Abstract:
A support pole including a baseplate attached to a footing and having a central opening formed therein. A hollow shaft has its lower end received by the central opening in the baseplate. The lower end of the shaft is shaped to provide one or more deformations which facilitate the shaft to baseplate connection.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a support pole and more particularly to a means for providing a mechanical connection of the shaft of the support pole to a baseplate with that connection providing a unique breakaway solution. 
     2. Description of the Related Art 
     Support poles for supporting lights, etc., thereon are commonly constructed of a composite material or a metal material such as aluminum or steel. In most instances, the support pole comprises a pole member or shaft which is secured to a flat baseplate which in turn is secured to a concrete footing. When the shaft is comprised of aluminum or steel, the shaft is normally welded to the metal baseplate. If the shaft is constructed of aluminum, the welding operation may weaken the shaft in the area of the weldment. Further, the welding operation adds to the overall cost of the support pole. When the shaft is comprised of a composite material, such as graphite fibers, carbon fibers, etc., it is usually necessary to form the baseplate with the shaft, which increases the cost of manufacturing or fabricating the same. Further, in all instances, whether the shaft is comprised of metal or composite materials, the breakaway characteristics of the shaft with respect to the baseplate must be considered. 
     SUMMARY OF THE INVENTION 
     A support pole is described which includes a horizontally disposed baseplate for attachment to a footing with the baseplate having an upper surface and a lower surface. The baseplate has an opening formed therein which extends between the upper surface and the lower surface and which is adapted to have the lower end of the hollow pole member or shaft received therein. The shaft is shaped at its lower end to create a deformation to provide a mechanical connection of the shaft to the baseplate. In one form of the invention, the deformation enlarges the diameter of the shaft. In another embodiment, the deformation may reduce the diameter of the shaft. In yet another embodiment, two deformations are created in the shaft, one above and one below the baseplate. In yet another embodiment of the invention, a single deformation is created in the shaft, with the deformation being located within the baseplate. The deformation(s) may extend completely around the shaft perimeter or in a selected area or areas. The deformation profile affects the load capacity, fatigue and breakaway performance of the support pole. The baseplate profile also affects the load capacity, fatigue and breakaway performance of the support pole. The opening in the baseplate which receives the shaft may be shaped to provide torsional resistance and may have material added for fatigue or abrasion issues. The baseplate to shaft connection described herein eliminates welding, post heat treatment and enables the weight of the support pole to be reduced. 
     It is therefore a principal object of the invention to provide an improved support pole. 
     Still another object of the invention is to provide a mechanical connection for the shaft of the pole to a baseplate. 
     Still another object of the invention is to provide a baseplate to shaft connection which provides a unique breakaway solution. 
     Still another object of the invention is to provide a support pole having a deformation provided on the shaft thereof for accommodating a baseplate. 
     Still another object of the invention is to provide a support pole wherein a deformation enlarges the diameter of the shaft. 
     Still another object of the invention is to provide a support pole wherein a deformation reduces the diameter of the shaft. 
     Still another object of the invention is to provide a support pole having a pair of spaced-apart deformations formed in the shaft thereof with one of the deformations being positioned above the baseplate and the other deformation being positioned below the baseplate. 
     Still another object of the invention is to provide a support pole having a deformation formed in the shaft thereof which is located within the baseplate. 
     Still another object of the invention is to provide a support pole having a deformation formed in the lower end of the shaft thereof which may extend continuously around the shaft perimeter or which may be provided in selected areas of the shaft perimeter. 
     Still another object of the invention is to provide a baseplate to shaft connection for a pole member wherein the baseplate opening is shaped to provide torsional resistance. 
     Still another object of the invention is to provide a baseplate to shaft connection for a support pole wherein the baseplate opening has material added therein for fatigue or abrasion issues. 
     Still another object of the invention is to provide a baseplate to shaft connection for a support pole wherein the baseplate opening has material added therein for strengthening purposes. 
     Still another object of the invention is to provide a baseplate to shaft connection for a support pole which may be comprised of metal or composite material. 
     Yet another object of the invention is to provide a baseplate to shaft connection for a support pole wherein the need for welding the support pole to a baseplate is eliminated. 
     Still another object of the invention is to provide a baseplate to shaft connection for a support pole which eliminates the need for post heat treatment. 
     Yet another object of the invention is to provide a baseplate to shaft connection for support pole which results in a weight reduction of the support pole and baseplate. 
