present invention, the guyed or freestanding tower is provided with a simple, relatively light and inexpensive antenna support which may be termed an outrigger and which projects radially from the tower at a selected level, usually the top of the tower. A plurality of these self-contained supports are usually provided and are disposed at angularly spaced positions around the tower. Also, the outrigger support, according to this invention, preferably takes the form of a cantilever truss or beam which is secured in a special manner at its inner end to the tower structure itself,

The nature of the cantilever truss and the novel manner in which the inner end of the cantilever truss is to be connected to the tower, facilitates the hoisting of the truss and its connection to the tower at the proper level as well as the hoisting and positioning of the antenna in an upright-supported position adjacent to the outer end of the truss. Thus, the need for the heavy platforms and the appendage knee braces is obviated.

Various other objects and advantages of this invention will be apparent as this description progresses.

In the accompanying drawings, one example of the present invention is illustrated but it is to be understood that this is for illustrative purposes only as the invention may be embodied in many forms.

In these drawings:

FIGURE 1 is a perspective view of a guyed tower having an antenna supporting structure on the upper end thereof in accordance with the present invention.

FIGURE 2 is a schematic view in side elevation illustrating the hoisting of one of the trusses of this invention on the tower.

FIGURE 3 is a similar view showing the hinging of the truss to the tower.

Patented July 23, 1968 ice FIGURE 4 is a similar view with the truss connected and braced at an inclined position on the tower to facilitate positioning of the antenna thereon and showing the antenna being hoisted.

FIGURE 5 is a schematic view showing the antenna mounted in the receiving socket on the outer end of the truss in a position angled from the vertical.

FIGURE 6 is a view similar to FIGURE 5 but showing the antenna-supporting truss being adjusted into horizontal, fixed position.

FIGURE 7 is a view similar to FIGURE 6 showing the truss in horizontal position with the antenna vertical and illustrating the hoisting of another truss.

FIGURE 8 is a view similar to FIGURE 7 but showing the second truss in final antenna-supporting position.

FIGURE 9 is an enlarged horizontal sectional view taken at the position indicated at line 9-9 of FIGURE 8.

FIGURE 10 is an enlarged side elevational view illustrating the hinge and temporary brace structure at the inner end of the truss and showing the truss in its temporarity connected inclined position on the tower.

FIGURE 11 is a view similar to FIGURE 10 but showing the trussin its final horizontal antenna-suppotring position.

FIGURE 12 is an enlarged horizontal sectional view taken along line 12-12 of FIGURE 11.

FIGURES 13 is a fragmentary elevational view showing a means for attaching the lower end of one of the antennas to its supporting truss.

With reference to the drawings, in FIGURES l and 2 there is illustrated generally a tower structure in which the present invention is incorporated. The main support tower 20 may be of various types but is illustrated as being of a triangular configuration in horizontal cross section to present three fiat sides or faces 21 to each of which one of the outrigger antenna support structures 22, according to this invention, is attached at the upper end of the tower. This tower may be fabricated in any suitable manner and may have three or more sides. In the example shown, the tower is adapted to support three separate upright antennas 23, each of which is carried on the outer end of one of the Outriggers 22 so that the antennas will be laterally spaced apart selected suitable distances. However, various numbers of antennas can be supported on various towers in a similar manner. In the example illustrated, the lower end of the tower is mounted on a suitable foundation or footer 24 and guy wires 25 have their upper ends connected thereto at various levels with the lower ends of the guy wires being anchored by suitable anchoring arrangements indicated at 26.

The outrigger assemblies 22, according to this invention, are designed and constructed to facilitate erection into place on the tower 20 and connection to the tower, to facilitate mounting of the antennas on the Outriggers and finally to adequately support the antennas. As indicated previously, the Outriggers 22 are in the form of cantilever trusses or beams. They may be fabricated in various ways to provide a cantilever structure but in the example shown they are of substantially square cross section providing a box-girder eifect. The specific structure of these cantilever trusses is not too important to this invention as long as they provide adequate support for the antennas at their outer ends when their inner ends are connected to the tower and as long as the upper and lower corners, at the inner ends of the upper and lower chords of the trusses, are adequately spaced vertically to facilitate connection to the tower according to this invention. This connection, for each cantilever truss, as will appear in detail hereinafter, comprises a hinge joint at the upper corner which permits angular adjustment of the truss relative to the tower in a vertical plane, in

3 combination with a temporary strut or brace at the lower corner which permits temporary retention of the truss in a predetermined angular position. The details of this connection are illustrated best in FIGURES -12.

