Centralizer

Abstract

Centralizer for centering rebar within a bore hole comprises a first sleeve section, a second sleeve section and a radially protruding section. A referential central axis of the centralizer passes through the first sleeve section, the referential central axis being a straight line, and the centralizer configured to receive the rebar along the referential central axis. The second sleeve section is spaced from the first sleeve section in a direction along the referential central axis. The radially protruding section is directly or indirectly connected to the first sleeve section and the second sleeve section. The first sleeve section comprises a first threaded interior surface configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first sleeve section along the referential central axis. The centralizer does not require a tie for attachment to rebar.

I claim: 
     
         1 . A centralizer for centering rebar within a bore hole, the centralizer comprising:
 a first sleeve section, the first sleeve section comprising a first aperture, a referential central axis of the centralizer passing through the first sleeve section, the referential central axis being a straight line, and the centralizer configured to receive the rebar along the referential central axis;   a second sleeve section, the second sleeve section comprising a second aperture through which the referential central axis passes, and the second sleeve section spaced from the first sleeve section in a direction along the referential central axis; and   a radially protruding section, directly or indirectly connected to the first sleeve section and the second sleeve section, an outer surface of the radially protruding section configured to form a convex surface that extends radially outwardly from the referential central axis;   the first sleeve section comprising a first threaded interior surface configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first sleeve section along the referential central axis; and   the radially protruding section configured to be provided in a configuration so that an outer surface of the radially protruding section extends beyond the outer surface of the first sleeve section and the outer surface of the second sleeve section in a direction radially outwardly from the referential central axis.   
     
     
         2 . The centralizer of  claim 1 , wherein the radially protruding section comprises a plurality of a radially protruding elements, and the plurality of a radially protruding elements curve outwardly from the referential central axis. 
     
     
         3 . The centralizer of  claim 2 , wherein the radially protruding elements are equally spaced along the circumference of a circle concentric with the referential central axis. 
     
     
         4 . The centralizer of  claim 1 , wherein the centralizer comprises a minimum of four radially protruding elements. 
     
     
         5 . The centralizer of  claim 1 , wherein the centralizer comprises a plurality of a radially protruding elements extending lengthwise between the first sleeve section and the second sleeve section. 
     
     
         6 . The centralizer of  claim 1 , wherein the centralizer consists of one and only one piece comprising the first sleeve section, the second sleeve section, and the radially protruding section. 
     
     
         7 . A method of using a centralizer for centering rebar within a bore hole, the method comprising: securing the centralizer on the rebar at a first position adjacent to a first end of rebar; and inserting the centralizer on the rebar into the bore hole, the centralizer configured to be coupled to the rebar without a coupling device that is not a sleeve section of the centralizer, optionally the end of the centralizer closest to the first end of the rebar is from ½ inch to 10 feet from the first end of the rebar. 
     
     
         8 . The method of  claim 7 , in which a plurality of centralizers comprising the centralizer are each installed along the rebar, wherein each centralizer in the plurality of centralizers is installed at a separation distance from adjacent centralizers in the plurality of centralizers, optionally wherein the separation distance between any two adjacent centralizers in the plurality of centralizers ranges from 1 feet to 10 feet, optionally wherein the end of the centralizer closest to the first end of the rebar is from 0 to 3 feet from the first end of the rebar; and optionally, the radial distance from the referential central axis of the centralizer to the outer edge of each of the radially protruding sections is ⅛ to ¾ inch less than a radius of the bore hole, optionally wherein the centralizer is arranged and/or configured so that ¼ inch to ¾ inch of grout can be positioned between the outer edge of each of the radially protruding sections and the surface of the bore hole. 
     
     
         9 . The method of  claim 7 , the method comprising: filling the bore hole with grout, optionally neat cement grout optionally after the step of inserting the centralizer. 
     
     
         10 . The method of  claim 9 , the method comprising: allowing the grout to cure so that the centralizer and the rebar are fixed in position relative to the bore hole. 
     
     
         11 . The method of  claim 7 , the method comprising: securing a second centralizer on the rebar at a second position adjacent a second end of the rebar, the second end of the rebar being opposite the first end of the rebar; and inserting the second centralizer on the rebar into the bore hole, optionally the end of the second centralizer closest to the second end of the rebar is from ½ inch to 10 feet from the second end of the rebar. 
     
     
         12 . The method of  claim 11 , in which a plurality of centralizers comprising the centralizer and the second centralizer are each installed along the rebar at a separation distance, optionally wherein the separation distance between any two centralizers in the plurality of centralizers is from 12 inch to 10 feet; optionally wherein the end of the centralizer closest to the first end of the rebar is from 0 to 3 feet from the first end of the rebar, and optionally wherein the end of the second centralizer closest to the second end of the rebar is from 0 to 3 feet from the second end of the rebar; optionally the end of the centralizer closest to the first end of the rebar is at least ½ inch from the first end of the rebar; optionally, the first position arranged and/or configured for the radial distance from the referential central axis of the centralizer to the outer edge of each of the radially protruding sections is ⅛ to ¾ inch less than a radius of the bore hole, optionally wherein the centralizer is arranged and/or configured so that ¼ inch to ¾ inch of grout can be positioned between the outer edge of each of the radially protruding sections and the surface of the bore hole; and optionally the end of the second centralizer closest to the second end of the rebar is at least ½ inch from the second end of the rebar. 
     
     
         13 . The method of  claim 12 , the method comprising securing a third centralizer around the rebar at a third position, wherein the third position is between the first position and the second position. 
     
     
         14 . The method of  claim 12 , the method comprising positioning a plurality of centralizers around the rebar between the first position and the second position. 
     
     
         15 . The method of  claim 7 , wherein the centralizer positions the rebar concentrically with the center axis of the bore hole to within a tolerance that is 0 to 10% of a bore hole dimension, the bore hold dimension being the diameter of the bore hole or the longest distance across the bore hole in a direction perpendicular to the center axis of the bore hole. 
     
     
         16 . A method of using a centralizer for centering rebar within a bore hole, the method comprising: securing the centralizer on the rebar at a position located on the rebar; inserting the centralizer, on the rebar, into the bore hole, the centralizer configured to space the rebar from the wall or walls of the bore hole, the centralizer configured to provide a grout cover of at least ½ inch in all directions at the position located on the rebar; and filling the bore hole with grout to fix the rebar permanently in the bore hole; wherein the centralizer comprises: a first sleeve section; and a second sleeve section; the first sleeve section comprising a first threaded interior surface configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first sleeve section along a referential central axis of the centralizer; the second sleeve section comprising a second threaded interior surface configured to engage the threaded outer surface of the rebar and to impede the ability of the rebar to slip through the second sleeve section along the referential central axis of the centralizer; and the first and second threads configured to engage the inner surface of the centralizer with the outer surface of the rebar without the centralizer needing to be tied to the rebar with a tie or otherwise coupled to the rebar with a coupling device that is not a sleeve section of the centralizer. 
     
     
         17 . The centralizer of  claim 16 , wherein the first and second threaded interior surfaces are each configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first and second sleeve section along the referential central axis. 
     
     
         18 . The centralizer of  claim 16 , wherein the first and second threaded interior surfaces are configured to engage a threaded outer surface of the rebar and to impede the ability of the rebar to slip through the first and second sleeve section along the referential central axis.