Abstract:
A system for reinforcing a tower is disclosed. The system includes a number of vertically elongated primary support risers. Each riser is attached to the tower at a series of spaced apart locations.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to reinforcing systems and constituent parts for reinforcing vertically elongated towers and like structures against more or less horizontally applied wind loads and the like. While these towers may be freestanding, self-supported, guyed or monopole towers, the invention will be described and illustrated here in connection with a monopole tower for purposes of clarity. It will be understood that it is not intended to limit this invention to its use with monopole towers. 
         [0002]    The erection of monopole and other towers has become an important industry as those towers are used to support antennas for wireless communications cell sites; for light fixtures used at stadiums, along highways and in parking lots; and for other purposes. Other tall towers are essential for radio, television and other broadcasting systems. The number of monopole and other towers has more than quadrupled since the inauguration of cellular telephone systems. Cellular telephone carriers are sharing the use of towers as a cost-effective method of delivering cellular telephone system service, and of sharing the expense of maintaining the towers. 
         [0003]    Cellular telephone towers are typically between 65 and 250 feet high, and each tower may support a number of antennas, some of which are large. These large antenna and support systems can experience high wind loads, and these wind loads must be transferred to the tower structure. Currently, at least some of the old towers will not pass structural analysis tests required by state, county and local municipalities. These and other towers require reinforcement to pass mandated structural load analysis tests. Reinforcement can be difficult and costly, due to the logistics involved in adding components to the tower structure; installation time and labor costs; and actual or potential interference of the reinforcements with the tower antennas or other operating equipment. 
         [0004]    This invention provide a system for reinforcing monopole and other towers and vertically elongated structures which minimizes the cost of bringing reinforcement parts, labor and support features to the tower site; which minimizes the cost of reinforcement installation time and labor costs; and which minimizes the interference of the reinforcing structure with the tower antennas or other tower access or operating equipment. 
         [0005]    While the invention will be described in connection with several preferred embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In particular, it is not intended to limit the invention to its use with a monopole tower. As noted above, the invention may be used in connection with guyed towers, self-supported towers, free standing towers, or other vertically elongated structures in need of reinforcement. The invention may also be used to form, by itself, a strong and efficacious tower. 
         [0006]    Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals referred to like parts. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is an isometric view of an exemplary monopole tower equipped with reinforcements embodying the novel reinforcing system. 
           [0008]      FIG. 2  is a fragmentary isometric view illustrating the reinforced base of an exemplary monopole tower and the adjacent foundation. 
           [0009]      FIG. 3  is a fragmentary elevational view of the exemplary monopole tower illustrating the attachment of reinforcing elements to the tower structure. 
           [0010]      FIG. 4  is a fragmentary isometric view of reinforcement elements attached to a portion of an exemplary monopole tower. 
           [0011]      FIG. 5  is an isometric view of a typical reinforcing element. 
           [0012]      FIG. 6  is an isometric view of a lateral support bracket. 
           [0013]      FIG. 7  is a top plan view of the lateral support bracket shown in  FIG. 6 . 
           [0014]      FIG. 8  is an isometric view of a device for attaching reinforcement pipe sections to one another. 
           [0015]      FIG. 9  is an isometric view of an exemplary monopole tower similar to  FIG. 1  but illustrating a reinforcement connecting collar. 
           [0016]      FIG. 10  is a fragmentary isometric view illustrating in further detail the reinforcement connecting collar suggested in  FIG. 9 . 
           [0017]      FIG. 11  is a fragmentary isometric view illustrating a chair element used to reinforce the interconnection between the tower base plate and the tower monopole. 
           [0018]      FIG. 12  is an exploded view showing in further detail parts of the reinforcement connecting collar. 
           [0019]      FIG. 13  is an isometric view of an exemplary monopole tower similar to  FIGS. 1 and 9  but illustrating an alternate embodiment of the reinforcing connecting collar. 
           [0020]      FIG. 14  is a fragmentary isometric view similar to  FIG. 10  but illustrating in further detail the alternate embodiment of the reinforcement connecting collar suggested in  FIG. 13 . 
           [0021]      FIG. 15  is an exploded view similar to  FIG. 12  showing in further detail parts of the alternate embodiment reinforcement connecting collar. 
           [0022]      FIG. 16  is an isometric view, similar to FIGS.  1 , 9  and  13  showing an exemplary monopole tower fitted with yet another embodiment of the connecting collar. 
           [0023]      FIG. 17  is a fragmentary isometric view similar to  FIGS. 10 and 14  showing in further detail the embodiment of the connecting collar suggested in  FIG. 16 . 
           [0024]      FIG. 18  is an exploded view similar to  FIGS. 12 and 15  showing in further detail parts of the alternate embodiment reinforcing connecting collar shown in  FIGS. 16 and 17 . 
           [0025]      FIG. 19  is a fragmentary isometric view showing an alternate embodiment of the tower base plate and foundation upon which it is mounted. 
           [0026]      FIG. 20  is a fragmentary isometric view similar to  FIGS. 10 ,  14  and  17  showing in further detail yet another embodiment of a connecting collar and the associated reinforcing elements. 
           [0027]      FIG. 21  is an exploded view showing in further detail the reinforcing collar of  FIG. 20 . 
           [0028]      FIG. 22  is an isometric view showing a reinforcing element as it appears when attached to a portion of the exemplary monopole tower. 
           [0029]      FIG. 23  is a top plan view showing a mounting bracket as it appears when secured to the exemplary monopole tower. 
           [0030]      FIG. 24  is a top plan view of yet another embodiment of a connecting collar and the associated reinforcing elements. 
           [0031]      FIG. 25  is a fragmentary elevational view of the connecting collar and associated reinforcing elements shown in  FIG. 24 . 
