Patent Publication Number: US-7721490-B1

Title: System and method for installing a base for a roadside utility pole

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   In general, the present invention relates to the underground support bases for roadside poles, such as street light poles and sign poles. More particularly, the present invention relates to the structure of such support bases and the methods by which such support bases are created and installed. 
   2. Description of the Prior Art 
   There are many poles that stand on the sides of various roadways. Some poles are merely stands that support signs or utility wires above the ground. Other poles, such as poles for street lights, illuminated signs and traffic lights receive underground power cables, therein providing electrical power to the supported signs. 
   Most every state has standards regarding the size, shape and construction of the support base for roadside poles, especially those that receive power cables. A typical pole base specification requires that the pole base be fabricated from poured concrete in a pier that is about 70 inches deep and 42 inches square. Such dimensions require the pouring of at least two cubic yards of concrete. 
   Such prior art pole base supports are exemplified in U.S. Pat. No. 3,630,474, to Minor, entitled Breakaway Pole Support And Structure. In the construction of such a prior art pole support base, a large hole must be excavated on the side of a roadway. A large monolithic foundation is then poured into the bottom of the excavated hole. A smaller cement mounting head section is then formed atop the below-grade foundation. The smaller mounting head section extends upwardly from the foundation to a point above grade. The base of a street pole attaches to the top of the mounting head section. Anchor bolts extend from the top of the mounting head section to enable a street pole to be attached to the base support. Furthermore, a conduit protrudes out of the top of the mounting head section so that an electrical cable can be passed into a street pole through the structure of the base support. 
   In order to properly form such a prior art pole support base, the anchor bolts and the cable conduit must be set in precise positions before they are encased in concrete. If an anchor bolt or cable conduit is misaligned, the pole support base will require repairs before a street pole can be mounted. Typically, such prior art pole bases are manufactured on site along the side of a road. To create such a pole base, a large hole must be excavated. A form is then set into the elevated hole. The anchor bolts and power cable conduit are set into the form using wires and positioning templates. Once the form is constructed and the bolts and conduit set in position, then form is the filled with concrete. The concrete is given time to cure. Finally, the form is broken away from the cured concrete and the remainder of the excavated hole is backfilled with dirt. As can be understood, the forming of a pole support base in such a manner is a very time consuming and labor intensive procedure. Furthermore, should an anchor bolt shift while the form is being filled, the anchor bolt many not align with the mounting holes of the pole being installed. Time consuming repairs must then be performed. 
   A need therefore exists for a system and method for installing a pole support base that greatly reduces the time and labor needed to set a pole base in place. A need also exists for a new system and method of installing a pole support that ensures that the pole support presents mounting bolts that are properly positioned and level, thereby reducing the need for repairs. These needs are met by the present invention as described and claimed below. 
   SUMMARY OF THE INVENTION 
   The present invention is a system and method for creating a pole support base for the installation of a road-side pole. A mounting head assembly is provided that has a top surface and a bottom surface. Support legs extend from the bottom surface of the mounting head assembly and support the mounting head assembly at a predetermined height that can be selectively adjusted. Pole mounts are provided on the top surface of the mounting head assembly that enable the base of a pole to be bolted to the mounting head assembly. 
   A hole is excavated in the place where the pole is to be erected. The mounting head assembly is placed into the hole. The legs support the mounting head assembly at a predetermined height within the hole and enable the mounting head assembly to be adjusted for height and levelness. The hole is then filled with poured concrete until at least the legs are submersed. 
