Guyed tower for microwave horns

Dec. 22, 1970 r. j. ererle 3,550,146

GUYED TOWER FOR MICROWAVE HORNS

Filed March 1, 1967 6 Sheets-Sheet 1

<img file="US3550146A_D0001.tif" />

BY . „

ATTORNEYS

Dec. 22, 1970 r. j. eberle 3,550,146

GUYED TOWER FOR MICROWAVE HORNS

Filed March 1, 1967

Sheets-Sheet

<img file="US3550146A_D0002.tif" />

Dec. 22, 1970

R. J. EBERLE

3,550,146

GUYED TOWER FOR MICROWAVE HORNS

Filed March 1, 1967

Sheets-Sheet 3

<img file="US3550146A_D0003.tif" />

ATTORNEYS

Dec. 22, 1970

R. J. EBERLE

3,550,146

GUYED TOWER FOR MICROWAVE HORNS

Filed March 1, 1967

Sheets-Sheet 4

<img file="US3550146A_D0004.tif" />

ATTORNEYS

Dec. 22, 1970

R. J. EBERLE

3,550,146

GUYED TOWER FOR MICROWAVE HORNS

Filed March 1, 1967

Sheets-Sheet 5

<img file="US3550146A_D0005.tif" />

<img file="US3550146A_D0006.tif" />

ATTORNEYS

Dec. 22, 1970 r. j. eberle 3,550,146

GUYED TOWER FOR MICROWAVE HORNS

Filed March 1. 1967 6 Sheets-Sheet 6

<img file="US3550146A_D0007.tif" />

<img file="US3550146A_D0008.tif" />

FIG. IO

INVENTOR.

RICHARD J. EBERLE

BY ' - ATTORNEYS

3,550,146

Patented Dec. 22, 1970

United States Patent Office

3,550,146

GUYED TOWER FOR MICROWAVE HORNS Richard J. Eberle, Gywnedd Valley, Pa., assignor to Stainless, Inc., North Wales, Pa., a corporation of Pennsylvania

Filed Mar. 1,1967, Ser. No. 619,807

Int.CI. HOlq 21/00,1/12

U.S. Cl. 343—879 7 Claims

ABSTRACT OF THE DISCLOSURE

A guyed tower for supporting microwave horns having three platforms. The upper two platforms accept three horns each at 120° spacing over full 360°. A third platform is provided for passive devices. Tower includes adjustable wave guide supports and wave guide bridge.

Guyed and self-supporting antenna towers have here- 20 tofore been constructed and used. Such towers are normally designed and built for a specific use with little or no thought being given to the provision of a tower with sufficient flexibility that it can be modified to take on additional electronic handling characteristics once 25 it is completed. The present invention relates to a guyed micro wave tower which is designed to support between 1 and 6 microwave horns. The number of horns can be changed at any time after the tower has been completed. Thus, the present invention provides a tower which per- ³⁰mits expansion of facilities in the future with only moderate additional costs as compared to the cost of completely redesigning and erecting a new tower.

The present invention relates to a guyed microwave tower in the range from 100 to 400 feet which is capable 3a of meeting the high specification and standards set forth by the telephone companies. The tower includes an upper and lower platform for mounting three horn reflector antennas each. The reflectors are mounted at angles of 120° on their respective platforms, and the upper and lower platforms are displaced 60° with respect to each other. Thus, when a tower carries a full complement of six horn reflectors, they cover a full 360° at spaced angles of 60°.

A third platform is provided for supporting passive re- _4gSectors if desired. The tower is so designed so that it can be initially constructed with one platform with provision for adding the second platform at a later time.

Adjustable wave guide supports are provided and a novel bridge structure adjacent the transmitter building is provided for supporting and protecting the wave guides.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this inven- ₅₅tion is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is an elevational view of a guyed tower constructed in accordance with the present invention and including a wave guide bridge structure for supporting θθ the wave guides into a transmitter building.

FIG. 2 is a top plan view of the upper platform illustrated in FIG. 1 taken along the line 2—2.

FIG. 3 is a partial sectional view of the platform illustrated in FIG. 2 taken along the line 3—3. eg

FIG. 4 is a top plan view of the lower platform illustrated in FIG. 1 taken along the line 4—4.