           [0032]      FIG. 26  is a fragmentary elevational view of primary support elements and element interconnectors. 
           [0033]      FIG. 27  is a fragmentary elevational view similar to  FIG. 26  of primary support elements and associated tension strap coupling elements. 
           [0034]      FIG. 28  is a fragmentary elevational view of an exemplary monopole tower foundation, base plate, secondary base plate and associated vertical reinforcing elements. 
           [0035]      FIG. 29  is a top plan view of the base plate, foundation, secondary base plate and associated vertical reinforcing elements shown in  FIG. 28 . 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    While the invention will be described in connection with several preferred embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In particular, it is not intended to limit the invention to its use with a monopole tower. As noted above, the invention may be used in connection with guyed towers, self-supported towers, free-standing towers, or other vertically elongated structures in need of reinforcement. The invention may be also used to form, by itself, a strong and efficacious tower. 
         [0037]    Turning first to  FIG. 1 , there is shown an exemplary free-standing tower, here illustrated as a monopole tower  50 . This tower  50  includes a central vertically elongated monopole structure  52  which may be subjected to wind loads W or similar horizontally applied forces. A structure top  54  is adapted to mount antennas  56  or other equipment, which subject the structure to a vertically applied load L. A primary base plate structure  58  affixes the tower to a foundation  59 . 
         [0038]    A reinforcing system structure  60  comprises a plurality of vertically elongated primary support risers  64  which are here located outside the central vertically elongated monopole structure  52 . In accordance with invention, each of these risers  64  is attached to the central vertically elongated monopole structure  52  at spaced apart points as suggested in  FIG. 3  and elsewhere. As explained in further detail below, these attachment devices can include straps  66  or any equivalent securement mechanisms. Tension straps  67  can be used to surround all the risers  64  so as to maintain the alignment of the risers  64  as shown in  FIG. 27 . 
         [0039]    As suggested in  FIGS. 1 ,  2 ,  9 ,  10 ,  13 ,  14   16 ,  17  and elsewhere, the support risers  64  are here located outside the central vertically elongated monopole structure  52 . In accordance with another aspect of the invention, however, the risers  64  can be affixed inside the central pole structure  52  if desired and if the central structure  52  can accommodate the risers  64 . As illustrated here, these risers  64  comprise hollow pipes. As such, the pipes have a substantially circular cross-section. They can, however, have cross sections taking the form of a triangle, rectangle, oval, or any other shape which provides maximum surface, so as to provide maximum modulus and consequent maximum stiffening effect to the support riser and the supported tower. The hollow support risers  64  can contain internal reinforcement webbing, in accordance with yet another aspect of the invention. 
         [0040]    As shown in  FIGS. 2 ,  19  and elsewhere, the central tower structure  52  is affixed to the foundation  59  by the base  58 . As shown and particularly in  FIG. 2 , a series of bolts  70  of suitable strength mounted on and in the foundation  59  accept the overlying base plate  58  which is welded or otherwise secured to the monopole  52 . To strengthen the poll/base connection in accordance with the invention, fins  72  are welded to the reinforcing risers  64  and also to the base plate  58 . If the fin connection of a particular riser  64  to the base plate  58  would be inhibited by a bolt  70 , a chair-like structure  74  formed of horizontally and vertically arrayed fins can be provided as particularly suggested in  FIGS. 2 and 11 . If required by good engineering design, a second base plate  57  can be affixed to the pole  52  at a position above the primary base plate  58 , and the plates can be interconnected by fins  74 , bolts, or other known devices as suggested in  FIG. 28 . 
         [0041]    As shown in  FIGS. 1 ,  9 ,  13 ,  16  and elsewhere, these risers  64  can extend up the sides of the exemplary tower  64  a considerable distance. In the interests of economy, and as explained above, the risers can be formed of strong pipe sections which are joined by primary support coupling elements  80  as shown in  FIG. 26 . Alternatively, as shown in  FIG. 8 , pipe splice devices  61  can include a threaded rod nipple  63  which mates with the pipe sections  64  or, alternatively, plugs  64   a  which are, in turn, fitted into the adjacent pipe sections. 
         [0042]    Lateral support brackets  82  as shown in  FIGS. 4 and 5  secure the risers  64  to the central tower outlet  52  at the upper end of the risers. Here, these securing devices  82  each include a flange  84  which is bolted to the tower  52 ; and a threaded element  86  is welded or otherwise affixed by means not shown to the pipe portion of the risers  64 . A nut  88  can be turned down the threaded element  86  so as to place each of the riser devices  64  in a desired amount of compressive force. 
         [0043]    At intermediate points, the risers can be secured to the tower structure  52  by lateral support brackets  85  shown in  FIGS. 6 and 7 . These brackets can take any convenient yet effective form. Here, they include one or two wings  87  and fastening devices such as bolts of the necessary strength. 
         [0044]    Alternatively, the risers  64  can be secured at their upper ends to the pole  52  by grillage transfer cages  90 . As shown in  FIGS. 10 ,  12 ,  15 ,  17 ,  18 ,  14 ,  21  and  25 , these grillage interconnectors or collars  90  take the form of one, two or more rings  92  which are welded or otherwise secured to connector fins  94 . In this embodiment of the invention, these fins  94  are bolted or otherwise secured together by threaded elements  96 . The rings  92  are secured to the upper ends of the risers  64 . Additional stiffening and securement action can be provided by plates  98  welded between the rings  92  as suggested in  FIG. 10  to provide a closed case. Spacer fins or shims can be provided to adjust the fit of the rings  92  with the surrounded tower structure. Adjustment can also be provided by threaded nipples  99  as shown in  FIG. 24 .