The hinge axis of the hinge joint (FIGURES 10 and 11) is indicated at 30 as comprising bolts and is horizontally disposed parallel to and slightly outwardly of the flat face 21 of the tower to which that particular truss 22 is connected. The hinge structure is shown as comprising a pair of upright bearing plates or gussets 31 (FIG- URE l0) welded or otherwise rigidly secured to the upper chord members 32 at the upper corners of the truss. The plates of each pair 31 are spaced laterally to provide a bifurcation having a space or socket which may be slipped over a single upright bearing plate or gusset 33 that is rigidly mounted on the tower and projects outwardly from the face 21 thereof at the respective vertical corner post 34 of the tower. When the plates 31 are slipped over the plates 33, transverse hinge bolts may be passed through aligning openings formed therein to provide the hinge connection. The respective plates 31 and 33 are provided with other openings which will align in the final relative positions of the plates to receive a plurality of locking and load-bearing bolts 36 (FIG- URE 11).

In the final position of each truss 22, the structure appears as in FIGURE 11 and in this position the lower corner of the truss is fixed to the face 21 of the tower 20 and with the truss in a horizontal position or normal to the vertical face 21. To permit this, the truss at this lower corner is provided at each laterally opposed corher with a pair of laterally spaced upright bearing or gusset plates 41 which are rigidly secured to the lower chord members 42 of the truss. These plates, with the truss in its final position, slip over the respective outwardly projecting upright plates 43 which are rigidly carried at the face 21 of the tower adjacent the corner posts 34 thereof. A main locking and bearing bolt 45a is passed through aligning openings in each set of cooperating plates 41 and 43, when they are in their final relative positions, and additional bolts 46 are passed through other aligning openings. This is the final connecting arrangement but before this final connection is made, it is desirable to use a temporary connecting strut arrangement for a purpose to be described in detail later. This temporary strut arrangement includes a pair of struts of the type indicated at 50 in FIGURE 10.

Each strut 50 comprises the sections 51 and 52 which telescope with each other for relative extension and retraction and are held in selectively adjusted position by means of a bolt 53 passed transversely through any of a series of aligning transverse openings laterally spaced along the sections. The strut section 51 is provided at its outer end with a clevis connector 54 which will straddle the projecting plate 43 on the tower face 21 and may be pivoted thereto by a transverse bolt 45a. The strut section 52 is provided at its outer end with an eye bar connector 55 which slips in between plates 41 and may be pivoted thereto by a transverse bolt 45b. A pair of these struts 50 can thus be used to brace the truss 22 at a selected angular position to which it is swung vertically about the hinge axis 30 but, as previously indicated, this is a temporary arrangement used during the erection of the antennas 23 in a manner to be described in detail.

The antennas 23 may be of any suitable type but usually are in the form of an elongated pole or shaft of circular cross section having an annular attaching flange 56 (FIGURE 13) at its lower end. Each outrigger cantilever truss 22 is provided with an upstanding antenna support adjacent its outer end which may be formed as a tubular member 60, which is upstanding from and suitably secured to a support plate 59 (FIGURES l and 13) that is suitably rigidly carried on the upper chord of the truss adjacent its outer end. This support member 60 may have an attaching flange 57 on its upper end for mating with the flange 56 on the lower end of the antenna. Attaching clamping bolts 58 may be passed through aligning vertical openings in the flanges 56 and 57 when they are mated.

The hoisting of the various trusses 22, their connection to the main tower 20 at its upper end, and the hoisting of the antennas 23 and the positioning of each on a respective outrigger truss 22 is illustrated diagrammatically in FIGURES 2 to 8, inclusive.

