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TECHNICAL FIELD 
     The invention relates generally to rebar used for reinforcing concrete and, more particularly, to an apparatus and associated method for elevating and securing rebar together to form a lattice for reinforcing concrete. 
     BACKGROUND 
     Conventionally, when concrete is to be poured, a form is first made to bound the concrete, and reinforcing bars (“rebar”) are positioned to be embedded within the concrete after it is poured. The positioning of the rebar typically requires that the rebar be elevated and that rebars that cross other rebars be secured together where they cross to form a lattice. Typically, rebar is elevated using plastic supports, and is secured to other rebar by being manually tied together with wire. While such use of plastic supports and wire is effective, it is also time-consuming, and often results in inconsistent quality. 
     Therefore, what is needed is an apparatus and method for preparing rebar for use in concrete in a manner that is time-efficient and results in consistent quality. 
     SUMMARY 
     The present invention, accordingly, provides an apparatus for positioning rebar for reinforcing concrete, wherein the apparatus includes a semi-cylindrical portion configured for receiving a first rebar extending in a first direction, wherein the semi-cylindrical portion defines first and second opposing straight edges, and two opposing ends. A first flange portion extends outwardly from the first straight edge, and a second flange portion extends outwardly from the second straight edge. First and second receiver portions extend longitudinally from the respective first and second flanges beyond one end for receiving a second rebar extending in a second direction substantially orthogonal to the first direction, and for urging the second rebar against the first rebar. 
     According to a method of the present invention, the first and second receiver portions of the apparatus are engaged with a lower surface of a first rebar extending in a first direction. The semi-cylindrical portion of the apparatus is then engaged with an upper surface of a second rebar extending in a second direction substantially orthogonal to the first direction, until the first rebar is urged against the second rebar. 
     In one aspect of the invention, legs are attached to or extend from the apparatus for supporting the apparatus in an elevated position within the concrete. 
     By use of the present invention, rebar may be secured together and supported in an elevated position much more quickly than is possible using conventional techniques. Furthermore, the present invention facilitates consistently good, high-quality results. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a rebar holder embodying features of the present invention for securing together two rebars, shown in dashed outline; 
         FIG. 2  is an elevation view of the rebar holder of  FIG. 1  showing how the holder is rotated into position to secure rebar according to principles of the present invention; 
         FIG. 3 , is a perspective view of an alternate embodiment of the rebar holder of  FIG. 2  adapted for receiving support legs; 
         FIG. 4  is a perspective view of an alternate embodiment of the rebar holder of  FIG. 2  wherein support legs extend from the holder; 
         FIG. 5  is a perspective view of an alternate embodiment of the rebar holder of  FIG. 3  configured with lips for receiving legs for supporting the holder; 
         FIG. 6  is a perspective view of an alternate embodiment of the rebar holder of  FIG. 2 , wherein support legs extend from the holder;. 
         FIG. 7  is a cross-section view of the rebar holder of  FIG. 6  taken along the line  7 — 7  of  FIG. 6 ; 
         FIG. 8  is a perspective view of an alternate embodiment of the rebar holder of  FIG. 1 , wherein a cam is formed on an interior surface of the holder for securing the holder in place on the rebar; 
         FIG. 9  is a cross-sectional view of the rebar holder of  FIG. 8  taken along the line  9 — 9  of  FIG. 8 ; 
         FIG. 10  is a perspective view of an alternate embodiment of the rebar holder of  FIG. 1 , wherein a cylindrical portion of the holder is extended; and 
         FIG. 11  is a cross-sectional view of the rebar holder of  FIG. 10  taken along the line  11 — 11  of FIG.  10 . 
     
    
    
     DETAILED DESCRIPTION 
     In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. Additionally, for the most part, details concerning rebar, how it is utilized in connection with concrete, and the like, have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the present invention, and are considered to be within the skills of persons of ordinary skill in the relevant art. 
     Referring to  FIG. 1  of the drawings, the reference numeral  160  generally designates a rebar holder embodying features of the present invention. The holder  100  includes a semi-cylindrical portion  102  defining two opposing edges  104  and  106 , and two opposing ends  108  and  110 . Two flange portions  112  and  114  extend outwardly from the edges  104  and  106 , respectively. Two preferably semi-circular receiver portions  116  and  118  extend longitudinally from the flanges  112  and  114 , respectively, for receiving a rebar. The semi-circular receiver portions  116  and  118  are configured and sized for receiving a first rebar  103 , shown in dashed outline. The semi-cylindrical portion  102  is configured and sized for receiving a second rebar  105 , shown in dashed outline. The first rebar  103  and second rebar  105  preferably define approximately the same diameter, and are preferably oriented with respect to each other in a substantially orthogonal relationship. 