FIG. 5 is a partial perspective view of the tower structure.

FIG. 6 is a plan view of the tower structure illustrated 70 in FIG. 5 taken along the line 6—6.

FIG. 7 is a partial sectional view of the flange con- nection for the vertical supporting member illustrated in FIG. 1 taken along the line 7—7.

FIG. 8 is a partial sectional view illustrating the adjustable wave guide support of FIG. 5 taken along the line 8—8.

FIG. 9 is a plan view of the wave guide supporting bridge.

FIG. 10 is a sectional view of the wave guide supporting bridge illustrated in FIG. 9 and taken along the line 10—10.

Referring now to the drawings in detail, wherein like numerals indicate like elements, there is shown in FIG. 1 a guyed microwave horn reflector tower designated generally as 10.

As shown, the tower 10 is vertically supported on a base 12 and laterally supported by one or more levels of guy wires. By way of example, three levels 14, 16 and 18 are shown. The guy wires 14, 16 and 18 extend from the vertical tower members to be described below and are anchored as at 20. The base 12 and anchors 20 are conventional. Accordingly, they will not be described in detail. The special saddle connection between the guy wires and the tower is described below.

The tower 10 is constructed to support six microwave horn reflectors such as the reflectors 22, 24 and 26. The reflectors 22, 24 and 26 form no part of this invention and will not be described in detail except to indicate that their function is to reflect and transmit microwaves. Each of the reflectors is connected to a wave guide, such as wave guides 28 and 30, which pass through wave guide restrainers supported on the tower 10 and a wave guide bridge 34 into the transmitter building 36.

Referring now to the remaining figures of the drawing, the tower 10 will be described in detail.

FIGS. 2 and 3 illustrate the uppermost platform 38 and the supporting structure therefor, as well as a detailed view of the support for horn reflector 24. The platform illustrated in FIG. 2 is shown with the grating in position except on one of the legs wherein it has been removed to show the detail of the structural elements.

As shown, the upper platform 38 is constructed to define three legs 40, 42 and 44 extending from the central tower 10 at angles of 120° with respect to each other. Each leg is constructed by fixing a plate, such as gussets 46, 48 and 50 to one of the vertical support members 52, 54 and 56. The main frame is defined by channel members 58, 60 and 62 which are bolted or otherwise fixed to the gussets 46, 48 and 50 to define a triangle rotated 60° from the triangle defined by the vertical support members. Extending outwardly from the channel member 58 are a pair of parallel channel members 64 and 66 which are joined to the gussets 68 and 70. A channel member 72 extends across the channel members 64 and 66 and is also joined to the gussets 68 and 70. Outer angle members 74, 76, 78, 80 and 82 are joined endwise and to the channel members 58, 64, 66, and 72 to define the outer perimeter of the platform leg 42. Angle members 84 and 86 extend at an angle from gussets 68 and 70 to gussets 88 and 90. Similar angle members such as 92 and 94 are provided for each of the platform legs so that when completely assembled, they define a triangle support with sides generally parallel to the side 10. This latter triangle is not a true triangle in the sense that the angle members defining its sides do not join each other to form the triangle apices.

The leg 42 described above is constructed to support a horn reflector within the opening defined by the angle members 64, 66, 72 and 96. The parallel angle members such as 64-74; 72-78; and 66-82 are adapted to receive

3,550,146 removable gratings illustrated schematically as 98 on which a workman can move about the horn microwave reflector.

Referring now to FIG. 3, a sectional view of the platform leg 40 illustrates the manner in which the horn reflector is supported. Leg 40 is identical with previously described leg 42. Accordingly, like elements have been designated with like numerals except a prime has been added. In addition, FIG. 3 illustrates how the safety railing 100 is supported over the perimeter of the platform 38 by posts 102 which are connected to the outer angle members.

The platform leg 40 receives additional support by means of the angle member 104 which extends outwardly from a gusset 106 that is fixed to the vertical support member 56. At its opposite end it is fixed to a gusset 108 depending from the angle member 66. As shown in FIG. 2, a similar angle member 110 extends from the post 52 to the angle member 64.

The horn reflector 24 extends through the opening in the platform leg 40 and is supported therein by conventional means which are not shown.

