Patent Publication Number: US-10781601-B2

Title: Link-plate connection for monopole reinforcing bars

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/894,473 filed on Feb. 12, 2018 and issued as U.S. Pat. No. 10,472,844 on Nov. 12, 2019, which is a continuation of U.S. patent application Ser. No. 15/371,680 filed on Dec. 7, 2016 and issued as U.S. Pat. No. 9,926,716 on Mar. 27, 2018, which is a divisional of U.S. application Ser. No. 14/552,263 filed Nov. 24, 2014 and issued as U.S. Pat. No. 9,546,497 on Jan. 17, 2017, which claims the benefit of U.S. Provisional Application No. 62/026,522, entitled “Link-Plate Boltless Connection For Monopole Flat Plate Reinforcement,” filed on Jul. 18, 2014, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present application relates to methods and devices for reinforcing monopoles. More specifically, the present invention includes link-plates reinforcing plates/bars attached to monopoles, where the link-plates include holes that mate with blocks welded or loose to pole reinforcing plates to provide a positive connection for transferring the axial loads between the two reinforcing plates/bars. 
     BACKGROUND OF THE INVENTION 
     The wireless telecommunications industry has been growing steadily for a number of years. Consumers continue to demand more coverage, faster access and improved functionality of wireless devices. The advent of data (in addition to voice) has taxed the ability of current networks to support the increased traffic and wireless Carriers are deploying newer, larger and more complex antennas and equipment to increase capacity. This affects both new and existing sites. 
     New sites are designed to support the larger and heavier equipment—but building new sites is very expensive and is usually done as a last resort and only when coverage areas are to be extended. The more common practice is to use existing sites and to simply replace equipment and antennas as needed. However, existing sites were not always designed for the lateral loads caused by the wind forces on the additional equipment and the supporting monopole must be augmented structurally to allow for these larger antennas and equipment. 
     A common type of tower built in densely populated urban areas is the monopole. These monopoles are usually multi-sided or round tapered or straight tubular structures with a very small profile and hence more attractive from a zoning and siting approval standpoint. However, these are also the more difficult to augment or modify structurally since the bolting of additional structural elements must be done from the outside as they are too narrow to access from the inside. 
     One of the more common methods of strengthening these monopoles has been the addition of flat plates or bars to the “flats or flat sides” of the multi-sided structures. Similar concepts are used for cylindrical structures. While this is fairly simple using bolts that can be installed from the outside, the magnitude of the forces seen in the flat plates or bars require very large quantities of bolts at the splice connections between the flat plates or bars for load transfer. For example, a typical splice requires the use of eighteen or more splice bolts per splice per reinforcing plate. Thus, a four-sided plate augmentation design would require seventy-two bolts at each splice elevation. Reinforcing a monopole from the ground to a one-hundred twenty foot elevation may require five or more splices, resulting in more than four-hundred bolts and four-hundred bolt holes to be drilled in the air in the field. As may be appreciated, drilling bolt holes into the monopole and installing such flat plates at elevated heights can be very costly and labor intensive. 
     As wireless networks continue to tax the structural capacity of existing monopole structures, structural augmentation of these structures with flat plate reinforcing solutions will continue. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention include a device for reinforcing a monopole. In one optional embodiment, a device includes a plurality of reinforcing plates or bars each having ends and a surface. Each of the reinforcing plates or bars includes at least one or two load transfer connectors attached to the reinforcing bar, proximate to at least one of the ends. The load transfer connectors may be attached to the reinforcing bars (such as by welding) or may be integrally formed with the reinforcing bars or keyed in holes in the reinforcing bars. In one optional embodiment, the load transfer connectors are attached to the reinforcing bar surface. In another optional embodiment, the load transfer connectors may fit into openings in the reinforcing bar. 
     A device also includes a link-plate having one or more openings shaped to mate with the load transfer connectors. In this manner, adjoining reinforcing bars may be spliced by overlaying the link plate over the reinforcing bars and mating the link plate openings with the load transfer connectors (also referred to as shear blocks) of each adjoining reinforcing bar. In an optional embodiment, the mating connection between the link plate openings and the load transfer connectors may be an interference fit, as known as a press fit or a friction fit, as those terms are commonly understood in mechanical engineering. 