     The holder  100  is preferably fabricated as a single integrated unit from a material, such as, by way of example, plastic, acrylic, metal, a composite material, or the like, effective for facilitating ready manufacture thereof, while providing sufficient flexibility to receive and retain rebar. Accordingly, the inside diameter of the semi-cylindrical portion  102  and the semi-circular receiver portions  116  and  118  is preferably about the same, and is slightly less than (e.g., about 95% of) the outside diameter of the rebar to be retained by the holder  100 , to thereby facilitate an interference fit between the rebar  103 ,  105  and the holder  100 , and secure the holder to the rebar. 
     In the use and operation of the invention, a plurality of rebars, such as the rebars  103  and  105 , are positioned to form a lattice configuration for reinforcing concrete (not shown). Then, as shown most clearly in  FIG. 2 , for each intersection formed by the rebar, the first and second receiver portions  116  and  118  of a holder  100  are preferably positioned to engage a lower surface (as viewed in  FIG. 2 ) of the first rebar  103 , extending in a first direction. The semi-cylindrical portion  102  of the holder  100  is then rotated downwardly in the direction of an arrow  204  into a position to engage with an upper surface of the second rebar  105 , extending in a second direction, preferably, substantially orthogonal to the first direction. The semi-cylindrical portion  102  is thus rotated until the first rebar  103  is urged against the second rebar  105 , thereby securing the first rebar  103  in position with respect to the second rebar  105 . 
       FIG. 3  depicts an alternate embodiment  300  of the rebar holder of  FIG. 2 , which is adapted for receiving support legs  302  and  304 , having nipples  306  and  308 , respectively. The support legs  302  and  304  are preferably fabricated from the same material from which the holder  300  is fabricated (i.e., preferably the same material described above with respect to the holder  100  of FIG.  1 ). The receiver portions  116  and  118  of the holder  300  define openings  310  and  312 , which are configured and sized for receiving the nipples  306  and  308 . In operation, when the nipples  306  and  308  of the legs  302  and  304  are positioned in the respective openings  310  and  312 , the holder  300  and rebar  103  and  105  supported thereby, may be suitably elevated for reinforcing concrete. Operation of the holder  300  is otherwise similar to that described above with respect to  FIGS. 1 and 2 . 
       FIG. 4  shows an alternate embodiment  400  of the rebar holder of  FIG. 2 , wherein support legs  402  and  404  extend from the receiver portions  116  and  118  of the holder  400 . The holder  400  and operation thereof is substantively similar to that of the holder  300  described above with respect to  FIG. 3 , but for the legs  402  and  404 , which are integrally formed with the holder  400 . 
       FIG. 5  depicts an alternate embodiment  500  of the rebar holder  300  of FIG.  3 . The holder  500  is similar to the holder  300 , but for the addition of lips  502  and  504 , which extend longitudinally from the receiver portions  116  and  118 . The lips  502  and  504  define openings  510  and  512 , similar to the openings  310  and  312  (FIG.  3 ), configured for receiving nipples  306  and  308  of the legs  302  and  304 . But for the positioning of the legs  302  and  304  with respect to the holder  500 , operation of the holder  500  is substantively similar to the operation of the holder  300 . It is noted that an advantage of positioning the legs  502  and  504  to the holder  500  over the legs  302  and  304  to the holder  300  is that, with respect to the former, the legs  502  and  504  utilize leverage to more effectively secure the holder  500  to the rebar  105 . 
       FIG. 6  depicts an alternate embodiment  600  of the rebar holder  400  of FIG.  4 . The holder  600  is similar to the holder  400 , but for the position of the legs  602  and  604 , which, as most clearly shown in  FIG. 7 , are positioned forward (i.e., in the direction of the arrow  606 ) along the receiver portions  116  and  118 . But for the positioning of the legs  602  and  604  with respect to the holder  600 , operation of the holder  600  is substantively similar to the operation of the holder  400 . It is noted that an advantage of positioning the legs  602  and  604  to the holder  600  over the legs  402  and  404  to the holder  400  is that, with respect to the former, the legs  602  and  604  utilize leverage to more effectively secure the holder  600  to the rebar  105 . 