The main tower 20 is erected in any suitable manner and the outrigger truss assemblies 22 may then be hoisted into position as indicated in FIGURE 2 merely by the use of the normal cradled gin pole P which extends from the upper end of the tower 20. The outrigger assembly 22 is hoisted by means of a load line L extending downwardly from the sheave S at the top of the gin pole, the lower end of the line L being connected to the upper chord of the assembly 22 at a point C. A control or tag line T is connected to the assembly 22 so that as the assembly is hoisted it can be prevented from contacting with the tower face 21 and can be tilted downwardly and inwardly towards the associated face 21 of the tower. Obviously, the gin pole is cradled adjacent that face 21 of the tower to which the particular assembly being hoisted is to be connected. The outrigger assembly 22 is raised to the position indicated in FIGURE 3 until the hinge connection may be made at the hinge axis 30, this connection being made by inserting the hinge bolts 30 previously referred to in the aligning openings in the cooperating sets of plates 31-31 (FIGURE 11). At this time, the assembly 22 will be tilted upwardly from the horizontal about the hinge axis 30 as indicated in FIGURE 3. When in this tilted angular position, the temporary struts 50 are inserted at the lower corners and are fastened in place by the bolts 45a and 45-12 which connect them respectively to the tower 20 and assembly 22.

The antenna 23 is now hoisted as indicated in FIG- URE 4. For this purpose, the load line L is connected to the antenna at a point G which is slightly above the center of gravity G of the antenna. A tag line T is also attached at the point G and will be used for controlling the position of the antenna during hoisting to prevent contact with the face 21 of the tower and to move it laterally to one side of the angled assembly 22 as it passes upwardly beyond that assembly. Another tag line T is attached to the upper end of the antenna 23, as indicated in FIGURE 5, and can be used for swinging it about the point G to cause the antenna 23 to axially align with the antenna support member 60 which projects upwardly from the assembly 22. Also, a workman may climb out on the assembly 22 and by grabbing the lower end of the antenna 23 can aid in axially aligning it with the member 60. When properly aligned, the attaching flange 56 on the lower end of the antenna 23 can be mated with and fastened to the attaching flange 57 on the upper end of the member 60 by means of the bolts 58. Obviously, the assembly 22 is initially adjusted and held by the temporary struts 50 at such an angle that as the suspending point G on the antenna 23 approaches the sheave S at the top of the gin pole P, the antenna can be swung into a position where it is at a right angle to the angularly disposed assembly 22 or, in other words, the antenna and the member 60 are axially aligned. With the antenna 23 securely fastened on the support member 60, the struts 50 may now be removed. When the struts 50 are removed, the tension on the line L may be relieved to permit downward pivoting of the antenna supporting assembly 22 about the hinge axis 30, as indicated in FIGURE 6, until it reaches its final horizontal position which is indicated in FIGURE 7 at which time it may be locked in position by the bolts 45a (FIG- URES 11 and 12). Thereafter, the assembly 22 will function as a cantilever beam or truss. As indicated in FIGURES 7 and 8, a second outrigger assembly 22 may be raised in a similar manner and attached to a different face 21 of the tower. This operation may be repeated for the third assembly.

In case it is desirable to replace any of the antennas 23, it is preferred that the erection operation just de scribed be reversed to facilitate removal and lowering of the antenna 23. In this case, the assembly 22 would be hinged upwardly about the hinge axis 30 to the position indicated in FIGURE 5 and held in such position by the inserted struts 50 and the antenna would be removed and lowered by a reversal of the steps as illustrated in FIGURES 5, 4, 3, and 2, successively.

It will be apparent from the above description that this invention provides an antenna supporting tower which, instead of using full platforms with knee braces for supporting the various antennas in laterally spaced relationship, uses separate outrigger assemblies to obtain the separate spacing. These Outriggers are hinged and designed in such a way as to be erectable from the normal cradled gin pole in the tower. Each outrigger assembly, when in its final position connected to the tower, is a self-supporting cantilever structure which will adequately support, without bracing, the weight of the antenna disposed on its outer end. With this outrigger arrangement, there is a reduction in platform cost, supporting structure cost, and considerable cost improvement in erection.

According to the provisions of the patent statutes, the principles of this invention have been explained and have been illustrated and described in what is now considered to represent the best embodiment. However, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

Having thus described this invention, what is claimed 1. An antenna supporting structure comprising a main tower disposed in upright vertical position, a cantilever truss having upper and lower chords and inner and outer ends, means connecting the inner end of the truss to the main tower, said means including a hinge bolt having a horizontally disposed axis transverse of the truss between the tower and the end of the truss at the upper chord permitting vertical angularity thereof and a locking means between the end of the tower and the truss at the lower chord, said truss having antenna-supporting means on its upper chord adjacent its outer end.