The entire platform 38 is constructed so that it can be partly or wholly assembled at ground level and then hauled to the top of the tower for installation. If the tower is originally intended for use for three or less horn reflectors, then the upper platform is not installed. However, if additional facilities are needed, then the platform can be assembled and mounted at the top of the tower to provide support for three additional horn reflectors. It should be noted that the longitudinal axis of each leg 40, 42 and 44 of the platform 38 extends outwardly from the vertical supporting members 52, 54 and 56. As will be explained below, central longitudinal axes of the legs of the lower platform extend outwardly from the center of the sides defined by the tower structure. Thus, the legs of the lower platform are displaced 60° from the legs of the upper platform.

The structure of lower platform 114 is generally similar to that of upper platform 38. Thus, it is constructed to define three platform legs 116, 118 and 120 at angles of 120° with respect to each other. Since all three legs are similarly constructed, only leg 120 will be described in detail.

As shown, channel members 122 and 124 extend outwardly from gussets 126 and 128 fixed to the vertical support members 48 and 56. A channel member 130 extends between channel members 122 and 124 and is fixed in common with them to the gussets 132 and 134. A similar channel member 136 extends between and is fixed to channel members 122 and 124 as well as to gusset 138. Channel members 122, 124, 130 and 136 define an opening in which a horn reflector can be supported. Reinforcing angle members 140 and 142 extend from gussets 126 and 128 to gusset 138. Channel members 144 and 146 extend from channel members 122 and 124 to gussets 148 and 150 and angle members 152 and 154 extend from gussets 148 and 150 to gussets 126 and 128.

Gussets 148 and 150 are fixed to channel members 156 and 158 which are common to leg 120 as well as legs 116 and 118. Angie members 160 and 162 extend from channel members 156 and 158 and are joined by angle member 164. Angle member 164 is in turn fixed to angle members 168 and 170 and to channel members 166 and 172 which extend between it and gussets 132 and 134. Parallel members 122-162; 130-164; and 124-160 are fitted with removable grating plates 174 which provide a walking surface on the platform for workmen.

Each leg of the platform 114 receives vertical support by parallel angle members 176 and 178 which extend upwardly and outwardly from the vertical support members 52 and 56 to the gussets 132 and 134.

The perimeter of platform 114 is bounded by a safety railing 180 which is supported by posts extending upwardly from the outermost angle members.

A horn reflector 182 is shown mounted in the opening in leg 116. No reflector is mounted in leg 118. Accordingly, the opening is shown covered by removable gratings 184 and 186.

Lower platform 114 is permanently fixed to the tower 10 and would be constructed with such a tower regardless of the number of reflectors to be supported by it.

Referring now to FIGS. 5 and 6, there is shown a detailed view of the tower structure. The primary tower support is provided by vertical support members 52, 54 and 56 which are preferably 3¼ inch diameter solid steel rods bolted together in .25 foot lengths as shown in FIG. 7. A flange 188 is welded to the lower vertical member 54α and a flange 190 is welded to the upper vertical member 54b. The flanges 188 and 190 are spaced approximately Vs of an inch away from the end surface of the vertical members 54α and 54b. Thus, a gap 192 of approximately of an inch appears between the flanges 188 and 190 when the vertical members 54α and 54b are brought into abutment. Four bolts 194 hold the flanges 188 and 190 together. The advantage of providing a gap between the flanges is so that the vertical members 54α and 54b can be held tightly together when the bolts 194 are drawn up.

Gusset plates are welded at regular intervals along the length of the vertical members 52, 54 and 56. In the preferred embodiment, the 25-foot vertical sections have sets of gusset plates mounted at each end and at intervals of six feet three inches. Typical sets of gussets are illustrated in FIGS. 5 and 6. Each set of gussets includes two plates 196 and 198 welded to the vertical members so as to define an angle of 60° betwen their planar surfaces. Typical sets of gussets including gusset plates 196, 198, 200, 202, 204, 206, 208, 210, and 212, 218 are illustrated in FIGS. 5 and 6.

Cross members are provided at each level defined by the three sets of gussets. As shown in FIGS. 5 and 6, the cross members are designated by the numerals 216, 218 and 220 at one level and by the numerals 222, 224 and 226 at the next higher level.