       FIG. 8  is a perspective view of an alternate embodiment  800  of the rebar holder  100  of  FIG. 1 , wherein a cam  802  is formed on an interior surface of the semi-cylindrical portion  102  of the holder  800  for further securing the holder  800  in place on the rebar  103  and  105 . Specifically, the cam  802  is preferably formed on the interior surface of the semi-cylindrical portion  102  approximately centrally between the edges  104  and  106  and, as shown most clearly in  FIG. 9 , preferably adjacent to the end  110 . The cam  802  is preferably shaped in accordance with conventional design principles so that the force required to effectuate rotation of the semi-cylindrical portion  102  from an angle  202  ( FIG. 2 ) of 90° to an angle  202  of 0° is met with greatest resistance just before reaching an angle  202  of 0° For example, the aforementioned resistance should be greatest when the angle  202  is between about 50° and about 45°, and preferably when the angle  202  is between about 10° and about 30°. In operation, when the semi-cylindrical portion  102  is rotated downwardly to engage the second rebar  105 , the cam  802  alters the pivot point, so that at an angle  202  of preferably about 10° to about 30°, additional resistance is encountered just before the second rebar  105  engages the second rebar  105  at an angle  202  of 0°. The additional resistance, however, is relieved once the semi-cylindrical portion  102  fully engages the second rebar  105 . The cam  802  action resulting in the additional resistance at an angle  202  of about 10° also acts to inhibit the holder  800  from becoming disengaged from the rebar  105 , thereby further securing the-holder  800  to the rebar  103  and  105 . 
     Operation of the holder  800  is otherwise similar to the operation of the holder  100  described above with respect to  FIGS. 1 and 2 . 
       FIG. 10  is a perspective view of an alternate embodiment  1000  of the rebar holder  100  of  FIG. 1 , wherein the cylindrical portion  100  of the holder  1000  is extended beyond the edges  106  and  104 . As shown most clearly in  FIG. 11 , the cylindrical portion  102  includes extended portions  1002  and  1004  which extend about 50° to about 30°, and preferably about 10 20   to about 15°, below (as viewed in  FIG. 11 ) the respective edges  106  and  104 . Operation of the, holder  1000  is similar to operation of the holder  100 , but during the process of engagement of the semi-cylindrical portion  102  with the rebar  105 , the extended portions  1002  and  1004  flex open, and then upon completion of engagement (FIG.  10 ), the extended portions  1002  and  1004  effect a clamping action to further secure the holder  1000  to the rebar  105 . 
     By use of the present invention, rebar may be secured together to form a lattice, and supported in an elevated position much more quickly than is possible using conventional techniques comprising, for example, wire. Furthermore, the present invention facilitates consistently good, high-quality results. 
     It is understood that the present invention may take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or the scope of the invention. For example, an upper portion of the semi-cylindrical portion  102  may be opened between the ends  108  and  110  to conserve materials and allow concrete to bond directly to rebar. The receiver portions  116  and  118  may be designed to allow for rebar that is not orthogonal; for example, the receiver portions may be configured to allow for rebar that is oriented 70° or 80° relative another rebar, rather than in a 90° relationship constituting an orthogonal relationship. Furthermore, aspects of the invention such as depicted by the legs (FIGS.  3 - 7 ), cam (FIGS.  8  and  9 ), and extended cylindrical, portion (FIGS.  10  and  11 ), may be combined in any number of different ways as desired. For example, the legs  302  and  304  of  FIG. 3  may be combined with the cam  802  of  FIG. 8 , or the cam  804  may be combined with the extended semi-cylindrical portions  1002  and  1004 , or the legs  602  and  604  may be combined with the extended semi-cylindrical portions  1002  and  1004  and cam  802 . Still further, the invention described herein is not limited to use with rebars, but may be adapted for use with any type of bars, rods, and the like, that may be used in applications related to concrete or other applications that utilize bars, rebar, rods, and the like. Still further, the semi-circular cross-sections of the semi-cylindrical portion  102  and the two opposing semi-circular ends  108  and  110 , may include cross-sections that are semi-elliptical, or may be defined by a plurality of concatenated flat sides, such as three flat sides, five flat sides, or ten flat sides, or a combination of a number of flat sides and semi-circular and/or semi-elliptical cross-sections. 
     Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it, is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.

Summary:
An apparatus for positioning rebar for reinforcing concrete, wherein the apparatus includes a semi-cylindrical portion configured for receiving a first rebar extending in a first direction, wherein the semi-cylindrical portion defines first and second opposing straight edges, and two opposing semi-circular ends. A first flange portion extends outwardly from the first straight edge, and a second flange portion extends outwardly from the second straight edge. First and second receiver portions extend longitudinally from the respective first and second flanges beyond one of the ends for receiving a second rebar extending in a second direction substantially orthogonal to the first direction, and for urging the second rebar against the first rebar. Optionally, legs extend from or are attached to the apparatus for supporting the apparatus in an elevated position.