Concrete dowel placement system and method of making the same

Abstract

A concrete dowel placement system and methods for making the same. The system allows for accurate and easy substantially-parallel or parallel placement of slip dowels within sections of concrete so that adjacent sections of concrete may be allowed to undergo thermal expansion and contraction while remaining in a common plane without cracking or faulting. The system includes a coupler and a sheath. The sheath is configured to be slidably extensible over the coupler and may be held to the coupler by friction. An outer surface of the sheath may be textured. Additionally, a method of constructing the concrete dowel placement system includes extruding material to form two tubes of different sizes. The tubes are then attached to each other, then material is extruded or injection molded to form a sheath. Alternatively, construction may include extruding material to form a tube, then removing some of the material from the tube in order to form a coupler.

What is claimed is: 
     
         1 . A method of constructing a concrete dowel placement system, the method comprising:
 constructing a coupler, the constructing comprising:
 extruding a polymer to form a first tubular element; 
 extruding a polymer to form a second tubular element, the second tubular element having a dimensional size different from a dimensional size of the first tubular element; 
 attaching an end portion of the second tubular element to an end portion of the first tubular element; and 
   extruding a polymer to form an elongated, tubular, dowel-receiving sheath, the sheath having an outer surface, at least one interior opening extending along the entire length of the sheath and the sheath being configured to be slidably extensible over the coupler to frictionally engage one of the first tubular element and the second tubular element;   texturing the outer surface of the sheath, thereby increasing the surface area of the outer surface.   
     
     
         2 . The method of  claim 1 , further comprising the step of attaching an end cap to an end portion of the sheath to completely cover the at least one interior opening at an end of the sheath. 
     
     
         3 . The method of  claim 1 , further comprising the step of crimping a free end of the sheath to close the free end of the sheath. 
     
     
         4 . The method of  claim 1 , wherein the step of extruding a polymer to form the first tubular element includes forming a body having a circular cross-sectional configuration along a longitudinal axis during extrusion of the polymer. 
     
     
         5 . The method of  claim 1 , wherein the step of extruding a polymer to form the first tubular element includes forming the first tubular element to have an inner sleeve and a plurality of splines extending radially outward from the inner sleeve and longitudinally along the inner sleeve. 
     
     
         6 . The method of  claim 4 , wherein the step of extruding a polymer to form the second tubular element includes forming the second tubular element to have an inner sleeve and a plurality of splines extending radially outward from the inner sleeve and longitudinally along the inner sleeve. 
     
     
         7 . The method of  claim 1 , wherein the first tubular element defines opposed first tubular element end portions having maximum outer diameters approximately equal to each other, and the second tubular element defines opposed second tubular element end portions having maximum outer diameters approximately equal to each other. 
     
     
         8 . The method of  claim 1 , wherein the step of extruding a polymer to form the first tubular element includes forming an inner sleeve, an outer sleeve, and at least one reinforcement wall extending therebetween. 
     
     
         9 . The method of  claim 1 , wherein the step of extruding a polymer to form a sheath includes forming at least one linear rib protrusion along a longitudinal axis of the sheath on an outer surface of the sheath during extrusion of the polymer. 
     
     
         10 . The method of  claim 1 , wherein the step of extruding a polymer to form the sheath includes forming at least one raised helical element on an outer surface of the sheath during extrusion of the polymer. 
     
     
         11 . A concrete dowel placement system comprising:
 a coupler comprising:
 a first tubular element comprising:
 an inner sleeve disposed about a central axis to define an aperture; and 
 an outer body disposed radially outward of the inner sleeve; 
 
 a second tubular element comprising:
 an inner sleeve disposed about a central axis to define an aperture; and 
 an outer body disposed radially outward of the inner sleeve; 
 
 an end portion of the outer element of the second tubular element being attached to an end portion of the outer element of the first tubular element; and 
   an elongated, tubular, dowel-receiving sheath having a textured outer surface, at least one interior opening extending along the entire length of the sheath and being slidably extensible over the coupler to frictionally engage one of the first tubular element and the second tubular element.   
     
     
         12 . The system of  claim 11 , wherein the outer body of the first tubular element includes a plurality of splines extending longitudinally along the inner sleeve. 
     
     
         13 . The system of  claim 11 , further comprising an end cap attachable to an end portion of the sheath to completely cover the at least one opening at an end of the sheath. 
     
     
         14 . The system of  claim 11 , wherein the texture on the outer surface of the sheath is formed from irregularly placed longitudinal linear gouges. 
     
     
         15 . The system of  claim 11 , wherein the texture on the outer surface of the sheath is formed from a regularly repeating pattern of dimples. 
     
     
         16 . A method of constructing a concrete dowel placement system, the method comprising:
 extruding a polymer to form a tubular element having at least one interior opening extending along the entire length of the tubular element; and   injection molding a polymer to form an elongated, tubular, dowel-receiving sheath, the sheath having at least one interior opening extending along the entire length of the sheath and the sheath being configured to be slidably extensible over the tubular element to frictionally engage the tubular element.   
     
     
         17 . The method of  claim 16 , further comprising the step of attaching an end cap to an end portion of the sheath to completely cover the at least one interior opening at an end of the sheath. 
     
     
         18 . The method of  claim 16 , further comprising closing the at least one interior opening at an end portion of the sheath by crimping the end portion so that the at least one interior opening collapses to form two abutting lines. 
     
     
         19 . The method of  claim 16 , wherein the step of extruding a polymer to form the tubular element includes forming an inner sleeve and a plurality of splines extending radially outward from the inner sleeve and longitudinally along the inner sleeve. 
     
     
         20 . The method of  claim 16 , wherein the step of injection molding a polymer to form the sheath includes forming at least one linear rib protrusion on an outer surface of the sheath during extrusion of the polymer.