Each cross member consists of a pair of angle pieces 228 and 230 bolted back-to-back on either side of a gusset plate. Thus, the angle pieces 228 and 230 shown in FIG. 6 are bolted at their ends to the gusset plates 196 and 200 and with their dependent angle plates at the top and extending laterally outward. The cross members are thus assembled to provide lateral internal support for the vertical members 52, 54 and 56.

Extending diagonally between each two sets of gussets are crossed tension rods to truss the tower and provide the necessary rigidity. FIG. 5 illustrates the manner in which the tension rods are positioned. Thus, tension rod 232 is bolted to gusset 196 and extends diagonally to gusset plate 208. Similarly, tension rod 234 is bolted to gusset plates 200 and 204. In a similar manner, identical tension rods extend between gusset plates on each side of the tower as defined by the vertical members 52, 54 and 56. Each tension rod is locked to its mate by a locking device 238. Such locking devices are conventional. One such device is readily obtained in a market under the name “Wrap Lock.”

As shown in FIG. 1, the wave guides 28 and 30 depend downwardly from the microwave horns 24 and 22. In accordance with the principles described herein, the wave guides for each of the horns are unsupported except at the horns and at the bridge 34. Intermediate of these support points, the wave guides are merely restrained by the wave guide restrainers 32. One such wave guide restrainer 32 is illustrated in FIG. 8. As shown, the restrainer 32 includes a collar 240 which is clamped to the vertical support member 54 by bolts (not shown). An arm 242 is welded to the collar 240 and extends laterally therefrom. An extension arm 246 is bolted to arm 242 by bolts 248 which extend through slotted holes so as to provide adjustment for the overall combined extension of arms 242 and 246.

3,550, 5

A cylinder 250 is fixed to the distal end of arm 256 by means of a releasable wire clamp 252. Cylinder 250 is flared at its end as shown.

The wave guide 30, whose outer diameter is substantially smaller than the inner diameter of cylinder 250 _ passes through it and is loosely restrained thereby.

As shown in FIG. 1, the wave guide restrainers attached to the vertical support members 52, 54 and 56 are positioned at every other level of cross arms. The amount of the lateral extension for the wave guide restrainers 32 is ₁₀dictated by conventional electronic principles for wave guides. The principles for correctly arranging the curvature of the wave guide are well known and therefore need not be discussed in detail. However, the use of adjustable wave guide restrainers permits the curvature to be pre- 13 cisely adjusted so as to obtain maximum transmission efficiency.

As illustrated in FIG. 1, and also in FIG. 5, the guy wires are bolted to gussets 254 which are welded to the vertical support members 52, 54 and 56. Intermediate the 20 terminal socket 258 on each guy wire and the gusset 254 is a saddle member 256. Saddle member 256 comprises a pair of spaced apart side pieces 258 and 260 which are fixed in position by top and bottom plates 264 and 266 that are welded thereto. The spacing between side pieces 25 258 and 260 is substantially wider than the width of one of the wave guides such as wave guide 28. Thus, the wave guides can extend freely along the length of the tower defined by the vertical support members without interference with the guy wires. ³⁰

Saddle member 256 is connected to the terminal socket 258 and gusset 254 by pins 270 and 268 which extend therethrough and are held in position by cotter pins or the like.

The foregoing describes the means for supporting and 35 restraining the wave guides which depend from microwave horns mounted on the uppermost platform. As explained above, the uppermost platform legs 40, 42 and 44 extend outwardly from the apices of the triangle defined by the vertical support members 50, 52 and 56. ⁴⁰On the other hand, the legs for the lower platform 114 extend outwardly from a point intermediate the sides of the triangle defined by the vertical support members 52, 54 and 56.

To guide and restrain the wave guides which depend 45 from the horns mounted on the lower platform 114, a support has been provided at every other level of cross members.

One such support is illustrated in FIG. 5 wherein three angle members 272, 274 and 276 are shown mounted on 50 the cross members 216, 218 and 220. The angle members 272, 274 and 276 are mounted so as to define a triangle with its apices extending from and disposed intermediate the sides of the triangle defined by the cross members 216, 218 and 220. Stated otherwise, the apices of the tri- 55 angle defined by the angle members 272, 274 and 276 define an included angle of 60° with the apices defined by the cross members 216, 218 and 220.

