Patent Abstract:
A spacer for securing a grout tube to a frame prior to the pouring of concrete to form a concrete structure. The spacer comprises a central portion and two free ends extending from the central portion. The central portion surrounds at least a portion of the grout tube and the free ends are fastened in some fashion to the frame. A plurality of spacers can be utilized for securing the grout tube in place. The central portion is preferably circular and the manipulation of the free ends can expand or contract the diameter of the central portion.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to provisional patent application 61/588,271 which was filed on Jan. 19, 2012, and is hereby expressly incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    There are numerous concrete products used in the construction industry in a variety of applications, such as foundations for supporting structures, as bridge and deck panels, and as beams for structures, just to name a few. Concrete is a material that is very strong in compression but relatively weak in tension. Masonry structures and the mortar holding them together have similar properties to concrete and also have a limited ability to carry tensile loads. 
         [0003]    In order to compensate for this imbalance in the behavior of concrete and masonry structures, reinforcement bars, which are common steel bars, are typically used as a tensioning device to produce reinforced concrete and reinforced masonry structures. These reinforcement bars, commonly called “rebars”, are usually formed from carbon steel, and are given ridges for better mechanical anchoring into the concrete. While any material with sufficient tensile strength could conceivably be used to reinforce concrete, steel and concrete have similar coefficients of thermal expansion. Therefore, a concrete structural member reinforced with steel will experience minimal stress as a result of differential expansions of the two interconnected materials caused by temperature changes. 
         [0004]    Traditional reinforced concrete is based on the use of rebars cast into a poured concrete structure. In addition, pre-stressed concrete is a method for further overcoming concrete&#39;s natural weakness in tension. It can be used to produce beams, floors or bridges with a longer span than is practical with ordinary reinforced concrete. Pre-stressing tendons, generally of high tensile steel cable, are used to provide a clamping load which produces a compressive stress that balances the tensile stress that the concrete compression member would otherwise experience due to a bending load. 
         [0005]    One concrete product that utilizes the foregoing principles is a prefabricated concrete pile used to support foundations. These piles are driven into the ground using a device such as a pile driver. Concrete piles are available in a variety of cross-sectional shapes, including square, octagonal, and round cross-sections, and they are reinforced with rebar and are often pre-stressed. Foundations relying on concrete driven piles often have groups of piles connected by a pile cap (a large concrete block into which the heads of the piles are embedded) to distribute loads which are larger than one pile can bear. Pile caps and isolated piles are typically connected with the piles to tie the foundation elements together, so that lighter structural elements bear on the piles while heavier elements bear directly on the pile cap. 
         [0006]    In the manufacture of reinforced and pre-stressed concrete structures, such as piles, a form of the desired shape is used with reinforcing spaced-apart steel bars positioned to create a frame. Then rebars or grout tubes are used to further strengthen the structure. When utilized, the rebars or grout tube must be centered and held in place as the concrete is poured to form the structure. Securing the rebars or grout tube within the steel bar frame is currently done by hand, using wires and cables to tie the rebars or grout tube to the frame. This is a time consuming and expensive process. 
         [0007]    There is therefore a need for an improved way of securing a grout tube and rebars in place while the concrete is poured to form the concrete structure. 
       SUMMARY OF THE INVENTION 
       [0008]    The invention is for preformed wire spacers that are shaped to grasp a grout tube and secure it to the steel frame within a concrete form. The spacer is formed from a continuous length of spring steel, wire that has a circular central portion of sufficient size to surround the grout tube. The free ends of the spacer extend outwardly from the central portion and are formed with hooks extending, with one free end having both a handle and a hook. Being a continuous length of spring steel, the central portion has a double wrap or overlapping portion which provides for the diameter of the central portion to be temporarily expanded in diameter by grasping the free ends and applying force to expand the central portion&#39;s size. This allows the spacer to be easily combined with the grout tube, since the spacers and tube can move relative to each other. Multiple spacers are used on a single tube and are spaced apart a distance to provide the proper support and positioning of the tube relevant to the frame and the finished concrete form. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a front view of a first embodiment of the invention; 
           [0010]      FIG. 2  is a side view of the first embodiment of the invention; 
           [0011]      FIG. 3  is a perspective view of the invention; 
           [0012]      FIG. 4  is a perspective view of a steel frame for a concrete beam which shows the spacers secured in place on the steel frame; 
           [0013]      FIG. 5  is a perspective view showing a grout tube with spacers in place to illustrate the positioning of the spacers on the tubes; and 
           [0014]      FIG. 6  is a perspective view of a finished concrete beam and shows the opening created by the grout tube. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]      FIGS. 1 ,  2  and  3  show the preferred embodiment of the invention. A spacer  20  comprises a central portion  22  and a pair of free ends  24 . The free ends  24 ,  26  extend outwardly from the central portion  22 . Preferably the free ends  24 ,  26  extend in opposite directions and are one-hundred eighty degrees apart. The spacer  20  is formed from a single continuous length of spring steel wire. 