     These and other objects will be apparent to those skilled in the art. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial perspective view of one embodiment of the support pole; 
     FIG. 2 is a partial exploded perspective view of the embodiment of FIG.  1  and further including a boot-like member positioned between the shaft of the support pole and the base plate; 
     FIG. 3 is a partial vertical sectional view of the embodiment of FIGS. 1 and 2; 
     FIG. 4 a partial sectional view of a further embodiment of the pole of FIGS. 1-3 wherein a compressible material is positioned between the base plate and the shaft; 
     FIG. 5 is a partial sectional view of a further embodiment of the invention wherein the shaft diameter is reduced; 
     FIG. 6 is a partial vertical sectional view illustrating a further embodiment of the invention wherein shaft diameter is increased; 
     FIG. 7 is a top view of the embodiment of FIGS. 1-3; and 
     FIGS. 8-10 illustrate oval, square and hexagonal pole cross sections. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The support pole of this invention is referred to generally by the reference numeral  10 . Pole  10  includes a hollow shaft  12  having an upper end  14  (not shown) and a lower end  16 . Pole  10  may be comprised of steel, aluminum,. or a composite material such as graphite fibers, carbon fibers, combinations thereof, etc. Pole  10  includes a base plate  18  which may be of single piece or multiple piece construction. Normally, base plate  18  is constructed of iron, steel, aluminum, or other suitable material. Base plate  18  is provided with bolt openings  20  which are adapted to receive anchor bolts  22  extending upwardly therethrough which are embedded in a concrete footing. Normally, adjustment nuts are mounted on the bolts  22  below base plate  18  to enable the base plate  18  (and pole  10 ) to be plumbed. Usually, base plate  18  is spaced above the upper surface of the footing. Base plate  18  is provided with a central opening  32 . 
     The primary purposes of this invention are to provide a means for mechanically securing the baseplate  18  to the shaft  12  and to provide a unique breakaway solution. The purposes are achieved by shaping the lower end of the shaft (tube)  12  to create a deformation with the deformation taking several forms. In the embodiment of FIGS. 1-3, a pair of deformations  34  and  36  are created by enlarging the diameter of the shaft  12  with deformation  34  being positioned above base plate  18  and deformation  36  being positioned below base plate  18 . For purposes of discussion, the exterior portion of the shaft  12  between deformations  34  and  36  will be identified by the reference numeral  38 . The diameter of opening  32  of base plate  18  may be considerably greater than the exterior portion  38  to define a space  40  therebetween. In those cases where space  40  is provided, it is preferred that a compressible material  42  will be positioned in space  40  to facilitate breakaway. 
     In FIG. 4, a shaft-baseplate connection is illustrated wherein the diameter of exterior portion  38  is just slightly smaller than the diameter of opening  32  in base plate  12 . In the embodiment of FIG. 4, it is preferred that an anti-abrasion member such as a boot-like membrane  44  comprised of graphite fiber, carbon fiber, or combinations thereof, be positioned between the shaft  12  and the baseplate  18  to prevent the baseplate  18  from sawing through the shaft  12  as shaft  12  is moved by the wind relative to baseplate  18 . This is especially important where the shaft  12  is comprised of an aluminum material and baseplate  18  is comprised of a steel material. 
     FIG. 5 illustrates another embodiment of the invention wherein the diameter of the shaft  12  is decreased to create the deformation  48  which receives the baseplate  18 . Preferably, an anti-abrasion membrane  49  is positioned between shaft  12  and baseplate  18 , as seen in FIG.  5 . FIG. 6 illustrates yet another embodiment of the invention wherein the diameter of the shaft is increased to form a single deformation  50  which is received by a recessed area  52  formed in baseplate  18  between the upper and lower surfaces thereof. Preferably, an anti-abrasion membrane  53  is positioned between shaft  12  and baseplate  18 , as seen in FIG.  6 . 
     When the shaft  12  is comprised of a composite material, it is preferred that a reinforcing or strengthening boot such as the boot-like membrane  44  be positioned between the shaft  12  and the baseplate  18 . In some cases, the boot  54  will be formed from the same material as the shaft  12  and will be secured to the shaft  12  and the deformation for deformations by epoxy or the like. 
     The deformations described above may extend completely around (360°) the diameter of the shaft  12  or may be provided in a selected area or selected areas as desired. The baseplate opening  32  may be shaped to provide torsional resistance to prevent rotation of shaft  12  with respect to base plate  18 . In other words, opening  32  may not necessarily be circular, but could be oval, have protrusions thereon, etc., which interact with the shape of shaft  12  to prevent rotation of shaft  12  with respect to baseplate  18 , such as seen in FIGS. 8-10. 
     The baseplate  18  may be constructed of a single piece or multiple pieces. If the baseplate  18  is formed as a single piece, the baseplate  18  will be positioned on the shaft  12  as the deformation or deformations are formed in the shaft  12 . 
     The deformation profile will affect the load capacity, fatigue and breakaway performance of the pole. The fact that the shaft  12  is secured to the baseplate  18  by a deformation or deformations eliminates the need for welding the shaft  12  to the baseplate  18 , thereby reducing the cost of manufacturing the pole, but also eliminating the possible weakening of aluminum shafts in the weldment areas. Further, the elimination of the welding process eliminates the need for post heat treatment. Additionally, the invention herein permits steel baseplates to be used. 
     Thus it can be seen that the invention accomplishes at least all of its stated objectives.