US 2844819 A
Description (OCR text may contain errors)
July 22, 1958 J. ANDREWS 2,844,819
GUIDE ARM FOR RADIO TOWER OR THE LIKE 2 Sheets-Sheet -1 v Filed Jan. 14, 1957 JOHNNIE ANDREWS v INVENTOR BY M ATTORNEY July 22, 1958 ANDREWS 2,844,819
GUIDE ARM FOR RADIO TOWER OR THE LIKE 2 Sheets-Sheet'Z Fil ed Jan. 14, 1957 JOHNNIE ANDREWS INVENTOR ATTORNEY United States Patent "ice 2,844,819 GUIDE ARM FOR RADIO TOWER OR THE LIKE Johnnie Andrews, Fort Worth, Tex. Application Januaryl l, 1957, Serial No. 634,116
' 2 Claims. (Cl. 343-874) This invention relates to microwave relay installations for transmitting highfrequency radio signals, and has reference to tower constructions such as referred to in my Patents Nos. 2,583,287, dated January 22, 1952, and 2,605,417, dated July 29, 1952. The present application is a continuation of my application Serial No. 232,995, filed June 22, 1951, co-pending with both of the above patents.
In installations of the type referred to, it is necessary to keep the antenna reflectors on adjacent towers beamed toward each other at all times. In many localities, and particularly where there are hills, the towers are sometimes very high, and are subjected to considerable torque loads due tothe wind bl'o'wi'ngagainst the reflectors and other parts" of the" towers. T he elasticity of each tower is such that even nominal winds twist towers to such an extent that the antenna reflectors are not properly beamed.
An object of the invention is to provide a guide arm for a radio tower or the like which will not only secure the tower against torque loads, but will accommodate the up and down movement of the guys as well.
Another object of the invention is to provide a tower of the described class which may be made smaller in cross-section than was previously feasible.
A particular object of the invention is to provide improved pivoted guide or anti-torque arms on a microwave relay tower or the like for attachment of guy wires or the like without subjecting such arms to the bending loads due to the weight and movement of the attached guys.
These and other objects of the invention will become apparent from the following description and the accompanying drawings, wherein:
Figure 1 is an elevation of a radio relay tower or the like embodying the features of the present invention.
Figure 2 is a broken elevation of the upper end of the radio relay tower illustrated in Figure 1, and showing the new guy arms attached thereto.
Figure 3 is a broken plan view of the tower and guide arms illustrated in Figure 2.
Figure 4 is a perspective view of the upper end of the tower.
The tower illustrated in Figure 1 is mounted on a base 11 and is secured in its upright position by means of guys 12, all in the usual manner. The tower construction includes vertical corners 13 of angle steel and the usual horizontal and diagonal struts 14 and 15, as shown, for example, in my aforesaid Patent No. 2,583,287.
The guy arm assemblies which comprise the present invention are mounted at the top of the tower 10 to prevent the latter from twisting under wind loads. It is not necessary to secure the intermediate portions of the tower 10 against twisting, so long as the antennae 18' and their reflectors 19 remain in their fixed directions for relaying signals from one tower to another. Each guy arm assembly 20 is comprised of a rigid substantially V-shaped assembly having side members 21 of angle steel, and which assemblies are slightly wider at 2,844,819 Patented July 22, 1958 their upper ends than the tower 10. The separate arm assemblies converge toward each other at their remaining ends where gussets 22 are-welded on opposite sides thereof, as shown in Figures 2 and 3. Cross members 23 are secured, as by welding, to the side members 21, and are arranged to cross each other in the manner shown in Figure 3. A bolt 24 is positioned through each pair of gussets 22, and the converging pairs of guys 12 are positioned around the bolts and so secured by cable clamps 25. a
g A square guy frame 26, comprised of horizontal lengths 2.7 of strap material longer than the width of the tower It), is welded to the upper end of the tower 10, the ends of which straps are outwardly and angularly turned as at 28 so as to form pairs of ears to accommodate the inner ends of corresponding ears 29 secured to and projecting from the inner ends of the side members 21. Bolts 30 'are positioned through the projecting ears 28 of the frame 26 and through the projecting ends of the arm ears 29 so as to provide at least a slight pivotal action between the lengths of the guy arms 20 and the tower. Preferably, there are two guide arm assemblies 20, one each on opposite sides of the tower 10, and whereby the wind loading on each arm is substantially the same so as to reduce the torque applied to the tower.