         [0016]    In the preferred embodiment, the central portion  22  transitions to the free ends  24 ,  26  at an angle. Additionally, the angle designated as A in  FIG. 1  is preferably between 60 and 90 degrees, with 75 degrees being shown in  FIG. 1 . The angle A can have an effect on the force needed to expand the central portion  22  as further discussed below. 
         [0017]    Free end  24  has a fastener  27  which is preferably a hook  28  formed at its outer end  29  while free end  26  has a fastener  31  again preferably a hook  32 , and a handle  34  at its outer end  35 . The hooks  28 ,  32  engage a frame  40  of a future concrete structure as shown in  FIG. 4 , Hooks  28 ,  32  grasp rebars  44  that form the frame  40  for the concrete structure, or, can be hooked over cables  46  on opposite sides of the frame  40 . The preferred embodiment has the handle  34  on one free end only, in the figures, free end  26 . 
         [0018]    Handle  34  provides a grip for installing the spacer  20  by first securing the hook  28  over a portion of the frame  40  or cable  46  after which handle  34  is grasped to secure the hook  32  over a portion of the frame  40  or the cable  46  on the opposite side of the frame  40 . Again, the angle of the handle  34  and the hook  32  can be varied, however, the angle designated as B shown in  FIG. 1  is approximately 45 degrees. The angle B can allow a user easier access to the handle and allow the user to more easily apply force to the spacer  22  during installation. 
         [0019]    The curved portions  50  of the spacer  20  are contiguous and form a secondary structure  52  in the central portion  22 . Preferably the curved portions  50  touch against each other within at least a portion of the central portion  22 , as shown in  FIGS. 2 and 3 . The secondary structure  52  in the preferred embodiment is a loop  54  which is circular. This structure and the use of spring steel for the spacer  20  provide for quick and easy installation of the spacer  20  on the frame  40 . 
         [0020]    Once spacers  20  are installed on the frame  40 , a grout tube  12  can easily be slid through the spacers which position the grout tube  12  in the approximate center of the form resulting in a finished product as shown in  FIG. 6 .  FIG. 5  shows a grout tube  12  with spacers  20  installed on it. In this instance, the grout tube  12  can be positioned inside the frame  40  and the spacers  20  hooked onto the frame  40  in the manner described above. In either case, it is evident that use of spacers  20  greatly reduces the time and effort to produce concrete products of this type and therefore significantly reduces the cost of the products a reinforced concrete beam or concrete pile  10  produced using a grout tube  12 . Referring to  FIG. 6 , the grout tube  12  provides an opening through which rebars (not shown) can be inserted to anchor the pile or beam  10  in place in a structure where beams  10  or piles are used. 
         [0021]    As is well known to those skilled in the art, a typical concrete pile or beam  10  is produced in a concrete form (not shown) of the desired length and cross-sectional shape. Referring to  FIG. 4 , the pile or beam almost always is produced using rebars  14  to form the frame  40  and high tensile cables  46  which may be pre-stressed, as described above.  FIG. 4  illustrates the skeleton metal frame in which a grout tube  12  can be placed. 
         [0022]    Although it is contemplated that the spacer  20  will have a set diameter “d” for accommodating a specific sized grout tube, the size of the spacer  20 , particularly the diameter of the central portion  22  can be varied during the manufacturing process to accommodate a specific sized grout tube. Additionally, the preferred material used to make the spacer  20  is spring steel which allows the spacer to have some flexibility. The flexibility allows the spacer  20  to go from its static first position to a second position when force is applied on the free ends  24 ,  26  toward the center portion  22 . This application of force expands the diameter of the center portion  22 . The greater the force applied the greater the expansion of the diameter of the center portion. Once the force is released, the spacer  20  returns to its normal first position. The ability to expand allows a particular spacer  20  to accommodate a variety of sizes of grout tubes. 
         [0023]    The above description is for a preferred embodiment. There are numerous contemplated changes to the spacer which could vary from the preferred embodiment. Beginning with the free ends  24 ,  26 , a variety of fasteners, other than hooks, with the ability to engage a portion of the frame  40  or cables  46 . Similarly, the shape of the center portion  22  could be varied without making the spacer  20  inoperable. Furthermore, another embodiment could utilize a center portion  22  which does not entirely wrap around the grout tube. Instead, the center portion  22  could be a semi circle which wraps around only a portion of the grout tube  12 . For instance, if the center portion wrapped the left side of the grout tube  12 , then the next flanking spacer  20  could wrap the right side of the grout tube  12 . Accordingly the grout tube  12  could be secured within the frame  40  without a complete circular center portion  22 . 
         [0024]    Having thus described the invention in connection with certain embodiments, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the invention.

Technology Classification (CPC): 4