2. The combination of claim 1 including a temporary brace structure for cooperating with said locking means and insertable between the tower and the truss to hold said truss in an adjusted position about said hinge axis.

3. An antenna structure comprising a main tower disposed in upright vertical position, a plurality of canti lever trusses spaced angularly around the tower, each of said trusses having upper and lower chords and inner and outer ends, means connecting the inner end of each truss to the main tower, said means including a hinge bolt having a horizontally disposed axis transverse of the truss between the tower and the end of the truss at the upper chord permitting vertical angularity thereof, and a locking means between the tower and the end of the truss at the lower chord, each of said trusses having antenna-supporting means on its upper chord adjacent its outer end, and an antenna connected to each of said supporting means in upright position so as to provide a plurality of laterally spaced antennas.

4. The combination of claim 3 including a temporary brace structure for cooperating with each of said locking means and insertable between the tower and the truss to hold said truss in an adjusted position about said hinge axis.

5. An antenna-supporting structure comprising a main tower disposed in upright vertical position, a cantilever truss having upper and lower chords and inner and outer ends, means for connecting the inner end of the truss to the main tower, said means including a hinge structure having a horizontally disposed axis transverse of the truss between the tower and the end of the truss at the upper chord and a locking structure between the tower and the end of the truss at the lower chord, said hinge structure comprising upright overlapping plates extending in opposite directions respectively from the tower and the upper corner of the truss with hinge bolts extending transversely through aligning openings therein, said locking structure comprising upright overlapping plates extending in opposite directions respectively from the tower and the lower corner of the truss with locking bolts extending transversely through aligning openings therein, said truss having antenna-supporting means on its upper end adjacent its outer end.

6. An antenna-supporting structure according to claim 5 comprising a temporary strut having clevis connections on its outer ends for cooperating with the plates of the locking structure respectively carried on said tower and truss, said connections having openings for alignment with openings in the respective plates for receiving connecting bolts.

7. An antenna-supporting structure according to claim 6 in which said strut is composed of relatively adjustable telescoping sections having means cooperating therewith for holding the sections in selected relatively adjusted positions.

8. The method of erecting an antenna on an upright supporting tower which comprises providing the tower with truss hinge-connecting means at a selected level, providing a cantilever truss, having hinge-connecting means on its inner end and antenna-supporting means on its outer end; hoisting said truss along the tower to said selected level and hinging the truss to the tower for vertical swinging movement relative to the tower by moving the hinge means on the respective tower and truss into cooperative relationship to provide a transverse horizontal hinge axis; positioning said truss about said hinge axis in an outwardly and upwardly inclined position relative to the tower and temporarily fastening the truss in said inclined position; raising an elongated antenna along the tower to a level above that of the truss by means of a load line passing around a sheave supported by the tower above the level of the truss and connected to the antenna with a pivotal connection; swinging the antenna about said pivotal connection until it is axially aligned with said antenna supporting means on the outer end of the truss; fastening the antenna to said supporting means; and adjusting the truss downwardly about said hinge axis into horizontal position where said antenna supported thereby is upright.

9. The method of erecting an antenna on an upright supporting tower which comprises providing the tower with truss hinge-connecting means at a selected level, providing a cantilever truss, having hinge connecting means on its inner end and antenna-supportig means on its outer end; hoisting said truss along the tower to said selected level and hinging the truss to the tower for vertical swinging movement relative to the tower by moving the hinge means on the respective tower and truss into cooperative relationship to provide a transverse horizontal hinge axis; positioning said truss about said hinge axis in an outwardly and upwardly inclined position relative to the tower and temporarily bracing the truss in said inclined position by a strut extending between the tower and the truss, raising an elongated antenna along the tower to a level above that of the truss by means of a load line passing around a sheave supported by the tower above the level of the truss and connected to the antenna with a pivotal connection intermediate the upper and lower ends of the antenna; swinging the antenna about said pivotal connection until its lower end is axially aligned with said antenna-supporting means on the outer end of the truss; fastening the lower end of the antenna to said supporting means so that it will be supported in a position at an angle relative to the vertical; removing the strut from its bracing position between the truss and the tower; adjusting the truss downwardly about said hinge axis into horizontal position where said antenna supported thereby is upright and connecting said inner end of the truss to the tower to prevent movement of the truss about said hinge axis.