   Since the pole mounts are prefabricated as part of the mount head assembly, the positions of the pole mounts are fixed and do not move during the construction of the pole support base. Consequently, provided that the mounting head assembly can be placed at the proper depth in a hole and can be leveled, a proper pole mounting base can be quickly and inexpensively constructed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is made to the following description of an exemplary embodiment thereof, considered in conjunction with the accompanying drawings, in which: 
       FIG. 1  is an exploded view of an exemplary embodiment of a pole support base shown in conjunction with a street pole and an excavated hole; 
       FIG. 2  is a cross-sectional view of the embodiment of  FIG. 1 ; 
       FIG. 3  is a side view of the prefabricated subassembly used to illustrate the initial steps involved in forming the present invention pole support base; and 
       FIG. 4  is a side view of the prefabricated subassembly used to illustrate the final steps involved in forming the present invention pole support base. 
   

   DETAILED DESCRIPTION OF THE DRAWINGS 
   Although the present invention system and method can be used to create the support base for many types of poles, such as sign poles, the present invention is especially well suited for the creation of support bases for roadside poles that receive electricity via a cable that passes through the support base. Accordingly, the exemplary embodiment of the present invention will set forth a pole support base that contains a conduit for the passage of an electric cable. Such an embodiment is merely exemplary of the best mode contemplated for the invention and should not be considered a limitation to the present invention. 
   Referring to both  FIG. 1  and  FIG. 2 , there is shown an exemplary pole base support  10 . The pole base support  10  contains a prefabricated subassembly  12 . The prefabricated subassembly  12  is manufactured off-site and is brought to the site of the pole base support  10  as a completed unit. The prefabricated subassembly  12  is comprised of a concrete mounting head  14  that has been precisely cast. The concrete mounting head  14  is formed around sections of anchor elements  16  and a section of a cable conduit  18 . The position of the anchor elements  16  and the cable conduit  18  are precisely maintained during the manufacturing of the prefabricated subassembly  12 . Accordingly, the positions of the anchor elements  16  and the cable conduit  18  can be precisely controlled and cannot be inadvertently altered on the site of the installation of the pole base support  10 . 
   In the shown embodiment, the anchor elements  16  terminate at one end with pole mounts  20 . The pole mounts  20  extend above the top surface of the precast concrete mounting head  14 . The pole mounts  20  are located at precise positions that correspond to the mounting holes  25  in the base of the pole  26  being erected. In this manner, when a pole  26  is placed upon the top surface  22  of the precast concrete mounting head  14 , the mounting holes  25  of the pole  26  will align exactly with the pole mounts  20  protruding from the top surface  22 . It will be understood that the male mounting bolt configuration shown in  FIG. 1  can be replaced with female threaded bores that receive bolts. The use of either a male bolt or a female threaded bore is a manner of design choice that may vary from state to state. What is of importance is that some type of precisely positioned pole mounts  20  are accessible on the top surface  22  of the precast concrete mounting head  14  and that the position of the pole mounts align with the mounting holes  25  of the pole  26  being erected. 
   Anchor elements  16  extend below the concrete mounting head  14 . The segments of the anchor elements  16  that protrude below the concrete mounting head  14  are configured as support legs  30 . The support legs  30  are symmetrically positioned about the concrete mounting head  14  so as to support the concrete mounting head  14  at a predetermined height. Preferably, there are at least three support legs  30  formed by the anchor elements  16 . In this manner, the support legs  30  can form a stable platform and can enable the concrete mounting head  14  to be free standing. 
   The anchor elements  16  that form the support legs  30  can terminate within the concrete mounting head  14 . However, in the shown embodiment, each anchor element  16  has two ends. The top end of each of the anchor elements  16  is formed to create the pole mounts  20  that extend out of the top surface  22  of the concrete mounting head  14 . The bottom end of each of the same anchor elements  16  extends from the bottom surface  23  of the concrete mounting head  14  and becomes one of the support legs  30 . It will be understood that with the pole mounts  20  and the support legs  30  being opposite ends of common anchor elements  16 , the pole mounts  20  cannot be separated from the support legs  30 , even if the concrete mounting head  14  were to crack. However, having the pole mounts  20  and the support legs  30  as part of common anchor elements  16  is merely a preferred embodiment and it will be understood that the present invention can be constructed where both the pole mounts  20  and the support legs  30  are separate elements. 