     In an optional embodiment, the device may further include cover plate positioned to overlie the link plate openings while mated with the load transfer connectors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevated perspective view of a pole and assembled link-plate according to an embodiment of the present invention; 
         FIG. 2  is an elevated perspective view of an assembled link-plate according to an embodiment of the present invention; 
         FIG. 3  is an elevated perspective assembly view of a link-plate according to an embodiment of the present invention; 
         FIG. 4  is an elevated perspective view of a pole and assembled link-plate according to an embodiment of the present invention; 
         FIG. 5  is an elevated perspective assembly view of a link-plate according to an embodiment of the present invention; 
         FIG. 6  is an elevated perspective view of a pole and assembled link-plate according to an embodiment of the present invention; 
         FIG. 7  is an elevated perspective view of a pole and assembled link-plate according to an embodiment of the present invention; 
         FIG. 8  is an elevated perspective assembly view of a link-plate according to an embodiment of the present invention; and 
         FIG. 9  is an elevated perspective assembly view of a link-plate according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION 
     Reference is now made to the figures wherein like parts are referred to by like numerals throughout. The present invention is a system for reinforcing a monopole which includes multiple reinforcing bars  100 ,  101 . In the optional embodiment illustrated in  FIGS. 1-8 , each reinforcing bar  100 ,  101  includes an elongated, flat plate section, although the shape and dimensions of the reinforcing bars  100 ,  101  may vary depending on the optional embodiment. As illustrated in the figures, the plate sections of the reinforcing bars  100 ,  101  are sized and shaped to lie along the surface of a monopole  200 . For example, in an optional embodiment in which the monopole  200  has a polygonal cross-section, the plate section of the reinforcing bars  100 ,  101  may be flat. In other optional embodiments in which the monopole  200  has a different shape, such as a cylindrical cross-section, the plate section of the reinforcing bars may have a different shape. 
     The reinforcing bars  100 ,  101  are secured to the monopole  200 , optionally using bolts or other fasteners  108 . As explained in greater detail below, the reinforcing bars  100 ,  101  are linked together to reinforce the monopole, whether the reinforcing bars are subjected to compression or tension forces. 
     The reinforcing bars  100 ,  101  also include load transfer connectors  105  (also referred to as “shear blocks”). In the optional embodiments illustrated in  FIGS. 1-5 , the load transfer connectors are rectangular. However, it is contemplated that the load transfer connectors  105  may take any shape such as round, oval, square, triangular, or the like. Likewise, while the optional embodiments illustrated in  FIGS. 1-8  show two load transfer connectors  105  per reinforcing bar  100 ,  101 , any quantity of one or more load transfer connectors  105  may be included. Likewise, the placement along the reinforcing bar  100 ,  101  could take any pattern or form. For example, in the optional embodiments illustrated in  FIGS. 1-8 , the load transfer connectors  105  are aligned along the long axis of the reinforcing bars  100 ,  101 . However, this should be interpreted as merely illustrative, since it is contemplated that the load transfer connectors  105  could be placed in any location and with any pattern. 
     The load transfer connectors  105  illustrated in  FIGS. 1-8  are attached to the reinforcing bars  100 ,  101 . In the optional embodiments of  FIGS. 1-5 , the load transfer connectors  105  are attached to the surface of the reinforcing bars  100 ,  101 . In the optional embodiment of  FIGS. 6-8 , the load transfer connectors  105  fit into openings  106  in a reinforcing bar  100 . As discussed in greater detail below, the load transfer connectors  105  transfer loads between adjoining reinforcing bars  100 ,  101  of the reinforcing system. Thus, in the optional embodiments of  FIGS. 1-8 , the load transfer connectors  105  are located proximate to one end ( FIGS. 4-8 ) or both ends ( FIGS. 1-3 ) of each reinforcing bar  100 ,  101 . However, it is contemplated that the load transfer connectors  105  could, in alternate optional embodiments, be additionally, or alternatively disposed along the surface of the reinforcing bars  100 ,  101  away from the ends of the reinforcing bars  100 ,  101 . Again, it is contemplated that any quantity of load transfer connectors  105 , of any shape and distributed in any manner, may be provided on the reinforcing bars  100 ,  101 . In the optional embodiment of  FIGS. 1-5 , it is contemplated that the load transfer connectors  105  may be attached to the surface of the reinforcing bars  100 ,  101 , such as by welding, or may be integrally formed with the reinforcing bars  100 ,  101 . In the optional embodiment of  FIGS. 6-8 , it is contemplated that the load transfer connectors  105  may be fitted into openings  106  in each reinforcing bar  100 ,  101  to be connected. 
     A link plate  102  overlies the connection between reinforcing bars  100 ,  101 . The link plate  102  includes openings  106  that mate with the load transfer connectors  105 . In one optional embodiment, the openings  106  mate with the load transfer connectors  105  with an interference fit (also known as a friction fit or press fit, as those terms are understood in mechanical engineering). Alternatively, the mating connection between the openings  106  and load transfer connectors  105  may be a looser fit, e.g., a transition fit or running fit. The link plate  102  serves to transfer loads between adjoining reinforcing bars  100 ,  101  through the interface of the openings  106  and the load transfer connectors  105 . Under load, the openings  106  of the link plate  102  bear against the load transfer connectors  105  of one or both of the underlying reinforcing bars  100 ,  101 , or vice versa, thereby reinforcing the monopole  200 . Specifically, as the monopole  200  is subjected to bending forces or moments, longitudinal tension or compression forces are created in the reinforcing bars  100 ,  101 . These forces are transferred between the reinforcing bars  100 ,  101  through the load transfer connectors  105  and openings  106  of the link plate  102  that connect to the load transfer connectors  105 . 