As is apparent from the foregoing description, and from a consideration of the drawings, each of the guy arm assemblies or anti-torque arms 20 is in the form of an isosceles triangle with the side members 21 forming the legs which are pivotally secured to one side of the guy frame 26, which side constitutes the base of the triangle, the guys 12 being secured to the apex of the triangle. The anti-torque guy arms 20 depend from the guy frame at an oblique angle, herein shown as approximately 45 to the vertical.
I have found that for most satisfactory results the length of the guy or anti-torque arms 20 measured from the apex of the triangle or point of attachment of the guy wires to the base of the triangle, should be at least equal, and preferably greater than the width of the tower at the point of attachment of the side members or legs 21.
The depending pivotal mounting of the guy wire assemblies as distinguished from the fixed transverse mounting of the guy beams 42 as shown in my Patent No. 2,605,417 is a feature of importance in the present invention since the depending pivotal arrangement places the arms 20 in tension and avoids bending loads. If the arms 20 were not pivoted they would be flexed at their upper ends and would tend to break, particularly in the case of high winds. Also, if such arms were not pivoted they would act as levers in the case of a wind storm, and would cause the guys to swing inwardly and outwardly relative to the tower, thereby deflecting the tower at its upper ends and interfering with the alignment or beaming of the antenna reflectors and the antennae themselves. 7
It will also be noted that each guy arm or frame assembly 20 is substantially flat and the side members 21 spaced apart at their point of attachment a distance at least equal to the width of the tower frame 26, while the guy cables 12 are attached to the apices of the arm assemblies 20, thus preventing twisting of the top of the tower which would be possible with an arrangement such as shown in my prior Patent No. 2,583,287. Also, as best shown in Fig. 3 of the present drawings the guy wires attached to a single guy arm assembly 20 are arranged in pairs and the cables, whose lower ends are spaced outwardly from the base of the tower, extend downwardly from the anti-torque guy arm assemblies 20 substantially within the plane of the arm.
By the use of my improved guy arm anti-torque assemblies 20 as herein described I have found it possible to maintain the antennae of the reflectors accurately beamed at all times, thus insuring beaming of the microwaves from tower to tower, even during high wind storms, a result which to my knowledge has been impossible heretofore.
The remaining parts of the illustrated tower 10 are not herein described in detail, it being sufficient to say that the antennae 18 and their reflectors 19 are suitably supported on the vertical shaft 17 by means of clamps 31 and bracket assemblies 32. A preferred construction of the antenna and reflector supporting means is illustrated and described in my referred to Patent No. 2,605,417.
The invention has been described in detail for the purpose of illustration but it will be obvious that numerous modifications and variations may be resorted to without departing from the spirit of the invention as set forth in the appended claims.
1. A microwave radio installation for transmitting high frequency radio signals comprising a radio tower having radio antennae and reflectors therefor and mounted at the upper portion of the tower, guy cables for maintaining the tower in upright position and having their lower ends spaced from the base of the tower, and means interposed between the guy cables and the upper portion of the radio tower for preventing twisting of the said upper portion of the tower and the parts carried thereby so as to keep the reflectors properly beamed at all times, said means comprising flat and rigid anti-torque arms having their upper ends pivotally connected with the opposite sides of the tower at the upper ends thereof and their opposite ends connected to the upper ends of the guy wires, said cables being substantially within the plane defined by the respective flat anti-torque arms to which they are attached, the said anti-torque arms extending downwardly from the tower at an oblique angle and being of at least as great a length as the width of the tower. 2. The combination of a vertical radio tower having a rectangular frame at the upper end thereof, radially outwardly projecting ears provided at the corners of said frame, a set of rigid anti-torque members disposed at opposite sides of the upper end portion of said tower, each of said anti-torque members comprising a substantially isosceles triangular frame-like body having its base disposed substantially in the plane of said rectangular frame and having its sides extending outwardly and downwardly therefrom at an oblique angle relative to the tower, pairs of angle brackets rigidly secured to the body of said anti-torque members at the base thereof, means pivotally connecting the angle brackets in each pair to said projecting ears at adjacent corners of said frame whereby to facilitate limited vertical swinging movement of the anti-torque members relative to said frame, and g-uy cables secured to and extending downwardly from the apices of said anti-torque members.
References Cited in the file of this patent UNITED STATES PATENTS 1,869,877 Austin Aug. 2, 1932 FCREIGN PATENTS 705,992 Germany May 15, 1941 104,388 Great Britain Mar. 2, 1917