   The bottom of each of the support legs  30  preferably terminates with a threaded leveling pad  32 . The leveling pads  32  are used to adjust the effective length of each of the support legs  30 . Furthermore, the leveling pads  32  are wider than the support legs  30  and prevent the support legs  30  from descending into the dirt at the bottom of an excavated hole. Accordingly, the leveling pads  32  are used to both stabilize and level the prefabricated subassembly  12 , as will later be explained. 
   A volume of poured concrete  34  surrounds the support legs  30 . The poured concrete  34  also envelops part of the precast concrete mounting head  14 . Accordingly, when the volume of poured concrete  34  is cured, it will be understood, that the prefabricated subassembly  12  is fixed within the poured concrete  34  and cannot be moved independently. 
   Referring to  FIG. 3 , the method of construction for the pole base support  10  can be initially described. A hole  40  is excavated in the ground. The hole  40  is preferably forty-two inches square and about four feet deep. This is much smaller than the holes needed for prior art pole base supports, because there is no need to excavate additional room for concrete forms. Rather, the excavated hole  40 , itself, serves as the concrete form, as will later become apparent. 
   The prefabricated subassembly  12  is placed within the excavated hole  40 . The support legs  30  of the prefabricated subassembly  12  rest upon the bottom of the excavated hole  40 . The leveling pads  32  are adjusted so that the top surface  22  of the concrete mounting head  14  lay flat in the horizontal plane. The leveling pads  32  are also used to raise and lower the prefabricated subassembly  12  so that the top surface  22  of the concrete mounting head  14  extends above the grade of the ground. 
   The flexible cable conduit  18  is bent to the side of the excavated hole  40 . If the supply conduit has yet to be run to the excavated hole  40 , a small side hole can be hand dug and the flexible conduit  40  pulled into this side hole. This will protect the end of the flexible conduit  18  from becoming encased in concrete as the excavated hole  40  is filled. If a supply conduit  42  is present, as is shown, the flexible cable conduit  18  can be attached directly to the incoming supply conduit  42 . 
   Referring to  FIG. 4 , it can be seen that once the prefabricated subassembly  12  is set in place and leveled, the excavated hole  40  is filled with poured concrete  34  to a depth of at least three feet. At his depth, the concrete rises in the hole  40  to a level approximately one-third up the length of the concrete mounting head  14 . The volume of concrete being poured is between 20 percent and 40 percent less than that required by many prior art pole supports. 
   As the poured concrete  34  hardens, the support legs  30  within the poured concrete act as reinforcement rods to the concrete. Once the concrete is cured, the support legs  30  are encased within the concrete and the precast concrete mounting head  14  becomes permanently affixed to the concrete base. Only a small area around the concrete mounting head  14  remains needing to be backfilled to ground grade level. 
   The pole  26  can then be attached to the top surface  22  of the concrete mounting head  14  in a traditional manner. Since the spacing of the pole mounts  20  on the top surface  22  of the concrete mounting head  14  is unaffected by on-site construction, the positions of the pole mounts  20  remains unchanged and precisely align with the mounting holes  25  on the pole  26  being installed. 
   By using the prefabricated subassembly  12 , the need to set forms in an excavated hole  40  is eliminated. The excavated hole  40  can therefore be quickly created. The prefabricated subassembly  12  has the ability to be leveled. Thus, the excavated hole  40  need not be leveled or otherwise prepped once dug. 
   It will be understood that the embodiment of the present invention pole support base is merely exemplary and that a person skilled in the art can make many variations to the shown embodiment using functionally equivalent components. For example, the number and shape of the legs is a matter of design choice. Furthermore, the size of the prefabricated subassembly and the excavated hole can be varied depending upon the size and weight of the pole that is being erected. All such variations, modifications and alternate embodiments are intended to be included within the scope of the present invention as described and claimed below.