     In the optional embodiment of  FIGS. 1-3 , the link plate  102  may include openings  106  that mate with load transfer connectors  105  on both reinforcing bars to be connected  100 ,  101 . In another optional embodiment illustrated in  FIGS. 4-8 , the link plate  102  may be welded to (or otherwise attached to fastened to, or formed with) one reinforcing bar  100  with openings  106  to mate with load transfer connectors  105  on the other reinforcing bar  101  to be connected. As may be appreciated, the link plate  102  of such an optional embodiment may be attached (e.g., welded, fastened, or the like) to the reinforcing bar  100  in the shop prior to installation, in the field during installation, or any other time. 
     In an optional embodiment illustrated in  FIGS. 1-5 , a cover plate  103  overlies the link plate  102  that connects adjoining reinforcing bars  100 ,  101  to one another. In one such optional embodiment, the cover plate  103  may be held to the link plate  102  with fasteners  104 , such as a Type HB Hollo-Bolt™ or other types of fasteners and such bolts were not intended to resist any of the longitudinal tension or compression forces but merely to secure the assembly together. 
     In use, reinforcing bars  100 ,  101  may be secured to a monopole  200  using bolts or other fasteners  108  that pass through the reinforcing bar  100 ,  101  and into the monopole  200 . Adjoining reinforcing bars  100 ,  101  may be secured to one another by positioning a link plate  102  over the adjoining reinforcing bars  100 ,  101 , with the openings  106  in the link plate  102  aligned with the load transfer connectors  105  of the underlying reinforcing bars  100 ,  101 . The link plate  102  is secured to the reinforcing bars  100 ,  101  with the openings  106  mated to the load transfer connectors  105 . As illustrated in  FIGS. 1-3 , the link plate  102  may mate with load transfer connectors  105  on both adjoining reinforcing bars  100 ,  101  through the openings  106  in the link plate  102 . Alternatively, as illustrated in  FIGS. 4 and 5 , the link plate  102  may be secured to one of the reinforcing bars  100 , such as through shop-welding or field-welding the link plate  102  to the reinforcing bar  100 , and mated to the load transfer connectors  105  on an adjacent reinforcing bar  101  through the openings  106  in the link plate  102 . 
     Referring generally to  FIGS. 1-5 , in an optional embodiment, a bolt  104  secures the link plate  102  to one or both of the underlying reinforcing bars  100 ,  101 . In a further optional embodiment, a cover plate  103  may be secured over the link plate  102  to cover the mated openings  106  and load transfer connectors  105 . In one such optional embodiment, a fastener  104  secures the cover plate  103 , link plate  102 , and reinforcing bars  100 ,  101  together. 
     Use of the link plate  102  would permit more standardization of parts as only a few link plate designs would be needed to properly splice many sizes and shapes of reinforcing bars  100 ,  101 . Additionally, the link plate  102  could be used on many types of monopole structures, such as wind turbines, pipe poles, stepped poles, tapered poles, or the like. Additionally, using the link plate  102  would be more aesthetic as it would minimize the number of bolts used at the splices. The completed installation would appear more like one continuous reinforcing bar connected to the monopole structure. Thus, the present invention seeks to reduce the amount of drilling needed for splicing the reinforcing plates to thereby speed the installation of monopole reinforcing plates and reduce the cost of augmenting and reinforcing monopoles. 
     In another embodiment illustrated in  FIG. 9 , a system for reinforcing a monopole includes a first reinforcing bar  900  having a first reinforcing bar opening  901  and a second reinforcing bar  902  having a second reinforcing bar opening  903 . A first load transfer connector  904  is configured to be received in the first reinforcing bar opening  901 , and a second load transfer connector  905  is configured to be received in the second reinforcing bar opening  903 . A link plate  906  is configured to overlay at least a portion of the first reinforcing bar  901  and the second reinforcing bar  902 . The link plate includes a first link plate opening  907  and a second link plate opening  908 . The first reinforcing bar  900  and the second reinforcing bar  901  are disposed to at least partially abut the monopole. The first load transfer connector  904  is configured to be received in the first link plate opening  907  to connect the link plate  906  to the first reinforcing bar  900  and the second load transfer connector  905  is configured to be received in the second link plate opening  908  to connect the link plate  906  to the second reinforcing bar  902 . The first load transfer connector  904  is received in the first reinforcing bar opening  901  and in the first link plate opening  907  through an interference fit, a transition fit, or a running fit. The second load transfer connector  905  is received in the second reinforcing bar opening  903  and in the second link plate opening  908  through an interference fit, a transition fit, or a running fit. The first load transfer connector  904  and the second load transfer connector  905  are disposed adjacent but do not penetrate the monopole. 
     In some aspects (not illustrated) one or more of the first load transfer connector and the second load transfer connector have a round or oval shape. 
     In further aspects a cover plate  910  is configured to overlay at least a portion of the link plate. 
     In yet further aspects the reinforcing bars  900 ,  901  are secured to the monopole using bolts or other fasteners  911 , and the cover plate  910  may be secured to the link plate  906  with bolts or fasteners  912 . 
     While certain embodiments of the present invention have been shown and described it is to be understood that the present invention is subject to many modifications and changes without departing from the spirit and scope of the claims presented herein.