10. The method of erecting an antenna on an upright supporting tower which comprises providing the tower with truss-connecting means at its upper end and which includes hinge means and hinge-locking means at ditferent levels; providing a cantilever truss having inner and outer ends and upper and lower vertically spaced chords with hinge connecting means at its inner end at the upper chord and hinge-locking means at its inner end at the lower chord and with antenna fastening and supporting means on the upper chord adjacent its outer end; hoisting said truss by means of a gin pole, extending upwardly from the upper end of the tower and having a sheave about which a line passes and which is pivotally connected to the truss intermediate its ends at its upper chord, to a level to permit movement of the hinge means on the respective tower and truss into cooperative relationship to provide a transverse horizontal hinge axis; swinging said truss about said hinge axis to an outwardly and upwardly inclined position relative to the tower and inserting a brace strut between the hinge locking means carried respectively on the tower and the inner end of the truss to retain the truss temporarily in said inclined position; providing an elongated antenna with fastening means at its lower end and raising the antenna along the tower, by a line passing around said sheave of the gin pole and connected to the antenna at a pivot point intermediate its upper and lower ends, to a level above that of the inclined braced truss; swinging the antenna about said pivotal connection to axially align the antenna-fastening means on its lower end with the antenna-fastening and supporting means on said truss and securing the cooperating fastening means together so that the antenna will be supported in a position substantially normal to the upper chord of the truss but at an angle relative to the vertical; removing the brace strut and lowering the outer end of the truss so that it is in a substantially horizontal position with the antenna substantially upright and so as to move said locking means on the respective tower and inner end of the truss into cooperative relationship.

11. The method of erecting an antenna on an upright supporting tower which comprises providing the tower with truss-connecting means at its upper end and which includes projecting hinge means and projecting hinge-locking means at diiferent levels; providing a cantilever truss having inner and outer ends and upper and lower vertically spaced chords with projecting hinge means at its inner end at the upper chord and projecting hinge-locking means at its inner end at the lower chord and with upstanding antenna fastening and supporting means on the upper chord adjacent its outer end; hoisting said truss by means of a gin pole, extending upwardly from the upper end of the tower and having a sheave about which a line passes and which is pivotally connected to the truss intermediate its ends at its upper chord, to a level to permit movement of the projecting hinge means on the respective tower and truss into overlapping cooperative relationship to provide a transverse horizontal hinge axis; swinging said truss about said hinge axis to an outwardly and upwardly inclined position relative to the tower and inserting a brace strut between the projecting hinge locking means carried respectively on the tower and the inner end of the truss and connecting said strut thereto to retain the truss temporarily in said inclined position; providing an elongated antenna with fastening means at its lower end and raising the antenna along the tower, by a line passing around said sheave of the gin pole and connected to the antenna at a pivot point intermediate its upper and lower ends but slightly above its center of gravity, to a level above that of the inclined braced truss; swinging the antenna about said pivotal connection to axially align the antenna-fastening means on its lower end with the upstanding antennafastening and supporting means on said truss and securing the cooperating fastening means together so that the antenna will be supported in a position substantially normal to the upper chord of the truss but at an angle relative to the vertical; removing the brace strut and lowering the outer end of the truss so that it is in a substantially horizontal position with the antenna substantially upright and so as to move said projecting locking means on the respective tower and inner end of the truss into overlapping cooperative relationship and connecting said overlapping locking means by means of locking pins passed through aligning openings therein.

References Cited UNITED STATES PATENTS 1,815,598 7/1931 Stroup 52-697 X 2,581,123 1/1952 Merkle 343-882 X 2,906,379 9/1959 Smalley 52697 2,963,125 12/1960 Finneburgh 52-697 3,158,866 11/1964 Powers 343882 FOREIGN PATENTS 1,049,696 12/1953 France.

427,137 1/ 1923 Germany.

363,112 12/1931 Great Britain.

FRANK L. ABBOTT, Primary Examiner.

P. C. FAW, Assistant Examiner.

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