As best shown in FIG. 6, angle members 272, 274 and 276 are joined at their apices by braces 278 and 280. 60 The braces extend between adjacent angle members and also serve to support the inner arm 242 for a wave guide restrainer 32. Only the arms 242 are shown inasmuch as the remainder of the wave guide restrainers 32 which are attached to the angle members are identical with those 65 shown in FIG. 8.

The angle members 272, 274 and 276 also serve another function. A ladder 282 is fixed to them and thereby supported within the tower structure. If desired, gratings 284 can be mounted at the various levels for providing a 70 space upon which a workman can stand to adjust the wave guide restrainers.

Tn the preferred embodiment, the tower 10 is provided with a third platform 290 for supporting additional electronic reflectors if desired. In the preferred embodiment, 75

146 the platform 290 is in reality three levels 292, 294 and 296 which are identical in structure and spaced approximately six feet above each other. The levels are constructed by providing a triangular shaped member attached to the vertical support members 52, 54 and 56 and then additional brace members are attached to the triangular member. The additional members define the perimeter of each platform level in the shape of a hexagon.

An additional feature of the present invention, a truss bridge structure is provided for supporting the wave guides from the tower 10 into the transmitter building 36.

As shown in FIGS. 9 and 10, the wave guide bridge 34 surrounds the tower 10 at its base 12. The bridge structure 34 is spaced from the tower 10 by a distance equal to the distance of the wave guides 300 from the tower. By way of example, six wave guides 300 have been illustrated as if the tower 10 were supporting six microwave horns.

The bridge 34 is supported on four braced legs 302, 304, 306 and 308 which are fixed to reinforce concrete footings 310, 312, 314 and 316. The legs 302-308 are in the nature of truncated A frames which support the bridge trusses 318, 320 and 322 as well as the cross trussses 324. 326 and 328.

All of the trusses are constructed of angle pieces assembled to define rectangular tunnels such as tunnels 330 and 332 in trusses 318 and 320. As shown in FIG. 1, appropriate cross bracing is provided for maintaining rigidity in the bridge trusses. The top of each bridge truss is fitted with cover plates 334.

Appropriate clamps for the wave guides 300 are provided to support wave guides as they extend into the opening 336 in the transmitter building 36.

The bridge 34 provides functional rigidity for supporting the wave guides at the ground level. Although the bridge is shown as supporting only six wave guides, it is designed to support as many as twenty-four wave guides when necessary.

The foregoing description of the structural details should make the advantages of the tower 10 readily apparent. Among the advantages are the fact that the tower can be assembled in twenty-five foot sections at ground level. Thereafter, the sections can be raised and bolted into position. All elements in the tower are bolted together to further simplify the assembly and erection. Another advantage as explained before, is the modular construction that allows for the installation of a first platform for supporting three microwave horns and then a second platform for supporting an additional three microwave horns when added facilities are required.

The use of a guyed tower in communications is an additional advantage because of its economy. Moreover, the guyed tower of the present invention more than meets the necessary rigidity required in telephone communication. The structure of the present invention is capable of withstanding wind velocities of over 112 miles per hour; or stated otherwise, 50 pounds per square foot wind load. The rigidity of the tower at 20 pounds per square foot (70 m.p.h.) is as follows.

Deflection plus or minus 0.25 °

Twist plus or minus 0.50 °

To obtain the design specifications, the vertical support members are 3¼ inch diameter solid steel. The cross members are 2 x 2½ x %e angle steel and the tension rods are % of an inch in diameter. All gusset plates for supporting the cross members and tension rods are Vz inch steel. The upper guy wires attached to the bottom of the lower platform have a test strength of 150,000 pounds and the lower guy wires have test strengths of approximately 80,000 pounds.

The tower is relatively light in relation to its load capacity which includes three microwave horn reflectors

3,550,146 on the top platform and three microwave horn reflectors on the lower platform as well as a capacity for two 8 x 12 passive reflectors on the platform 290. Each set of three horn reflectors covers a full 360°.

The present tower is designed to provide top platform heights ranging from 100 to 400 feet in multiples of 12 feet 6 inches.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.